Is relativistic mass real?
ฝัง
- เผยแพร่เมื่อ 4 ก.ย. 2017
- One of the oddest features of special relativity is the inability to go faster than the speed of light and this is absolutely true. The most common explanation is that the mass of an object increases with speed, but this particular explanation simply isn’t true. In this video, Fermilab’s Dr. Don Lincoln explains the truth behind this. (And, no, don’t send him emails about how this proves relativity is wrong. He is a strong believer in properly-understood relativity.)
Dig in deeper here: arxiv.org/pdf/hep-ph/0602037.pdf - วิทยาศาสตร์และเทคโนโลยี
In fact, i want more equations
Seconded
Omar Adel thirded?
tripled
Foured
Not before understanding something intuitively! Just learning the equations alone is why you get some people thinking that **F=G(m_relativistic*m_2)/r^2** works.
Earlier, I found relativistic mass concept very difficult but after watching this video, I finally understood the whole concept. You are just awesome.
layman: so, how do we go from newtonian mechanics to relativistic?
physicist: just put in the lorentz gamma factor into every equation bro
No u have to put a gamma raise to power 3 in force equation I.e. Newton's second law 🤓🤓
I like this. It's FUNNY... and it's TRUE!
rapper: ain' no god bro
physicist: let there be Light fool
In the numerator or the denominator?
Equations are fine! they're just more precise (and so more useful) than saying exactly the same thing, in any spoken language. Please use them often! With, of course your usual clarity of explanation. Thanks!
His T-shirt says: "It's all fun and games until someone divides by zero"
is that a negative zero?
@@peterbourke I can infinitely say it isn't negative zero🤣
Danny Byrge I’m infinitely confused lol
If you make it magnatic fild of wold attack by electromagnatic superhigh
Around time of your unless ability gravity and spacetime of the wold
The energy source releases the particles. pressure Atom and matter
Keep away
The time gap creates a black hole and is the fourth dimension. 4D
That energy must be enough to conquer the world mass.
🤣🤣🤣🤣
1:43 i think all your viewers are "physics minded"
or simply very curious ... like me ... I'm not a physicist or a mathematician but certain subjects interest me so much that I took the trouble to learn certain notions. In fact, I would like some videos to be even more present on youtube.
I'm just here for the jokes.
Fantastic video! I love that you give the equations but still make the theory easily understood for people who aren't interested in them. More formulas would be great as long as you can continue to explain the concepts without needing them.
Thank you for this video! I remember my prof at university explaning this (in 1995) and adding: "Imagine a Lorentz-Transformation of an object with mass m. Time and velocity changes under this transformation - what would identify this object as itself, when its mass would change, too? Mass needs to be invariant under Lorentz-Transformation."
I very much love these videos in any format, so I'd do what feels comfortable for you
Aidan Andrewson same
collab with pbs spacetime...
This guy is better than Spacetime.
Let's not go there.
Whatever happened to the first guy on spacetime?
I enjoy the more technical, mathematical, deeper discussion. Good work!
Important post since we hear "rest mass" too often. Thanks for giving it a rest.
Finally. I was confused af when I learned that when something move at the speed of light it should have an infinite mass, while the photons have 0 mass, and after that I thought when u move a bigger mass it would be harder to move than a lighter mass so imagine that you should move an infinite mass that would be infinitely hard, but that turned out to be not true thanks to your explanation 😃
Too technical? not at all! you explained the equations used in really simple terms. Bring more equations in! they don't take away they ad to it. I am a teacher my self from Finland, history thou not physics, and primary sources are always welcome. Like a historian might bring up radiocarbon dating method physics need to show what tools it uses. Not everyone might understand the whole thing, but in general scientific understanding videos, like all fermilab videos, aim is to show and tell how we do these things and how science works. Keep up the good work!
Pena Urkuri I would've actually preferred to see the equation under inertia when you had it up! (1:50)
AGREED, Pena Urkuri!!
I really liked this video and would love to see more similar to it. I'm not in physics but I do have a passing interest. Thank you for what you guys do
Thank you for improving my understanding of physics. No problem with your use of equations. No problem with your tackling fundamental errors or explaining more deeply than popular physics explanations. Please continue to drill down into fundamental ideas, even if more equations are needed. It's worth the work.
I am a theoretical chemist earlier in my career an organic chemist and I love these explanations with more fundamentals and formulas already known and yet with a digestible way to explain them to the general public. I believe these should be taught to more people so that they now how modern World functions and spell the act of charlatans off.
I love your explanations I am a fan.
I liked the fact that this video was more technical than others. In fact, I'd like to see more equations, but this is just me. I think is not bad to put the equations as long as you explain the idea behind them. Then people that can understand the equations and the ones that don't will benefit from the videos.
Agreed, though I would like to see a deeper brakedown on the equations done on a part by part series basis.
A simple gedankenexperiment is better than any number of equations.
A particle in a super-future accelerator is travelling so fast that its 'relativistic mass' is 100 times the mass of the earth.
Therefore it attracts the earth in such a high gravitational field, due to its...mass..., that the earth could revolve around the particle more than vice-versa (of course, they revolve around a common center, but never mind).
Now, I'm sure there are people that would, barring the technical challenges, say "yup, that's relativity". To insure they are also dissuaded, now consider _two_ such particles, now travelling side by side. Either one has the gravitational field that at some 100,000 kilometers distance they would attract each other with a force 100 times that of the earth at the same distance.
The relativistic 'mass' disappears in the mind, without a single equation. Of course no such attraction would exist. And the mass would not exist.
There wasn't too much math but too little, we want to see what effects the kinetic energy of a moving objects excerpts on the gravitational field, because we know gravity couples not only to the rest mass but also to the momentum (a box of gas weights and gravitates more if you heat it up because of the kinetic energy of the gas atoms divided by c²)
Yukterez Net so why it weight more if there are the same amount of subatomic particles? I don't understand that! I think "mass" is some kind of resistance in between matter and dark matter (space-time), the more speed, the more resistance so, we think the mass increases but, in fact is the resistance. The momentum could be the action = reaction, in the case of gravity the action > reaction due to differences of dark matter densities.
@@celiogouvea Energy is just a number. It is a potential of something. Nothing more. Yes, more energy at one spot creates bending of spacetime. It is in Einstein's equations. But you have to derive them. Good luck with that.
@Yukterez Net: The math for the gravitational effect of kinetic energy of a (relativistically) moving object would likely be overwhelming; you'd have to break out Einstein's Field Equations to show that, with the stress-energy tensor containing the large momentum term.
I think you'd want to start with the Schwarzschild solution for, say, the Earth, and do some kind of perturbation for the "cosmic bullet."
Maybe after some appropriate approximations it could be reduced to a dull roar? I'm not prepared to attempt that, but maybe someone is...
Fred
Relativistic mass is not real, of course. Conservation of momentum shows that mass is also conserved.
sites.google.com/view/physics-news/home/transformation
@@ericsu4667 If you treat mass and energy as the same, i.e. being momentum, then mass is conserved. But if you think of mass as a special state then it is obviously not conserved. E.g. in matter/anti-matter annihilation both viewpoints are valid. This non-conservation view of mass indicate to me that it is not a core property of nature, rather momentum is a more basic concept.
I'm not a physicist. I barely got through Algebra! But I know enough that I took a few minutes and worked out some examples of the equation you invited us to play with and saw you were right (as I expected you were). I learned several neat things in this video, so thank you for it. Not too technical at all. Keep up the good work!
Love all your videos. This was as technical as you felt you needed to make it in order to explain the concept fully. I watched it twice just to make sure I'd understood the concept of gamma in all this!
I'm a huge fan of the channel and I really enjoyed this video in particular. I thought you were, indeed, gental when you used those few equations. I love how much you smile throughout the videos; it brightens up my day. Keep up the great work!
gentle
Fantastic video. And i think , in order to understand these concepts this much amount of technicality is absolutely essential. I would love to see even more videos from you explaining these difficult concepts using some equations.
I thought the video was eloquent and informative, and thanks for introducing gamma
I'm glad you cleared this up. I always had an issue with the idea that the actual mass of something grew with velocity. If that were true, event horizons would cause runaway spacetime curvature!
sir really this video is very good and interesting like your other videos and sir please keep making videos, i know that your videos got less views than your videos deserve but I love your videos and many others like me who love Physics also love you and your videos so sir please please keep on making them..,I Love Fermilab and I want to come there in future..
and sorry sir for my bad english
I prefer a little math in these types of explanations. However, I might be more math oriented than some.
Relativistic mass is not real, of course. It is merely a concept from Lorentz Transformation which violates conservation of momentum in elastic collision in any reference frame that is not center-of-mass frame.
vixra.org/abs/1802.0099
his comment is about relativistic mass which does not exist.
Do you know about Lorentz transformation in detail?
I am actually asking you how much you know about physics, relativity, and Lorentz transformation. It all depends on your major in college.
What 's wrong with this: E=gamma*m*c^2
With a bit of manipulation we can get E^2 -v^2*E^2 /c^2=m^2 c^4
When v increases, the left hand side term decreases, which means the right hand side (m^2c^4) is decreasing. Which simply means the rest mass decreases. Does it mean an increase in velocity implies a decrease in rest mass?
Thanks for removing the confusion regarding relativistic momentum! ALL physics professors should ditch the concept of relativistic mass and ALWAYS include gamma when explaining Einstein's famous equation! It would make it MUCH easier for ALL students to grasp!
It's quite easy for the average person to see mathematically, that as you approach the speed of light, you get closer to division by zero in the gamma term, which is ALWAYS equal to infinity.
- But infinities in equations are non sensical terms, like black hole singularities with "g". So then;
= is the gamma hypothesis truly valid?
The video was fine. Its Nice to know that some concepts that us morons cherish is actually dumbed down hogwash. So, gamma tells us how "p" increases. But why isnt it directly proportional to v all the time?
@My dog Brian : The infinity is a sign that the concept has reached a boundary, ie that no greater speed is possible. So its not meaningless or an error but a sign that there is a physical limit. This becomes clearer when you watch his space time video on why its not possible to move faster than the speed of light.
This is excellent content. The way to really understand physics , not getting bogged down in math but using the math appropriately as needed. I’m not shying away from long advanced math calculations just expressing the right ideas first or understanding them. Love your channel . Subd. Can’t wait to watch more videos.
This is the first video of yours I've watched and I found it excellent. The balance between scientifically correct and intuitively accessible content was perfect for my needs. I'm looking forward to watching more. Thank you.
Great explanation, very useful. I was not at all bothered by the (slightly) more technical nature of this one, and I think you could go even further. There definitely is a point where it becomes "math majors only," and I think PBS Spacetime has been crossing that line lately, but you're definitely doing a good job keeping it in intuitive territory.
Thank you for the work you are putting into to make what I call your great, "Explaining Physics Series". The speed at which you explain subjects and the clarity of your explanations really makes learning easier. But it is the example of the thinking process that helps the most.
Now I know why my idea of how to beat the energy generation requirement to exceed the speed of light is most likely wrong! I thought that if I used the increase in relativistic mass applied to a nuclear reaction power generation process the energy generated would approach infinity as the mass approached infinity, WaLa!
Now time to reset my thinking. On the other hand if we did manage to exceed the speed of light then we would never know, we would have lost all references by which to comparatively measure the event. I think. In therms of energy I call Zero point energy and the energy at the speed of light the energy bounds/limits of our Universe. The other side of these limits exist other Universe Dimensions. Again I think.
I have so much more to Learn, I need all the help I can get! Thank you for sharing your knowledge and your thinking process.
I am so glad I stumbled across this video because that has always been something I could never quite wrap my head around.
I remember the very first time that I ever heard that term used.
I thought to myself so if I were sped up to the speed of light then would I lbe everywhere all at once.
Your explanation makes far more sense.
Thank you for this video and for clearing that up.
This was an excellent balance of assumption of knowledge and explanation of concepts. You produce some of the best videos on these relatively complex physics concepts. Keep it up! (and definitely don't dumb it down...)
I appreciated this video and the detail that you went into. Without the details, one cannot hope to really understand the distinction in concepts like this . Thank you very much for this.
I think that relativistic mass is a very useful concept in relativity. In SR, we have F = dp/dt where t is the proper time and p = mv in which m is the relativistic mass. The equation tells us the the larger the m, the larger the force required to produce a given acceleration. This shows that m has the meaning of inertia of a body.
Love you sir ,you are a real gem!please continue making such great videos for curious science students!
Don't worry about putting ecuations in your videos as long as they are simple like this one! :-)
I mean I could watch a whole set of videos explaining Eistein's ecuations but only if they start from highschool educ
My definition of simple stops at tensor calculus.
Sometime ago I saw a 2+hour long lecture in youtube on general relativity that explains all the math involved from linear algebra and, I think some multivariable calculus
Sometime ago I saw a 2+hour long lecture in youtube on general relativity that explains all the math involved from linear algebra and, I think some multivariable calculus
It is all about exposure. Even tensor algebra gets simple once you get used to the ideas.
I think the base level is perfect. I'd actually enjoy more 'advanced' videos where these more basic ones are further explored. Perhaps confine the math to those 'advanced' videos instead of having to apologe for using maths in many videos?
Try PBS Spacetime, Sixty Symbols, Numberphile etc
PBS Spacetime will melt your brain
I used to the think the energy used to accelerate was literally converted to mass it took so much of it. These days I like to look at it from the time dilation standpoint; the faster you are moving the less time you have to accelerate. If you are in a ship that can do 1G (9.8m/s^2) acceleration at rest (or close enough to it from a relativistic standpoint) that doesn't do very much when you are already going 90% lightspeed and the time dilation makes your acceleration slow to about 4.45 m/s^2 with the same apparent thrust/energy. At 99% it's down to 1.4m/s^2, 0.47 m/s^2 at 99.9% and just gets about 3x slower for every 9 added = accelerate forever you will just get closer and closer but never reach it. Sounds easy enough until you realize the amount of energy/antimatter needed for a 10,000-ton ship, even with 100% conversion efficiency. To keep that acceleration up 24/7 for 9 months ship time (about what it takes to hit 99.9%) just to reach Proxima Centari (and fly right past it since you aren't slowing down) is many times the weight of the ship itself. (~22x assuming 100% efficiency). Not to mention it'd have a kinetic energy of 24M megatons of TNT, comparable to the asteroid impact that took out the dinosaurs (well, same order of magnitude). Rocket problem all over again, just with antimatter instead of chemicals. Also kinda hard to find 220,000 tons of antimatter lying around.
Really good. I have a bit of equation phobia, but you explained it really well and I had this urge to hit a sheet of paper and start playing with the terms. Super cool, haven't had that urge since college!
It was not confusing at all! Please more equations in future videos. There's stuff that's meant for everyone to understand, not excluding even those who have a fear of equations, and there's some university level lecture stuff, but really no middle ground.
So far I've found that Fermilab's videos have a good selection of topics, but leave at least me hoping for longer, in-depth information on the topics introduced. (Maybe consider starting another channel?)
Beautifully explained, as always - thank you.
when calculating Gamma, do you use m/s as a unit for c and v?
Hello sir,
Wanted to ask what are the other applications of relativistic mass apart from using it in the momentum equation
Think you could go more technical. Videos like this, with a simple and a less simple part, would be welcome
Please feel free to delve deep, but beware the balrog.
5:39 - This formula can be derived geometrically. In fact, I once did so without knowing what exactly it was after someone postulated to me that everything travels through space-time at the speed of light, and all we can change is the direction, not the magnitude, of that 4D vector. And I'm no math whiz.
Let C, the speed of light, be 1. 1 what? One lightyear per year, if you'd like. This is the speed at which you're going through space-time. For any of us on Earth, that's going to be pretty much all time, and no space. We're not going through space very fast, so almost all of our traversing is happening through time. There's another video on this channel about that.
That's four dimensions, which is kind of a pain. But you can collapse it down to two dimensions by having one dimension represent time and another dimension represent the three spacial dimensions. You're allowed to do that for what we're about to do.
So now your velocity vector is always the same magnitude, or length, and it's just pointing in different directions based on how quickly you're traveling through space. You can split that vector into a right triangle. Side A is your spacial speed, as a fraction of C. Side B is the rate at which you're traveling through time. And side C, the hypotenuse, is... well, C, the speed of light. And we already decided that we're going to use a unit system where C can be 1. That's OK. We can do that as long as we're consistent.
So, good old C^2 = A^2 + B^2
C = 1
A = speed divided by C. Since C is 1, it's just going to be some number between zero and one.
B = the rate at which we travel through time.
We want to solve for B to answer the question, "at what rate do we travel through time depending on the rate at which we travel through space".
B = sqrt(C^2 - A^2)
And remember, A is equal to velocity divided by C, and C is 1 therefore...
B = sqrt(1 - (v/C)^2)
Look familiar? It's the inverse of the equation shown on the board. That makes sense. If our traversal through time is 0.5, or half its normal speed, then the equation on the screen represent the factor by which time has slowed down. Not "time" as in the speed the thing is moving. Rather, the speed at which the object's attributes can be changed. The factor by which inertia is effectively increased even though its mass--and its gravitational influence, and also any other factors that are supposed to scale with mass--remain unchanged. And that's gamma.
And again, I'm hardly a math whiz. It's just a right triangle.
I'm late to the show but since I found this channel, I've found myself watching (and rewatching) a number of videos from this series. Thanks Don!
I have a question about the relationship between gamma (scalar?), mass, and velocity . Slower objects' momentum is more heavily influenced by mass. Faster objects approaching the speed of light sees gamma far exceed any significance mass has on momentum. Is there any special defining qualities of an object moving at a velocity that finds gamma equal to its mass? It would have to be travelling very fast, obviously, but I feel like it describes a unique state when gamma and mass contribute equally to momentum ..
Yes Sir we want more Math more and more equations. Great video sir.
For me it is amazing!! Keep pushing!
o.O
How harder you may push, you can't reach speed of light😜
True agree 100%
I am enjoying the added complexity. It clears up some confusion I’ve had when thinking about relativistic velocities. Thanks! 🙇
Don’t dumb down your content for any reason... I appreciate the hard ideas even if I don’t fully grasp them immediately, and contemplating what it all means is the joy of life.
It wasn't really technical. I love these equations. They help you get a better understanding of what is truly going on. I like it this way, please do not fall into the trap of treating your viewers as morons. We can do math. :)
Yes we can \ - . - / We make math great again.
Not understanding this doesn't keep me from enjoying listening to it.
You might enjoy his audiobooks then. They are very good.
You're very good at this. First you take up a confusing topic, one that people may not have recognized being problematic. Then you use a proper perspective and simple way to explain it. Then your speed rate of talking is perfect. Not like those video with the guy talking too fast and linking sentences together in fear you'll leave the video. You're very good at this.
I can't thank you enough for the explanation of the concept of " relativistic mass"
Fermilab: *towards the end of the video* “but don’t worry, I’ll make a video explaining the REAL reason you can’t go faster than light”
Me: *looks at recommended* “How to travel faster than light, by Fermilab”
Also Me: Hmmmmmmmm...
@Star Trek Theory *too much.
@Star Trek Theory How high were you at the moment of writing that comment?
Equations is better for better understanding.
"is better" is equal to "for better" but in respect there are different parameters, how weird.
Yo.Can u tell me what books to read;ones that u recommend?I will transcend past normal (shall I say conventional and a traditional way regardless) but to maximize my time spent on all my self studies "emphasised" id appreciate some help to avoid erroneous intuitive way of thinking to get on with the search to intertwine one equation to embody all systems.
OMG! Thank you!
I've been writing a sci-fi story about space travel and I couldn't get straight answers about relativistic mass. Specifically, did that mass only apply vs the forces acting against it or did it affect the universe around it as if it had that actual increased mass? In other words, did its gravity well increase as the speed increased?
The answer means I have to do some re-writing.
I'd prefer a bit more depth than even this to be honest, but keep it up, whatever you feel is best.
Now we are owned a video that explains why is the Lorentz factor in that equation in the first place :)
The simple explanation is that the entirety of the special relativity can be derived from the assumption that speed of light is the same for all observers. (Don can sure give us a more complete explanation.)
MikeRosoftJH - It may be a bit more accurate to state that the Principle of Relativity which states that all physical laws are the same regardless of frame of reference, together with the axiom that there exists a finite rate of interaction due to the spacetime interval, eg, the "speed of light", is the basis for the geometric Lorentz transformation for inertial reference frames.
+Haar Megiddo
*owed
Thanks, such a wonderful explanation. I still have a question though. I really thought the relativistic mass is because of the energy of your motion (kinetic energy) being manifested into mass because of Einstein's most famous equation E=mc^2.
Relativostic mass stands on the Idea that E=mC^2 then m=E/c^2 so more kinetic energy then more mass but that equation works only when the object isn't moving
I'd say if anyone really had a problem with the equations or subject matter they'd be watching something else. Do what you do.
Yes ! a new Don video !
I have never used the term relativistic mass in my classroom. It leads to all sorts of crazy misconceptions. I have had students who said all you have to do is get a body moving fast enough to increase its mass to the point where a black hole will be created.
I usually tell my students that the force required to accelerate the body a known amount increases as the body travels at higher velocities. In other words, the inertia increases and we simplify the concept by calling it a mass increase, but the actual amount of matter does not change.
A physics student performs a simple experiment where he applies a force to a body and measures its acceleration. Just as he is doing the experiment, ALF (Alien Life Form) flies over at some relativistic velocity and observes the experiment. Since motion is relative, ALF observes the experiment being performed in a moving frame of reference. When he does his calculations, he finds the force required to accelerate the body to be greater than the result the physics student obtained. The faster ALF is traveling, the greater the difference. It's as though the mass had increased giving rise to greater inertia, but there has been no actual mass change.
Particle accelerators have to adjust for this inertia increase as they accelerate particles to velocities close to the speed of light.
One more important point, inertia is never equal to mass unless the body is stationary in the observer's frame of reference. it's just that the relativistic effects are so small that they are insignificant and undetectable. That is also so true for time dilation, length contraction, and velocity addition. There are not separate equations that suddenly kick in at high speeds. The reason the relativistic effects are negligible in our everyday world of low speeds is because of the (v/c)^2 term. v/c is extremely small and (v/c)^2 is ridiculously small. For instance, the Space Station orbits at about 17,600 MPH which gives us (v/c)^2 = 0.00000000069. if we subtract that from 1 we get 0.99999999931. In fact my calculator gives 1 when I do the calculation because the value is smaller than the precision of the calculator.
Wayne Adams
B.S Chemistry
M.S. Physics
R&D Chemist 9 yrs.
Physics Instructor 33 yrs.
Your explanation of the equations involved here are clear enough to make it easy to follow what you are saying without having to understand the equations. It's like discussing quantum physics - no one really undertands it but that doesn't stop us from discussing it.
I feel like it was not hard to follow, although I'm an electrical/software engineering student, but I have not had general physics classes in over 5 years (turns out computers dont care about gravity?)
so i welcome more videos like these
maybe one day... watch?v=lKXe3HUG2l4
I will have to watch it again, maybe a couple of times. Don't change your approach. I love that you take the time to explain these complicated science explanations of reality.
Hello sir, how did the observer measure the light observation while it did not hit his/her sensors. are we assuming that the speed of observation is absolute considering the that the stationary observer has the emitter and he sensor.
High five to whoever owns the dorito with the wing. (Rx-8)
Answer, the info wasn't hard to follow at all.
I had a dorito once and then I developed taste.
boost goes in, apex seals come out :)
i want more equations
1+1=2
F(x)= (4x^3 - 3x) / (45x^32 + 6x^2x)
2=2
1,5+0,5=2
0,8+1,2=2
-5+3=2
Enough ?
I love these videos and believe you have the content, including equations and math, at an appropriate level. For me, the equations clearly make the point.
Thank you, this really clarifies my understandig of mass. I never heard of such relativistic mass (and I am a physics teacher in high school level), so I searched the web, finding very little about it, until I finally found your video, and now I understand both why I never heard of it, and why so few references were available.
0:33 ha ha ha. "unsolicited correspondence", another words "stop sending me mail!"
Or, "stop sending me comments that question the status quo or that which is politically correct in the physics community."
Correspondence is probably still welcome as long as you aren't a schizophrenic layman who doesn't understand the equations but still thinks he's smarter than Einstein and the thousands of physicists and thesis-writing post-grads since, believing that he's found a brilliant new way of "looking at things" that no one has ever considered before.
In science discussion forums, I see "Einstein was wrong" quite a bit. They never really explain why they think so.
Well, there goes my theory that dark matter is only the increased mass of everything in the universe moving at very high velocities.
The slightly more technical videos are a perfect compliment to more introductory lessons that those who follow these topics crave. Me included.
Thank you for making your videos easy to understand, greetings from Greece.
thanks for teaching right lesson
Oh dear, so is length contraction even real ?
Indeed, just try and jump in cold water!
Yes. The fabric of spacetime gets distorted and the length of the body changes accordingly.
Yes; but in a sense somewhat similar to constancy of mass, no it isn't.
What *does* change, is the 'length component' in the frame wrt which the object is moving. There is a spacetime 'hyperbolic rotation' connecting the two frames, in which the distance and time components both change in a way that preserves the spacetime interval, ds² = dx² - c²dt²
This is analogous to a spatial rotation, in which two spatial components both change, but in a way that the spatial interval, ds² = dx² + dy², is preserved.
If you stand in front of a rectangular building, you see its full width in front of you.
If you walk partway, say 60º, around it, that same front face of the building now looks half as wide. Did it actually shrink?
No. Its actual width is still the same; its apparent width is only half that.
In the case of 'boosting' a meter stick into a moving frame, the proper length of the stick is still a meter; but its apparent length is shorter.
Masses, proper lengths, and proper times, are all constants; they are invariants; apparent lengths and times *do* vary.
Science is the best way to esecalate a dick joke, well done!
Nope, it is a matter of perception to who observe it, as parallel tracks of a railway seems to converge at infinity when you look at them ( perspective geometry in case of the railway). They seem to converge, but never really do. It is a little bit as thinking that the whole world expand while it would be you who shrink (yes, it would takes less energy to have only you shrinking instead of the whole universe to expand, .. but then, why the other parts of the universe would not shrink too?) But if you were shrinking because you were speeding ? Anyhow, you could come with a perspective geometry which will describe the same effects around you, with no one really shrinking. Does )( look like parallel segments of straight lines? Take || and a piece of lens like fisheye lens, the || will become, to you, through the lens, curves like )( . That would be your perception, but in reality, they didn't changed at all just because you look at them through fisheyes lens, isn't it? Same for speeding objects, they may appear smaller when you look at them, but they, in their local frame, it is you who become smaller, not them.
Does this same concept apply to changing length with speed, is length not actually changing as well?
Is there an increased interaction with the Higgs field as one approaches c and if so is this a way of connecting relativity with the quantum world?
This should be the minimum
I really like this”show” but you could add more equations.
"How about a bullet from a sniper rifle?"
*Shows someone shooting an AR-15*
(Love the video btw)
I suppose that knowing your AR15s from your sniper rifles is not important to people interested in realtivity.
@@drottercat Well said
Do electrons ever move fast enough that they require a gamma to describe momentum? The math I have been working with in my intro to quantum class uses p=mv when when working with the momentum and Hamiltonian operators. In an atom electrons don't move near the speed of light but a free particle conceivably could? Does it have something do to with the wave nature of matter or is that just because the problems we've been working with are with electrons that are too slow and the gamma can be ignored?
A professor used this relativistic momentum idea to explain to us why photons have "mass" for the purpose of momentum despite not having any rest mass. I'm glad I knew about this video for a more complete explanation.
So if I put the two together properly, it's that in p = γ * m * v, the multiplication with m=0 at light speed can still give a non-zero result because γ becomes an infinity that happens to yield an actual result for this equation. At least as a rough plausibilisation which clearly can't be entirely correct since not every massless particle has the same momentum.
Zero times infinity is still zero. What are you talking about?
Relativistic mass is real. You found one possible answer yourself why denying this makes no sense.
Most physicists simply don't like how its used, because calculating around with it induces mistakes quite quickly and doesn't usually offer much use.
That's not a sniper rifle. It's a normal, everyman's AR-15
Bible in a science video....wth is going on over here?
Even for 4 years ago, this anti religion attitude is outdated. this isn't the early 2010s anymore.
dear mr Lincoln;
a) doesnt the kinetic energy not represent some mass ? I mean p=gamma*m*v and E=1/2 *gamma*m*v^2 (and therefor E=mc^2 (or its more correct version) is pretty much close the same.
b) from what I understood (correct me if I am wrong) is that the mass of for example protons /neutrons ect largely is represented due to the kinetic energy of the subatomic particles that make up these particle and that, for about 98%. so that we basically can say we consist for the majority of kinetic energy, mass wise speaking…
c) can we not say the more kinetic energy an object contains the harder it gets to deliver some more kinetic energy to speed things up ? because of the energy content (and therefor impulse but also mass)
d) so inertia is basically the resistance of an object containing kinetic energy to gain more kinetic energy.
So gamma factor is always there in momentum equation but changes noticeably at relativistic velocities and hence momentum is changed but the mass is always constant? Did I conclude it correctly?
I dunno, some of MY relatives are pretty massive.
I valued the equation because it clarified the distinction between inertia and the substance of matter we call mass. The substance is not gaining more molecules nor are the molecules gaining more “material” somehow. Rather it is getting harder and harder to “push” that material as it gets closer to the speed of light.
One of my favorite discoveries was when I found Isaac Asimov not only wrote my favorite science fiction, but also explained some science and mathematical concepts clearly and simply. I guess the smarter you are the clearer you can make a concept for cleare for us less informed individuals. Dr. Lincoln is my new favorite discovery. Mahalo for your videos
Another argument against relativistic mass is that when we write the relativistic acceleration & Force equations we will have to declare separate longitudinal & transverse relativistic masses! Which is a very strong argument against considering relativistic mass as the same object will have two relativistic masses (longitudinal & transverse)!
True, if relativistic mass were real, then it shouldn’t be depend on the direction of the force!
Aw, this is now my new favorite. I was trying to explain this to a younger friend of mine and my mother the other day. A better understanding of gamma would have been very useful. Many Thanks!
In SR, we have the law of conservation of mass-energy. We can either consider the conservation of the total energy (mc2) of an isolated system or equivalently the conservation of relativistic mass just by dividing the previous equation by c^2.This shows the equivalence of mass and energy.
Huh. Interesting. I was taught about relativistic mass too. It’s nice to have a glimpse of the more detailed and accurate answer to the funkiness that happens at those velocities.
This was a great video. I now have a better, albeit, nonintuitive conceptualisation of what is at play when matter moves at relativistic speeds. Thanks for making this concept so accessible.
How are the values for gamma derived if v> c?