I envy people who can understand all of this and more than this on a whim, and then be able to explain it to others at any given time. Great to have you in this world!
Dont underestimate your own level of understanding. You seem to have a humble attitude which is ideal for learning about science! But it takes alot of hard work and dedication. People who figure out stuff like this are human beings just like you, remember that!
OK well her explanation everything was extremely tiny at the very beginning and you can figure that out by knowing PLANCK Time because our standard unit of measurement and seconds doesn’t do justice things were happening so fast that we created Planck Time to show you how fast things were happening so Planck Time there are more planks in one second than all of the seconds Since the big bag that’s pretty mind-boggling so about six planks in the universe is the stage and inflation it expanded 100 trillion trillion trillion trillion trillion times to the size of a grapefruit.
Physics Girl If the universe was "flat" as you state that would mean the rate of expansion is slowing down but does that not contradict what we observe? According to our measurements the rate at which the universe is expanding keeps accelerating at a faster and faster rate, would that not imply that this idea of a "flat" universe is flawed? Other than that I have to say you're great at explaining things, I love how enthusiastic you can get about the things you explain :D Keep the good work up you're awesome ;)
Let's face it. The definition of the word "flat" regarding an n-dimensional space is just too much for most people. In day to day context, "flat" refers strictly to a 2-dimensional space , as in "flat surface". In the context of the video, space is seen as a 3 dimensional surface, a hypersurface, a submanifold of a 4-dimensional space. The human mind cannot grasp the concept of flatness in this context as we are 3dimensional, unless you look at it through math. But most people in the comments just think she says the universe is really long, really wide, but not very thick, therefore it's flat... as in flat flat, which is not the case at all.
Thank you. I wish they'd explain that in the videos. I keep waiting for them to explain why or how 3 dimensions can be flat but they don't. They gloss over it.
Thats why its called universal theory of gravity! 😂😂 because its not an actual law of physics Picture an 11 deimensional plane. Where the layers of the universe interact with each other like vibrating strings of a violin. 👀
@Kenneth John Kelly Hahaha! I was just thinking something alongside your thoughts dude. Neil de Grass says there's no centre of the Universe, he gives his reason {am not trash talking by the way, am conversing, in case any children are in the room! Boom burn 🚸🤺🔥 lol} Story short, we are all the centre, because we started small and now we occupy everything, so centre. Think of the earth, there's no centre to it's surface. That was his conclusion. But I don't bite. You see, maybe the center, is not a centre, but a top. Or if it we have a centre, then there's a centre point - which is really what everyone is trying to get to. Now, if there really were no centre, even if there is - the question remains - what energy made it begin in the first place? The universe, that is. Someone had to put it in place. The same with a child. Someone had to place them somewhere, under the right conditions for it to become. And here we are, yet expanding to the critical mass of old age. Someone is definitely out there, scientists are great, but they don't know everything, and they don't own the universe. Men and women, humans like me that live and die between 100 years couldn't tell me how this all started.
@@wilton999 "Someone had to put it in place" - sigh...sorry, but some old man with a beard in the sky didn't create existence. In fact, the very concept of 'someone' didn't even exist until the last couple million years or so when our ancestor's brains evolved enough to start processing such concepts. Existence happened simply because it either does or doesn't (if existence didn't happen, there'd be nothing...that is the 'WHY' of the universe, not because some old man with human thoughts decided it would be nice if we had planets and stars and plants and rocks and water and everything).
@Kenneth John Kelly Explain to me how i've seen with my own eyes distant mountain tops (but not their bottoms) at sea, but could see their bottom as we sailed closer to shore, if the Earth is flat. And if i can see that the moon and at least 4 of the planets (even their moons) are sphere's with my cheap telescope, why is the Earth flat yet they're all spheres. Explain. "Does it scare you that you science may be wrong" - you don't understand how science works. According to science, it's possible that gravity suddenly doesn't work and everything floats away into space...but the thing is, every time science makes an observation, we find gravity pulls things together. Science isn't about 'right or wrong', it's about what can be repeatedly observed (so who knows, maybe one day science will observe gravity not working, but because it's been observed working a bajillion times, we can call it a law of physics that will very very VERY likely never be broken).
Lawrence Lui...What is it you do not understand...As the man Scientist said...”It is Simple! .. “ He did not say that! Did He? Yep he said that! Now in plain language for you to understand.....”It is like tying shoe laces You try starting to the left, and then you go to the right, if that does not work then you go to the right and you go to the left, now because that does not work either. You shake it all about...and come up with the biggest mumbo jumbo imaginable! Now I hope You Understand, because we The Public are so gullible we believe anything....and then we find that Shoelaces are not required at all....because Where did they come from....? Oh well “It is Simple” He really said that! Who employs these people? RDR
*of the observable universe else we have know the temperature of the oceans for a long while now. But I get your intention, just pointing it is a false comparison.
We are far better equipped to gather data from the EM spectrum than we are to overcome the extreme conditions of deep sea diving. It's not about lack of focus, it's about technology.
exactly, we don't...lol.. astrophysicists are basically people who make guesses based on limited information... like thunder comes from gods fighting in the heavens...lol They also have very limited imaginations and so won't explore all possible explanations, only the ones that fit into their current understanding of the universe. Not to get off topic but I find it funny now that some scientific schools of thought think that our world is simply a virtual reality simulation... seems to be catching on as a "good" idea... but yet somehow a "creator" of a similar virtual reality system is beyond their comprehension.... take also into account that current science is now saying the universe runs, in the background or underlying code, similar to website code...lol... but no no one "Created" it lol.... I find science quite funny at times how opposing they can be in thinking and how biased they can be.
Jason, when I saw mathematicians explaining universe with 4, 5, up to 20 dimensions, the non-existing (atleast never observed to be fair) matter and energy, I saw what they did there. Its just a playground. Its nothing serious... They just show off what they can calculate, not what is actually there. The physics now, at this moment, has no real definition for mass of matter nor it has a good (lets be frank, it has nothing) explanation on gravity, yet it praises E=mc2 like it was the Gospel. In physics so little is understood in terms of universe, in mathematics its even worse, its so confusing, that we all the time get predictions like: the universe might collapse at any second, universe is a hologram, pulsars are just fine with how are they described now (even tho they tend to change rotating speed by order of magnitude of several thousand resolutions per minute to just a few in matter of hours) etc... Its all just so childish.
New video! Why is the universe flat? And why is it the same temperature throughout? The physics of Cosmic Inflation with Cosmologist Alan Guth buff.ly/1pPb9Ea
Physics Girl Yeah but it does explain why it expanded and then stopped to me that is a huge problem. Basically changing the laws to explain something we see.
Chris Lucas the universe is expanding due to its evolution from a big-bang billions of years ago (Power which decreases by time): yet, eventually after this stage of expansion " the entire universe will collapse and shrink by gravity into limited space as it happened to be at the beginning. for example if you throw a stone into the sky it will go higher and higher, but it will come back and fall.
Abdelaziz Galoul Thank you but I think you misunderstood what I meant. Nice Allegheny though. But since the universe happens to be flat you would be wrong.If it was curved then you would be correct. What I was talking about was the physics be-hide the inflation and sudden stop of inflation at the first .0000000000000000000000000000000000000000000001 plank seconds after the big bang. To me and many this model breaks every law of physics. The model only explains the effect of inflation and does not explain how or what forces caused and then stopped it. Since nothing in the know universe is know to cause this. Kinda of like adding dark matter and energy to everything just to balance the equations. I think it is silly.
I know this is an old video, but it is the best explanation of inflation theory in layman's terms that I have seen so far. Really good work! Thank you!
If the Earth was flat cats would have knocked everything off by now, Seriously, unless you were joking about a flat Earth, I can honestly say there is plenty of evidence to prove that Earth is not flat.
Paul Foor - -Hmm About Flat Universe’s! You obviously are at the front door of Understanding.....Cats need a door flap....and then only the door knocker gets knocked on...Perhaps you should find your own cat flap, and stop knocking things over....”Nothing is possible because Nothing is not impossible!” RDR
@Kenneth John Kelly Myth and superstition only hold all of humanity back. You gullible religious zealots are preventing humanity from growing and bettering ourselves. Your gullibility and inability to grasp reason and logic truly depress me.
@@tsamuel6224 just like a beer, the longer the universe remains outside our stomach the flatter it'll get. So the only way to stop the universe from going flat is to consume it before it becomes flat.
I think her excitement is what makes me so interested in these videos. Anyone who is so enthusiastic about something will attract the attention of others. I particularly enjoy the cosmology related videos.
I totally agree with you. She has all that enthusiasm and energy, like it was during the big bang ......... That was not meant to be crude or derogatory, I like her, she's fun.
So here we are. 5 years later and flat universe might be wrong all along. With light from distance universes seems to bend just a tiny bit indicating that the universe has a curvature of Omega > 1, which might make it a ball. Thank you Plank-Telescope for this possible finding. Science is a wierd place nowadays. "Planck evidence for a closed Universe and possible crisis for cosmology" from Nov. 2019 by Eleonora Di Valentino, Alessandro Melchiorri and Joseph Silk
@@bonztubezI mixed up Planck with Keplar but yeah... "Planck evidence for a closed Universe and possible crisis for cosmology" from Nov. 2019 by Eleonora Di Valentino, Alessandro Melchiorri and Joseph Silk You can also find some recent videos about it Nov, Dec here on youtube if you do a quick search.
as i understood, it is accelerating while decreasing the acceleration like, now i am at 100m/s, then i am at 190m/s, then 275m/s, etc. each step i'm faster, but the increase in the acceleration is getting smaller (+90m/s, +85m/s, etc)
3:25, "It will expand for ever but at an accelerating slower rate" but we know that the universe's expansion is acceleration so our universe should be open? Please explain!
Is this still valid? PBS Spacetime says that the universe is expanding at an accelerated rate, in contrast to this video. Don't make me go out and measure it!
Not just PBS, a lot of sources say it's expanding at an accelerated rate... This is the first time I heard it's not expanding at an accelerated rate...
I think it's true that the expansion of the universe is accelerating; but that's due to the effects of dark energy, which she didn't mention in this video.
Curvature of 3d space would probably be so much easier to understand if we could draw/think with 4 spacial dimensions. It is easy for us to understand 2d but a 2d creature would have problems with it because it would only see lines/1d. I guess it's the same with us. We live in 3d, but see 2d. If we could go to 4d, we could see 3d space how it really is. Or our brains would blow up because it can't comprehend it :D
Undercover Wookiee C'mon, it's not that hard :D Just some simple analogies... :D If you're interested, watch the film "Flatland" here on YT, really helped me undestanding the dimension stuff :)
+Critical Ravi It's not at all hard to think in 3d. 1d is a point, 2d is a surface and 3d is area. You have to think outside the box... literally. Pun-ny huh!
Pecker Wood As far as I know, a point is 0d, a line 1d, a square 2d, and a cube 3d. And, as I said, we see images, think in words of course, or in images. We can see the whole square of 2d, while 2d beings would only see lines. Same with us. 4d beings can see a Cube from all sides at the same time, probably even the inside of it. We can only see and imagine 2d images of that cube, and our brain simulates distance of objects by lighting and size, and so on. I mean, I can't imagine how a 4d being would see a cube. It's just not possible for our brains, because we don't know the next direction. Assuming there is a 4th spacial dimension that is, of course. Another interestin thing is, that we can only see one side of a "2d" paper. we have to turn it through 3d to see the other side, or go underneath it, assuming a levitating piece of paper. How would this work with 4d and 3d? If someone has an idea about this, feel free to reply :)
I simply do not understand. I'm having trouble understanding how expansion can happen while the density doesn't change. How does the volume of something change wile the density stays constant unless it's getting filled by something?
That's exactly the right question, only in the flatness model does first law of thermodynamics hold mathematically, and yet the inflation is the flatness model that breaks it, but there is one more, if the energy can appear from ether why is it appearing at exactly the same rate for the universe to remain equally dense.
Aleksandar Rajkovic jeez take a joke mate also, this is where creationism seems more logical btw, if there is an ageless creator in the sky it makes more sense than a universe just 'appearing', you're right about matter having to appear for density to stay at an equilibrium. But think about this: what if the world was in fact created out of nothing, the monotheistic creation theories line up with inflation, so don't rule anything non-scientific out of your oh-so-serious debate. *nerd mode off*
Aleksandar Rajkovic the speed of expansion is directly proportional to the speed of light moving outward from a 'universal centre', you can see in the early time values that the rate of change is very fast, however an obvious trend approaching present is that the universe's growth rate of change is decreasing, but the actual increase in size is not changing, it's just that there's more initial universe to compare the growing universe amount to. But dank memes will never slow down, submit to the dank memes.
Obviously not a thing wrong with the offerings of anything from SciShow to MinutePhysics, but it’s nice to be able to come to a video without knowing all the ‘why’s, ‘if’s, and ‘but’s beforehand. Only then to be profoundly awestruck at how much smarter all the commenters are than me! Very cool community, rallied about some very cool videos :) Ps. I know I shouldn’t have been *abashed* but I was very distracted by your eyes… you’re not wearing coloured contacts, are you?
I know! I was warned about commenters when I started making videos, but I have found the comments to be insightful, constructive, and hilarious at times. It's great to see so much high quality content in education on TH-cam. For some reason, the sunlight in my room makes my eyes look really weird in these videos. I haven't figured out how to fix it yet.
Just… please don’t be fazed when the trolls inevitably descend. I think this space is still sheltered under relative obscurity, something for which I’m both thankful and wistful. After all, you deserve more fans intelligent as these than TH-cam has to offer. ’Til then, I'm thankful for the community you've created :) Now, now, as the Physics Girl, I’m sure you must have plausible explanations for the glare! I’m imagining the muscle fibres of your iris acting as a diffraction- upon reviewing a [very flattering (just kidding about, I promise)] frame at 0:26, I definitely overcomplicated things, ahah. Looks like the reflection of the window on your eye, with the camera where it is, perfectly covers your pupil. Maybe rotating your camera-backdrop setup relative to the window would help? It’s always difficult to get good lighting, though. Perhaps a diffuser on the window while filming? Even a large sheet of white tissue paper would do!
Not a problem - always happy to help! I’m generally a candid photographer, so I don’t dabble much in artificial lighting. But I got my first flash a couple months back, which was very exciting and opened up a world of possibilities… promptly after which I sold my camera body to a friend *sigh* patiently waiting for Sony to launch a new full frame.
+Physics Girl "I was warned about commenters when I started making videos, but I have found the comments to be insightful, constructive, and hilarious at times" *scrolls down to see much confusion about "flat" vs. "2-dimensional"* Physics Girl, is there an SI unit of irony? More seriously, kudos on an entertaining and informative channel. :)
Came along this "old" video.... Amazing how you changed your presentation skills since then. Your passion and slightly "weirdness" ;-) is so much better today.
I’d always learned that the universe was expanding, and that this was accelerating, and galaxies were literally growing farther apart from one another... (e.g. observable via the Doppler effect). How does that line up with consistent mass density or flatness?
Shakil Khatri really? I wonder if it is expanding exponentially? Would that mean we are accelerating in time and space? Will our time be faster than past time?
It's an understandable misconception but when they say the universe is flat they don't mean 2-dimensionally flat, they're actually referring to 3-dimensional flatness, in essence a near perfect cube. Also it's kind of a mixture of certainty and generality, the orders of magnitude they're working with allow for near approximation where 99.9% accuracy can still be off by a lot. Also if you measure the density of light from a distant star over a sufficient period of time the change in brightness coupled with the constant speed of light can still give you a percentage rate of change even if your distance calculations are somewhat off.
You are the first person that has made the point of the Big Bang being a theory, something that scientists call a fact, even though they can’t prove it. Well done 👍 missy. I salute you.
The universe certainly will "expand forever" according to observation and theory, even in a flat universe, and the acceleration will accelerate. Why does the intro say otherwise...?
+djayjp Yea, I was just joking. I was just trying to give her the decency trying to cover up that not only her but the producers of the video etc all made a mistake... But it's a pretty big one that not only is it wrong but no one seemed to have noticed before it was put up. Especially since her name is Physics girl :/
connorp2402 Exactly, couldn't believe what I was hearing :S. Would make me question everything else she says in other videos (making me not interested). And this was only the first video of hers I saw.
+djayjp That is if the universe is actually flat. We call it the observable universe for a reason, and that is because we base all our conclusion on what we are able to observe. Since we cannot calculate anything with infinite precision, we can't say we have not made a mistake. There is a possibility that the observable universe is just the surface of a larger spherical universe. This will support the multiverse theory. It could just be that like the earth's crust gets recycled in the mantle, the flat universe that we see is just being recycled through whatever is in the center of the 5th dimensional spherical universe.
I don't understand the whole "all the matter in the universe being in a volume smaller than a proton" statement. I never have. Doesn't this violate the Pauli exclusion principle? Isn't this just implying a singularity, I.e., an error in the theoretical model? If this idea is derived from the works of Stephan Hawking, saying that the universe started as a gravitational singularity, shouldn't it be worth noting that the general theory of relativity breaks down at Planck time scales? Please help elucidate this for me! Thanks!
electrocat1 Great question sir, and one I can not answer. However I have posed similar questions like if Einstein was correct then light , having a finite speed is not the fastest rate in the universe. In fact it can not be since quantum theory shows that matter can move from one place to another faster than light. So if light can travel it's speed and it is made of photons and photons are made of particles and as such do have mass, then something else must be able to do the same.
Nuckelhedd Jones okay no quantum mechanically things can not move faster than light and photons are not made of particles, they are themselves fundamental particles. you can not convey information faster than the phase speed of light in a vacuum.
electrocat1 "Doesn't this violate the Pauli exclusion principle?" No, because the exclusion principle applies to particles; when the universe was this dense, it was pure energy. While general relativity would brand this stage of the very early universe as a singularity, it must be noted that quantum effects would be important, and we don't really know how gravity works at the quantum level.
Physics girl clearly has a great understanding of physics by the fast and succinct explanations. Very good communication skills too, someone untrained but interested in these cosmological topics, like me, can easily follow them. Some of these concepts I’ve never heard before but make the early universe a little clearer and interesting. Maybe you could be the next Brian Cox or Alice Roberts.
A question, if we never calculated the one way light speed itself, isn’t it possible that light actually reached the other side of the universe and that light speed on a side is infinity and on the other is c/2?
I don't understand it either. She should have made a distincion between the curvature of space and the curvature of spacetime. As far as I know, space is flat and spacetime curved.
Q: is the earth flat? A: we know the earth is flat but the real question is why! Q: Umm... what? A: presents theories, the universe expanding and earthly geometry and physics as reasons just read about on Tuesday. Eureka! Modern day science!
I'm slightly confused. I't is my understanding that the universe is not only expanding, but am doing so at and increasing speed, thus we arrive at the subject of "The Big Freeze". Have I missed some scientific breakthrough, or have I simply been misunderstanding everything?
HerrWagnerfreund Yes, but they basically said how the expansion of a flat universe would be (slower) without dark energy concluded to understand the model. This doesn't mean they aren't aware of the effects of dark energy
@@bubblezovlove7213 But it is still believed to be spatially flat. So the reason for its flatness that was given in this video must be replaced. What is the real reason it is flat?
So if the universe is like a balloon stretching flatter over time, doesn’t that mean the universe is still round? But so big that we can’t see the curvature of space??
'There is One who dwells above the circle of the earth, And its inhabitants are like grasshoppers. He is stretching out the heavens like a fine gauze,' - Isaiah 40:22 The book of Isaiah was written during the time period (778 - 732) BCE It refers to the 'circle of the earth' (as viewed from space) long before humans were able to view this for themselves by travelling up into earth's orbit. Further, the wording indicates a dynamic, expanding Universe (heavens) “He stretches out the northern sky over empty space, suspending the earth upon nothing.” - Job 26:7 The book of Job was written between (1473 and 657) BCE indicating a knowledge that the earth is suspended in space by an invisible force (gravity), contrary to some human myths that suggested an earth supported by pillars or resting on the back of a turtle (or other animals such as elephants)
Tony07UK ...Hmm....I prefer to think from a Holistic Thought store....Thinking for oneself nowadays seems less....and in the past only about 2000 BCE! Thinking suggests to me that there was And probably still is advanced technical skills that are endemic throughout 13,500,000,000 years of Observable effects. These Unlimited abilities are for us to discover on our Earth journey.....However much clearer your Awareness Perception Conscious Window is Becoming. If at all...Through Independent Thinking....Not Thought Which is only ever Of the Past. Thinking discerns what is Leftist processing or Rightist significant other, giving You a Choice from multiple choices...leading to Choices recurrently, Developing strident attitudes which control your Altitude! RDR
Kenneth John Kelly Hmm......The scroll....this would equal infinity......Repetition! But The Ultimate is more...more than Infinity! Unlimited which can equate only to Flat. Layers of flat Holistic Unlimited Spokes Flat packed Quantum dimensional Zero. Unlimited Nothing giving Everything Unique Oneness! RDR
*WHY DO THEY CALL HAVE TO CALL THAT FLAT!?!?!?!?!?!?!* When I search shape of universe, I wanna hear ball or cube shape, not flat! Why they can't call it the EXPANDYNESS of the universe!?
Yeah, its like when they say "dark" matter. They should call it invisible matter. If it were dark, and it is most of the matter in the universe, then we wouldn't be able to see anything. Who names this stuff?
While I do not comprehend flatness, I learned that flat is unstable like standing a pencil on its end. It should fall over. However this idea of inflation actually stabilizes the flatness.
Let's just say there's a vertically floating stick in front of you. That stick could be looking like either of these 3: ")" or "|" or "(" Universe flatness is just like that. If you point a very long stick towards each of 6 directions of universe, AND if you don't find it curving, we would say universe is flat!
@@IDMYM8 My god, I think I finally understand it now, thanks. So it's not flat in a sense that it's like 2D or anything like that, it just means that it's not bending around anything and a beam of light could theoretically go from one side of the universe to the other in a straight line?
Cosmological red shift can be interpreted as time dilation due to distance & not velocity in a positively curved Universe. Parallel transporting is no measure of Flatness in certain higher dimensional spaces,but red shift can (tempral curvature) .If a field can be treated as a geodesic.(“ERER” bridge). No need for Dark Energy,No matter-antimatter asymmetry problem. Conservation of Energy is the Law.
Can you please slow down? You're throwing technical term and concept one after another. Let some concepts sink in a bit. Too fast cutting and too fast speaking. What's the rush to get through?
+YTEdy -- That's so sad. However, there is hope! If you become a multi-millionaire, or even a billionaire, the effect will disappear COMPLETELY. Give it a try!
It can't anymore. To be succinct, it may have been possible during an early stage of the universe before certain symmetries broke (check CPT symmetry for a nice head ache), but since they have broken now and gravity, to the best of our knowledge, is dominated by particles that have spin 2, gravity is always attractive.
I love how we "now know..." something at the beginning of this video (expansion theory) but by the end it's "still a hot topic of debate." If a theory is still in debate why is it taught as fact?
your are confusing the word know to mean that we couldn't know more. You know many things, but there are many more things you could know. This is the same with theoretical science. We know many things and those things aren't any less "known" just because we don't have the complete picture. When you put a puzzle together, you 'know' where a certain peice goes becuase you have fit it into its place. But knowing where that piece goes does not automatically mean you know where all the pieces go. A puzzle, like human understanding of the universe, goes together slowly and builds off of the previous pieces having been put in place.
I love the verse in the Bible that says, "Let him that is wise in this world, become a fool, that he TRULY may become wise." There is so much to know about this world, and yet we can only potentially know a very miniscule of what can be known, putting us in a very weak and humble position. But if our response to this puts us on our knees in faith and homage toward God, then we have acted in the wisest fashion possible.
@@rickledford2953 Hey, bro, I was commenting on what you wrote. If it's a matter of scientific understanding, then what does "your mind" and what you can "wrap it around" have to do with anything?
You know what I always wondered if I had got a talented sister like you who loved physics so much as me , then I would have been the luckiest person on earth...
Thank you. And mathematicians would not be so lost if they would cut down on imaginary numbers surely. Revisit what Wilhelm Reich reported on before you killed him for it, and see if any of that might replace those imaginary number cardboard math bridges.
I envy people who can understand all of this and more than this on a whim, and then be able to explain it to others at any given time. Great to have you in this world!
Dont underestimate your own level of understanding. You seem to have a humble attitude which is ideal for learning about science! But it takes alot of hard work and dedication. People who figure out stuff like this are human beings just like you, remember that!
Nice Selensewar! You are amazing. 😅
@@chlintvalenzuela6567 D: why? Thank you.
@R i'd really like to understand instead of just repeating. But i guess that'll never happen.
OK well her explanation everything was extremely tiny at the very beginning and you can figure that out by knowing PLANCK Time because our standard unit of measurement and seconds doesn’t do justice things were happening so fast that we created Planck Time to show you how fast things were happening so Planck Time there are more planks in one second than all of the seconds Since the big bag that’s pretty mind-boggling so about six planks in the universe is the stage and inflation it expanded 100 trillion trillion trillion trillion trillion times to the size of a grapefruit.
She is a joy to watch. Very articulate, bright, and energetic. Makes learning fun.
But I didn't understood much :(
She's phlat
I can't believe it took me this long to find this channel! It's awesome!
Glad you like it!
Physics Girl If the universe was "flat" as you state that would mean the rate of expansion is slowing down but does that not contradict what we observe? According to our measurements the rate at which the universe is expanding keeps accelerating at a faster and faster rate, would that not imply that this idea of a "flat" universe is flawed?
Other than that I have to say you're great at explaining things, I love how enthusiastic you can get about the things you explain :D Keep the good work up you're awesome ;)
***** need answer for this...
Abarajithan Gnaneswaran What do you meean by that?
I'm also expecting the answer for ur question.. :-)
Perfectly balanced, as all things should be
Ard-Jan van Etten too soon 😢
It's inevitable.
I used the stones to destroy the stones lol
Ok Thanos!
Bryh
Let's face it. The definition of the word "flat" regarding an n-dimensional space is just too much for most people. In day to day context, "flat" refers strictly to a 2-dimensional space , as in "flat surface". In the context of the video, space is seen as a 3 dimensional surface, a hypersurface, a submanifold of a 4-dimensional space. The human mind cannot grasp the concept of flatness in this context as we are 3dimensional, unless you look at it through math. But most people in the comments just think she says the universe is really long, really wide, but not very thick, therefore it's flat... as in flat flat, which is not the case at all.
Dong In Kim That gif was really cool. Btw at some point the grid becomes slightly red near the body. Does that mean something?
Maybe these sci pop shows should start saying "space is not warped" instead of being flat.
and alcoholically, flat is the correct term for a beer that has had too much fun.
Thank you. I wish they'd explain that in the videos. I keep waiting for them to explain why or how 3 dimensions can be flat but they don't. They gloss over it.
"Clifford torus" sounds kinda dirty.
Flat earthers should adopt the flat universe instead.
Thats why its called universal theory of gravity! 😂😂 because its not an actual law of physics
Picture an 11 deimensional plane. Where the layers of the universe interact with each other like vibrating strings of a violin. 👀
We were once you
@Kenneth John Kelly Hahaha! I was just thinking something alongside your thoughts dude. Neil de Grass says there's no centre of the Universe, he gives his reason {am not trash talking by the way, am conversing, in case any children are in the room! Boom burn 🚸🤺🔥 lol}
Story short, we are all the centre, because we started small and now we occupy everything, so centre. Think of the earth, there's no centre to it's surface. That was his conclusion.
But I don't bite. You see, maybe the center, is not a centre, but a top. Or if it we have a centre, then there's a centre point - which is really what everyone is trying to get to.
Now, if there really were no centre, even if there is - the question remains - what energy made it begin in the first place? The universe, that is.
Someone had to put it in place. The same with a child. Someone had to place them somewhere, under the right conditions for it to become. And here we are, yet expanding to the critical mass of old age. Someone is definitely out there, scientists are great, but they don't know everything, and they don't own the universe. Men and women, humans like me that live and die between 100 years couldn't tell me how this all started.
@@wilton999 "Someone had to put it in place" - sigh...sorry, but some old man with a beard in the sky didn't create existence. In fact, the very concept of 'someone' didn't even exist until the last couple million years or so when our ancestor's brains evolved enough to start processing such concepts. Existence happened simply because it either does or doesn't (if existence didn't happen, there'd be nothing...that is the 'WHY' of the universe, not because some old man with human thoughts decided it would be nice if we had planets and stars and plants and rocks and water and everything).
@Kenneth John Kelly Explain to me how i've seen with my own eyes distant mountain tops (but not their bottoms) at sea, but could see their bottom as we sailed closer to shore, if the Earth is flat. And if i can see that the moon and at least 4 of the planets (even their moons) are sphere's with my cheap telescope, why is the Earth flat yet they're all spheres. Explain.
"Does it scare you that you science may be wrong" - you don't understand how science works. According to science, it's possible that gravity suddenly doesn't work and everything floats away into space...but the thing is, every time science makes an observation, we find gravity pulls things together. Science isn't about 'right or wrong', it's about what can be repeatedly observed (so who knows, maybe one day science will observe gravity not working, but because it's been observed working a bajillion times, we can call it a law of physics that will very very VERY likely never be broken).
Could you stop blowing my mind? I need it for stuff
I know right? Just damn disrespectful lol.
Is sexism necessary just because she is much smarter than you?
Thankfully I´m to stupid to understand what she´s talking about..So my dump mind can remain un-blown.
Alexander Schestag It seems like sexism is needed just because she is a female TH-camr...
That's a good one.
This young lady should be do tv programs .she is brilliant and makes it interesting with he contagious interest
I understood every single word she said, but when you string them together, nope.
Critical density is what she said
You are critically dense
@@nikoskabbadias plus one like for the kindergarten retort 😂
@@oWarlock360o Stop speaking German you NAZI.
Lawrence Lui...What is it you do not understand...As the man Scientist said...”It is Simple! .. “ He did not say that! Did He? Yep he said that! Now in plain language for you to understand.....”It is like tying shoe laces You try starting to the left, and then you go to the right, if that does not work then you go to the right and you go to the left, now because that does not work either. You shake it all about...and come up with the biggest mumbo jumbo imaginable! Now I hope You Understand, because we The Public are so gullible we believe anything....and then we find that Shoelaces are not required at all....because Where did they come from....? Oh well “It is Simple” He really said that! Who employs these people? RDR
We have barely explored less than 5% of our Oceans, and yet we know the temperature on both edges of the universe
*of the observable universe
else we have know the temperature of the oceans for a long while now. But I get your intention, just pointing it is a false comparison.
We are far better equipped to gather data from the EM spectrum than we are to overcome the extreme conditions of deep sea diving. It's not about lack of focus, it's about technology.
exactly, we don't...lol.. astrophysicists are basically people who make guesses based on limited information... like thunder comes from gods fighting in the heavens...lol
They also have very limited imaginations and so won't explore all possible explanations, only the ones that fit into their current understanding of the universe.
Not to get off topic but I find it funny now that some scientific schools of thought think that our world is simply a virtual reality simulation... seems to be catching on as a "good" idea... but yet somehow a "creator" of a similar virtual reality system is beyond their comprehension.... take also into account that current science is now saying the universe runs, in the background or underlying code, similar to website code...lol... but no no one "Created" it lol....
I find science quite funny at times how opposing they can be in thinking and how biased they can be.
Jason, when I saw mathematicians explaining universe with 4, 5, up to 20 dimensions, the non-existing (atleast never observed to be fair) matter and energy, I saw what they did there. Its just a playground. Its nothing serious... They just show off what they can calculate, not what is actually there. The physics now, at this moment, has no real definition for mass of matter nor it has a good (lets be frank, it has nothing) explanation on gravity, yet it praises E=mc2 like it was the Gospel. In physics so little is understood in terms of universe, in mathematics its even worse, its so confusing, that we all the time get predictions like: the universe might collapse at any second, universe is a hologram, pulsars are just fine with how are they described now (even tho they tend to change rotating speed by order of magnitude of several thousand resolutions per minute to just a few in matter of hours) etc... Its all just so childish.
Yeah but we know more about our oceans than about our universe
New video! Why is the universe flat? And why is it the same temperature throughout? The physics of Cosmic Inflation with Cosmologist Alan Guth buff.ly/1pPb9Ea
Nice video, poorly understood :(
Could the beginnings of our universe be matter that has exited from a massive black hole from another universe, or is that a silly question?
Physics Girl Yeah but it does explain why it expanded and then stopped to me that is a huge problem. Basically changing the laws to explain something we see.
Chris Lucas
the universe is expanding due to its evolution from a big-bang billions of years ago (Power which decreases by time): yet, eventually after this stage of expansion " the entire universe will collapse and shrink by gravity into limited space as it happened to be at the beginning.
for example if you throw a stone into the sky it will go higher and higher, but it will come back and fall.
Abdelaziz Galoul
Thank you but I think you misunderstood what I meant. Nice Allegheny though. But since the universe happens to be flat you would be wrong.If it was curved then you would be correct. What I was talking about was the physics be-hide the inflation and sudden stop of inflation at the first .0000000000000000000000000000000000000000000001 plank seconds after the big bang. To me and many this model breaks every law of physics. The model only explains the effect of inflation and does not explain how or what forces caused and then stopped it. Since nothing in the know universe is know to cause this. Kinda of like adding dark matter and energy to everything just to balance the equations. I think it is silly.
I know this is an old video, but it is the best explanation of inflation theory in layman's terms that I have seen so far. Really good work! Thank you!
If the universe was flat cats would have knocked everything off by now
yep.
If the Earth was flat cats would have knocked everything off by now, Seriously, unless you were joking about a flat Earth, I can honestly say there is plenty of evidence to prove that Earth is not flat.
Paul Foor - -Hmm About Flat Universe’s! You obviously are at the front door of Understanding.....Cats need a door flap....and then only the door knocker gets knocked on...Perhaps you should find your own cat flap, and stop knocking things over....”Nothing is possible because Nothing is not impossible!” RDR
@Kenneth John Kelly Myth and superstition only hold all of humanity back. You gullible religious zealots are preventing humanity from growing and bettering ourselves. Your gullibility and inability to grasp reason and logic truly depress me.
@@planexshifter Well said.
- I used to always worry about my beer going flat.
- Now, I have to worry about the universe too?
@Austin Prather - So if we drink the universe real fast it will stop going flat?
@@tsamuel6224 mhm
@@tsamuel6224 just like a beer, the longer the universe remains outside our stomach the flatter it'll get. So the only way to stop the universe from going flat is to consume it before it becomes flat.
This is so profound it’s difficult to even fathom.
I am so glad that at 62 years old I descovered you! I wish you were there when I studied physics 40 years ago!
you do such a great job of explaining complicated concepts in a fun, relatively easy to understand manner- great job!
I think her excitement is what makes me so interested in these videos. Anyone who is so enthusiastic about something will attract the attention of others. I particularly enjoy the cosmology related videos.
I totally agree with you. She has all that enthusiasm and energy, like it was during the big bang .........
That was not meant to be crude or derogatory, I like her, she's fun.
Beauty and brains...what's not to like?!
Let's not go shaming the universe about being flat, guys. It looks beautiful to me, whatever it decides to do.
This is really quite spectacular. Physics girl has a gift for teaching.
So here we are. 5 years later and flat universe might be wrong all along. With light from distance universes seems to bend just a tiny bit indicating that the universe has a curvature of Omega > 1, which might make it a ball. Thank you Plank-Telescope for this possible finding. Science is a wierd place nowadays.
"Planck evidence for a closed Universe and possible crisis for cosmology" from Nov. 2019 by Eleonora Di Valentino, Alessandro Melchiorri and Joseph Silk
No idea what you said.
where did you read that about keplers findings?
First off, kepler is satellite that has stopped its work now. Kepler finding are available on wikipedia btw.
@@bonztubezI mixed up Planck with Keplar but yeah...
"Planck evidence for a closed Universe and possible crisis for cosmology" from Nov. 2019 by Eleonora Di Valentino, Alessandro Melchiorri and Joseph Silk
You can also find some recent videos about it Nov, Dec here on youtube if you do a quick search.
So, distant objects can and are effected by gravitational lensing as well as being disrupted by concentrations of dark matter
There is a problem with this explanation: the expansion of the universe is actually ACCELERATING.
The logic gymnastics is boggling.
Don't upset the scientific community with facts. They don't like it when the facts disprove their foolish ideas.
as i understood, it is accelerating while decreasing the acceleration
like, now i am at 100m/s, then i am at 190m/s, then 275m/s, etc.
each step i'm faster, but the increase in the acceleration is getting smaller (+90m/s, +85m/s, etc)
If the universe is so flat, why do I still have to iron my shirts?
Madder Hat Flat=/= 2D
Ironed shirts are 3D, not 2D. I gUeSs YoU'vE gOt To StUdY MoRe
entropy
You iron shirts by choice.
his debunk level is over 9000!
3:25, "It will expand for ever but at an accelerating slower rate" but we know that the universe's expansion is acceleration so our universe should be open? Please explain!
yeah, that's what I thought...
Is this still valid? PBS Spacetime says that the universe is expanding at an accelerated rate, in contrast to this video. Don't make me go out and measure it!
That's what I was wondering as well.
Not just PBS, a lot of sources say it's expanding at an accelerated rate... This is the first time I heard it's not expanding at an accelerated rate...
I think it's true that the expansion of the universe is accelerating; but that's due to the effects of dark energy, which she didn't mention in this video.
I got a tape measure if you need it. 😀
Accelerated expansion of the Universe, yes. Hubbles Constant. Inflation was also accelerated expansion just at a much faster.
If we have to give some math metaphor for this, Harmonic Series would be perfect. It is a divergent series but the expansion is slow.
Curvature of 3d space would probably be so much easier to understand if we could draw/think with 4 spacial dimensions. It is easy for us to understand 2d but a 2d creature would have problems with it because it would only see lines/1d. I guess it's the same with us. We live in 3d, but see 2d. If we could go to 4d, we could see 3d space how it really is. Or our brains would blow up because it can't comprehend it :D
+Critical Ravi you sir know alot more about dimensions then most people do.
+Critical Ravi my brain is blowing up just reading your comment.
Undercover Wookiee C'mon, it's not that hard :D Just some simple analogies... :D If you're interested, watch the film "Flatland" here on YT, really helped me undestanding the dimension stuff :)
+Critical Ravi It's not at all hard to think in 3d. 1d is a point, 2d is a surface and 3d is area. You have to think outside the box... literally. Pun-ny huh!
Pecker Wood As far as I know, a point is 0d, a line 1d, a square 2d, and a cube 3d. And, as I said, we see images, think in words of course, or in images. We can see the whole square of 2d, while 2d beings would only see lines. Same with us. 4d beings can see a Cube from all sides at the same time, probably even the inside of it. We can only see and imagine 2d images of that cube, and our brain simulates distance of objects by lighting and size, and so on. I mean, I can't imagine how a 4d being would see a cube. It's just not possible for our brains, because we don't know the next direction. Assuming there is a 4th spacial dimension that is, of course.
Another interestin thing is, that we can only see one side of a "2d" paper. we have to turn it through 3d to see the other side, or go underneath it, assuming a levitating piece of paper. How would this work with 4d and 3d? If someone has an idea about this, feel free to reply :)
The precision of the paramaters of the universe only give us an option, GOD.
Introducing Physics Girl (now in more frames per second)!
Is it noticeably different? My internet is too slow to tell...
Physics Girl It is to me. Looks smoother/more real-time.
"My internet is too slow to tell..."
Paging Elon Musk and his many satellites...
Physics Girl Yep, I noticed the higher framerate almost immediately.
I'm glad I finally found your channel, you make physics fun and that's the way it's susposed to be, thanks!
Why the hell this channel is not verified by TH-cam.. !!
IKR?
Cause she kinda needs a license...... or a degree... i forget now
She got a degree in Physics !!
Then she probably needs a license, let alone be more noticable on youtube *subs*
Verified by TH-cam? What's that matter? That's like giving someone credibility because someone stole their identity. Irrational.
I just love this girl's brains and communication talents. And, she's great to look at.
no thing, is ever flat.
funny back in 56
+kleintjuhD An infinitely flat surface is infinitely flat
if it existed.
+kleintjuhD The Earth is flat.
uhmn... no. try again. youll get it!
I simply do not understand. I'm having trouble understanding how expansion can happen while the density doesn't change. How does the volume of something change wile the density stays constant unless it's getting filled by something?
That's a stupid question. The universe is being filled with naught but the dankest of memes, which is its true purpose.
That's exactly the right question, only in the flatness model does first law of thermodynamics hold mathematically, and yet the inflation is the flatness model that breaks it, but there is one more, if the energy can appear from ether why is it appearing at exactly the same rate for the universe to remain equally dense.
oh and there had to be something to effect the change in the speed of expansion, now you know why inflation is "highly debated theory"
Aleksandar Rajkovic jeez take a joke mate
also, this is where creationism seems more logical btw, if there is an ageless creator in the sky it makes more sense than a universe just 'appearing', you're right about matter having to appear for density to stay at an equilibrium. But think about this: what if the world was in fact created out of nothing, the monotheistic creation theories line up with inflation, so don't rule anything non-scientific out of your oh-so-serious debate. *nerd mode off*
Aleksandar Rajkovic the speed of expansion is directly proportional to the speed of light moving outward from a 'universal centre', you can see in the early time values that the rate of change is very fast, however an obvious trend approaching present is that the universe's growth rate of change is decreasing, but the actual increase in size is not changing, it's just that there's more initial universe to compare the growing universe amount to. But dank memes will never slow down, submit to the dank memes.
Obviously not a thing wrong with the offerings of anything from SciShow to MinutePhysics, but it’s nice to be able to come to a video without knowing all the ‘why’s, ‘if’s, and ‘but’s beforehand. Only then to be profoundly awestruck at how much smarter all the commenters are than me! Very cool community, rallied about some very cool videos :)
Ps. I know I shouldn’t have been *abashed* but I was very distracted by your eyes… you’re not wearing coloured contacts, are you?
I know! I was warned about commenters when I started making videos, but I have found the comments to be insightful, constructive, and hilarious at times. It's great to see so much high quality content in education on TH-cam.
For some reason, the sunlight in my room makes my eyes look really weird in these videos. I haven't figured out how to fix it yet.
Just… please don’t be fazed when the trolls inevitably descend. I think this space is still sheltered under relative obscurity, something for which I’m both thankful and wistful. After all, you deserve more fans intelligent as these than TH-cam has to offer. ’Til then, I'm thankful for the community you've created :)
Now, now, as the Physics Girl, I’m sure you must have plausible explanations for the glare! I’m imagining the muscle fibres of your iris acting as a diffraction- upon reviewing a [very flattering (just kidding about, I promise)] frame at 0:26, I definitely overcomplicated things, ahah. Looks like the reflection of the window on your eye, with the camera where it is, perfectly covers your pupil. Maybe rotating your camera-backdrop setup relative to the window would help? It’s always difficult to get good lighting, though. Perhaps a diffuser on the window while filming? Even a large sheet of white tissue paper would do!
siddyrocks Interesting! I'll have to try the tissue paper. Camera work is not my strong point, so thank you for the suggestion.
Not a problem - always happy to help! I’m generally a candid photographer, so I don’t dabble much in artificial lighting. But I got my first flash a couple months back, which was very exciting and opened up a world of possibilities… promptly after which I sold my camera body to a friend *sigh* patiently waiting for Sony to launch a new full frame.
+Physics Girl "I was warned about commenters when I started making videos, but I have found the comments to be insightful, constructive, and hilarious at times"
*scrolls down to see much confusion about "flat" vs. "2-dimensional"*
Physics Girl, is there an SI unit of irony?
More seriously, kudos on an entertaining and informative channel. :)
Came along this "old" video.... Amazing how you changed your presentation skills since then. Your passion and slightly "weirdness" ;-) is so much better today.
I’d always learned that the universe was expanding, and that this was accelerating, and galaxies were literally growing farther apart from one another... (e.g. observable via the Doppler effect). How does that line up with consistent mass density or flatness?
I don't know if I'm in love with physics or with physics girl.
Recent studies by NASA and ESA suggest that the universe is not only expanding but also found to be expanding 5% to 9% faster than thought earlier.
Shakil Khatri really? I wonder if it is expanding exponentially? Would that mean we are accelerating in time and space? Will our time be faster than past time?
It's an understandable misconception but when they say the universe is flat they don't mean 2-dimensionally flat, they're actually referring to 3-dimensional flatness, in essence a near perfect cube. Also it's kind of a mixture of certainty and generality, the orders of magnitude they're working with allow for near approximation where 99.9% accuracy can still be off by a lot. Also if you measure the density of light from a distant star over a sufficient period of time the change in brightness coupled with the constant speed of light can still give you a percentage rate of change even if your distance calculations are somewhat off.
Yes. She missed a major point in that the expansion of the universe is speeding up.
You are the first person that has made the point of the Big Bang being a theory, something that scientists call a fact, even though they can’t prove it. Well done 👍 missy. I salute you.
The universe certainly will "expand forever" according to observation and theory, even in a flat universe, and the acceleration will accelerate. Why does the intro say otherwise...?
+djayjp Clearly she must be a troll who has reached 368 thousand people and counting :/
connorp2402 Are you trolling? Seriously, why does she contradict herself in the intro?
+djayjp Yea, I was just joking. I was just trying to give her the decency trying to cover up that not only her but the producers of the video etc all made a mistake... But it's a pretty big one that not only is it wrong but no one seemed to have noticed before it was put up. Especially since her name is Physics girl :/
connorp2402 Exactly, couldn't believe what I was hearing :S. Would make me question everything else she says in other videos (making me not interested). And this was only the first video of hers I saw.
+djayjp That is if the universe is actually flat. We call it the observable universe for a reason, and that is because we base all our conclusion on what we are able to observe. Since we cannot calculate anything with infinite precision, we can't say we have not made a mistake. There is a possibility that the observable universe is just the surface of a larger spherical universe. This will support the multiverse theory. It could just be that like the earth's crust gets recycled in the mantle, the flat universe that we see is just being recycled through whatever is in the center of the 5th dimensional spherical universe.
Dianna: Both edges of the universe have the same temperature.
Me: 𝐓𝐡𝐞 𝐮𝐧𝐢𝐯𝐞𝐫𝐬𝐞 𝐡𝐚𝐬 𝐞𝐝𝐠𝐞𝐬?? 𝐓𝐡𝐞𝐧 𝐰𝐡𝐚𝐭'𝐬 𝐛𝐞𝐲𝐨𝐧𝐝 𝐭𝐡𝐞 𝐮𝐧𝐢𝐯𝐞𝐫𝐬𝐞?
All these discussions are about the Observable universe. It is generally assumed that outside of it, is just more of the same.
Other universes in the flower of life pattern
Same same. it just had no chance to ever interact with us, so it is "out" of our universe.
@Rad Derry sure, why not? The big bang happened everywhere, not just where we are. Everything is in the centre of the expansion
Another edge???
i thought the universe is accelerating in expansion?
In some beliefs
and i thought the universe is just a lint from god's belly button
+a pool player and i thought who cares? We are all gonna die anyways...
+LUIS V TON Not everyone dies at the same time, so every dies but at separate times.
+LUIS V TON buzzkill
I still like watching your videos and getting a refresher course. Keep getting better, I look forward to new content to fill my brain
Thank you universe for giving us this person
WAIT! What do you have to say about the accelerating expansion of the universe? Isnt that the opposite of what you said at 3:35?
I don't understand the whole "all the matter in the universe being in a volume smaller than a proton" statement. I never have. Doesn't this violate the Pauli exclusion principle? Isn't this just implying a singularity, I.e., an error in the theoretical model? If this idea is derived from the works of Stephan Hawking, saying that the universe started as a gravitational singularity, shouldn't it be worth noting that the general theory of relativity breaks down at Planck time scales? Please help elucidate this for me! Thanks!
electrocat1 Great question sir, and one I can not answer. However I have posed similar questions like if Einstein was correct then light , having a finite speed is not the fastest rate in the universe. In fact it can not be since quantum theory shows that matter can move from one place to another faster than light. So if light can travel it's speed and it is made of photons and photons are made of particles and as such do have mass, then something else must be able to do the same.
Nuckelhedd Jones okay no quantum mechanically things can not move faster than light and photons are not made of particles, they are themselves fundamental particles. you can not convey information faster than the phase speed of light in a vacuum.
electrocat1 "Doesn't this violate the Pauli exclusion principle?" No, because the exclusion principle applies to particles; when the universe was this dense, it was pure energy. While general relativity would brand this stage of the very early universe as a singularity, it must be noted that quantum effects would be important, and we don't really know how gravity works at the quantum level.
***** I know we don't. And GR doesn't see it as a singularity because the timescale is smaller than the Planck time.
electrocat1 I don't think you need to worry. there are many who think the big bang is junk science, and I am in agreement.
Physics girl clearly has a great understanding of physics by the fast and succinct explanations. Very good communication skills too, someone untrained but interested in these cosmological topics, like me, can easily follow them. Some of these concepts I’ve never heard before but make the early universe a little clearer and interesting. Maybe you could be the next Brian Cox or Alice Roberts.
That look at 2:24 "How could've it expanded so fast?"
Welp, that's what she said.
A question, if we never calculated the one way light speed itself, isn’t it possible that light actually reached the other side of the universe and that light speed on a side is infinity and on the other is c/2?
I ask the same questions. We don't even know what the one way speed of light is.
If the universe is flat, then why can I move upward?
What's "upward"?
Three-dimensionally flat.
You can't, you already live on the second floor.
None of that makes any sense. You can't call something that's three-dimensional flat. It kind of doesn't have only two dimensions.
RCapricot Yes you can. If you can connect 3 parts of space, add the inner-angles, and have them equal 180, it is flat.
Great explainer and good Guth segments!
3:55 - That stick figure archer holds the bow like a physics boy!
Wait, I'm confused. I thought the expansion of the universe was accelerating.
th-cam.com/video/-4PayaEgEZc/w-d-xo.html
@Xanthan Gum boomer
it burns.
everyone is confused. thats the point
I don't understand it either. She should have made a distincion between the curvature of space and the curvature of spacetime. As far as I know, space is flat and spacetime curved.
Q: is the earth flat?
A: we know the earth is flat but the real question is why!
Q: Umm... what?
A: presents theories, the universe expanding and earthly geometry and physics as reasons just read about on Tuesday. Eureka! Modern day science!
3:34 universe is not expanding in slower rate it gets faster due to dark energy
I'm slightly confused. I't is my understanding that the universe is not only expanding, but am doing so at and increasing speed, thus we arrive at the subject of "The Big Freeze".
Have I missed some scientific breakthrough, or have I simply been misunderstanding everything?
Felix Nielsen "Have I missed ..." No. What you say here is, insofar as we currently understand the Universe, correct. What is it that confuses you?
***** The unverse is flat an thus will not expand forever, and yet it will.
The reason is dark matter, moreover dark energy
HerrWagnerfreund Yes, but they basically said how the expansion of a flat universe would be (slower) without dark energy concluded to understand the model. This doesn't mean they aren't aware of the effects of dark energy
Felix Nielsen The fate of the universe is unknown. The big freeze is just one theory.
Is this still correct info? I think I've heard that the expansion of the universe has been found to be accelerating.
It has yes...
@@jdkhaos4983 I think you replied in the wrong thread.
@@bubblezovlove7213 But it is still believed to be spatially flat. So the reason for its flatness that was given in this video must be replaced. What is the real reason it is flat?
She did not say why it was flat. She talked a lot about density. But no discussion of the geometry.
I love your channel! Everything in the vid’s is perfect. Weldone,! I’m a big fan! I hop you guys continued with these scientific topics.
I feel like I know Physics Girl but I've never met her. Like I've met her dopplelgaenger or something
That was in a different universe. You know, the one where some of your dreams come true.
She looks alot like Blake Lively imo
So if the universe is like a balloon stretching flatter over time, doesn’t that mean the universe is still round? But so big that we can’t see the curvature of space??
2000 B.C. of course the Earth is flat!
2000 A.D. of course the universe is flat!
Did you mean....BCE AND THEN CE. Or The Flat beginning at 00...or 13,400,000,000 BC....BCE? RDR
'There is One who dwells above the circle of the earth, And its inhabitants are like grasshoppers. He is stretching out the heavens like a fine gauze,' - Isaiah 40:22
The book of Isaiah was written during the time period (778 - 732) BCE It refers to the 'circle of the earth' (as viewed from space) long before humans were able to view this for themselves by travelling up into earth's orbit. Further, the wording indicates a dynamic, expanding Universe (heavens)
“He stretches out the northern sky over empty space, suspending the earth upon nothing.”
- Job 26:7
The book of Job was written between (1473 and 657) BCE indicating a knowledge that the earth is suspended in space by an invisible force (gravity), contrary to some human myths that suggested an earth supported by pillars or resting on the back of a turtle (or other animals such as elephants)
Tony07UK ...Hmm....I prefer to think from a Holistic Thought store....Thinking for oneself nowadays seems less....and in the past only about 2000 BCE! Thinking suggests to me that there was And probably still is advanced technical skills that are endemic throughout 13,500,000,000 years of Observable effects. These Unlimited abilities are for us to discover on our Earth journey.....However much clearer your Awareness Perception Conscious Window is Becoming. If at all...Through Independent Thinking....Not Thought Which is only ever Of the Past. Thinking discerns what is Leftist processing or Rightist significant other, giving You a Choice from multiple choices...leading to Choices recurrently, Developing strident attitudes which control your Altitude! RDR
Kenneth John Kelly Hmm......The scroll....this would equal infinity......Repetition! But The Ultimate is more...more than Infinity! Unlimited which can equate only to Flat. Layers of flat Holistic Unlimited Spokes Flat packed Quantum dimensional Zero. Unlimited Nothing giving Everything Unique Oneness! RDR
@Kenneth John Kelly I do that every morning!
I'm worried that I have stuffed so many videos in my head that there might be a rapid expansion one day!
*WHY DO THEY CALL HAVE TO CALL THAT FLAT!?!?!?!?!?!?!*
When I search shape of universe, I wanna hear ball or cube shape, not flat! Why they can't call it the EXPANDYNESS of the universe!?
Yeah, its like when they say "dark" matter. They should call it invisible matter. If it were dark, and it is most of the matter in the universe, then we wouldn't be able to see anything. Who names this stuff?
I find gravity pretty repulsive every time it makes it hard for me to get off the couch.
Its amazing how many theories are posing as facts
like religious theory?
Theory in science is actually a fact or a way we interpret facts ;)
ram0l noooo, theory is an "Educated Guess" *based* on the known facts at the time. Theory is not deemed Fact (aka "Law") until it is proven to be so.
As much as I like PBS Spacetime, this video was much easier to understand. Thank you.
If I understand there is *Flat Universe Society* ? 🤣😂😭
Tawe Lo ..No no no....A Flat Universe first...then the Flat Universe Society.....With Unlimited potential...for Expansion. RDR
"not expand forever"? I thought that the expansion is even accelerating!
Correction for title*** Why does the universe seem flat?
While I do not comprehend flatness, I learned that flat is unstable like standing a pencil on its end. It should fall over. However this idea of inflation actually stabilizes the flatness.
nah this is too advanced for me at the moment
me to but I still wach it!
i'm confused. how can the universe be flat and at the same time expansion be accelerating?
That concept of flatness still struggles a lot to fit within my brain.
Let's just say there's a vertically floating stick in front of you. That stick could be looking like either of these 3: ")" or "|" or "("
Universe flatness is just like that. If you point a very long stick towards each of 6 directions of universe, AND if you don't find it curving, we would say universe is flat!
The rest of the physics stuff is just about finding a method that we could use to see just that, without the very long stick.
@@IDMYM8 My god, I think I finally understand it now, thanks. So it's not flat in a sense that it's like 2D or anything like that, it just means that it's not bending around anything and a beam of light could theoretically go from one side of the universe to the other in a straight line?
@@the_headless_horseman9682 You got it!
Cosmological red shift can be interpreted as time dilation due to distance & not velocity in a positively curved Universe. Parallel transporting is no measure of Flatness in certain higher dimensional spaces,but red shift can (tempral curvature) .If a field can be treated as a geodesic.(“ERER” bridge).
No need for Dark Energy,No matter-antimatter asymmetry problem.
Conservation of Energy is the Law.
Can you please slow down? You're throwing technical term and concept one after another. Let some concepts sink in a bit. Too fast cutting and too fast speaking. What's the rush to get through?
I thought it was just me.
Slow down? I watched this in 4x speed. It's simple info , if you already have an M.Sc. in Astrophysics
charmerci I am pretty sure you have not heard John Green
Adarsh Ranjan - No, I have not! (And I guess I won't!)
I have a reverse gravity effect on women whenever I drink too much. It's quite remarkable.
+YTEdy -- That's so sad. However, there is hope! If you become a multi-millionaire, or even a billionaire, the effect will disappear COMPLETELY. Give it a try!
GregoryTheGr8ster
I save as much money as I can and I buy lottery tickets with what I have left every week, with that outcome in mind.
YTEdy
Exactly! Send me a postcard from paradise when you get there, will ya?
When I try to talk to women, their hand gravitates toward their cell phone and dials 9-1-1 every time.
brad h
You might just have really bad breath.
Woah woah woah, you're just going to drop something like "gravity can sometimes push" on a brother and then move on without an explaination?!?!
WTF!
It can't anymore. To be succinct, it may have been possible during an early stage of the universe before certain symmetries broke (check CPT symmetry for a nice head ache), but since they have broken now and gravity, to the best of our knowledge, is dominated by particles that have spin 2, gravity is always attractive.
Thank you so much for that clear und simple explanation. Struggled alot with that topic before this video.
I love how we "now know..." something at the beginning of this video (expansion theory) but by the end it's "still a hot topic of debate." If a theory is still in debate why is it taught as fact?
your are confusing the word know to mean that we couldn't know more. You know many things, but there are many more things you could know. This is the same with theoretical science. We know many things and those things aren't any less "known" just because we don't have the complete picture. When you put a puzzle together, you 'know' where a certain peice goes becuase you have fit it into its place. But knowing where that piece goes does not automatically mean you know where all the pieces go. A puzzle, like human understanding of the universe, goes together slowly and builds off of the previous pieces having been put in place.
broke: flat earth
woke: flat u n i v e r s e
Woke? Awake.
Anyone else here on the 5th November 2019? They say it is closed.
Whatever ya flat universer conspiracy theorist
That CMB data is wrecking a lot of things. This time its the physics Girl.
I love the verse in the Bible that says, "Let him that is wise in this world, become a fool, that he TRULY may become wise." There is so much to know about this world, and yet we can only potentially know a very miniscule of what can be known, putting us in a very weak and humble position. But if our response to this puts us on our knees in faith and homage toward God, then we have acted in the wisest fashion possible.
When the universe was so tiny, what surrounded it?
If you figure that out you have a Nobel Prize waiting for you.
So far all we can say is there was nothing, not even matter.
+Michael Schemmel I just don't see how "nothing" could exist in science. As a matter of fact, it is impossible.
+brad h Well science can't explain everything.
+Michael Schemmel Evidently.
She's adorably cute
+Reck Tominvayed Or is she adorably adorable?
Right?
Lol
For real though, I would love to just hang out with her and talk science. Turns me on more than the thought of anything physical ;)
:P
VSauce meets Beauty and the Geek
I tear up when I think about space. This video has me bawling my eyes out.
We know the universe is flat because the Flat Earthers think it's a sphere
th-cam.com/video/JUmsrpKu2mc/w-d-xo.html&start_radio=1
LOLMAO
These questions is sometimes what makes me believe in something supernatural power.
Agreed.I was thinking the same thing. It’s too perfect.
My god this girl's so gorgeous!😍😍😍😍😍😍❤️❤️❤️
As I sit in my Lazy Chair and watch your videos I get flatter and flatter. Please slow down!
Her hair looks pretty nice.
I didn't understand a word she said, but I enjoyed watching her say it. Why are smart girls so attractive?
For starters, she was attractive with the sound off.
Breaking news 2019 the universe is not flat thank the Lord I never could wrap my mind around the flat universe theory
Oh, right, but the other versions are perfectly comprehensible.... 😂
@@KingoftheJuice18 scientifically yes
@@rickledford2953 You said "wrap your mind around"--that sounds more like an issue of imagination, not math.
@@KingoftheJuice18 smartass imagination is not truth
@@rickledford2953 Hey, bro, I was commenting on what you wrote. If it's a matter of scientific understanding, then what does "your mind" and what you can "wrap it around" have to do with anything?
You know what I always wondered if I had got a talented sister like you who loved physics so much as me , then I would have been the luckiest person on earth...
That was a disgustingly large amount of milk into that tea... Of course being American I don't blame her for blundering a tea job :/
Since the proper amount of milk or sugar one should add to tea is precisely "none," I agree.
It's not flat. Read the newest theory!
Thank you.
And mathematicians would not be so lost if they would cut down on imaginary numbers surely. Revisit what Wilhelm Reich reported on before you killed him for it, and see if any of that might replace those imaginary number cardboard math bridges.
Latest theory: "It still looks pretty flat, but it might not be, we're less sure about flatness now than we were a few years ago"
Ivan Laharnar Oh Yes it is.....Unlimited cannot be anything but flat!.....Why can you not understand that!
When I was in college, the physics girls were flat.
When I was in college physics, There were no females.
The only thing flat earthers fear is sphere itself
I lyke it!