We can see things moving faster than light

[@garyglad]

I'm curious: why wasn't the Hubble Sphere called the Hubble Bubble? How much toil and trouble would it be to change the name?

[@castleanthrax1833]

I would think the answer to your question would be self evident.

[@Memphio88]

Your wit is wasted here...

[@Lordstephen7813]

Very good ! 🤣

[@mrcryptozoic817]

Easy. Use the correct incantation: "Presto changeo toil and trouble Rollo chunky double bubble"

[@abigailhowe8302]

Gary... I love you XD

[@ScienceAsylum]

6:05 *"The space between two objects can expand such that it moves those objects apart faster than the speed of light."* This is perfectly worded. It acknowledges that it _is_ a speed (distance over time) while still highlighting the difference from what we would normally consider a speed.

[@codemang87]

Kinda like two cars traveling opposite directions at 50 mph each are expanding the distance between them at a rate of 100 mph.

[@prabuddhachatterjee9467]

Hey Science Asylum..want a video of yours on this plzz

[@rdallas81]

No object or mass can travel at or faster than the speed of light. Its Impossible. It would require all the energy in the universe. That is impossible.

[@rdallas81]

@@codemang87 but, they are not going 100. They are going 50. Perspective is not speed.

[@codemang87]

@@rdallas81 indeed. Just like these distant objects appear to be moving faster than the speed of light. They aren't; it just appears so because we are also moving too. You gotta remove our perspective to understand it; hence my car anology.

[@brucecrane9605]

Just when you think you're beginning to understand the universe it humbles you and you've got to rethink everything. Love your videos. Thanks for sharing this knowledge.

[@justignoreme7725]

I was wondering why is the Universe only expanding outward? Away from each other? Why can't it contract or ossilate or interact so that it orbits each other??

[@NickRoman]

@@justignoreme7725 , I don't think there's anything that says that it can't, only that it isn't. They don't really know why space is expanding. So, they call the force that is causing it, dark energy. Dark because we can't see/tell what it is.

[@justignoreme7725]

@@NickRoman so is it that we can only measure movement in one direction and that we are incapable of measuring in any other direction or is it we are capable of measuring movement in all directions but can detect movement in one axis??

[@timjohnson979]

@@justignoreme7725 No. It's that in whatever direction we look, the universe is expanding; same rate in all directions.

[@NickRoman]

@@timjohnson979 , yes and with the distances we're talking about, I think we really can only measure in one direction. That is, we can't tell if two very distant galaxies are moving laterally with respect to each other. Look into how we know how far away things are to understand that. There are several ways, each depending on how much distance we're talking about. It's an interesting subject and methods get refined over time.

[@justinanderson267]

Damn I think I actually understood that. It's a bit like a car moving north at 60mph and you jump off south. Even though you jump south, you're still going north. Same thing with the light. It leaves the distant object still moving away from us, but eventually it works it's way to moving toward us at the speed of light

[@AleyCZ]

The difference is people can watch and see your jump, regardless how fast is the car moving. ;-)

[@MrTrevortxeartxe]

I think its more like you jumped off when the car was still going 10mph, and by the time you ran back to us, the car was going 60mph, and it was much further away.

[@arturama8581]

@@MrTrevortxeartxe And there's another difference. If the car is moving 10mph North and you jump off going 15mph South, you only have a Southward speed of 5mph the moment you leave the car. If light leaves an object doing lightspeed going 'North', the light travelling 'South' is doing it at lightspeed, no matter the opposite direction of the body it came from.

[@nargileh1]

Nope think about it as the road stretching out, not the car moving. The car moving has no impact on the foton's speed, they always travel lightspeed Imagine you keep jumping, every jump takes some time T, if during that time the remaining distance has increased by more than your jump distance, you'll never make it. This is creates the dividing line between the observable and unobservable universe.

[@physicsgirl]

I wanted to call this series "In here 🧠 Out there 🌿"

[@0xMN]

I love this series. Something for the brain, something for the eyes and something for the heart ;)

[@nadamuchu]

I'm still not clear why you called the path of the light a boomerang motion? I understand the concept of it appearing to stop due to the expansion of space but doesn't a boomerang return to its origin?

[@wookidoo]

"In here brain Out there asparagus"? 😂

[@CSpottsGaming]

@@nadamuchu In this case it isn't that the object (in this case, a photon) is returning to its origin, just that it's sort of turning around. It starts out moving toward us relative to its origin, but away from us relative to our frame of reference (because the space between us and the photon's emitter is expanding faster than the light is moving through it). Eventually that boundary catches up to the photon, though. When that happens, the space between the photon and Earth is no longer expanding faster than the photon is moving, so it can actually make progress toward reaching Earth. If we could view that photon in real time, we would suddenly see it go from moving very slowly away from us to briefly appearing to stop, to then moving very slowly toward us. It's a bit like the photon is a person swimming upstream in a powerful current, but the current is getting weaker over time. Initially the stream is too strong, and the person is swept away but over time as they swim the current weakens until eventually the person can overcome the force of the water and start making progress upstream.

[@jopauljoy7728]

Will time get slower if the space is expanded? How would that affect speed of light?

[@upandatom]

Your editor sounds really smart

[@username3543]

Lol

[@Bleeto]

I guess?

[@ravijangrax]

Hey! Up and atom I think I learned the similar concept from one of your video. Where you talked about why sky is dark at night despite having so much stars.

[@afwaller]

Love your channel. One of the best on youtube!

[@Undaglibenglaubengloben]

Well he had no clue about the expansion of space time so….

[@mbackmsn1510]

I am currently attending school at south Albany highschool in Oregon, I was told by my physics 2 teacher mrs.Jones that this girl went to the same highschool and was taught by the same instructor. It’s great to know I have such an amazing physics teacher who can mold minds as great as the one we see in this video!

[@iz6962]

I love everything space related and the way you put it for us not so smart folks is just great! Keep doing what you’re doing. Ps. How can I steal your editors job?! I would LOVE to learn on the job lol

[@MrTrevortxeartxe]

You can help support her on her Patreon page, shes sick and not doing well you know.

[@wecantry4393]

Just imagine the wonders and poetry of deep space . No limitations. As Stephen hawking once said " There should be no boundaries to human endeavor. We are all different. However bad life may seem, there is always something you can do, and succeed at. While there's life, there is hope."

[@Rick_Cleland]

My life has been a complete and total misery ever since Bigfoot stole my precious girlfriend in the middle of the night.😒 He even took all her clothes and the T.V.

[@TheMightyZwom]

And as we all know: "Life... erm... finds a way."

[@baneverything5580]

Twitter will someday find this comment to be VERY offensive and you`ll be in big trouble!

[@reactionisst]

The concept of light traveling towards us while also moving away from us as space expands reminds me of trying to walk the opposite way on an escalator...although I'm sure it's quite a bit more complicated than that analogy, if I understood anything from this video

[@SoWAHHHT]

just add some acceleration to your walking in the opposite direction since space expands less as you move closer

[@avasam06]

I used a similar analogy by swimming up a river

[@papalouis9111]

@@SoWAHHHT well I guess the deceleration of the escalator as you move down it, would be more accurate

[@FrarmerFrank]

You can walk the opposite way on a escalator by walking faster then the escalator Thats the flaw with the "Universe is expanding faster then light" thing......light would never reach us from such objects as we wouldnt be stationary in an expanding universes Either (it e 64 billion light years away and a "blank" spot not decernable from empty space) 13.8 billion years would be a late 80's-early 90's Astrophysics/Cosmology/Theology text book......mostly thumped on not actually read (My professors favorite discussion was turning a sack of potatoes into a Universe,never had us open the textbook once, just told us what was in there😶)

[@icosthop9998]

@@FrarmerFrank So you're saying this girl is wrong ❔️❓️❔️

[@neurotransmissions]

Wait, so does that mean that, even if it were possible, we would never be able to see the “edge” of the universe because it’s moving away faster than the speed of light? Or am I misunderstanding?

[@stuntmonkey00]

Yes, that is correct. Eventually, far far in the future the amount of stuff that we can "see" will actually grow less and less over time because everything is so spread out. Talking like, long after the sun explodes kind of time scale though.

[@physicsgirl]

Depends what you mean by the "edge" of the universe. If you're talking about the edge of the theoretically "observable universe," well WHOOEE it gets complicated. - We can't see that edge because the universe was opaque to light at the very beginning. - But we can see pretty close (that's the cosmic microwave background light). With the CMB, we're seeing the universe as was about 13.7 billion years ago. If you're asking about the edge of the WHOLE universe, we don't even know if there is an "edge." But if there were, and it were beyond the observable universe, then we'll never see it as it is now.

[@carpemkarzi]

As the rest have said..yep. Love it.

[@mltorrefranca]

Might not even be an edge. One possible model is the Universe is like the surface of an expanding balloon. Not the interior volume where the balloon surface is the edge, but the surface where if you went along far enough, you might circle back like going around a globe.

[@НиколайХанзо]

warp drive.

[@lonjohnson5161]

During the ad, she says that I probably have a 3M product in arms reach. Since I'm physically at 3M Center (I work here) this is absolutely true.

[@Variety_Pack]

I looked at my Command Strips and grimaced.

[@MarylandFarmer.]

You guys make some great stuff with quality that's hard to beat!

[@iwantitpaintedblack]

can i get some retroreflector tape? .)

[@doomforge11]

I love how passionate and excited you are about all of this stuff, it is absolutely infectious and your videos are always a joy to watch.

[@anntakamaki1960]

The Earth is flat! There is no proof that the Earth is round and NASA is an anti religious organisation so don’t listen to them. Even Russian are atheist organisation, so you can’t trust them.

[@jchinckley]

@@anntakamaki1960 The Earth isn't flat--it's concave. We live on the inside of a spheroid and the sky is only an illusion at the center of everything... tfic.

[@Damian-ek5lz]

I live in Argentina. My 10 year old daughter loved your video but she relied on my translation to understand it. You should make a channel with a Spanish translator in the audio. You would capture many children and adolescents in these latitudes. You have a great way to spread science. Keep it up.

[@counterproductivity]

Closed captioning perhaps? But KZbin ... The captioning can be very inaccurate. Much like, say, Google translations are often inaccurate. This is 2022, where's my jetpack? Oh wait, that's right, we can't even get our own spoken words to come out correctly, nevermind something useful like major planet wide languages to be supported here on you tube... Seems what you've had to do, translate it yourself, is about as good as we can do. I think your idea would serve well the needs of English as second language speakers of the world. Til then, I'm just gonna wait around til the future gets here... Maybe then, we can work out the kinks of more accessable media options... And jetpacks!

[@anthonystark5412]

This has just become my "go-to" method for persuading people that I'm smart. Great video; clearly explained; with good use of props and diagrams to illustrate potentially confusing concepts. 5 STARS! Sorry, I couldn't help myself. Granting stars on an astrophysics or cosmology video is empowering.

[@saltycreole2673]

The smartest person I ever met said little to nothing..., just saying.

[@dragonman101]

It's cool you couldn't help out. You have more important things to do. Like giving birth to Tony :)

[@francispalmer9737]

It's great to see your excitement when talking about cosmology , I see it in you and I know how you feel, I am 57 years old and have been into Science, cosmology and space since I was very young after seeing the Moon landings that was the spark for me. It is a lonely subject to be into because in all my years I have had very few deep conversations about cosmology and when you meet someone who wants to listen I just feel like I can't get it all out with the excitement. I still think and watch about cosmology, Science and space every day and am still as excited like you about it all.

[@moonshiner2977]

seeing is one thing believing is another :)

[@mybleachhouse]

I was talking to a guy who told me his onewheel had a malfunction causing him to nosedive and crash. I mentioned it could have been caused by a cosmic ray from a quasar or gamma ray burst billions of light years away in the far distant past. The conversation instantly went awkward and quickly ended lol. Your plight must be common.

[@johnchessant3012]

Fun fact: If the universe was expanding at a constant rate instead of an accelerating rate, then there would be no event horizon; light from every object would eventually reach us. This is called the "ant on the rubber rope" puzzle

[@koulster2]

Thank you John.

[@michaelwachendorf2096]

Wouldn't we have a big crunch as well?

[@GTAVictor9128]

@@michaelwachendorf2096 Plausibly yes.

[@pillarmenn1936]

@@michaelwachendorf2096 we should in theory, that is if dark energy decreases over time then gravity will eventually become dominant again

[@konstantinkh]

@@michaelwachendorf2096 Not necessarily. Hypothetically, you could balance matter and dark energy so that universe forever expands at a constant rate. I don't know if that'd be a stable equilibrium, but if it was attainable, things would forever recede at superluminal speeds, and from any point and any time, light would _eventually_ reach us. But if the expansion is accelerating, even just a little bit, an event horizon is formed, and that appears to be the real case of our universe.

[@res00xua]

Thanks!

[@anotherhardcase]

I ABSOLUTELY LOVE YOU YOUR CONTENT!!!! and so does my granddaughter!!! She’s 5 and we love doing your experiments at home. YOU ROCK!!!

[@nominalnostalgia1347]

My favorite thing in the world is when old people type on caps on the internet. Its this really weird cultural phenomenon. But like its very pervasive. I wonder if we can track the reason and inception.

[@kennyj4366]

@@nominalnostalgia1347 One reason could be eyesight difficulties. Don't let the small things distract you brother.

[@raincheck5892]

@@nominalnostalgia1347 With enough counseling/therapy you’ll eventually be able to move forward in your life… it’ll just take some time (lots of time in your case)

[@stanimirborov3765]

@@nominalnostalgia1347 ъеааyeaaaaaaaaaaaaaaaaaa

[@stanimirborov3765]

@@raincheck5892 eeeey that didnt sound nice

[@AlEbnereza]

Mr. Editor: you didn’t give her the slide transition! Awwwww.

[@physicsgirl]

We had a good laugh at this. Sometimes we leave things that make us laugh hoping someone else will laugh, but knowing they'll probably just think it's awkward.

[@MeppyMan]

@@physicsgirl can we laugh and think it’s awkward? Awkward isn’t necessarily bad :)

[@derryberry16]

@@physicsgirl It was so awkward but cute too. It gives your videos it's own character. It's why we keep coming back to you!! Keep it up, Dianna!!

[@hadishstreet3066]

@@physicsgirl I found it hilarious

[@YuriAnderson1]

He should have given you a more elaborated transition then a slide one.

[@VallisYT]

Zooms like the one at 0:28 never fail to give me goose bumps. It is astonishing that by simply looking into the depths of the sky we can reconstruct the history of the earth and the whole (expanding) universe. Truly awe-inspiring.

[@Rick_Cleland]

@@youngmom5586 🤬🤬🤬

[@IanGrams]

@@Rick_Cleland it's a spambot, please just report it as spam or explicit content.

[@JTheMelon]

@@IanGrams 🤬🤬🤬

[@prototropo]

@@IanGrams I thought she was trying to represent space expanding so fast between her words that strange, new matter began popping up in our view . . . maybe I’m over-imagining things?

[@IanGrams]

@@JTheMelon er, what? Are you upset I asked someone to report spam?

[@jpmendozajp]

She’s so passionate about what she is explaining; I love it.

[@smnbrgss]

I'd love to go on a hike deep in the woods while getting deep into conversations

[@ypey1]

Its kind of cringe as well indunno feels like a quirky act

[@wvufo]

yes! I listen to her cause shes filled with joy when she's teaching it.

[@fredwerza3478]

Just imagine being at a campfire where she is explaining all this confusing physics stuff

[@seanwatts8342]

@@ypey1 You're right, it's acting. NOT that she doesn't get it but the channel is a commercial business.

[@erictaylor5462]

5:30 There once was a girl who was bright She could travel much faster than light She set off one day, in a relative way And returned the previous night. Perhaps the bright girl was Physics Girl.

[@SpaceTim-sr9lf]

For the light that moves away from us and then back toward us, I'm imagining photons running at a constant speed on a treadmill that slows down over time.

[@austinjames1368]

11:02 I find it especially touching that Diana appears to value the camera more than physics demonstrations and, possibly, her editor...

[@mpd2101]

Really well presented in an accessible and understandable way, even if my poor brain was hanging onto comprehension by its fingernails! 🤯Thank you for a great video

[@cubertmiso]

Please watch the older version of the cosmos with carl sagan. It has much more neatly packed information bits. This is just 3-4 times telling the same thing over and over to make youtube algo happy.

[@ggoddkkiller1342]

I have say she explained this terribly, bumerang really? Light's direction never changes rather universe is expanding slower and slower as the light is traveling so it eventually reaches us, it is like swimming against current that there is higher slope at the edge of observable universe so current is very strong. But still it isn't higher than light speed so it keeps traveling up the current and the slope decreases more and more so light travels faster even if the actual speed of light never changes. So even if actual speed difference between Earth and an galaxy at the edge of observeable universe is 3 times higher than light speed there is actually nothing moving faster than light speed rather current becomes longer as it is expanding in every point not just around that galaxy..

[@brianscott5153]

Love your work. It's rare that someone like yourself is charismatic and devoted towards higher learning. Very cool.

[@gregheavlin2430]

I miss her regular videos. Get well soon physics girl! The world is praying for you

[@LeoAngora]

This is the first time ever I hear a physicist saying that engineers are the best scientists. THANKS 3M!

[@Dylon1981]

Sheldon Cooper will tear you apart if you do not retract your comment.

[@isaacstone7899]

That’s true because they solve problems than to believe without prove.

[@bobtom2633]

That's because they're a terrible physicist.

[@Dylon1981]

@@isaacstone7899 in defense ofPhysicists, they prove with their mathematical computations to back up their theories. As an Engineer myself, i feel insultated whenever Sheldon belittle Engineers... But i like the comedy of the show. Computations and theories are for scientists. Engineers put them to actual.

[@RBsRealm]

@@Dylon1981 both are less without the other. Thereby neither is better.

[@yajmsdepseudo]

4:38 The Scotchlite is vastly used in motion capture because MotionCap camera takes profit of this specific property to reflect the light in the opposite direction. that's why they have multiple infrared LED around the camera.

[@physicsgirl]

I didn't know that! The retroflection is also all over street signs. I always wondered why they appear rainbowy sometimes, and now I know.

[@inshadowz]

​@@physicsgirl Also used as an effect prop in the 1982 movie TRON to make a (real life) helicopter appear computergraphicsy (although it's just referenced as 3M reflective tape). From what I can tell it was the first movie to do so.

[@dogguyful]

@@physicsgirl Copernicus was wrong. You are the center of my universe. According to Newton’s law of universal gravitation, If I’m attracted to you, then you’re attracted to me. I’d really like to study this heavenly body😉😉😍😍😁😁

[@robbie9706]

Even though I’m in nursing school right now pursuing my BSN, I love science and more specifically astronomy. The size of the observable universe is truly beyond amazing 🤩

[@MH-nc5jd]

Two things about the universe always get me thinking.. 1st is how small we truly are compared to everything we can see out there.. and 2nd is our place in time, is this 13.4 billion years at the beginning or end of the past 100 trillion years?.. 13.4 billion is such a small number relatively speaking, so where in time are we?. or did time cease to exist before this big bang.. and if so, how long did that last, lol..

[@ebo1983]

@@MH-nc5jd if time had ceased, how could that 'timeless' period last for any period of time?

[@danielsiebert5714]

I’m a huge fan of all things science and Physics Girl. She’s a great science communicator and I look forward to watching her career unfold over the coming years. Live long and prosper.

[@MrTrevortxeartxe]

You know her current situation?

[@daviddefortier5970]

This is such a sad comment to see after what happened to her.

[@do_d_dola_d_dan5105]

I love that sometimes it feels like I'm learning things at the same time as you and that you get as excited about it as I do.

[@wrangler0829]

My brain had a hard time understanding the vastness of our universe. I love how you genuinely get excited talking about this topic!

[@EricBurbeck]

Fantastic video, thanks! I think a more complex graphic would have been really helpful in describing the travel of light from beyond the Hubble sphere - my mind is still trying to put it together!

[@sebastiandierks7919]

Thanks for the great explanation! Something which always bended my mind. I would love a follow-up, where you explain how during a Big Rip, one of the horizons gets closer until light from even say Andromeda wouldn't reach us anymore, while the observable universe still gets larger as time since the Big Bang increases. I'm still a bit confused about that, how that works.

[@fahimabrar3992]

Sometimes I wanna cry feeling how little I know. We feel lucky to get such a mentor like you @Physics Girl.

[@ApexHerbivore]

You probably know more than me about something :)

[@ahoksbergen]

pay attention in the science and math classes. of course, it could be too late at this point. u must accept indoctrination, which in itself will lower your IQ, before you will be taught some truths. i feel sorry for yall, because the one thing all these commies wont tell you is that there is a Creator. He not only creates, He stretches space. So, knowing that you'll also know that there no such thing as extra-terrestrial visitations, because living things cant cross the firmament..He lets you see very far, but we cant go there.

[@ApexHerbivore]

@@ahoksbergen *cough BS cough*

[@chrisvesy7245]

Thank you!! I've been trying to comprehend this Astronomical stuff for decades...you just explained it in a way I can grasp! I'll watch again several times because I'm getting older & my brain doesn't retain knowledge like it used to...😎

[@princessbuttercup8954]

Signed my kids up for STEM classes and we had so much fun making chemical clocks and elephant toothpaste last weekend. Can't wait for the next one. I love seeing the excitement in my kid's eyes when they get their kits in the mail.

[@gallowglass719]

Thanks for doing stuff like this for your kids. My parents did the same thing and it's part of the reason why I'm pursuing a career in physics.

[@jamarjames9501]

How do you sign up for this and how much does it cost? I'm on a budget bUt my daughter and I enjoy home projects so depending on how expensive it is I will find a way lol. We watched videos on elephant toothpaste and she loves it. If I make one more bowl of slime I will go crazy.

[@williamthomas1298]

Physics Girl, you are awesome! Thank you for making complex physics understandable. One question, if we are at the center of the observable universe then where is the actual center of the universe and is there anything there if everything is expanding away from that point? Sincerely, Dr. B.

[@kirkjamison4520]

I went to her KZbin channel a couple days a go and there was a post saying she's dealing with long covid. It bummed me out.

[@NookoftheNorth]

Try PBS spacetime as a companion series

[@waqasusmans]

"where is the actual center of the universe" I don't think anyone knows where the center of the actual universe is, because we don't even know how big the universe is.

[@nettewilson5926]

Every point is the center and no point I the center. Think of the surface of a ball if the ball expands. The universe is like that

[@CARBON10]

Off course we are at the center of the observable universe, we set the boundary, but due to the vastness of the actual universe there is no centre at all .... And definitely not one we could ever ever find Think

[@fleurbird]

I've seen so many videos on this topic. And it still melts my mind

[@Michael_Michaels]

For the first time in my KZbin activity, I watched a sponsor time in its entirety! That new 3M tape is actually pretty awesome! About the video itself, amazing content as always! Mind-bending science always amazes me! Thank you!

[@SpydersByte]

haha yea same, its such a weird sponsor but it works great for this channel :D and the tech in that tape is really cool

[@NolePTR]

9:20 I've been doing some pondering and thinking of it as velocity rather than displacement makes a lot more sense. The Hubble sphere is moving away faster than the light is moving away. Once the hubble sphere overtakes the photon, then the displacement starts decreasing.

[@JTuaim]

If you're at an opposing side of the Hubble sphere it would appear that the opposite side is moving at twice the speed of light? Everything is relative, so how do we really know how fast anything is moving? We could be moving at a million times the speed of light collectively and never know it.

[@djksfhakhaks]

Hope everything is getting better!!!!

[@Dave-Huston-Dublin]

Very well put together, Thanks Dianna.

[@Macakiux]

Last week I read that GN-z11 wasn't the gamma rays burst that got us into thinking it was the most distant galaxy. It could have been sunlight reflected on a russian rocket :(

[@tbbbtoolsbooksbladebones556]

Trust me mate, you're better off being a human than a sunlight.

[@_BangDroid_]

@@tbbbtoolsbooksbladebones556 I disagree. Being human is both a blessing and a curse. Whereas being sunlight is only a blessing

[@sajidrafique375]

@@_BangDroid_ Being sunlight is neither blessing nor a curse ..lol

[@sajidrafique375]

@@tbbbtoolsbooksbladebones556 Dont punish him for a typo ... lol

[@tbbbtoolsbooksbladebones556]

@@sajidrafique375 I didn't do anything🦋😇

[@peteketners5939]

I really enjoy your videos and the fresh look at physics they provide. You're like the 'Taryn Southern' of the physics world.

[@krucible1]

And in another mind blowing concept, every object in the universe has it's own "Hubble sphere". All those photons reaching every other galaxy/star system/planet/molecule that make their way into every other "Hubble sphere" will eventually reach those objects. The light wave doesn't change, just the perception of it and its travel time/distance from every view point it seems. Don't know if that all makes sense.

[@itisimatadvc]

@gilbert Godfrey, you can have a like just for the last comment you made about the cigar lol

[@danielkushner5963]

This format is really great, you should do more of it!

[@AlanSizzlerKistler]

I appreciate this video a lot. When I think of the light of stars and galaxies taking so long to reach us, so long that they may no longer be here, it sometimes feels like looking at the ghosts of the universe.

[@Fwootgummi]

It makes me kinda sad. Theoretically we could see those galaxies and stars but never know much about it. If that galaxy contained life we'd never know, and to other galaxies that far away our fate will eventually be the same. If there's life out all the way out there, either now our billions of years from now, we would never know each other existed.

[@francoisdoucet6468]

I'm just going to watch your videos again. I've always enjoyed learning from you. Rest as much as you need but please don't quit. I'm sending good vibes your way. ♥

[@MrWilsonsChannel]

Does each planet in the universe have its own hubble sphere? In other words, if we were on a distant planet outside of Earth's Hubble sphere, would Earth appear to be the one that was moving away faster than the speed of light?

[@imissfreedom3952]

Yea. What he said.

[@JustinShaedo]

Yes. Yes, each location in the universe has its own Hubble Sphere. Yes, each one is also called aHubble Sphere as the term describes the area surrounding a point/object in which things are not moving away faster than the speed of light. A Hubble sphere is the same size for all points/areas (as far as we know) and whilst it's based on a constant, its now looking like the universe's expansion is increasing, so the Hubble Sphere (volume) is expanding (probably), whilst the observable universe is expanding too!

[@JS-xi5nk]

@@JustinShaedo that is only theory. Not a proven fact. Nearly everything "known" about space is only theory.

[@Concrete1998]

@@JS-xi5nk The English definition of "theory" and the scientific definition of "theory" are VERY different. Just because you have a 'theory' of relativity doesn't mean it can't be proven factual. "theory" =/= non-factual

[@JS-xi5nk]

@Concrete1998 I'm not saying it can't be proven as fact. I'm merely stating it is theory/"speculation" until it is proven to be fact.

[@SPHYNX99752]

Due to the constraints of measurement in regards to light and time, we are always looking into the past because, everything you see when you see it, is not where it was when it emitted or reflected the light that allows its visible presence to be detected.

[@avidnongetit8710]

Sounds like you're a philosopher-scientist... Also reminds me of my Marijuana use decades ago... Hopefully like me we all move forward in a Significantly positive manner.. if we survive as a species we will attain use of gravitational force to move faster than light while not violating Einstein's special relativity.

[@rylian21]

I wish I had nerdy friends like this to hike with while talking about crazy physics.

[@reflectcard6258]

Mine doensn't even like hiking

[@BrentHollett]

I always liked the example of walking on a travelator (flat escalator). You can only move along the travelator at the speed of light, but the fact that it itself is moving, means the sum total is moving faster away from the start point.

[@BadgersEscape]

This was an extremely beginner-friendly take on a very unintuitive topic. This kind of stuff has always fascinated me, but trying to explain it to all my friends is hard. Thank you for creating a better presentation of it than I have managed to do! :)

[@EthanShalev]

Besides having 3m products within arm's reach, all of us have some 3m products inside our bodies. Forever. Thanks Dupont!

[@Minox_]

Yay for forever chemicals being so in everything that the only place they could find blood for their "clean blood control group" WITHOUT PFAS IN IT was blood that was taken from people before 1951!

[@cybrfriends5089]

I was having mixed feelings about 3M sponsoring this great video. While they are poisoning humanity.

[@ben-lopez]

Pretty sure this is why they wanted to get sponsored by a KZbinr. Ever since John Oliver smeared them, they're trying to get into ppl's good side... Not gonna happen 3M! We wont' forget!

[@davesutherland1864]

You state that the Hubble sphere increases in size and that means we see more. However, I understand that while the Hubble sphere increases, more and more of the galaxies are actually outside of it and that means we see less. (We might have more space to observe, but it has less in it). In the distance past I believe that the Hubble sphere, the comic event horizon and the limit of the observable universe were all the same. All that stuff between the observable universe and the cosmic event horizon were once emitting light we could observe, but now they don't because they are moving too fast. Therefore there is less we can see.

[@charlesshreeve319]

FYI, the comic event horizon is where Dave Chappelle's comedy crosses over into the woke sphere....

[@Suko120]

yea, that confused me too. Astrophysicists said that we see less and less galaxies and they predict that in the distant future we might only see stars from our own galaxy because all the other galaxies left the hubbles sphere.

[@BurtTMacklin-fbi]

@@Suko120 Same. I actually found this video to be poorly done. It's a spastic brain dump of thoughts rather than a scripted video with some effort behind it.

[@faustoefulvio]

@@BurtTMacklin-fbi pretty much

[@benjaminfranklinkivettiv9433]

This is the best explanation i have ever heard. You make it easier to understand. I miss you. We need you back Dianna so you can teach us more!! Hope your doing well!!

[@chrisr4482]

You're amazing! I can't get enough of your content.

[@AjmerPhull]

Thank you. You really did explain this well, much better than most, not to take anything away from all the other great content creators. Mind blown.

[@neoanderson7]

Always learn something great from Dianna! 🤯👏🏻

[@sierramantrvlnus]

Much love and positive energy to you!

[@peterjamesfoote3964]

I love it when you blow my mind. Going to have to watch this again but it’s filled with fascinating concepts.

[@louisloudogtrottier3310]

Love this video format, You look genuine and feel like your taking to a friend, and you look amazing no matter what.

[@justignoreme7725]

Why is it important that she look amazing? Does hetronormativity help with the acquisition of knowledge? I ask because whilst I am also female I'm not pretty or attractive guys have never chatted me up the way other girls had to deal with. Would I be considered more suitable to only do voice over not appear in front of a camera. This is really important, it might be sexist but when the aim is to communicate knowledge the utilitarian viewpoint might be my not appearing on camera is the better option no matter what it does to my personal ego?

[@publiclyshamed5383]

@Just IgnoreMe Don’t get too wrapped up in the importance of looks. Personality goes a long way. Live your truth and let the world sort out their own reaction.

[@chrisroberts5355]

Thank you. I discussed this concept with a physics teacher over 50 years ago. My simplistic way of looking at the expansion of the universe was to compare it with a rocket/firework explosion, everything flying away in all directions. My question was, if the light from a star traveling at close to the speed of light is being 'pushed' by the expansion, wouldn't it have to exceed the speed of light?

[@drf4270]

No, because i's moving relative to the star. Even if the star is supposedly moving faster than light, the light it emits still travels at the speed of light, relative to it. If there was a tertiary obeserver, both the star and its vectored away from the observer move faster than light. But that doesn't really mean anything as it wouldn't be observable. I think...it's the only way I can get it to make sense.

[@ReadABookAndLearn]

Think of raisins in a loaf of bread that’s baking/rising. Or dots on a balloon that’s being inflated. Those work as good analogies.

[@leoncampagna6933]

​@@drf4270 I know the Michelson-Morley experiment says there's no luminous aether, but I still look at space as such. That's the only way I can wrap my head around it. I kind of think Michelson & Morley forgot to look up, and gravity is that aetherial wind they were looking for. It make sense, if you imagine mass is constantly consuming the aether at it's location. While at the same time the universe is getting aether added to it uniformly from an outside source. There's a flow like a cosmic rainmaker, if you will. Trickling through the dimensions.

[@FrarmerFrank]

Because we would be moving away from the the light coming towards us in the opposite direction faster then light (you are not supposed to use your brains in college, how dare you) Yes, those who dont ask questions remain static Static is for faith and philosiphy,not science

[@zaggo3425]

@@drf4270 I think you're right, the star and the light would only *technically* be moving at the speed of light if you used a speedometer while stationary in the void of space. The star won't be pushed to FTL by the space, because if the star was stationary and the space was expanding, the star would still take up the same space as it did before. but that space would be in a different spot because of the universe's expansion. So the only thing moving at FTL in that situation would be the space itself, not the star.

[@Jim-he4km]

I hope you see this, get well soon we miss you!!!!!

[@BlueSkyBonsai]

1 hour and 333 comments already 👍🏻 loved this video 😍

[@priyanshugandhi2123]

Now this is ''the physics girl'' I wanted to watch!

[@RonBest]

Perfect. This mean we can radio out insults to planets between the hubble and the event horizon, and if there is intelligent life, they will never be able to retaliate nor send insults back that we can recieve. Earth: 1 - Aliens: 0 Unless they already did the same to us.

[@StraightShooter01]

Love the way your mind works - just awesome - lol

[@ritzzzblitzz6833]

If they are more super advanced than us, then we are doomed.

[@aqynbc]

Cannot wait to see you again Dianna explaining the wonders of our world! Hope you feel better very very soon...at the speed of light of course!! ❤💛💚

[@xkgbciax5286]

"You've never heard of the Millennium Falcon?…It's the ship that made the Kessel Run in less than twelve parsecs."

[@timhallas4275]

So, what's a parsec? and how far is the Kessel run in miles?

[@m1k1254]

you made me snort xD

[@fredwerza3478]

They made a whole movie about the Kessel Run

[@bistromathics6]

That was such an enjoyable conversation, thanks for sharing it with us!

[@iampuzzleman282]

Awesome scenery

[@adriangabrielgramada1016]

Lovely everything :) Explanations and the whole vibe / setup :)

[@nelsonarmor]

Wow, You just made the LED light in my head go on! Thank you Physics Girl. You helped me understand the relationship between observed distance based on light speed travel time and the adjusted distance based on the expansion! Cool video! (Yes, 6 months late in responding but I just discovered you on KZbin). Catching up. (I think I may understand that Cosmic Event Horizon now: The Hubble Sphere is like a faster “shock wave” overtaking the slower “shock wave” of the CEH yet never catching up with it, yielding the effect of light in the CEH appearing to move away initially but eventually appearing to move towards us? Is that a change in the red shift? Or am I way off the mark?

[@SaMiNM]

Assuming a spaceship leaves earth at 0.9C velocity relative to earth travelling away from us into outerspace, will there be a point in time where the relative speed of the spacecraft with respect to the earth be greater than the speed of light ?

[@sarahscott5305]

Yep. But it'll take billions of years to get there.

[@toadehadrian2804]

I think that's the point of no return

[@vshah1010]

No, nothing can move at the speed of light or faster than the speed of light.

[@jolan_tru]

@@vshah1010 The spacecraft wouldn't be moving faster than c, but the distance between us and the spacecraft would be getting bigger at a rate faster than if the spacecraft was traveling FTL.

[@basildaoust2821]

OK, I think I might have understood some of that :) I like how you ended saying what I said only is valid outside of a galaxy. I also love how things like 97% of things are moving away yet they still manage to collide. You would think that the Galaxies would have enough room to not collide with a second galaxy.

[@robertnewhart3547]

She mentioned that gravity is strong enough to overcome spacetime expansion. So for local superclusters it essentially isn't expanding.

[@Honorablebenaiaha]

She is horrible at explaining this, check out David Butlers channel, he explains so much better.

[@adrianbundy3249]

And here's the kicker. The fringes on the outside of that 97%? Yeah, everyday there is probably one thing that has moved away from us, that we can't see anymore. And we will never be able to see again. Most of that though, we can't see. It is far out, and we are still developing astrological tools to view them! We have perhaps lost much that we don't know we didn't see. As she said, we don't know how big it really is, not truly.

[@basildaoust2821]

@@adrianbundy3249 It is so big we can't even figure it out and the best part is that tiny big bag happened EVERYWHERE even where we can't see.

[@goahnary]

Crazy thing is about that though is when galaxies "collide" most of it will not actually collide because most of the galaxy is empty space! The two galaxies pass through eachother only significantly interacting through the gravitational pull of the objects inside them. 90% (which is just a number I made up but it's on that order of magnitude) of the matter is not affected at all.

[@pepperandzip]

Listening to you and watching your videos are just so captivating

[@DhaoistAzazel]

I've wondered this, thanks for explaining in greater detail than my thought!

[@blademaker4263]

Outer space is so terrifying and mind blowimg at the same time.

[@robadams5799]

When I was about ten years old, I was looking up at the night sky with my older brother. He told me that some of the stars in the sky might not be there anymore. They're gone, but their light is still reaching us. Mind. Blown.

[@vyor8837]

Ya, not quite. The human eye can't see that far. That light you see is only a few hundred years old at most.

[@robadams5799]

@@vyor8837 why couldn't I have been looking at a star only 50 light years away?

[@vyor8837]

@@robadams5799 so light that's been traveling for 50 years?

[@robadams5799]

@@vyor8837 yes, exactly. What is it we're not on the same page with?

[@vyor8837]

@@robadams5799 do you think those stars would die in 50 years?

[@TheSmileyTek]

Ran across this video from a couple years ago. Please recover quickly! Looking forward to your full recovery.

[@davidbrooks187]

Loving the discussions on the expansion theory, relativity & space time. Keep up the great work 🌟

[@rajveerkanojiya2985]

For gnz11 we are moving faster than the speed of light isn't it 🤔

[@mattkellerman5038]

Soooo. Yeah. I’m going to need a deep dive on the whole “light makes unassisted u-turns” bit.

[@p.io7]

Yeah that U-turn theory is probably just a misunderstanding...if the light cannot approach us because of the space expanding faster, then I don't see how that light could reach us at all.

[@kenh9508]

I wish I could go to a planetarium and you were the one doing the presentation.

[@tomikola1864]

Subscribed. Thanks for these fascinating content.

[@SUPERHA2IQ]

Nobody: Dianna: imma just hike to a random location with my friend while talking about the wonders of the expanding universe

[@MrPDawes]

My kind of floor play

[@Xiph1980]

Everything in space is remote, so it makes sense to be somewhere remote.... 🤔😂

[@LeCharles07]

"The clearest way into the Universe is through a forest wilderness." - John Muir

[@tbbbtoolsbooksbladebones556]

”You shall not pass!” - Gandalf

[@jchinckley]

@@tbbbtoolsbooksbladebones556 So now we as a species are relegated to the status of a Balrog... seems legit.

[@tbbbtoolsbooksbladebones556]

@@jchinckley Are you legit?

[@jchinckley]

@@tbbbtoolsbooksbladebones556 I am no Balrog. I'd probably be Tom Bombadil. I guess that's legit.

[@seanc6128]

I have a roll of that reflective tape within reach actually.

[@fery-socials]

Discovered this channel today and it has to be the single best channel on all of youtube! I have HOURS ahead of me to catch up.

[@mhansl]

It is truly a wonderful channel. Here's to hoping Diana gets better.

[@anjelicay9687]

Wait, how can light be travelling away from us to start, then travel toward us as the universe expands? If the universe is expanding, shouldn't the space that the light occupies be moving away from us? So shouldn't the light be moving away from us even quicker than before?

[@StraightShooter01]

Because the light heading toward us isnt treading a fixed rate of expansion, as it moves closer, space expansion slows down - light itself isnt actually speeding up - it is constant - the variable is the rate of space expansion.

[@luciobaggio8695]

@@StraightShooter01 But it does NOT move closer, because the space is receding faster than light (that's the definition of Hubble sphere). What gets out of the Hubble sphere, stays out the Hubble sphere. The whole second part of the video does make little sense, unless you imply also that the universe expansion is slowing down. In that case, when it slows down enough, the space traversed by the light will be expanding slower than the speed of light: only then the light will start moving closer to us. In other words, the Hubble sphere is contracting only in a decelerating universe. She never said however that she thinks the universe expansion is slowing down. As a matter of fact, it isn't. In fact, to the best of our knowledge, the actual expansion of the universe is today accelerating. Which means that the contrary of what she says is happening: some of the light that is currently inside the Hubble sphere and getting closer may start receding away in the future (in other words, the Hubble sphere is contracting).

[@KSparks80]

@Anjelica Y This might help you out. (If anyone sees that I'm explaining this wrong, please correct me!) I think you mistook the explanation of the light originally "moving away from us to start, then travel towards us...", as if it changed its direction of travel. Picture a little round object way out in space. Light from it is going out in every direction. Any light we'll see came from the "face" of the object, and began heading towards us. But the space that the light had to swim through to get here was spreading away from us faster than the speed of the light that was heading our way. It could appear that the light was moving farther away from us, in the wrong direction. But the light from the object was always headed our way. (It was trying to swim upstream in a river flowing faster than it could swim, but it kept going and never changed the direction it was swimming. It was determined! lol). Eventually it was inside the Hubble Sphere, and made it here. Any light "travelling away from us to start", came from the backside of the object, and kept on going that way. I don't think there's any way we'll see that light. (But who knows with this stuff!)

[@donlightbody8270]

please get better Diana 😓🥰

[@UltimateMegaMaster]

A good demonstration is having an ant moving on a infinitely elastic rubber string. The ant must move from point A to point B, at the same speed (light speed), while you, stretch the rubber string faster than the ant's. The ant will still move at the same speed, but arrived late eventually, because you pull the strings faster than it can cover over a short period of time. Hence, by the time it reaches point B, if at light speed, the distance it travels cannot have the same magnitude as to the light speed.

[@1fast72nova]

This makes no sense. I'm going to watch the video again but something doesn't seem correct

[@UltimateMegaMaster]

@@1fast72nova I used the same example as Veritasium used. Perhaps you can watch his video first. I just can't remember which one.

[@1fast72nova]

@@UltimateMegaMaster I think I'm saying there's something wrong with the underlying theory. I'm watching videos and will sleep on this. But something does not seem correct.

[@UltimateMegaMaster]

@@1fast72nova Oh really? Great. Post whatever your findings here. Would be nice to know.

[@netzah771]

@@1fast72nova What if the universe is actually contracting? Like as if two pieces of metal were placed close to a magnet at different distances. The one closest to it moves farther away from the one at a greater distance and at an increasingly faster rate since it gets ever closer to the magnet. So if our galaxy was one of these pieces it would seem to us that the other galaxy is moving away from us at an increasingly greater speed because it's moving being attracted to some center? So it would also make sense that the galaxies closer to the center or for some reason being more attracted to whatever the center would be would at some point move faster than the speed of light??? Maybe?

[@thesuburbanxplorerschannel]

Thank you for helping me finally get my head around this really tricky topic!

[@thehonestabe]

It really saddens me, that there are a lot of amazing discoveries going to happen in the future that we will miss because we will be dead by then :(

[@seanwebb605]

I'm a little dead inside right now.

[@alwaysdisputin9930]

I know. We can't even say if I eat a lot of salad I'll be ok. In fact every1 who eats salad ends up dying. Never eat salad. Because if 2 things exists together then 1 MUST have caused the other. Similarly brain & consciousness always exist together. Therefore brain must have caused consciousness. Therefore there is no possibility of our consciousness existing after the brain dies. There is no chance that when we die we wake up next to a playstation see our whole life was a computer game

[@seanwebb605]

@@alwaysdisputin9930 The main ingredient of salad should be bacon.

[@synthnseq]

freez ur brane

[@mokongthe3856]

This is depressing but true.

[@AlphaCentauri24]

This feels much more than just a science hike. 😍

[@Dave.A.R]

That last question. I've been wondering the same for quite a while. Thank you for the explanation. :D In my case, my confusion came from the statement that if space is always expanding so does the space inside objects. For a non-expert (as myself) it would be just natural to come to that conclusion. Now, I can see the mistake in my intuition.

[@RoySATX]

@@deepak_nigwal I'd be very careful in making a statement of fact that the expansion of the universe does not expand galaxy-sized objects, the mushing and pushing you speak of also seems to muck up the spin, slowing down galaxies not only outside but within.

[@RKabasaC]

Thanks for your video!! Great explanation!! Great work!!!

[@sjosephmann]

Dianna, my 10 yr old son and I love your channel. I was always told that objects could not travel faster than the speed of light. I often argued this point with my physics prof (MANY years ago). I said, if the universe is expanding at the speed of light, doesn’t that mean that objects on the opposite side of the universe center are then expanding away from each other at twice this speed of light? Would you consider doing a video discussing the topic of the speed of light and how objects can travel faster than it, and what it means to the objects in our universe? Thanks!!

[@HeliBenj]

Still true, nothing exceeds the speed of light. And space doesn’t expand at the “speed of light”. It expands at a fixed speed per fixed distance, but it’s “cumulative”, that’s why things further away appear to be getting away faster. But still nothing moves in space faster than light, there is no argument around it

[@jamesbull6266]

@@HeliBenj That is the video she does did! She explained that it is not the objects that are moving faster the speed of light, but the universe itself within which they object is moving, that is moving faster than the speed of light. I thought she explained this very well. Still a difficult concept to gets one's head around.