Do You Expand With The Universe?

čas přidán 23. 10. 2020
As the universe expands, #expanding #space is said to "stretch" photons. But if it stretches photons, does it also stretch molecules, galaxies and you? A portion of this video was sponsored by Salesforce. Go to to learn more.
Special thanks to Geraint Lewis - this video was based on his paper "On the relativity of redshifts"
Check out his CS-tv channel: and books:
Expanding Space: the Root of all Evil?
Matthew J. Francis, Luke A. Barnes, J. Berian James, Geraint F. Lewis
Editing and VFX by Trenton Oliver
Thumbnail by Ignat Berbeci
Music from
#SMB #smallbiz #startups #SalesforceEssentials


  • Died a little inside when he mispronounced homogeneous.

  • So Thanos removed the electromagnetic forces, and changed the reference frames. Got it.

  • "No".

  • So if blue appears red to another observer, doesn't it violate the law of conservation of energy as red carries less energy than blue

  • Really informative video, Derek. Thanks so much. My brain just exploded into my roommate's face so fast that to him, it was blueshifting.

  • Wanna stay at your country sir..

  • Does the energy lost violat the law of conservation of energy

  • Yo mamma's so fat she's not expanding with the universe, the universe is expanding with her

  • I don't get it

  • dark matter stops or prevents expanding of space // this is why the space around galaxies dose not expand // all matter is built the back of dark matter // and why galaxies rotate as a wagon wheel

  • If photons with longer wavelengths have less energy, then where does the energy of red shifted photons go?

  • Shaved Derek looks like Iron Man and Ant Man at the same time. Change my mind

  • So this thought disturbs me. The thought of an expanding universe, but granted I can understand how our universe is expanding. I see our universe as a black hole, the black hole can be feeding, but it can also leaking hawking's radiation. One process is extremely slower then the other, feeding being the faster of the two. Which means a big bang and expanding of the universe would be a normal event in making a new universe. Also I want to point out I do not agree with a big crunch, I think hawking's radiations explain away the need for such an event. The real problem with what's going on with astronomy, is that we think of the hobble constant is a constant. Depending on which direction your looking at in the sky, it should change. This so called constant should change over time and depending on which direction your looking at in the sky should change due to how the earth spins, rotates, how the sun rotates in the galaxy, and how the galaxy moves. Which at this time we can only really say we have good guesses at a couple of those measurements. Movement is by far the hardest thing to account for in the universe

  • "Wavelength and energy are not intrinsic properties of photons." Professor Farnsworth voice: "Wwwwhhhhhhaaaahhhhtttt?" 🤯

  • Question, since we are near a gravity well and space is stretched, if you exit the gravity well and space returns "not streched" do you shrink? Or is your size the same no matter where you are in universe. Another question, the fastest anything can travel is the speed of light, including gravity, so it's I can assume that time also travels at that same speed, which isn't necessarily the speed of light, it's the speed that the universe is created. In other words, light travels instantly from one point to another, which means that light is just waiting for a point, directly in front of it, to be created. And is that point the size of a Planck length? Which is created in a Planck time, which explains the ultraviolet catastrophe? Oh one last question, is the slowest something can exist known, in other words when something moves in any direction it starts moving towards the speed of light and time starts slowing down for it, what is the speed of something not moving at all in any direction in the universe, is that known?

  • McDonald's definitely expend some people

  • **wide putin flashbacks**

  • 4:42 well that just stupid

  • The photon does not stretch, only the space through which it travels. Because it has to travel through more space, the wavelength of the particle-waveform changes.

  • So wait, there won't be a point in the expansion of the universe where it accelerates fast enough to rip the bonds between atoms? I thought this was the case. Can someone confirm this for me?

  • I tend to accreat mass over the holidays..

  • If the entire universe is expanding, how does stars form in the nebula ? Why is matter clubbing together ? How far is too far to prevent matter to aggregate ?

  • Well, now I'm sad. The one reason I said to everyone for me getting fat is now debunked. Thanks, Derek!!

  • So does space expand or is there just more space appearing?

  • I am not sure that the arguments put forth in this video lead to a conclusion that we are not expanding. as the space around us expands. Is the claim that the space around us is not expanding? Does a photon not expand as it passes by us? Matter has been shown to have wave like properties. As matter passes through space does it do so at a fixed frequency? Perhaps what happens is that matter does slow down as it passes through space even though no force is applied to it. So matter that is close together is not expanded by the expansion of space but it does loose energy relative to a distant observer as it travels through space?

  • Wait i have a question. I dont exactly understand half the things you say on the video, but if we suppose general relativity is real and earth is accelerating at 1g, is there the possibility that the earth reaches a point where it is faster than light itself?

  • 1:32 veritasium: In a gravitational field also veritasium: Gravity is not a force

  • So the room expands, not the content of the room. It's not the dimensions themselves expanding.

  • everyone is expanding after the pandemic started

  • Red shift

  • Yeah, I'm really trying to hit a blunt state with this mind-blowing stuff but I didn't understand any of it

  • Is this a coincidence with quantum superimposition, red and blue shifts at the same time, it only depends on the system that we observe or measure from.

  • So wide putin can also be red shifted putin

  • In my opinion, the best proof that the universe does not expand uniformly down to molecules: you can measure expansion. If your "eye" would expand the same, nothing would expand at all. See also his video about the gravity wave detector.

  • 11:19 _“except under extraordinary circumstances.”_ You mean McDonald's and Ice-cream?

  • The Universe doesn't even expand, so how could anyone expand with it?

  • wait what the universe is stretching though? that's how it's expanding, the only possible way for it to expand since the galaxies don't have a velocity when they're moving away. perceived velocity and actual velocity are different, the galaxies don't ACTUALLY have a velocity they just look like they do because space is stretching. doppler shift equations don't work for stretching of space, only actual velocity. the reason we don't stretch and atoms don't stretch is nothing to do with it all being doppler shift, it very very very much isn't all doppler shift, and using Doppler shift would give completely wrong answers for the Hubble constant. We don't stretch because the forces holding us together and the forces holding our atoms together are strong than the "dark energy" stretching the universe. In the vacuum of space, there is not an atom that can counteract the force and thus it expands.

  • What is the opposite of an existential crisis? I just had that.

  • you explained very hard topic, but i enjoyed and understand it very well, really so much thank you for this content video. at the end video there was a great smart work done by you.

  • i am expanding by feeding

  • Is the photon getting the real time data of the position of observer and the initial position of the source Still wonder what's a photon

  • Well.. I'm too stupid

  • Hourra! all the dots connect together with such BIG BANG based theory! However, a scientific analysis of this theory (LEMAIRE a Belgian Christian Church Jesuit-astronomer contributed to propose that one new theory) in the matter of the cosmological scientific proves for it show that it is a very speculative theory. First the big bang is centered around the earth position in the Universe (wherefrom we observe no space time expansion at all,instead contraction (by gravity) in our "nearby Universe "space-time"" (God finger? Which one human postulated God? "). Two we use a HUBBLE constant for qualifying the expansion. The value of that constant started with 500 to be nowadays measured (statistically) around 60.! The redshift phenomena is of course a data based observation, but are we sure we dont messs with the real causes of,it beeing well understood that we use tables ( cosmic cloud dust scattering effects, supernovae implosion-explosion-dust-particles clouds phenomenom.) where values used for calculations are subject to our understanding of what we observe.(and such understanding vary with time, (like the SURPRISING supernovae after-"explosion" cloud observed by a NASA airborned infrared telescop in 2019) Einstein theory is used everywhere and nowhere really proved. Physicists now use it to "prove" that some quite complicated to explain mecanical forces dont exist but are due the relastivistic (frame of reference) observation of it only!

  • We Arabs want translation into Arabic

  • U and Vsauce are my favourite youtubers

  • I expand with fritos

  • I started watching more of Veritasium videos since Michael forgot his V-sauce password

  • Light changes frequency over time?

  • Direct comment to the title of the video: Yes, this seems like a very reasonable explanation...

  • ohh the ending is so sweet:)

  • That thumbnail 😂😂

  • So anyway I have a new solution to why redshifting happens that actually makes sense at first glance. A shorter wavelength means a lot more movement and more movement needs more energy. But as light travels it loses small amounts to heat and thusly has a longer wavelength, moving towards the red end of the spectrum. Please tell me this has already been proven wrong because I am going to be ashamed of humanity if I, an 8th grader, figured out why redshifting happens in five mintues, but the harvard scientists couldn't do it at all.

  • B I G C H U N G U S

  • I wanna be able to see red shifting... I really do

  • Love from India ❤️❤️

  • Thanks, for the convenient excuse. Now I know that I don't gain weight cause I eat too much and exercise too little ... the Universe makes me expand.

  • We have only talked about whether these non homogenous collections expand or do not expand. Their mass and nature of forces acting on these particle collections must have an effect on the degree of expansion experienced by different collections of particles. Is it that the distribution of these heterogenous collections is fairly homogenous that we are able to define the expansion as a single global event. But the universe was not always this homogenous especially in the early stages of the baryon acoustic oscillations... does that mean this kind of understanding towards expansion invariably pushes us towards the multiverse theory can we even define the shape of the universe if it happened in a heterogenous universe. Is there where inflation comes in? It would be nice if you could add on these topics and make video that deals with all this crap in one blow. No more expansion confusion

  • As far as I know, there IS a situation where expanding and contracting space does expand and contract physical objects: gravitational waves, as this property is how these waves are detected.

  • The light house approximation in Derek's reasoning is just covering up the continuous nature of the expansion to make you think that the expanding is not continuous. In reality, the approximation is just an approximation. Thing are expanding no matter how small the scale is. Yes, even you are expanding, maybe 0.00000000000000000000000000000000000000000001% per year, which is too small for any instrument to detect. But you are expanding for sure. And the galaxies are 1000000000000000000000000000000000000000 times bigger than you, so they expand 0.00000000001% per year, which is detectable.

  • I mean, if everything was expanding equally at the same time, it would appear as if nothing was expanding at all.

  • So we know that space expands between galaxies because of Hubble's discovery as most galaxies are redshifted away from us. But here on Earth wouldn't we be experiencing a contraction of space-time due to the mass of our planet, moon and the sun? Don't we feel the space-time contraction as gravity?

    • Gravity is not actually a force, but a convergence of parallels formed through distorted space-time.

    • @Vincent Chen Dark Energy doesn't expand our planet or us or any type of matter because it doesn't interact with photons.

    • @Vincent Chen Dark energy is generally the term used to describe the force responsible for expanding universe, it is called dark because it doesn't interact with light (or any photons).

    • I think his answer is somewhat confusing or misleading. I think the conclusion is that there is some sort of 'force' expanding us, our planet, our solar system, our galaxy, etc. It's just that we occupy such a small space that this expanding 'force' is negligible compared to other forces like electromagnetism and gravity, and this is why we don't expand over time (we are being 'held together' by these stronger forces), but we are still affected by the effects of the universe's expansion. The more space there is between two objects, the more powerful the expansion effect will be, and the more gravity would be needed to prevent it, so that's why all the galaxies are flying apart (because their gravity is not strong enough to pull themselves together in defiance of the expansion of the universe).

  • another good video

  • with the amount of food i consume and lack of exercise, yes. yes i am

  • I hope that one day my rocket expand, my girlfriend would appreciate it.

  • How could we realize that everything is scaling - including us - if our distance measuring tools do the same?

    • Because if it where so, then we wouldn’t detect any expansion at all, exactly for the reason you suggest.

  • The other day I saw a video that said everything inside space-time is also expanding with it like our Earth but it’s just gravity that is holding us down

  • So, the universe being 93,000,...,000 light years across, with red shift... and giving that there is an upper limit on RF... in the gamma rays area... how do we get gamma rays here to earth that are still gamma rays? ... and not shifted toward xrays...

  • I'm expanding , time for a universal diet plan

  • Yeah i feel expanded too... But i think thats due to quarantine 😂

  • So that’s why am fat

  • 10:52 Thanos Snap

  • You can sell your staff for free through this channel ( Dawn list )

  • If you drive fast enough at a red light in traffic it will have a shorter wavelength and look green so you won’t be running a red light. Though you might get a speeding ticket.

  • YOU MY FRIEND HAVE JUST CONTRADICTED YOURSELF. According to your theory the earth would have to be expanding at 9.81m/s in order for us to experience gravity, which means that the whole universe would have to expand along with it(earth), including us, which means that we are expanding in order to keep up with the size of the earth....

    • The earth is not expanding. He explains what it means to accelerate while standing still in the pinned comment of the gravity video.

  • А почему решили, что смещение спектра - это расширение вселенной? Как много звёзд было проверено? Когда земля отлетает от марса, ведь никто не говорит, что солнечная система расширяется. Так может смещение спектра происходит из-за того, что орбитальная скорость солнца отличается от скорости соседних звёзд, и они разлетаются, как земля и марс? Why did they decide that the spectrum shift is an expansion of the universe? How many stars have been verified? When the earth flies off Mars, nobody says the solar system is expanding. So maybe the spectrum shift is due to the fact that the orbital speed of the sun differs from the speed of neighboring stars, and they scatter like earth and Mars?

  • Are you calling me fat?

  • I have an idea for a video you could make: "Is the conversion rate between Lbs and Kgs a rational number?" - not a simple answer.

  • Let's bioengineer pistol shrimp eyes and give humans 16 cones so we can have our minds blown. What if there is a more-red shift?

  • Is light speed unspendable?

  • For start, isn't it fractal perspective?

  • Welp I guess no wide putin walk in the future

  • Okay, I reckon I got about 50% of that. Anyone do better?

  • No more expand dong man. Now expand man

  • I appreciate the video, but from working with Salesforce at two companies - it's garbage sold upon the hopes and dreams of bean-counters.

  • Sweets and soda are the primary cause for my expansion.

  • The conclusion is don't blame a Big Mac for your expansion

  • The answer is no hijueputa.

  • Is my understanding correct?: All particles that keep the same distance in our universe, would move towards each other in a universe that didn't expand - and all particles that keep the same distance there, would move apart here. Secondly: If you have two particles next to each other and seemingly not moving, how can you know if they are maybe actually moving towards each other but the space between them expands, or they are moving apart and space shrinks in just the amount, so you don't notice? My guess: It has something to do with the constant speed of light and/or "real" acceleration requiring energy while "passive" acceleration by just sitting on the fabric of space doesn't need energy. The expansion of space is often illustrated as a balloon with dots expanding. A balloon actually needs energy to exand, so I guess, that's why you would call that a case of *true* movement *within* constant space while the expanding universe, on a macro level, has galaxies that aren't actually *pushing* each other away, but they seem to, because *space* exands. (Technically, a balloon, that keeps dots at apparently constant distance, is actually slightly pulling them towards each other to make up for the expanding universe. Don't quote me on that - this sounds confusing and is probably wrong. If you don't need energy to move apart, you need energy to stay the same distance.)

  • The doppler shift analogy seems incorrect to me. We cant model the galaxies as merely moving, because that would break conservation of momentum. The explanation for galaxies motion is the expansion of space, only. Its kind of like saying ‘we can model a cars motion as spontaneous, without the engine, see! We still get a change in velocity.” The fact is space is expanding, its not merely relative motion. At a local scale space is also expanding, is in the space your body is in. However at a local scale the energy density of this expansion (provided by dark energy) is far less than the various electromagnetic and gravitational potentials holding your body together, so matter retains its shape. I dont see the link to homogeneity?

  • The comments on new are all idiotic. Dont bother

  • I wondered this exact question when I found out the expanding universe. Thx for doing a video on ir

  • what? i cant wrap my head around the fact that our galaxy moves 600km per sec! It moved of 9776160000km since i was born!

  • may be our biological increase in age is due to this expansion of universe :'-D

  • What about Parallel universe What if there are infinite parallel universe Like every unit of time infinite parallel universe are created....

  • Am I the only guy nerdy enough to say that “not homogeneous” is wrong. Please just say heterogeneous

  • The free falling observer would see the ground approaching all too quickly.

  • My mid-section is absolutely expanding with the universe...

  • So explain to me the missing dogs playing poker Mandela effect!!? lmao maybe to some extent it does happen at a subatomic (brain/ connective consciousness) level in humans? I am not ruling it out. Maybe there is a collective memory which can be changed based on the majority of observers,. What leads me to want to know more in this area is the Mandela effect. Particulairly the painting dogs playing poker... For me there is A missing dog, smoking a cigar, gold and green opaque visor, missing dark dog standing on its hind legs holding (monocle style) glasses and dog with a ruff (1600's style collar) playing poker. ? I would at least like someone to think of where I may have possibly seen it? So strange. To me this explained maybe how some people remember it and some don't but it has never been documented so it never existed? Who knows. Or it was a dream I had.

  • "You won't be torn apart by an expanding universe" The Big Rip Theory: "Yeah, about that.... " I hate the way I seem to be pointing out so many competing theories that this channel flat out ignores.