The images of this video were simulated with the following effects taken into account: - Doppler effect (with emission lines spectrum for the background nebula, and blackbody spectrum for the stars) - Magnification (change of brightness for point-like stars due to aberration and lensing) - Aberration (change of the perceived direction of light)
Thank you so much for the high quality content! It is extremely appreciated! I used to watch the first videos of the channel and now I am on my second year of Physics degree!
lol if you take 1 second to reach a thing on universe at speed of light the 1 second in normal clock its just a second! So in earth it is a second not 1000 years
@ScienceClic you say that nothing prohibits "space" from moving faster than the speed of light. If that is the case, should not gravity propagate at superluminal speeds since gravity is the warping of space-time? Hence the famous thought experiment. If the sun physically disappeared instantly, we on Earth wouldn't know for 8.5 minutes until the final light rays reached us. But how long would Earth remain in orbit? If space is not confined to moving at the speed of light, Earth should takeoff on a tangent instantly the sun disappears. However, if LIGO is indeed measuring gravity waves (undulations in the fabric of space-time) it seems like space-time does have a speed limit. Which idea is correct? Has the speed of gravity actually been correctly measured? Inflation would imply superluminal movement of space-time would it not?
@@AdrianBoyko COSMOS is cool, but there were no visuals like these in the 1980s (and neither are there many of these types of visuals elsewhere even now, to be honest).
I'm not much of a commenter, but what a great video. This guy explains some of the most complex stuff in our universe in a realistic, intuitive way while somehow not sacrificing important details. Never seen someone tackle so many tough subjects and explain them all to the level this guy does, one of my favorite channels of all time
Yeah I agree, great video. I find the idea that travel near light speed would seem instantaneous to the people on the ship to be intriguing. If we assume it could be done, to the people on the ship the trip wouldn't be a big deal. You'd just have to accept that once you left Earth, you're gone from there for good, unless you don't mind coming back there again thousands of years in the future.
Amazing video. Absolutely blew my mind. Just know that by making these videos you are inspiring a new generation of physicists that might change the world someday. You are also teaching people the beauty of our universe and are allowing us to see the universe in ways we would never get to in our regular lives.
Hi, no want be rude just saying that i don't think he needs your little money to thrive in this world,.. also other thing about this videos is: If you take 1 second to reach a thing on universe at speed of light then 1 second in normal clock its just a second! So in earth it is a second when you travel at that speed reaching that distance in just 1 second and NOT 1000 years! OBVIOUSLY.
So in conclusion you learn much more investigate yourself than watching this videos some of them is just copy paste garbage that you can watch everywhere he's not the only one and also not helping that much and its almost useless this type of information and to make things worst much of "information" like this video are CLEARLY lie/s to just have some views...
@@imlost..ineedhelpfromyoulord I’m sorry but you are very wrong. Everything he said in this video is true thanks to einsteins theory of relativity which has been proven many many times
If travelling near the speed of light contracts spacetime, videos like this contract the time taken to wrap your head around such complex phenomena by helping us visualize what we can't otherwise experience firsthand. The clarity and quality of the narration and animation, paired with the familiarity of style across videos, provide way too much value for me not to contribute at least once. Mindblowing video, absolute goldmine of a channel, thank you!!
no want be rude just saying that i don't think he needs your little money to thrive in this world,.. also other thing about this video is: If you take 1 second to reach a thing on universe at speed of light then 1 second in normal clock its just a second! So in earth it is a second when you travel at that speed reaching that distance in just 1 second and NOT 1000 years! OBVIOUSLY.
So in conclusion you learn much more investigate yourself than watching this videos some of them is just copy paste garbage that you can watch everywhere he's not the only one and also not helping that much and its almost useless this type of information and to make things worst much of "information" like this video are CLEARLY lie/s to just have some views...
personally i've been able to visualize all this in my head since i was a kid. only thing i dont like about this video, is the mention of "space-time", because there's no such thing. there's fabric of space, but time doesn't exist, time is just unit of measurement. time is to space, as liter is to water. you don't say that ocean consists of "water-liter", do you? you say ocean consists of water and you measure it in liters (or whichever country you're from, might be gallons or whatever, but same principle). otheriwse i agree, nicely visualized for those who don't have ability to visualize basic stuff.
🤔Do you have space sickness? Maybe you should make an appointment with your physician. I know a good one from the 24th century, that has no name and no hair😋
I find that "nature" repeats itself EVERYWHERE. Sometimes even things that are not even close to being related to each other yet the process of one thing (even though they produce a different end result and have a different prcesses) can be the same as the other. One of these examples is Electricity and how to explain volts and amps.... water moving through a garden hose. The 2 have nothing in common and are complete different processes and the processes are not even related but if electricity were water going through a hose the amps is the amount of water going through the hose and volts is the water pressure through a hose like if you put a adjustable nozzle on the hose and you open it all the way open the water pressure would be very low or low volatage but the same amount of water is moving through it. Begin to close the nozzle and the water seems to come out harder and faster the more you close the nozzle but no more watter is comming out, the volume of water is still the same as going though the hose or amps. A LOT of people HATE this example precisely because it is nothing like how electricity works but as it explains volts and amps it also shows you how 2 completely unrelated processes and mechanisms in nature repeat. The light slanting like the rain is another example, the 2 process CANNOT be related because as you accellerate into the rain that is falling downward, the rain is not smashing into your windshield from the front.... you are smashing into the rain drops from the side. If you move at different speeds, it does not effect light's relationship to you. If you ride a bike at 30mph and as you ride at 30mph, you throw a baseball 50mph while riding, it would be traveling at 80mph because of inertia and momentum. You carrying it on bike gives it default speed of 30 + 50 from being pitched = 80mph. But now if you have a laser mounted on your handlebar of your bike you are riding at 30mph and you reach up and turn on the laser..... that light or "baseball" that you pitch in front of you ALWAYS travels at light speed. .. YOU have NO EFFECT on it and even though you are already going 30... it is not 30 + speed of light = speed of light + 30..... it is 30 + speed of light = speed of light. SO..... the raindrops, if they were light would never "slant" towards you and appear to hit you head on as you speed up because YOU have no effect on IT. Just like light leaving you always leaves you at light speed and that speed is constant , you can go 30mph or 1000000000000mph... the rain would still appear to fall vertically. Nature repeating itself...
can anyone heer explain to me wtf is going on with light contraction, im so confused ab if the universe is PHYSICALLY getting shorter or its just explaining that the faster u move the quicker u get places
@@starthejar1419 "The faster you move the quicker you get places" ??? That statement explains itself :) Anyway Lets say you are in a race car on the starting line. Your opponent is next to you and the light turns green. You both take off and... you notice their car is keeping up with you almost perfectly. BUT!!! you have a little secret surprise and you flip a switch that fires your NOS canister you had hidden and now your car lurches forward and pulls away from the other guy and you get to the finish line WAY before he does. Not exactly the same thing but replace the extra speed with time moving faster for the other guy (yes the "effect" is reversed). Faster you travel, the slower time moves forward for you. So if time is slower for you and his time is faster, why do you move faster? If you can take 5 steps in 3 seconds, it takes you 3 seconds to take 5 steps (kind of redundant there lol). Lets speed TIME up now by dobule. So you take your 5 steps but it now take you 6 seconds to finish the same 5 steps because more time has passed for you. Now lets make time slower by dobule slow. You take your 5 steps but now only 1.5 seconds has passed in the same distance traveled so you could now take 10 steps because you have another 1.5 seconds of SLOW time to go further. The video is explaining what you would SEE if you were to go that fast so nothing really contracts it only APPEARS to do so... kind of like going down the road in a car... if you look at the ground right where the road ends, everything passes by you in almost a blur its so fast. Now look in the distance at a tree that is far away... it looks as if it is barely moving past you while ground next to road is going super fast. It is perspective and how you SEE it.
That graphic showing the rocket moving on the time axis and the second path diverging is the best illustration of the time dilation I've seen. Simple and exceptionally easy to understand.
The problem is that the illustration is showing the distance being different and not the time. It is the speed of the rocket changing in relation to the constant speed of the planet that causes you to imagine that the time would be different when the rocket returns. And that is part of why Einstein’s theories are actually not quite right.
It's something that I would love for someone to prove wrong, because at the core of it, it just doesn't make sense to me. One would think that the passage of time would be a universal constant. For someone to leave, experience less time, and then reunite with people that have experienced more, just because they moved fast enough.. it doesn't sit right with me logically.
@@samvansomething No shit bro, it doesn't make logical sense for anyone - even for Einstein, but that's just how the universe works as proven by Einstein. Lots of shit we know about how the universe works doesn't make any logical sense but we have to accept the reality no matter how much it doesn't fit with our "Logic".
@@veritasabsoluta4285 This is so counterintuitive to the path of discovery that it's laughable. Looking for answers is the basis of science. It's why I got into theoretical physics. Calm down and don't shit on people who aren't satisfied with the answers that we have.
Thank you for giving us a glimpse into what the future may hold. Though I won't be alive to see it, the way you explain these immensely complex theories and visualize them gives me hope that one day, we as humans can achieve FTL travel. Please keep making more videos.
I have stopped this video so many times trying to Google information to make sure I understand it before proceeding with the next info. Amazing video. Thank you
One of the small details you do that I love is you'll often give a little 4-5 second pause before moving on to the next fact so it can just simmer for a moment in our brains, and it also allows the iconic ScienceClic music to come through a little extra
'The length of the journey to our destination is shorter than expected'. Finally, a proper explanation of near light speed travel! So few people understand that one can theoretically travel accross the universe in a single lifetime without travelling faster than light.
I love this in Project Hail Mary by Andy Weir (of Martian fame) when one of the protagonists, Rocky, has an absurdly overengineered ship due to his people never discovering the Lorentz factor. Brilliant book, check it out :)
One of the most, if not the most, detailed and comprehensive videos I've seen on the topic of speed of light. Truly astonished by the effort put into this and the explanation of all the phenomenae that take place. Thank you for this piece of art, you are the hero we need, but do not deserve. Edit: grammar mistake.
Not sure what youre talking about. I was waiting to see what it would look like, but I kinda had to use the progress bar and scroll along while imagining what the visualization probably looks like uninterrupted. Because we never actually got to see what it would look like. The point of the video
if you were to go the speed of light you souldnt see anything as you would reach the end of time instantly and die being sucked into the black hole at the end of the material plane
I'm a little confused though. As the ship goes faster won't the wavelength's of the light shorten and go out of the visible range? Won't they become xrays and the even shorter? When traveling very near the speed of light, what will the wavelength of oncoming light be? Won't it be near 0?
As an animator trying to make a realistic warp affect your time and effort into making this is greatly appreciated I hope all future sci-fi shows take a lesson from your video
It would be nice to see all of these perspectives taken into account with travel and the effects of black holes properly in a non fiction based film. No bs, just straight shooting. I watched the last two films that featured black holes just to see the perspective they came up with. I still feel disappointed.
@@elakstein Interstellar and High Life. Last ones to attempt to show what traveling around or in a black hole. Haven’t really seen a movie that does light speed properly.
@@brown2889 I agree, but realistic is not relatable for people. At least the things that we didnt encounter in our evolutionary past. I remember Interstellar. Yeah, still bs. Lots of assumptions and fiction, lots of subjective emotional manipulation. Hmmm, on the other hand, how would one even portray anything resembling true infinity in a movie?(people just dont care for most things in any infinite set)
@@greenanubis Are you talking about that library scene from inside the black hole or the black hole imagery itself? Because if the latter, that was literally the most accurate representation of a black hole we had until we got the first images back from the EHT. If the former, then yeah, you can only show people the concept of infinity metaphorically; and, it's a movie about people, so why wouldn't there be "subjective emotional manipulation?"
As someone who spends countless hours watching astronomy videos this one is by far one of the best ever . Explained everything really well and the visuals are amazing!
I have seen many videos on this topic, but have never had length contraction explained so comprehensively before. I can’t believe nobody has ever pointed out to me that the journey feels instantaneous at light speed
@@bapples1233 exactly my point as well.. Say for example in 1 sec I travelled some thousands of kilometers at speed of light going from point A to B While someone on earth travelled few inches in 1 sec, going from his point A to B. Now though the distance travelled by both is exponentially different, but still we took 1 sec only. Then how does the person on earth age faster?
@@bapples1233because at the speed of light, time basically stops and with it our perception of time stops, the faster you go the the slower your time becomes, including your perception of time. At light speed you essentially never age. I guess in a spiritual sense that’s why after death your spirit is eternal, because the energy that was once in you, that made you is given back to the universe as light and will forever be.
This video far and above so much better, than the dozens of amateurish videos on this subject here on TH-cam. Concise, to-the-point and lucidly explained.
This video ( and this channel) is the result of astonishing dedication and effort. The scientific intelligence and the ability to effectively communicate the complexities of these subjects are UNMATCHED on TH-cam. Many congratulation, ScienceClic!
The only part of this that I had never heard before or tried to grasp was the idea that if we could travel close to the speed of light, that the time it would take us to travel to our destination would seem instantaneous. That is mind blowing and really a different take on this than any I had heard before. I would love to hear this explained in more detail
@@NatMart9394 The 2nd option is true. And if we´d once return, more than 20000 years earthtime had passed, considering the time of staying at the destination and the months it took to accelerate to approximatly lightspeed each way. And still, this is only what it seems to be in our mind, since time is just an illusion of our awareness.
@@zardoz1970 it doesn't make logic since if you teleport from point A to point B , which means going at speed of light is basically teleportation, it just means that you go from A to B in less than a second and get back from B to A in less than a second , so it just passed a second and no one aged. Another example is that , you fly in a jet for two hours, you age the same as people on the ground , they continue their life for 2 hours , you travel for 2 hours but you age the same as them, so logically it's the same with the speed of light, you just go from earth to another dimension in one second and come back the next second, so nothing changed really
This is truly one of the best explanations I've ever seen for relativity and the effects light speed travel have. Honestly absolutely incredible work. Congrats
I remember watching an old Vsauce video and being blown by massless particles experiencing NO time and that the concept of time not even applying to them. Mass-less objects must always have to travel at "c", have neither a beginning nor an end, and the particle's origin, journey, and destination all happen simultaneously for it. This video just reminds me of all the complexities and awe the universe contains that we humans may never understand in the entirety of our existence.
But all this is just a reflection of you only you haven’t recognised it yet! Understanding the relative point of View is not necessary the point of view of the absolute therefore the theory’s they use and relatively are only tools to the absolute. They are not completely understanding the concept of truth. And just writing something they don’t fully understand, comprehend or know like a mule carrying a message. What they are saying is partly true but their theory is a relative truth not the absolute truth. When one wakes up and recognises what’s really going on we recognise these are all reflections of ourselves. It is all one happening! There are no seperate events or separations between you and the entire cosmos. Yes we feel like we are separate because we can only experience it one at a time but that you and the other even though they may be different or seem separate as 2 but in reality they arnt these 2 things you and other are really one but the illusion of self and other make you believe they are 2 and separate happenings. True relativity is unity. You and the other go together. These duality’s only exist for us to recognise. You would never know what light was if darkness never existed or what sweet was if bitter never existed etc. it’s a truely beautiful and amazing universe. So in reality 2 really =1 but not 1 in number but as a whole. So really we are the heavens and the earth and everything in-between but it’s fear and ignorance that doesn’t allow you to progress! So the true real evidence is the NOW You are always here It’s just we don’t recognise it And that’s part of the wake up call! It’s infinite. What most people see is relativity instead of the absolute Absolute is singular but not in number but as a whole. You spoke of those particles having No beginning nor end but that is who we are! If it has a beginning or an end that limited. And the system is unlimited. No beginning no end always forever connected and that’s what Adam represents the dome the circle, the wheel of life as some call it the earth goes round and round between light and darkness, our blood goes round and round circulating our body 24/7, the tide goes up and down always etc etc and we are part of that. The beginning that has no beginning and the end that has no end otherwise it’s limited. Sorry for the essay hope it helps just felt I had to write this to you peace
Elegantly explained! I’m studying astro physics 101 and this was such a tremendous help. Superbly articulated. I love the excellent illustrations which help with the understanding. Thank you so much.
Yes, it is very well done. And Einstein visualised all this in one of his trances. Main take-away being time dilation and length contraction... that a photon does not experience time. A trip to Proxima Centauri being a mere blip, yet we hear ad nauseam (even from physicists) that even if we could travel the SoL it'd take 4 years to get there. Nope; only for the outside observer. The SoL is the ultimate speed.
if you travel at the speed of light, particles with no mass would reach and destroy your optic nerve before you ever processed a single photon. Just sayin. This explained nothing, and it should not have helped you at all. In fact, every frame of this video is a detriment to your understanding of reality and the universe.
@@ZennExile "cosmos" is a masonic(satanic lie. Know who is who lies, masons. Know what are their lies, all which this world believes. Expose them and their lies, not support them and their lies. Extraterrestrial Life? - the existence of demons among the mankind. As the BIBLE says, we grow up with a offspring who is not like us, only look like us for a short time, until the harvest time has arrived. The wheat and the tares: Matthew 13:25 But while men slept, his enemy came and sowed tares among the wheat, and went his way. Matthew 13:26 But when the blade was sprung up, and brought forth fruit, then appeared the tares also. Matthew 13:29 But he said, Nay; lest while ye gather up the tares, ye root up also the wheat with them. Matthew 13:30 Let both grow together until the harvest: and in the time of harvest I will say to the reapers, Gather ye together first the tares, and bind them in bundles to burn them: but gather the wheat into my barn.
I'm so glad you mentioned that "for us, the trip seems instantaneous". So many people don't consider the inertial observer's perspective. Though there are so many ways to look at it, when you consider the affects of near light speed travel from the perspective of time, things are far more interesting. Time controls not only the progression of change, but also motion, mass, scale... Time is what makes gravity attractive. It isn't that we are being pulled magically by some mysterious force, no... rather its the composition of our bodies (or the composition of matter in general) at which different parts are traveling thru time at different rates relative to one another. From a motion standpoint, this affects the relative speed of every particle of an object in a gradient fashion. This gradient in time has the same gradient affect on motion; parts closer to the source of gravity move slower relative to those further away, and thus a parabolic curve of motion is formed toward the source of gravity. When traveling at near the speed of light, from our perspective, the trip from any point in space would be near instantaneous. It makes you realize that light itself knows no time because it knows no space. We wonder how the universe could be all fit within an infinitely small point (a singularity) at the time before the big bang, yet light itself, if it could observer, would still think it is... that space never expanded. The only reason we perceive space and its expansion (distance, scale, etc...) is because we are not traveling at the speed of light (or rather we are moving faster in time). Thus, the faster you move in time, the slower you go in space, and in turn the larger (in scale) the universe becomes. I think looking at thing from the perspective of time is far more interesting than looking at the effects of motion or gravity on time and space. Thanks for the awesome video!
When we start moving away from our planet..into different corners of space..as a species, maybe our whole perception on travelling will change..as we will no longer be moving in the linear motion which is parallel to earth, like a sitting duck blitzing from past to future but instead we would be taking a detour in space....we could go back in the time, in different time zones in space. People living in the past and the future at the same time, relatively speaking, like literally a point in space where you were before as that point in space has it's own pace in time...almost like the flow of time itself becomes irrelevant... we'll have our own natural time though...like our body itself is on a grind, on it's own natural order of things, so we will probably feel like we are aging normal...like the stationary trees that blitz pass us in speeding bus, all the time blitzes pass us once we come out the bubble...imagine that!...maybe we can get so far from earth that we can see it in it's beginning phase(when it was just a hot rock) than move towards it and capture all the evolution that happens til the day you reach earth...it would be a instant time lapse but if we could somehow see it.....opens up all kinds of possibilities...or maybe not😂😂
@@anobodyfromnowhere8427 I could def see how perhaps we could see the past in an object such as earth after moving past the speed of light for a while. This whole thing is quite a bit confusing for my mind.
@@dragondudeyt2344 frame of reference...from our frame of reference, the light takes a year to travel the light year distance...but if you were light itself, it would feel like an instant....it could be like one thing happened and the other thing happened immediately after, cause nothing travels faster than light.
My heart leaps when I see a new ScienceClic video among my subscriptions. But when I hear, "To conclude", the gravity of the situation crashes it back down to earth...
This video was absolutely fantastic! I loved that you both distinguished between and illustrated the physical and visual effects of both The Doppler Effect and Special Relativity. This video was very much needed, especially the warp drive part!
@@doylegaines1319 there is, only thing is its practically not possible now due to lack of technology ,in brief an engine when run should be able to attain near speed of light magnitude ... Which ll be possible after 200-300 yrs once civilization starts consuming more energy as consuming more energy ll increase the need for energy thus expand the energy in earth and force the civilization to capture energy from sun in vast amount....
@@henrykashyap8913 Why is there no Superman in real life?? Lack of technology. If we had "the technology" we could make the earth spin in reverse 3 times a day , right? That's all we need to do - just develop "the technology". One day we'll have the technology to walk to Mars. My bet is that we'll walk to Mars looooong before we travel at near light speed. Of course, I know that's probably not a popular opinion among sci-fi fans.
Is it possible you can make a video of how you guys make these videos, and how you actually sustain yourselves economicly; just like Kurzgesagt. These are literally best astrophysics 101 lessons ever. Production is beyond top notch.
Thanks a lot! I was thinking of doing a "making of" video, I might just do that. Economically I actually produce everything myself except for the translation/dubbing, so there are not that many expenses.
But you do spend many, many, hours on this right? You work a lot to make these videos happen, and "thank yous" are great, but you should get some sort of compensation for making these for us as well, you do an amazing job
[insert falling to knees emoji, if it, existed, here]. Excellent presentation! I can't do the math but I innately understand and appreciate what you've done here. Mind still blown especially as I've always held the belief that altough the Speed of Light is absolute, there are ways of going FASTER than the speed of light. My grade school science teacher hated me LOL
Your channel is just something special! Thanks to your videos I understand topics I never thought I could. So please keep up and teach us some more amazing things ✨️
This is the one channel on TH-cam that will always describe physical qualities of the universe in a way that makes me feel a sense of child-like curiosity. So many other channels sometimes stay on the more technical side, but the voiceover, music and visuals in the videos on this channel all complement each other in a very unique and special way that remind me why I love science. And it is also thanks to this channel that I started reading about special and general relativity purely as a hobby. ❤
Without exaggeration, this is probably the most clear illustration on this topic on the net. Without getting too abstract and obscure in explanation; it actually makes quite a great deal of sense to little humble me.
What I realized about speed is that speed is not an easy thing. Speed should be considered as movement in space. Moving in space we slow down time (taking into account the acceleration). Best video I've watched..
I think about this concept so often when watching a Star Trek or Star Wars show. Now I can just rewatch this for a refresher, and to blow my own mind over and over again.
Honestly, the amount of work, knowledge and understanding it takes to condense this topic into this very understandable, yet comprehensive and well-written video is way beyond what I could do. Or what most of us could. Yet, this channel only has 414K subscribers? Deserves way more. You should REALLY team up with PBS Space Time on some form of a collaboration.
I have watched every single video uploaded on this channel and it is by far one of the best physics and science channels on TH-cam. Bravo Mr. Roussel, the quality and information conveyed in these videos is excellent and easy to comprehend. The animations and music are also top tier. Please keep uploading.
Yeah. I'd just like a video about how the non-Euclidean geometry makes the "longer" route actually shorter. Maybe it's due to what was said in a past video on this channel regarding movement through space necessarily creating less movement through time and vice versa, but I'd still like to hear more about that.
@@Rationalific That's correct. ScienceClic mentions in the video "We all move at the Speed of Light" that all matter and energy in the universe travels at 1.0c, the speed of light. A TL;DR explanation is that if you are moving through space, you are moving less so through time, so less time has passed for you; thus, your path is shorter. But how does that happen in the first place? I'll try to explain it as simply as I can, though it might be too long to read. Perhaps though, my comment could be the script of a video complete with diagrams and such. When objects accelerate, in the eyes of relativity, we redistribute a 1.0c velocity through space-time. The simplest example is linear acceleration aligned with our x-axis, so that we can ignore y and z. Rest will be no spatial motion relative to the origin. We now accelerate. Formerly, our velocity was solely through time. All of our 1.0c velocity was along the time axis: our velocity vector is parallel to the time axis. For every 1 second that passes on our spaceship, 1 second passes for an outsider at rest. But now, we are moving through space. Part of our 1.0c velocity is distributed along the x-axis. This vector would point up and to the right, but mostly up. We then turn off our engines. Relative to the origin, we are no longer at rest because our spatial speed is non-zero. Our vector still has a magnitude of 1.0c, but it has rotated. This is called a different frame of reference. Objects are in the same frame (co-moving) if they have parallel vectors. TH-cam won't let me post the link, so look up "hyperbolic orthogonality" on Wikipedia and enlarge the diagram that looks like many green circles and a purple hourglass shape. The 3 axes of space are Euclidean relative to each other, meaning we can use the Pythagorean theorem to calculate distances involving more than one axis. However, comparing any of the 3 axes of space to the axis of time will not yield a Euclidean relationship. The relationship relies not on Euclidean geometry but hyperbolic geometry. Euclidean geometry uses circles to define angles and distances; hyperbolic geometry uses hyperbolas. In the green universe, there is no universal speed limit. When the axis of time is pointing toward the old direction of the x-axis, that is infinitely fast speed (undefined). The tangent function (tan) is the relationship between angle and speed. (Notice how at 90 degrees it goes to positive infinity and wraps back around from negative infinity). This doesn't mean you can achieve infinite speed, however, because the tangent of 90 degrees approaches infinity. The inverse tangent function (arctan, from "arc of tangent", or tan^-1) lets you plug in a desired velocity and spits out what angle you will have rotated the axes by to achieve that speed. Because you can plug in any number from negative infinity to positive infinity into arctan(x), you can achieve any speed between negative infinity and positive infinity. On this graph, accelerating at a constant rate would look like the axes are rotating to the side, but slower and slower over time, never quite reaching 90 degrees. In our universe (diagram on the right), however, the relationship between space and time is hyperbolic, not Euclidean. As you accelerate (rotate the time and x-axes), they don't spin around as the green ones did. The points follow the hyperbolas rather than circles. The axes get closer to each other like the blades of a pair of scissors closing together. The axes are dragged toward that red diagonal as the purple points continue moving; the red diagonal limits the angle to 45 degrees, the inverse tangent of which is 1 (1.0c). To understand how this finite speed can be a universal speed limit, we have to abandon our naïve notion of velocity and replace it with a new one called rapidity. We can describe the velocity of an object using the numbers between -1 and +1, but the number 1 is the finite boundary. With rapidity, however, we can use numbers between negative infinity and positive infinity. In this system, the speed of light really is infinite, which makes it unattainable. We convert between velocity and rapidity using hyperbolic trigonometry. The hyperbolic tangent function (tanh) lets you convert from rapidity to velocity. The inverse hyperbolic tangent function (artanh, from "area of tangent", or tanh^-1) lets you convert from velocity to rapidity. Some example calculations: Velocity 0c = Rapidity 0 Velocity 0.01c = Rapidity 0.0100003 Velocity 0.1c = Rapidity 0.1003 Velocity 0.5c = Rapidity 0.549 Velocity 0.8c = Rapidity 1.099 Velocity 0.9c = Rapidity 1.472 Velocity 0.99c = Rapidity 2.647 Velocity 0.999c = Rapidity 3.800 Velocity 1 m/s below c = Rapidity 10.11 Velocity 1.0c = Rapidity is undefined, approaching positive infinity As you can see, velocity and rapidity are initially almost identical, which is why we don't experience significant time dilation at ordinary speeds. The departure of rapidity from velocity is the hallmark of time dilation. In fact, the Lorentz factor (how much a reference frame is distorted with respect to another) is cosh(x), with x as the rapidity. Thus, if we replace velocity with rapidity, we now have a situation similar to the green diagram on the left; bounded by an infinite speed. It is only when we use our intuitive version of velocity that we appear to be bounded by a finite speed. Now that we can convert from hyperbolic to Euclidean, we retrieve the case before, where plugging in any rapidity between negative and positive infinity into tanh(x) gives us a velocity, and then, plugging any velocity into arctan(x) gives us the angle. We cannot exceed 45 degrees (the speed of light). Now imagine Earth at the center of the diagram on the right, moving forward through time (up). Now imagine our spaceship at the center as well. We will depart from Earth at high speed and then return at about the same speed. Earth's motion is only along the time axis. Ours will be partly on the x-axis and partly on the time axis. We will accelerate (change frame) from 0.0c relative to Earth to 0.8c relative to Earth. artanh(0.8) is about 1.09 (this is rapidity), and cosh(1.09) is 1.667 (exactly 5/3 actually), so for every 5 seconds that passes on Earth (chosen rest frame), 3 seconds passes on our spaceship. arctan(0.8) is about 0.675 radians, or about 38.7 degrees, so you can imagine a line above the red diagonal but very close to it representing our spaceship's trajectory. (The angle is measured relative to the time axis, because an angle of zero with respect to time is the definition of rest in just the spatial axes.) Let 5 years pass for Earth. Earth will have moved along the time axis a distance of 5 purple lines (I am asserting 1 purple line = 1 year.) If we arrive on our ship at this time on Earth, how much time will have passed for us on the ship? We now track the motion of our spaceship on the graph. Assume we accelerate to 0.8c quickly enough to not affect our calculations. We move up and to the right at an angle 38.7 degrees away from Earth's time axis (our time axis has rotated with us). According to the axes as measured by Earth, we are passing each purple line (each year according to Earth time) slower than Earth is. From our perspective, however, we are crossing purple lines at the ordinary rate because we have our own axes. But according to Earth's axes, we are crossing purple lines slower. This is equivalent to Earth observers watching our clocks tick slower than those on Earth. Therefore, our frame is different from that of Earth; we cross Earth's purple lines (moments in time) slower than Earth crosses them. Earth has crossed 2.5 purple lines (halfway between the second and the third), so 2.5 years have passed for Earth. Our spaceship has crossed 1.5 purple lines (halfway between the first and the second), so 1.5 years have passed on our clock. We must now return to Earth. We accelerate to reverse our 0.8c velocity so that it is now 0.8c toward Earth instead of away. Because we have accelerated to a different velocity (0.8c in one direction is a different velocity from the same speed in a different direction), we are now in a new frame. Because a vector of a given direction and magnitude is identical no matter where you move it on the graph, we can superimpose a copy of Earth's axes on our ship even though our ship is way off to the right in the diagram. (Put simply, 2 miles north is 2 miles north, no matter if you are in Kenya or Canada.) That would be very visually crowded, so we will instead say that our spaceship is at the origin again, with the origin being the point where we turned around from to start heading back. The axes are still parallel to Earth's so all calculations will still be correct. We now move up and to the left 38.7 degrees away from the time axis. While Earth crosses 2.5 purple lines again, totaling 5 years, we cross 1.5 purple lines again, totaling 3 years. We accelerate (negatively, to slow down) to land on Earth, so we return to Earth's frame and make Earth the origin again. We are now in the same frame as Earth. However, because we accelerated into different frames of reference, whereas Earth never changed its frame (because we designated it as the rest frame), our clocks will no longer agree with Earth. It is by this simple fact, that vectors are the same no matter where they move*, plus the non-Euclidean geometry of the universe, that we can show that motion through space does indeed result in less motion through time. This particular combination of Euclidean and hyperbolic geometry is called Lorentzian geometry. *When this is not true, we call this curved spacetime. That is general relativity, not special relativity.
@@Rationalific Mathematically, it's because time has a "square root of negative one" (imaginary) unit factor... so when you do the A² +B² = C² pythagorean length using space on one side of the triangle, and time on the other side, you wind up subtracting the time² from space² (So longer spacetime intervals measure shorter proper time.) The reason for this mathematical trick, is because every location in space is in the past of every other location in space. Things that you see come from the past... the negative time direction. (You could also turn this around so that every location in space is located in the future of every other location too... the important thing is that "right now" for any arbitrarily chosen point time and place sits at the intersection of an incoming sphere of light from the past, and an expanding sphere of light towards the future.) Distance in space is also distance in time.
@Julia Vixen Thanks for the explanation. If I understood correctly (a big "if"), then it does seem like it does in fact stem from the fact that you go through less time if you go through more space... And it does come down to that circle graph using "i" that I saw in a past video... Anyway, it's wacky but thanks for explaining more about that!
I have to say it is one of the best physics videos i've ever seen ! And i'm so glad you even thought to implement a " what would we see at warp speeds " section ! The trekkie in me is much pleased
Wow. I've, "armchair", studied these concepts for many years, and thought I had a pretty good grasp of even the most complicated especially relative theoretical effects but, the way you've visualized them for me here, seems to cause a deeper "sinking in" of the ideas at play. Thank you! You've done a terrific job!
interesting, but wrong. This is the old if your car was traveling close to the speed of light thing. light would still look like it was travelling super fast ahead of you AND the light from behind you could catch you and pass you (so it isn't super dark behind you 11:55).
This was an incredible masterpiece. I hope teachers pick this up and show it in their curriculum. However, that ending was beautiful! I've always said, in theory, there is so much ahead of us that we cannot even see.
Not only a masterpiece ... but a piece of crystal clear thinking and a genius of conveying knowledge to us , mere morons... thank you for the light in a vast darkness....
By far, the best science explanation channel out here on the platform and I’ve watched a lot. The visualization and easy to grasp comparisons makes it understandable in a whole different level and really makes you think about said subject.
This clip reminds me of the comedian, Steven Wright, when he says, "If your car could travel at the speed of light, would your headlights work?". His comical question made me laugh but, it has haunted me since. It speaks to me of a future so uncertain. It's great to see that these great young minds are seriously exploring these possibilities. It's inspiring to see the tenacity of the Human Race to explore, and how we see our future... well, being there as if we are already looking back on ourselves. I only hope that our Race to the future will be of collaboration and not against each other. Thumbs-up for this great presentation!
I believe that to the driver, the car's headlights would appear to work normally, as much as they could in that contorted reality. To an outside observer, the photons emitted from the lights would essentially build up in front of the car rather than continually stream forward, and upon dropping out of lightspeed, would be unleashed on whatever is in front of the car when it stops. A bit like a solar snowplow obliterating whatever unlucky destination you happened to be headed toward.
If the car's headlights were shining upon a target ahead, would the image disappear when the car reached the speed of light or would the target remain illuminated? If it remained illuminated, would it suggest that light is travelling faster than light, which reached the target before the car, which was aleady travelling at the speed of light? The video showed light getting brighter as the rocket accelerate towards it, which makes sense when considering the Doppler effect, but it didn't seem to consider light which was being emitted by the rocket towards a target ahead of it.
It's a good question though.... Really!! It seems from this video that they would still work because we won't ever be able to reach the speed of light as described in this video. And it makes sense to say the light from our car travelling at the speed of light would still project light travelling at the speed of light ahead of us! Sounds crazy, but in my mind it makes perfect sense!
The way I look at it, light moves instantaneously, relatively. A photon will not experience time because it instantly appears everywhere in the universe, things that are slower on the other hand see it travel. So unless you yourself move instantaneously light will always be faster than you at the speed of light relative to you. However, if you're moving at light speed, instantaneously, you'd not see anything until you stop because the process of moving is just an instant no matter the distance, something you couldn't experience. So your head lights would work, but you couldn't see it. You couldn't even experience it.
Thanks for finally sharing with people the time distortion for those ON the ship. We are constantly told about the other effects but very few people actually address the fact that the reason photons can travel such vast distances is that they do so without respect to time themselves. In short, they are timeless. They are everywhere, all at once. Their path is a dagger through time itself.
I've been super interested in light speed theories and time dilation since I was young. This one video has shown me more than I've ever seen anywhere else. Fascinating.
11:20 I like that. externally we get really close to light speed and are almost catching up to the photon in the same direction. (so its only moving away very slowly) but internally since time seems so slow for us, the photon moving away from us slowly seem to move away at lightspeed from out point of view
Phenomenal exploration of the mind-bending concept of traveling at the speed of light! This video does an exceptional job of breaking down complex ideas and visualizing them in a way that's easy to understand. Truly makes you appreciate the vastness of our universe and the wonders of science!
I TOTALLY UNDERSTAND THIS VIDEO!!! I've been wondering for years about the viewing point of light speed. This video answered some of my theories and gave me a better understanding. Great video!
Same here! I'm 60 and a lover of science fact and fiction. Just in my lifetime I've seen what was once fiction become reality or on its way to becoming so . What an awesome time to be alive and to have watched many of these advances come into being a reality!
This video helped me intuitively understand time dilation. I already knew the concepts and all the effects, but I never truly understood why without reciting a definition or something. But when you talked about the ship chasing a photon and how from the perspective of the ship it would move away at the speed of light but to an outside observer the would be following each other at almost the same speed made it really click in my head why time dilation needs to happen and why the trip would feel faster to the ship than an outside observer. Thank you for the fantastic video
Awesome illustration! Very few content creators can explain things so effortlessly. After watching the warp drive segment at the end, I can now imagine a corollary of Alcubierre warp drive - creating a center point from where an infinite density is formed in front (contracting the space time like black hole) and forming a massive infinite explosion that sets a forward motion (expanding the space time like a big bang or probably we can call it a white hole). What intrigues me is : 1. If we create such a center point then how do we know we are moving forward towards the future or backward in the past? We don’t have a multidimensional navigation system to understand where we are actually heading to. 2. If from the reference frame of Big Bang, a complete space time stand still is the past then from the reference frame of a center of a black hole where time stops, a Big Bang is the past or we can say exactly otherwise if we replace past with future. It appears as such past and future are just like an optical illusion visible to us between these motionless and motioned states of space time. They simply don’t exist! 3. If we consider an epoch between a Big Bang like expansion and a giant black hole like gravitational pull to be our dimension of existence or merely our universe then would existence of such several epochs make multiverse? And if it’s considered true, then the universal space time is just a string forming a fabric of multiversal space time which must be totally different than our understanding of space time. 3. Isn’t a warp drive a kind of a mini epoch (micro universe) created by us to actually travel the space time? So we want to create space time itself to travel space time? 4. If we consider a spacetime as a gap between an infinite explosion and an infinite gravitational pull then there must be several gaps like these with different dimensional varieties. Some might have been created and destroyed at a faster pace giving them a different type of time dimension. Likewise there maybe different types of lengths, breadths and height systems in various other universes. How we experience this dimensions in our known universe maybe not be the same way they are experienced or manifested in other universes. @ScienceclicEn, We need more information on this
Amazing video. I've watched so many videos regarding near light speed travel and this is the best one. You covered so many important points. Thank you!
Someone’s been upping their animation game :-) Another classic to add to your repertoire! And great to finally see a realistic tackling of length contraction, which is generally under-treated in most works. Plus your warp drive visualization at the end really was quite intriguing - there’s definitely some food for thought in there… interested to see what you’ll be tackling next!
You two are my absolutely most favourite channels and I would like to thank you for your videos. Do you think it would be worth making a video about 4th dimension? I was wondering whether it has any conection with the gravity. Does gravity cause things to "fall" into the 4th dimension? Does the rocket launching from earth need to "climb" from the "hole" of 4th dimension? I found this video th-cam.com/video/JmvHNatZgVI/w-d-xo.html it does not mention gravity but i think its very cool :)
I feel like the hardest part would be determining HOW to get where you are going when bending space time. You would move so fast and you would have to have a predetermined end point. So somehow a computer would have to acurately determine the distance to your destination and bend space for a set duration and then stop to get you there. So if you were bending space and collapsing space directly in front and behind of you, then you would have to be able to control a specific measurement of space. You wouldnt want to warp just half of your ship. You would probably see a lensing effect all around you until the warp was complete. If you warped a finite measurement of space all the way from the start point to the end point.(like a wormhole) You would probably instantaneously see a distorted view of your destination out the front window for however long it takes to complete the warp.
@@jamesofallthings3684 the math is not encouraging in this case. the bubble can move, but there is no way to enter or exit it, nor change its speed/direction, or even create/destroy one. It would simply exist, disconnected from causality.
@@neeneko- It would require an enormous amount of energy to move a space/time bubble, to the order to several thousand Suns all at once. Till we can figure out another shortcut, it will remain science fiction.
I have to assume if you're in the bubble you're essentially blind, as you're disconnected from the universe. If light were to enter the bubble, it would: a. Cause drag that could maybe drag you out of the bubble. b. Be the same as super high-energy gamma rays blasting your ship, because of blue shifting. And of course the trick is to effect the command to stop the ship. What if you start your warp bubble and the ship decides to keep going in that direction forever, because your controls are also disconnected from the universe?
There are countless animated TH-cam channels with narrators explaining everything you can imagine. They’re pretty much all garbage, so I almost didn’t click on this one. This is excellent. The animation is great and the explanation is really, really well articulated and makes it easy to understand. I’m only four minutes in and I’ve already subscribed. Keep up the good work.
The best is… when you reach almost speed of light and turn on the front lights of your vehicle, that light will travel at the speed of light in reference to you, but still only at speed of light from an external observer, not twice the speed of light. Wonderful… love it
i didnt understand if its travelling at speed of light for the driver then how the observer would see it as only at the speed of light not twice the speed
The images of this video were simulated with the following effects taken into account:
- Doppler effect (with emission lines spectrum for the background nebula, and blackbody spectrum for the stars)
- Magnification (change of brightness for point-like stars due to aberration and lensing)
- Aberration (change of the perceived direction of light)
Thank you so much for the high quality content! It is extremely appreciated! I used to watch the first videos of the channel and now I am on my second year of Physics degree!
lol if you take 1 second to reach a thing on universe at speed of light the 1 second in normal clock its just a second! So in earth it is a second not 1000 years
@ScienceClic you say that nothing prohibits "space" from moving faster than the speed of light. If that is the case, should not gravity propagate at superluminal speeds since gravity is the warping of space-time? Hence the famous thought experiment. If the sun physically disappeared instantly, we on Earth wouldn't know for 8.5 minutes until the final light rays reached us. But how long would Earth remain in orbit? If space is not confined to moving at the speed of light, Earth should takeoff on a tangent instantly the sun disappears. However, if LIGO is indeed measuring gravity waves (undulations in the fabric of space-time) it seems like space-time does have a speed limit. Which idea is correct? Has the speed of gravity actually been correctly measured? Inflation would imply superluminal movement of space-time would it not?
There something wrong mentioned in length contraction please check again if I’m wrong
STOLEN VIDEO FROM COOL WORLDS.
I watch tons of physics videos, but I’ve never seen anything like this before. Exact reason I’m a Patreon. This channel is truly something else.
COSMOS, by Carl Sagan
@@AdrianBoyko COSMOS is cool, but there were no visuals like these in the 1980s (and neither are there many of these types of visuals elsewhere even now, to be honest).
I agree. I watch a lot of great science material on other channels but this channel is very special indeed.
He’s actually insane anyone can understand this
Patreon allows warcriminals to use their site, everyone should use an other service.
I'm not much of a commenter, but what a great video. This guy explains some of the most complex stuff in our universe in a realistic, intuitive way while somehow not sacrificing important details. Never seen someone tackle so many tough subjects and explain them all to the level this guy does, one of my favorite channels of all time
Thank you so much for your appreciation 🙏 Glad you enjoyed the video!
That’s why I watch utube
Yeah I agree, great video.
I find the idea that travel near light speed would seem instantaneous to the people on the ship to be intriguing. If we assume it could be done, to the people on the ship the trip wouldn't be a big deal. You'd just have to accept that once you left Earth, you're gone from there for good, unless you don't mind coming back there again thousands of years in the future.
@@johna6767 If everything becomes instant, wouldn't the travelers be stuck or frozen in some way as they pass through their destination?
@the UN = MASS MURDERERS
Well define close? You can always get mega closer without touching C.
Man.. life really is stranger than fiction. Absolutely mind blowing.
Nothing is stranger than AOC
@@martinsmith6049the politician? Huh?
@@martinsmith6049 How did you make this about politics???? Get a grip on reality and what actually matters
It’s like a piece of string.
@@tw1nn319 Regardless of subject matter, someone always makes a political comment.
1:20 reminds me of "Speed never killed anyone. Suddenly becoming stationary is what gets you."
Wise words
GOOD ONE. HA,HA.
Speed never does. Acceleration does.
Amazing video. Absolutely blew my mind. Just know that by making these videos you are inspiring a new generation of physicists that might change the world someday. You are also teaching people the beauty of our universe and are allowing us to see the universe in ways we would never get to in our regular lives.
Perfectly stated my thoughts abt this channel and channels like it. I think saying its a service to humanity is not a stretch.
Surprised, by the fact your comments are exactly same with what I thought!
Hi, no want be rude just saying that i don't think he needs your little money to thrive in this world,.. also other thing about this videos is: If you take 1 second to reach a thing on universe at speed of light then 1 second in normal clock its just a second! So in earth it is a second when you travel at that speed reaching that distance in just 1 second and NOT 1000 years! OBVIOUSLY.
So in conclusion you learn much more investigate yourself than watching this videos some of them is just copy paste garbage that you can watch everywhere he's not the only one and also not helping that much and its almost useless this type of information and to make things worst much of "information" like this video are CLEARLY lie/s to just have some views...
@@imlost..ineedhelpfromyoulord I’m sorry but you are very wrong. Everything he said in this video is true thanks to einsteins theory of relativity which has been proven many many times
If travelling near the speed of light contracts spacetime, videos like this contract the time taken to wrap your head around such complex phenomena by helping us visualize what we can't otherwise experience firsthand. The clarity and quality of the narration and animation, paired with the familiarity of style across videos, provide way too much value for me not to contribute at least once. Mindblowing video, absolute goldmine of a channel, thank you!!
no want be rude just saying that i don't think he needs your little money to thrive in this world,.. also other thing about this video is: If you take 1 second to reach a thing on universe at speed of light then 1 second in normal clock its just a second! So in earth it is a second when you travel at that speed reaching that distance in just 1 second and NOT 1000 years! OBVIOUSLY.
So in conclusion you learn much more investigate yourself than watching this videos some of them is just copy paste garbage that you can watch everywhere he's not the only one and also not helping that much and its almost useless this type of information and to make things worst much of "information" like this video are CLEARLY lie/s to just have some views...
personally i've been able to visualize all this in my head since i was a kid. only thing i dont like about this video, is the mention of "space-time", because there's no such thing. there's fabric of space, but time doesn't exist, time is just unit of measurement.
time is to space, as liter is to water. you don't say that ocean consists of "water-liter", do you?
you say ocean consists of water and you measure it in liters (or whichever country you're from, might be gallons or whatever, but same principle).
otheriwse i agree, nicely visualized for those who don't have ability to visualize basic stuff.
@@SethiozProject Thank you for pointing out "spacetime"!!!
That's propaganda.
We also don't experience the movement of the earth and we can't see the curve.....
Amazing. Your videos never fail to astound me. Always look forward to more, well done.
Simply out of this world quite literally!! WOW! I'm dizzy just by listening to all the explanations!
🤔Do you have space sickness? Maybe you should make an appointment with your physician. I know a good one from the 24th century, that has no name and no hair😋
I love the rain analogy, never really understood why light behaves that way until you'd explained that way. Thanks!
Easier seen w/ snow
I find that "nature" repeats itself EVERYWHERE. Sometimes even things that are not even close to being related to each other yet the process of one thing (even though they produce a different end result and have a different prcesses) can be the same as the other.
One of these examples is Electricity and how to explain volts and amps.... water moving through a garden hose. The 2 have nothing in common and are complete different processes and the processes are not even related but if electricity were water going through a hose the amps is the amount of water going through the hose and volts is the water pressure through a hose like if you put a adjustable nozzle on the hose and you open it all the way open the water pressure would be very low or low volatage but the same amount of water is moving through it. Begin to close the nozzle and the water seems to come out harder and faster the more you close the nozzle but no more watter is comming out, the volume of water is still the same as going though the hose or amps.
A LOT of people HATE this example precisely because it is nothing like how electricity works but as it explains volts and amps it also shows you how 2 completely unrelated processes and mechanisms in nature repeat.
The light slanting like the rain is another example, the 2 process CANNOT be related because as you accellerate into the rain that is falling downward, the rain is not smashing into your windshield from the front.... you are smashing into the rain drops from the side. If you move at different speeds, it does not effect light's relationship to you. If you ride a bike at 30mph and as you ride at 30mph, you throw a baseball 50mph while riding, it would be traveling at 80mph because of inertia and momentum. You carrying it on bike gives it default speed of 30 + 50 from being pitched = 80mph. But now if you have a laser mounted on your handlebar of your bike you are riding at 30mph and you reach up and turn on the laser..... that light or "baseball" that you pitch in front of you ALWAYS travels at light speed. .. YOU have NO EFFECT on it and even though you are already going 30... it is not 30 + speed of light = speed of light + 30..... it is 30 + speed of light = speed of light.
SO..... the raindrops, if they were light would never "slant" towards you and appear to hit you head on as you speed up because YOU have no effect on IT. Just like light leaving you always leaves you at light speed and that speed is constant , you can go 30mph or 1000000000000mph... the rain would still appear to fall vertically.
Nature repeating itself...
can anyone heer explain to me wtf is going on with light contraction, im so confused ab if the universe is PHYSICALLY getting shorter or its just explaining that the faster u move the quicker u get places
@@starthejar1419 "The faster you move the quicker you get places" ??? That statement explains itself :)
Anyway Lets say you are in a race car on the starting line. Your opponent is next to you and the light turns green. You both take off and... you notice their car is keeping up with you almost perfectly. BUT!!! you have a little secret surprise and you flip a switch that fires your NOS canister you had hidden and now your car lurches forward and pulls away from the other guy and you get to the finish line WAY before he does.
Not exactly the same thing but replace the extra speed with time moving faster for the other guy (yes the "effect" is reversed). Faster you travel, the slower time moves forward for you. So if time is slower for you and his time is faster, why do you move faster?
If you can take 5 steps in 3 seconds, it takes you 3 seconds to take 5 steps (kind of redundant there lol). Lets speed TIME up now by dobule. So you take your 5 steps but it now take you 6 seconds to finish the same 5 steps because more time has passed for you. Now lets make time slower by dobule slow. You take your 5 steps but now only 1.5 seconds has passed in the same distance traveled so you could now take 10 steps because you have another 1.5 seconds of SLOW time to go further.
The video is explaining what you would SEE if you were to go that fast so nothing really contracts it only APPEARS to do so... kind of like going down the road in a car... if you look at the ground right where the road ends, everything passes by you in almost a blur its so fast. Now look in the distance at a tree that is far away... it looks as if it is barely moving past you while ground next to road is going super fast. It is perspective and how you SEE it.
@Rusty Koenig Check Joe Marshalla and his theory of "Repeatlessness".
According to him, nothing repeats itself.
That graphic showing the rocket moving on the time axis and the second path diverging is the best illustration of the time dilation I've seen. Simple and exceptionally easy to understand.
The problem is that the illustration is showing the distance being different and not the time. It is the speed of the rocket changing in relation to the constant speed of the planet that causes you to imagine that the time would be different when the rocket returns. And that is part of why Einstein’s theories are actually not quite right.
@@DarrylAJones If you can prove Einstein wrong, where is your nobel prize?
It's something that I would love for someone to prove wrong, because at the core of it, it just doesn't make sense to me. One would think that the passage of time would be a universal constant. For someone to leave, experience less time, and then reunite with people that have experienced more, just because they moved fast enough.. it doesn't sit right with me logically.
@@samvansomething No shit bro, it doesn't make logical sense for anyone - even for Einstein, but that's just how the universe works as proven by Einstein. Lots of shit we know about how the universe works doesn't make any logical sense but we have to accept the reality no matter how much it doesn't fit with our "Logic".
@@veritasabsoluta4285 This is so counterintuitive to the path of discovery that it's laughable. Looking for answers is the basis of science. It's why I got into theoretical physics. Calm down and don't shit on people who aren't satisfied with the answers that we have.
Thank you for giving us a glimpse into what the future may hold. Though I won't be alive to see it, the way you explain these immensely complex theories and visualize them gives me hope that one day, we as humans can achieve FTL travel. Please keep making more videos.
Great that you donated ❤
nobody travels like this too caveman like thinking. besides 5757 you will be given quantum nobody will use it
You're in the future!
Anyway .. who is here just before the night sleep .
Yo
2 am baby
😊
Afternoon nap
Me and my cigarettes
The animation quality in these videos has increased dramatically, this channel deserves a lot more recognition.
I have stopped this video so many times trying to Google information to make sure I understand it before proceeding with the next info. Amazing video. Thank you
That’s a problem with the video. I don’t think that many concepts were explained well, like time dilation.
@@JustinDickinsthat's why human have brain, use ur brain and do research information by your self duh, lazy
@@JustinDickinsit's 15min not 600h of courses + PhD thesis... But warp stuff was useless
@@pokitobountoWarp drive is a real thing conceptually
One of the small details you do that I love is you'll often give a little 4-5 second pause before moving on to the next fact so it can just simmer for a moment in our brains, and it also allows the iconic ScienceClic music to come through a little extra
'The length of the journey to our destination is shorter than expected'. Finally, a proper explanation of near light speed travel! So few people understand that one can theoretically travel accross the universe in a single lifetime without travelling faster than light.
Wait 400 years then we know
Thought it was one light-year in a lifetime the earth travels
I love this in Project Hail Mary by Andy Weir (of Martian fame) when one of the protagonists, Rocky, has an absurdly overengineered ship due to his people never discovering the Lorentz factor. Brilliant book, check it out :)
One of the most, if not the most, detailed and comprehensive videos I've seen on the topic of speed of light. Truly astonished by the effort put into this and the explanation of all the phenomenae that take place. Thank you for this piece of art, you are the hero we need, but do not deserve.
Edit: grammar mistake.
Not sure what youre talking about. I was waiting to see what it would look like, but I kinda had to use the progress bar and scroll along while imagining what the visualization probably looks like uninterrupted. Because we never actually got to see what it would look like. The point of the video
It's done with AI ...calm down
if you were to go the speed of light you souldnt see anything as you would reach the end of time instantly and die being sucked into the black hole at the end of the material plane
I'm a little confused though. As the ship goes faster won't the wavelength's of the light shorten and go out of the visible range? Won't they become xrays and the even shorter? When traveling very near the speed of light, what will the wavelength of oncoming light be? Won't it be near 0?
As an animator trying to make a realistic warp affect your time and effort into making this is greatly appreciated
I hope all future sci-fi shows take a lesson from your video
It would be nice to see all of these perspectives taken into account with travel and the effects of black holes properly in a non fiction based film. No bs, just straight shooting. I watched the last two films that featured black holes just to see the perspective they came up with. I still feel disappointed.
@@brown2889 what are those movies?
@@elakstein Interstellar and High Life.
Last ones to attempt to show what traveling around or in a black hole. Haven’t really seen a movie that does light speed properly.
@@brown2889 I agree, but realistic is not relatable for people. At least the things that we didnt encounter in our evolutionary past. I remember Interstellar. Yeah, still bs. Lots of assumptions and fiction, lots of subjective emotional manipulation. Hmmm, on the other hand, how would one even portray anything resembling true infinity in a movie?(people just dont care for most things in any infinite set)
@@greenanubis Are you talking about that library scene from inside the black hole or the black hole imagery itself? Because if the latter, that was literally the most accurate representation of a black hole we had until we got the first images back from the EHT. If the former, then yeah, you can only show people the concept of infinity metaphorically; and, it's a movie about people, so why wouldn't there be "subjective emotional manipulation?"
I cant belive this video explained everything to me that i thought i will never understand,amazing work.
As someone who spends countless hours watching astronomy videos this one is by far one of the best ever . Explained everything really well and the visuals are amazing!
Finally I’ve come across the best of TH-cam. Great content and the presentation is worthy of any classroom. Thank you.
yes, watched this a year back
I have seen many videos on this topic, but have never had length contraction explained so comprehensively before. I can’t believe nobody has ever pointed out to me that the journey feels instantaneous at light speed
The only other video that mentions instantaneous transport is Vsauce from 10 years ago. All other channels overlook this principle.
im still a bit confused on how it appears instantaneous to us but very long time for people on earth?
@@bapples1233 exactly my point as well..
Say for example in 1 sec I travelled some thousands of kilometers at speed of light going from point A to B
While someone on earth travelled few inches in 1 sec, going from his point A to B.
Now though the distance travelled by both is exponentially different, but still we took 1 sec only.
Then how does the person on earth age faster?
@@bapples1233 photons do not experience time at all. The moment they are created and absorbed is the same moment in time - to them.
@@bapples1233because at the speed of light, time basically stops and with it our perception of time stops, the faster you go the the slower your time becomes, including your perception of time.
At light speed you essentially never age.
I guess in a spiritual sense that’s why after death your spirit is eternal, because the energy that was once in you, that made you is given back to the universe as light and will forever be.
One of the best science/astronomy video i've ever watch on the TH-cam. I love all about the universe
This video far and above so much better, than the dozens of amateurish videos on this subject here on TH-cam. Concise, to-the-point and lucidly explained.
makes mny mistakes tho
@@efdbjon2114what mistakes do you think this video made?
@@efdbjon2114Shut up, ignorant. It doesn't
Your channel is amazing
No you’re amazing 😁
It’s amazingly false
@@hosoiarchives4858why
@@hosoiarchives4858elaborate
This video ( and this channel) is the result of astonishing dedication and effort.
The scientific intelligence and the ability to effectively communicate the complexities of these subjects are UNMATCHED on TH-cam.
Many congratulation, ScienceClic!
yea
computers sure have helped propel our understanding with visual effects, gaming has helped with these models aswell
I’ve always liked the rain analogy, but [8:23] that I finally understood why light behaves that way. Thank you!
The only part of this that I had never heard before or tried to grasp was the idea that if we could travel close to the speed of light, that the time it would take us to travel to our destination would seem instantaneous. That is mind blowing and really a different take on this than any I had heard before. I would love to hear this explained in more detail
Would we age and die very, very quickly. Or would we make it to the destination 10,000 light years later, perfectly fresh like it took seconds ?
Certainly the second@@NatMart9394
@@NatMart9394 The 2nd option is true. And if we´d once return, more than 20000 years earthtime had passed, considering the time of staying at the destination and the months it took to accelerate to approximatly lightspeed each way. And still, this is only what it seems to be in our mind, since time is just an illusion of our awareness.
@@zardoz1970 it doesn't make logic since if you teleport from point A to point B , which means going at speed of light is basically teleportation, it just means that you go from A to B in less than a second and get back from B to A in less than a second , so it just passed a second and no one aged. Another example is that , you fly in a jet for two hours, you age the same as people on the ground , they continue their life for 2 hours , you travel for 2 hours but you age the same as them, so logically it's the same with the speed of light, you just go from earth to another dimension in one second and come back the next second, so nothing changed really
It does confuse me, but there's no way for us to test it first hand.
This is truly one of the best explanations I've ever seen for relativity and the effects light speed travel have. Honestly absolutely incredible work. Congrats
@@davidsheckler4450 do you even know what is science and how it does work? where are the scientists who support your claims?
@@en5374 David just thinks he is cool tossing around the word sheeple when in fact he has absolutely no clue what is being discussed in this video.
@@617aaron617 spoken like a true sheep
@@lostpockets2227 Typical response. But, I wouldn't expect any less.
I remember watching an old Vsauce video and being blown by massless particles experiencing NO time and that the concept of time not even applying to them. Mass-less objects must always have to travel at "c", have neither a beginning nor an end, and the particle's origin, journey, and destination all happen simultaneously for it. This video just reminds me of all the complexities and awe the universe contains that we humans may never understand in the entirety of our existence.
But all this is just a reflection of you only you haven’t recognised it yet!
Understanding the relative point of View is not necessary the point of view of the absolute therefore the theory’s they use and relatively are only tools to the absolute.
They are not completely understanding the concept of truth. And just writing something they don’t fully understand, comprehend or know like a mule carrying a message.
What they are saying is partly true but their theory is a relative truth not the absolute truth.
When one wakes up and recognises what’s really going on we recognise these are all reflections of ourselves. It is all one happening! There are no seperate events or separations between you and the entire cosmos. Yes we feel like we are separate because we can only experience it one at a time but that you and the other even though they may be different or seem separate as 2 but in reality they arnt these 2 things you and other are really one but the illusion of self and other make you believe they are 2 and separate happenings. True relativity is unity. You and the other go together. These duality’s only exist for us to recognise. You would never know what light was if darkness never existed or what sweet was if bitter never existed etc. it’s a truely beautiful and amazing universe. So in reality 2 really =1 but not 1 in number but as a whole.
So really we are the heavens and the earth and everything in-between but it’s fear and ignorance that doesn’t allow you to progress!
So the true real evidence is the NOW
You are always here
It’s just we don’t recognise it
And that’s part of the wake up call! It’s infinite. What most people see is relativity instead of the absolute
Absolute is singular but not in number but as a whole.
You spoke of those particles having No beginning nor end but that is who we are! If it has a beginning or an end that limited. And the system is unlimited. No beginning no end always forever connected and that’s what Adam represents the dome the circle, the wheel of life as some call it the earth goes round and round between light and darkness, our blood goes round and round circulating our body 24/7, the tide goes up and down always etc etc and we are part of that. The beginning that has no beginning and the end that has no end otherwise it’s limited. Sorry for the essay hope it helps just felt I had to write this to you peace
You were being what by massless particles? 🤨
@@kevoelevo88photon
@@kevoelevo88timeless sloppy
@@kevoelevo88the timeless gawk
Wou, what a good video. The voice ,the explanation, is just brilliant.
Elegantly explained! I’m studying astro physics 101 and this was such a tremendous help. Superbly articulated. I love the excellent illustrations which help with the understanding. Thank you so much.
Yes, it is very well done. And Einstein visualised all this in one of his trances. Main take-away being time dilation and length contraction... that a photon does not experience time. A trip to Proxima Centauri being a mere blip, yet we hear ad nauseam (even from physicists) that even if we could travel the SoL it'd take 4 years to get there. Nope; only for the outside observer. The SoL is the ultimate speed.
if you travel at the speed of light, particles with no mass would reach and destroy your optic nerve before you ever processed a single photon. Just sayin. This explained nothing, and it should not have helped you at all. In fact, every frame of this video is a detriment to your understanding of reality and the universe.
@@ZennExile "cosmos" is a masonic(satanic lie.
Know who is who lies, masons.
Know what are their lies, all which this world believes.
Expose them and their lies, not support them and their lies.
Extraterrestrial Life? - the existence of demons among the mankind.
As the BIBLE says, we grow up with a offspring who is not like us, only look like us for a short time, until the harvest time has arrived.
The wheat and the tares:
Matthew 13:25
But while men slept, his enemy came and sowed tares among the wheat, and went his way.
Matthew 13:26
But when the blade was sprung up, and brought forth fruit, then appeared the tares also.
Matthew 13:29
But he said, Nay; lest while ye gather up the tares, ye root up also the wheat with them.
Matthew 13:30
Let both grow together until the harvest: and in the time of harvest I will say to the reapers, Gather ye together first the tares, and bind them in bundles to burn them: but gather the wheat into my barn.
@@ZennExilelmao ok? It’s not like it teaches people some special relativity and other concepts of Astrophysics or anything…
@@ZennExileassume we are in a special spaceship that isolates us from any harm, how would you refute the mathematics?
This is hands down the best channel on TH-cam (for me).
This content is the most amazing, full stop.
I'm so glad you mentioned that "for us, the trip seems instantaneous". So many people don't consider the inertial observer's perspective. Though there are so many ways to look at it, when you consider the affects of near light speed travel from the perspective of time, things are far more interesting. Time controls not only the progression of change, but also motion, mass, scale... Time is what makes gravity attractive. It isn't that we are being pulled magically by some mysterious force, no... rather its the composition of our bodies (or the composition of matter in general) at which different parts are traveling thru time at different rates relative to one another. From a motion standpoint, this affects the relative speed of every particle of an object in a gradient fashion. This gradient in time has the same gradient affect on motion; parts closer to the source of gravity move slower relative to those further away, and thus a parabolic curve of motion is formed toward the source of gravity.
When traveling at near the speed of light, from our perspective, the trip from any point in space would be near instantaneous. It makes you realize that light itself knows no time because it knows no space. We wonder how the universe could be all fit within an infinitely small point (a singularity) at the time before the big bang, yet light itself, if it could observer, would still think it is... that space never expanded. The only reason we perceive space and its expansion (distance, scale, etc...) is because we are not traveling at the speed of light (or rather we are moving faster in time).
Thus, the faster you move in time, the slower you go in space, and in turn the larger (in scale) the universe becomes. I think looking at thing from the perspective of time is far more interesting than looking at the effects of motion or gravity on time and space. Thanks for the awesome video!
When we start moving away from our planet..into different corners of space..as a species, maybe our whole perception on travelling will change..as we will no longer be moving in the linear motion which is parallel to earth, like a sitting duck blitzing from past to future but instead we would be taking a detour in space....we could go back in the time, in different time zones in space. People living in the past and the future at the same time, relatively speaking, like literally a point in space where you were before as that point in space has it's own pace in time...almost like the flow of time itself becomes irrelevant... we'll have our own natural time though...like our body itself is on a grind, on it's own natural order of things, so we will probably feel like we are aging normal...like the stationary trees that blitz pass us in speeding bus, all the time blitzes pass us once we come out the bubble...imagine that!...maybe we can get so far from earth that we can see it in it's beginning phase(when it was just a hot rock) than move towards it and capture all the evolution that happens til the day you reach earth...it would be a instant time lapse but if we could somehow see it.....opens up all kinds of possibilities...or maybe not😂😂
Excellent comment.
@@anobodyfromnowhere8427 I could def see how perhaps we could see the past in an object such as earth after moving past the speed of light for a while. This whole thing is quite a bit confusing for my mind.
does this mean that the thing we call the 'lightyear' is just the distance covered in an instant for light itself ?
@@dragondudeyt2344 frame of reference...from our frame of reference, the light takes a year to travel the light year distance...but if you were light itself, it would feel like an instant....it could be like one thing happened and the other thing happened immediately after, cause nothing travels faster than light.
Terrell-Penrose rotation is the perfect explanation of why I think some portrait paintings/pictures are always looking at me 👀😂
As a truckie once said to me "speed can effect you like that its when the telegraph poles start turning into giant parrots you know its bed time."
My heart leaps when I see a new ScienceClic video among my subscriptions. But when I hear, "To conclude", the gravity of the situation crashes it back down to earth...
This video was absolutely fantastic! I loved that you both distinguished between and illustrated the physical and visual effects of both The Doppler Effect and Special Relativity.
This video was very much needed, especially the warp drive part!
There is no such thing as warp drive.
Huh
@@doylegaines1319 there is, only thing is its practically not possible now due to lack of technology ,in brief an engine when run should be able to attain near speed of light magnitude ... Which ll be possible after 200-300 yrs once civilization starts consuming more energy as consuming more energy ll increase the need for energy thus expand the energy in earth and force the civilization to capture energy from sun in vast amount....
@@henrykashyap8913 Why is there no Superman in real life?? Lack of technology. If we had "the technology" we could make the earth spin in reverse 3 times a day , right? That's all we need to do - just develop "the technology". One day we'll have the technology to walk to Mars. My bet is that we'll walk to Mars looooong before we travel at near light speed. Of course, I know that's probably not a popular opinion among sci-fi fans.
Is it possible you can make a video of how you guys make these videos, and how you actually sustain yourselves economicly; just like Kurzgesagt. These are literally best astrophysics 101 lessons ever. Production is beyond top notch.
Thanks a lot! I was thinking of doing a "making of" video, I might just do that. Economically I actually produce everything myself except for the translation/dubbing, so there are not that many expenses.
@@ScienceClicEN Kudos!
But you do spend many, many, hours on this right? You work a lot to make these videos happen, and "thank yous" are great, but you should get some sort of compensation for making these for us as well, you do an amazing job
@@davidgamer7267 1m views in the matter of 13 days on ONE of these videos generates compensation .
@@ElectricCityBox Not that much though, considering there is only TH-cam ads
[insert falling to knees emoji, if it, existed, here]. Excellent presentation! I can't do the math but I innately understand and appreciate what you've done here. Mind still blown especially as I've always held the belief that altough the Speed of Light is absolute, there are ways of going FASTER than the speed of light. My grade school science teacher hated me LOL
Your channel is just something special! Thanks to your videos I understand topics I never thought I could.
So please keep up and teach us some more amazing things ✨️
Holy cow ! That planet rotating in 4D was astounding. I'm not exaggerating, your content shocks me as much as when I watched Sagan on my very old TV
This is the one channel on TH-cam that will always describe physical qualities of the universe in a way that makes me feel a sense of child-like curiosity. So many other channels sometimes stay on the more technical side, but the voiceover, music and visuals in the videos on this channel all complement each other in a very unique and special way that remind me why I love science. And it is also thanks to this channel that I started reading about special and general relativity purely as a hobby. ❤
Can't wait to show this specific video to my actual child once he's a bit older.
Try "Cool Worlds Lab" & "The Complete History of the Universe" 😎❤
This is truly one of the best channels on TH-cam! Awesome job, as always! Please, keep the amazing work!!!
Outstanding!
Agreed! It's the best science channel on TH-cam!!!
Without exaggeration, this is probably the most clear illustration on this topic on the net. Without getting too abstract and obscure in explanation; it actually makes quite a great deal of sense to little humble me.
This may be the the most comprehensible and on-point video I have ever seen about this topic, and there are a lot of those
I’ve watched many others and I agree
the first vid i watched from this channel, absalutaly amazing, the gravity one still baffles me a bit, cant fully wrack my mind around it
The animation and explanation quality of this video is impressive. Loved it
That was the single best explanation of Time-Dilation I’ve ever seen. Perfectly illustrated
For real I’ve literally watched like 5 other videos trying to get it but didn’t until this one
Time dilation of special relativity is very easy to follow by the light+mirror clock on a train thought experiment
The intelligence to be able to comprehend such things is impressive 👏
Indeed. If everyone was like me we'd still be living in caves!
What I realized about speed is that speed is not an easy thing. Speed should be considered as movement in space. Moving in space we slow down time (taking into account the acceleration). Best video I've watched..
I think about this concept so often when watching a Star Trek or Star Wars show. Now I can just rewatch this for a refresher, and to blow my own mind over and over again.
Honestly, the amount of work, knowledge and understanding it takes to condense this topic into this very understandable, yet comprehensive and well-written video is way beyond what I could do. Or what most of us could. Yet, this channel only has 414K subscribers? Deserves way more.
You should REALLY team up with PBS Space Time on some form of a collaboration.
This is truly exhilarating and extraordinary.
This is hands-down the best science TH-cam channel ever.
If the speed of light doubled. The old speed of light would be a reachable speed. Key word: if
I have watched every single video uploaded on this channel and it is by far one of the best physics and science channels on TH-cam. Bravo Mr. Roussel, the quality and information conveyed in these videos is excellent and easy to comprehend. The animations and music are also top tier. Please keep uploading.
This video has arguably one of the best time dilation visual support (if It is accurate) I have ever seen. Good job 👏
It’s perfectly accurate. Sources used involve astrophysics research from the university of Colorado, and Dr Andrew Hamilton
What about eye dilation😁😁😁😁🙂?
th-cam.com/video/K62SHNxmQlI/w-d-xo.html
Finally a new video! We were waiting patiently❤ You’re the GOAT of physics on YT.
This video is PHENOMENAL!
The time-dilation illustration @ 7:35 is wonderfully instructive. Great video.
Yeah. I'd just like a video about how the non-Euclidean geometry makes the "longer" route actually shorter. Maybe it's due to what was said in a past video on this channel regarding movement through space necessarily creating less movement through time and vice versa, but I'd still like to hear more about that.
@@Rationalific That's correct. ScienceClic mentions in the video "We all move at the Speed of Light" that all matter and energy in the universe travels at 1.0c, the speed of light.
A TL;DR explanation is that if you are moving through space, you are moving less so through time, so less time has passed for you; thus, your path is shorter.
But how does that happen in the first place? I'll try to explain it as simply as I can, though it might be too long to read. Perhaps though, my comment could be the script of a video complete with diagrams and such.
When objects accelerate, in the eyes of relativity, we redistribute a 1.0c velocity through space-time.
The simplest example is linear acceleration aligned with our x-axis, so that we can ignore y and z. Rest will be no spatial motion relative to the origin.
We now accelerate. Formerly, our velocity was solely through time. All of our 1.0c velocity was along the time axis: our velocity vector is parallel to the time axis. For every 1 second that passes on our spaceship, 1 second passes for an outsider at rest. But now, we are moving through space. Part of our 1.0c velocity is distributed along the x-axis. This vector would point up and to the right, but mostly up.
We then turn off our engines. Relative to the origin, we are no longer at rest because our spatial speed is non-zero. Our vector still has a magnitude of 1.0c, but it has rotated. This is called a different frame of reference. Objects are in the same frame (co-moving) if they have parallel vectors.
TH-cam won't let me post the link, so look up "hyperbolic orthogonality" on Wikipedia and enlarge the diagram that looks like many green circles and a purple hourglass shape.
The 3 axes of space are Euclidean relative to each other, meaning we can use the Pythagorean theorem to calculate distances involving more than one axis. However, comparing any of the 3 axes of space to the axis of time will not yield a Euclidean relationship. The relationship relies not on Euclidean geometry but hyperbolic geometry.
Euclidean geometry uses circles to define angles and distances; hyperbolic geometry uses hyperbolas.
In the green universe, there is no universal speed limit. When the axis of time is pointing toward the old direction of the x-axis, that is infinitely fast speed (undefined). The tangent function (tan) is the relationship between angle and speed. (Notice how at 90 degrees it goes to positive infinity and wraps back around from negative infinity). This doesn't mean you can achieve infinite speed, however, because the tangent of 90 degrees approaches infinity. The inverse tangent function (arctan, from "arc of tangent", or tan^-1) lets you plug in a desired velocity and spits out what angle you will have rotated the axes by to achieve that speed. Because you can plug in any number from negative infinity to positive infinity into arctan(x), you can achieve any speed between negative infinity and positive infinity. On this graph, accelerating at a constant rate would look like the axes are rotating to the side, but slower and slower over time, never quite reaching 90 degrees.
In our universe (diagram on the right), however, the relationship between space and time is hyperbolic, not Euclidean. As you accelerate (rotate the time and x-axes), they don't spin around as the green ones did. The points follow the hyperbolas rather than circles. The axes get closer to each other like the blades of a pair of scissors closing together. The axes are dragged toward that red diagonal as the purple points continue moving; the red diagonal limits the angle to 45 degrees, the inverse tangent of which is 1 (1.0c). To understand how this finite speed can be a universal speed limit, we have to abandon our naïve notion of velocity and replace it with a new one called rapidity.
We can describe the velocity of an object using the numbers between -1 and +1, but the number 1 is the finite boundary. With rapidity, however, we can use numbers between negative infinity and positive infinity. In this system, the speed of light really is infinite, which makes it unattainable. We convert between velocity and rapidity using hyperbolic trigonometry.
The hyperbolic tangent function (tanh) lets you convert from rapidity to velocity. The inverse hyperbolic tangent function (artanh, from "area of tangent", or tanh^-1) lets you convert from velocity to rapidity.
Some example calculations:
Velocity 0c = Rapidity 0
Velocity 0.01c = Rapidity 0.0100003
Velocity 0.1c = Rapidity 0.1003
Velocity 0.5c = Rapidity 0.549
Velocity 0.8c = Rapidity 1.099
Velocity 0.9c = Rapidity 1.472
Velocity 0.99c = Rapidity 2.647
Velocity 0.999c = Rapidity 3.800
Velocity 1 m/s below c = Rapidity 10.11
Velocity 1.0c = Rapidity is undefined, approaching positive infinity
As you can see, velocity and rapidity are initially almost identical, which is why we don't experience significant time dilation at ordinary speeds. The departure of rapidity from velocity is the hallmark of time dilation. In fact, the Lorentz factor (how much a reference frame is distorted with respect to another) is cosh(x), with x as the rapidity.
Thus, if we replace velocity with rapidity, we now have a situation similar to the green diagram on the left; bounded by an infinite speed. It is only when we use our intuitive version of velocity that we appear to be bounded by a finite speed.
Now that we can convert from hyperbolic to Euclidean, we retrieve the case before, where plugging in any rapidity between negative and positive infinity into tanh(x) gives us a velocity, and then, plugging any velocity into arctan(x) gives us the angle. We cannot exceed 45 degrees (the speed of light).
Now imagine Earth at the center of the diagram on the right, moving forward through time (up). Now imagine our spaceship at the center as well. We will depart from Earth at high speed and then return at about the same speed. Earth's motion is only along the time axis. Ours will be partly on the x-axis and partly on the time axis. We will accelerate (change frame) from 0.0c relative to Earth to 0.8c relative to Earth.
artanh(0.8) is about 1.09 (this is rapidity), and cosh(1.09) is 1.667 (exactly 5/3 actually), so for every 5 seconds that passes on Earth (chosen rest frame), 3 seconds passes on our spaceship.
arctan(0.8) is about 0.675 radians, or about 38.7 degrees, so you can imagine a line above the red diagonal but very close to it representing our spaceship's trajectory. (The angle is measured relative to the time axis, because an angle of zero with respect to time is the definition of rest in just the spatial axes.)
Let 5 years pass for Earth. Earth will have moved along the time axis a distance of 5 purple lines (I am asserting 1 purple line = 1 year.) If we arrive on our ship at this time on Earth, how much time will have passed for us on the ship?
We now track the motion of our spaceship on the graph. Assume we accelerate to 0.8c quickly enough to not affect our calculations. We move up and to the right at an angle 38.7 degrees away from Earth's time axis (our time axis has rotated with us). According to the axes as measured by Earth, we are passing each purple line (each year according to Earth time) slower than Earth is. From our perspective, however, we are crossing purple lines at the ordinary rate because we have our own axes. But according to Earth's axes, we are crossing purple lines slower. This is equivalent to Earth observers watching our clocks tick slower than those on Earth.
Therefore, our frame is different from that of Earth; we cross Earth's purple lines (moments in time) slower than Earth crosses them. Earth has crossed 2.5 purple lines (halfway between the second and the third), so 2.5 years have passed for Earth. Our spaceship has crossed 1.5 purple lines (halfway between the first and the second), so 1.5 years have passed on our clock.
We must now return to Earth. We accelerate to reverse our 0.8c velocity so that it is now 0.8c toward Earth instead of away. Because we have accelerated to a different velocity (0.8c in one direction is a different velocity from the same speed in a different direction), we are now in a new frame. Because a vector of a given direction and magnitude is identical no matter where you move it on the graph, we can superimpose a copy of Earth's axes on our ship even though our ship is way off to the right in the diagram. (Put simply, 2 miles north is 2 miles north, no matter if you are in Kenya or Canada.)
That would be very visually crowded, so we will instead say that our spaceship is at the origin again, with the origin being the point where we turned around from to start heading back. The axes are still parallel to Earth's so all calculations will still be correct. We now move up and to the left 38.7 degrees away from the time axis. While Earth crosses 2.5 purple lines again, totaling 5 years, we cross 1.5 purple lines again, totaling 3 years.
We accelerate (negatively, to slow down) to land on Earth, so we return to Earth's frame and make Earth the origin again. We are now in the same frame as Earth. However, because we accelerated into different frames of reference, whereas Earth never changed its frame (because we designated it as the rest frame), our clocks will no longer agree with Earth.
It is by this simple fact, that vectors are the same no matter where they move*, plus the non-Euclidean geometry of the universe, that we can show that motion through space does indeed result in less motion through time. This particular combination of Euclidean and hyperbolic geometry is called Lorentzian geometry.
*When this is not true, we call this curved spacetime. That is general relativity, not special relativity.
@@Rationalific here's a picture that worth a thousand words; to play with! :D
th-cam.com/video/v6KdrZrsBjY/w-d-xo.html
@@Rationalific Mathematically, it's because time has a "square root of negative one" (imaginary) unit factor... so when you do the A² +B² = C² pythagorean length using space on one side of the triangle, and time on the other side, you wind up subtracting the time² from space² (So longer spacetime intervals measure shorter proper time.)
The reason for this mathematical trick, is because every location in space is in the past of every other location in space. Things that you see come from the past... the negative time direction.
(You could also turn this around so that every location in space is located in the future of every other location too... the important thing is that "right now" for any arbitrarily chosen point time and place sits at the intersection of an incoming sphere of light from the past, and an expanding sphere of light towards the future.)
Distance in space is also distance in time.
@Julia Vixen Thanks for the explanation. If I understood correctly (a big "if"), then it does seem like it does in fact stem from the fact that you go through less time if you go through more space... And it does come down to that circle graph using "i" that I saw in a past video... Anyway, it's wacky but thanks for explaining more about that!
I'm left speechless. this video is by far the most well done amongts your other animated science/education videos
I have to say it is one of the best physics videos i've ever seen ! And i'm so glad you even thought to implement a " what would we see at warp speeds " section ! The trekkie in me is much pleased
Simply spectacular narration of physics phenomenon demonstration.
Channels like these that explain science in a super easy to comprehend way are very important for future. Thank you for doing this.
Holtzmann effect. Traveling without moving, folding space-time, not just surfing it. Very informative and entertaining!
Wow. I've, "armchair", studied these concepts for many years, and thought I had a pretty good grasp of even the most complicated especially relative theoretical effects but, the way you've visualized them for me here, seems to cause a deeper "sinking in" of the ideas at play. Thank you! You've done a terrific job!
interesting, but wrong. This is the old if your car was traveling close to the speed of light thing. light would still look like it was travelling super fast ahead of you AND the light from behind you could catch you and pass you (so it isn't super dark behind you 11:55).
This was an incredible masterpiece. I hope teachers pick this up and show it in their curriculum. However, that ending was beautiful! I've always said, in theory, there is so much ahead of us that we cannot even see.
Not only a masterpiece ... but a piece of crystal clear thinking and a genius of conveying knowledge to us , mere morons... thank you for the light in a vast darkness....
This may just be one of the coolest videos on your channel yet! Incredible on all fronts!
I like the intuitive analogies that you provide, like the behavior of apparent light at high speeds being similar to driving into rain drops
This is really good. Thanks for making, and sharing. 🔥
By far, the best science explanation channel out here on the platform and I’ve watched a lot. The visualization and easy to grasp comparisons makes it understandable in a whole different level and really makes you think about said subject.
This clip reminds me of the comedian, Steven Wright, when he says, "If your car could travel at the speed of light, would your headlights work?". His comical question made me laugh but, it has haunted me since. It speaks to me of a future so uncertain. It's great to see that these great young minds are seriously exploring these possibilities. It's inspiring to see the tenacity of the Human Race to explore, and how we see our future... well, being there as if we are already looking back on ourselves.
I only hope that our Race to the future will be of collaboration and not against each other. Thumbs-up for this great presentation!
I believe that to the driver, the car's headlights would appear to work normally, as much as they could in that contorted reality. To an outside observer, the photons emitted from the lights would essentially build up in front of the car rather than continually stream forward, and upon dropping out of lightspeed, would be unleashed on whatever is in front of the car when it stops. A bit like a solar snowplow obliterating whatever unlucky destination you happened to be headed toward.
If the car's headlights were shining upon a target ahead, would the image disappear when the car reached the speed of light or would the target remain illuminated? If it remained illuminated, would it suggest that light is travelling faster than light, which reached the target before the car, which was aleady travelling at the speed of light? The video showed light getting brighter as the rocket accelerate towards it, which makes sense when considering the Doppler effect, but it didn't seem to consider light which was being emitted by the rocket towards a target ahead of it.
It's a good question though.... Really!! It seems from this video that they would still work because we won't ever be able to reach the speed of light as described in this video. And it makes sense to say the light from our car travelling at the speed of light would still project light travelling at the speed of light ahead of us! Sounds crazy, but in my mind it makes perfect sense!
The way I look at it, light moves instantaneously, relatively. A photon will not experience time because it instantly appears everywhere in the universe, things that are slower on the other hand see it travel.
So unless you yourself move instantaneously light will always be faster than you at the speed of light relative to you.
However, if you're moving at light speed, instantaneously, you'd not see anything until you stop because the process of moving is just an instant no matter the distance, something you couldn't experience. So your head lights would work, but you couldn't see it. You couldn't even experience it.
Man, this was an awesome video. Totally blew my mind.😅
😍 You have an incredible talent for storytelling; your narratives are captivating.
Thanks for finally sharing with people the time distortion for those ON the ship.
We are constantly told about the other effects but very few people actually address the fact that the reason photons can travel such vast distances is that they do so without respect to time themselves. In short, they are timeless. They are everywhere, all at once. Their path is a dagger through time itself.
Yes! A new ScienceClic vid!! Beautifully and expertly done as ever! Thank you!
I've been super interested in light speed theories and time dilation since I was young. This one video has shown me more than I've ever seen anywhere else. Fascinating.
11:20 I like that.
externally we get really close to light speed and are almost catching up to the photon in the same direction. (so its only moving away very slowly)
but internally since time seems so slow for us, the photon moving away from us slowly seem to move away at lightspeed from out point of view
Phenomenal exploration of the mind-bending concept of traveling at the speed of light! This video does an exceptional job of breaking down complex ideas and visualizing them in a way that's easy to understand. Truly makes you appreciate the vastness of our universe and the wonders of science!
I TOTALLY UNDERSTAND THIS VIDEO!!! I've been wondering for years about the viewing point of light speed. This video answered some of my theories and gave me a better understanding. Great video!
Absolutely stunning 3D visuals, have been thinking about how this would look like for years!!!!
I remember watching so much about relativity and light and you made it so much simpler to grasp, well done!
This video was completely fascinating and very well articulated. Enjoyed it very much. Thank you
Wow! OUTSTANDING illustration! I have never in my 53yrs of life had relativity explained to me like that. Thank you!!
Same here! I'm 60 and a lover of science fact and fiction. Just in my lifetime I've seen what was once fiction become reality or on its way to becoming so . What an awesome time to be alive and to have watched many of these advances come into being a reality!
@@chefscorner7063 Agreed! 😊
I'm thankful for the time and effort put into this video!
the time to make it ? It only took a second....he was moving at the speed of light :-)
This video helped me intuitively understand time dilation. I already knew the concepts and all the effects, but I never truly understood why without reciting a definition or something. But when you talked about the ship chasing a photon and how from the perspective of the ship it would move away at the speed of light but to an outside observer the would be following each other at almost the same speed made it really click in my head why time dilation needs to happen and why the trip would feel faster to the ship than an outside observer. Thank you for the fantastic video
Awesome illustration! Very few content creators can explain things so effortlessly.
After watching the warp drive segment at the end, I can now imagine a corollary of Alcubierre warp drive - creating a center point from where an infinite density is formed in front (contracting the space time like black hole) and forming a massive infinite explosion that sets a forward motion (expanding the space time like a big bang or probably we can call it a white hole). What intrigues me is :
1. If we create such a center point then how do we know we are moving forward towards the future or backward in the past? We don’t have a multidimensional navigation system to understand where we are actually heading to.
2. If from the reference frame of Big Bang, a complete space time stand still is the past then from the reference frame of a center of a black hole where time stops, a Big Bang is the past or we can say exactly otherwise if we replace past with future. It appears as such past and future are just like an optical illusion visible to us between these motionless and motioned states of space time. They simply don’t exist!
3. If we consider an epoch between a Big Bang like expansion and a giant black hole like gravitational pull to be our dimension of existence or merely our universe then would existence of such several epochs make multiverse? And if it’s considered true, then the universal space time is just a string forming a fabric of multiversal space time which must be totally different than our understanding of space time.
3. Isn’t a warp drive a kind of a mini epoch (micro universe) created by us to actually travel the space time? So we want to create space time itself to travel space time?
4. If we consider a spacetime as a gap between an infinite explosion and an infinite gravitational pull then there must be several gaps like these with different dimensional varieties. Some might have been created and destroyed at a faster pace giving them a different type of time dimension. Likewise there maybe different types of lengths, breadths and height systems in various other universes. How we experience this dimensions in our known universe maybe not be the same way they are experienced or manifested in other universes.
@ScienceclicEn,
We need more information on this
Unbelievable quality. This is the best science/physics channel on the internet.
The level of satisfaction I reach just watching these videos is beyond the speed of light
At last someone explaining the theory of relativity in a way I can actually understand! Absolutely fascinating. Thank you for posting.
Amazing video. I've watched so many videos regarding near light speed travel and this is the best one. You covered so many important points. Thank you!
Someone’s been upping their animation game :-) Another classic to add to your repertoire! And great to finally see a realistic tackling of length contraction, which is generally under-treated in most works.
Plus your warp drive visualization at the end really was quite intriguing - there’s definitely some food for thought in there… interested to see what you’ll be tackling next!
Thanks a lot, glad you enjoyed it! I think I'll post more simulation or the warp drive in a separate video :)
You two are my absolutely most favourite channels and I would like to thank you for your videos. Do you think it would be worth making a video about 4th dimension? I was wondering whether it has any conection with the gravity. Does gravity cause things to "fall" into the 4th dimension? Does the rocket launching from earth need to "climb" from the "hole" of 4th dimension? I found this video th-cam.com/video/JmvHNatZgVI/w-d-xo.html it does not mention gravity but i think its very cool :)
@@ScienceClicEN It would be helpful if it were more realistic. Everything uses energy, but where is it?
I feel like the hardest part would be determining HOW to get where you are going when bending space time. You would move so fast and you would have to have a predetermined end point. So somehow a computer would have to acurately determine the distance to your destination and bend space for a set duration and then stop to get you there. So if you were bending space and collapsing space directly in front and behind of you, then you would have to be able to control a specific measurement of space. You wouldnt want to warp just half of your ship. You would probably see a lensing effect all around you until the warp was complete. If you warped a finite measurement of space all the way from the start point to the end point.(like a wormhole) You would probably instantaneously see a distorted view of your destination out the front window for however long it takes to complete the warp.
And thus The Flux Capacitor !! ...thanks to Dr Emmett Brown.
Not a hard thing to accomplish if the math on ftl is worked out.
@@jamesofallthings3684 the math is not encouraging in this case. the bubble can move, but there is no way to enter or exit it, nor change its speed/direction, or even create/destroy one. It would simply exist, disconnected from causality.
@@neeneko- It would require an enormous amount of energy to move a space/time bubble, to the order to several thousand Suns all at once. Till we can figure out another shortcut, it will remain science fiction.
I have to assume if you're in the bubble you're essentially blind, as you're disconnected from the universe.
If light were to enter the bubble, it would:
a. Cause drag that could maybe drag you out of the bubble.
b. Be the same as super high-energy gamma rays blasting your ship, because of blue shifting.
And of course the trick is to effect the command to stop the ship. What if you start your warp bubble and the ship decides to keep going in that direction forever, because your controls are also disconnected from the universe?
So well explained, have never seen anything comparable. So much food for thought! Thanks for an outstanding video.
The Expanse does a great job of explaining accereration and braking using an Epstine drive. A must watch.
There are countless animated TH-cam channels with narrators explaining everything you can imagine. They’re pretty much all garbage, so I almost didn’t click on this one.
This is excellent. The animation is great and the explanation is really, really well articulated and makes it easy to understand. I’m only four minutes in and I’ve already subscribed. Keep up the good work.
This is really great work! Just love your simulations, illustrations and explanations. So good, well done 👏🏼🎉
Thank you for the disclaimer concerning the Alcubierre type warp drive. Too many lesser YT channels imply this is a real possibility! Suscribed!
The best is… when you reach almost speed of light and turn on the front lights of your vehicle, that light will travel at the speed of light in reference to you, but still only at speed of light from an external observer, not twice the speed of light. Wonderful… love it
i didnt understand if its travelling at speed of light for the driver then how the observer would see it as only at the speed of light not twice the speed
@@godofgods4854I'm wondering about the same thing