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

[@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?

[@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!

[@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.

[@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!

[@supremelordoftheuniverse5449]

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

[@donlightbody8270]

please get better Diana 😓🥰

[@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😉😉😍😍😁😁

[@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

[@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

[@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.

[@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.

[@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...😎

[@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!)

[@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!!

[@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.

[@dave-huston-dublin]

Very well put together, Thanks Dianna.

[@JDofSweden]

If you (like me) struggle with concepts like "Hubble sphere", here is a cute analogy/bedtime story for you. :) Once upon a time, a baker (unknown) left a giant loaf of bread (the universe) to swell. This bread housed tiny little raisins (galaxies), one of which was our very own Milk Dud (cute for Milky Way). Buzz Lightyear, a raisin far away as bread distances go, had a huge crush on our Milk Dud. One day, he decided to blow her a kiss. He watched the kiss travel at the speed of love (light). To his disappointment, the ever-working yeast (dark energy) was consuming sugar (perhaps representing the universe's hidden source of energy) at a ferocious rate, causing the bread to swell and the two raisins to glide apart so fast that not even the kiss, traveling at the speed of love, could match it. Heartbroken, he realized that his kiss might never reach his loved one. Little did he know that the sugar was slowly running out, and the yeast would begin to starve. Day and night, the tireless kiss continued its travel at the speed of love. One day, he watched with astonishment as the kiss overcame the tired yeast. It was finally heading towards Milk Dud! For in the end, love, just as light, shall overcome. Sweet dreams to all you curious minds. / a whimsy nuclear scientist

[@peteketners5939]

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

[@bistromathics6]

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

[@TheSmileyTek]

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

[@peterjamesfoote3964]

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

[@michaelccopelandsr7120]

Time is fascinating. I worked the subway stations for nearly 10 years. From one end of the city to the other. Every so often I would notice the city would be saying that, "Today just flew by" or "The day was just dragging along." How can an entire city complain about the same time paradox unless it was effected by it. Maybe a time distorted bubble the earth passes through in its revolution around the sun. Maybe random waves of time distortion hitting the earth? Maybe they're randomly given off by the sun. Maybe they're from outside our Terran system and reach us in intervals. ???? Ti-i-i-ime, is on my side. Yes, it is!

[@blademaker4263]

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

[@anothervanwinkle]

Wow, that also means that WE are actually moving with 3x the speed of light away from these distant objects! You guys, faster-than-light travel is possible and we've been doing it all along! 🎆

[@calebgangte1228]

My analogy is that just because something is the fastest, doesn't mean that you can't be fastee than that

[@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.

[@iampuzzleman282]

Awesome scenery

[@72151]

The point of observation is a bit important. At the equator we’re going almost 1,000mph. 93m miles per second (roughly) is our perceived speed of light as I understand it. If we moved faster than the speed of light, what would one see? Well we’d see a bright white spot because our eyes and brain couldn’t process anything at that speed. It would look like a flashlight shining in our eyes.

[@brandonmcclain9988]

It’s so cool how the complex structure of photons can be conserved over distance to retain a memory of the image once there, same with sound, I wonder if you could develop a technology that taps into that sort of universal memory, depicting and transcribing past events with image and sound. With ancient vases, tiny oscillations in sound waves carved grooves in the vase when it was malleable, and through sort of an air sonicator, you can blast air though he space and here the frequency of the vibration of that sound, or the pressure created by the air going though the grooves space. Light doesn’t have mass, as E=mc^2 is derived from the fact that p=0 so E/c^2 = m does not work, yet photons are affected by gravitational lensing, perhaps the change of frequency in E/h = v manifested up the organisation of matter can account for that, perhaps photons really do have charge. Perhaps they really do have mass, nothing that exist can truly be massless, frequency fundamental is observed trough vibration of things with mass. So perhaps a chronovisor is possible, idk.

[@kevinfrey1435]

Because the frequency of an electromagnetic wave changes with time and distance, we'd have to figure out how to reverse those changes. For instance, if I'm remembering correctly, the cosmic microwave background radiation began as visible (or maybe infrared) light, but now it can only be picked up by radio telescopes.

[@RifaiAL]

"Verily it is We who have Created the heavens with our creative might, and verily it is We who are constantly EXPANDING it." Quran 51:47

[@derangius]

That has no meaning, explains nothing and doesn't allow anyone to make a prediction. Give your faith some respect and keep it private.

[@jtischCB]

​@derangius Give your lack of faith some dignity and keep it private. You haven't disproved anything. Why take offense where none is intended? Are your beliefs threatened?

[@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 🤔

[@SandCrabNews]

If you were to travel to a distant star, would you #1 head straight to the star as you see it, or #2 go to the calculated future location of the star? Path #1 would be a long curve, but path #2 would be a shorter, straight path.

[@MinimumViablePicnic]

Snicker 😁

[@bigtxbullion]

It was on that walk he realized he couldnt let her get outside his event horizon. He popped the question and landed that ring on her delicate finger, forever ensuring she would stay well within his hubble sphere.

[@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.

[@lawrence.porter]

They’re not just moving away from us, we’re moving away from each other. Who’s to say we aren’t closer to the edge of the universe than the galaxies that are the farthest away from us? Like when we talk of the edge of the observable universe and put us in the centre of that we imagine we’re the centre of the universe but we might be closer to the real edge, if there is one.

[@acecel]

It must be cool to be your "editor", so many interesting discussions you have must have/had. :) I never had a friend as smart as you with whom i would be able to have discussions about this kind of stuff.

[@davidanderson9074]

What is this "space" that is expanding? If this "space" is expanding faster than the speed of light, how do photons propagate against that expansion and eventually reach us? ( If I was driving from one city to another, a 100 mile distance at 100 miles an hour, and the distance between the cities was increasing at three hundred miles an hour, then in one hour I would be two hundred miles from my destination yes?) Does it appear that this variable rate of expansion, accelerating from our location (galaxy or solar system?) is happening in such a manner that appears to make us the center of this universe? If we tried to put a map together of the known universe now, as it is everywhere at this moment, forward projecting the motions of the known universe to where a galaxy say three billion years ago is now, ( and we would have to know the relative motions of all the galaxies, AND the relative "space" expansion rates) what would that universe look like? And what is meant by a "flat" universe?

[@Concrete1998]

@@davidanderson9074 From what I gathered in this video, your city wouldn't be 200miles away after an hour of travel, as it's mentioned that (yes it is expanding and it should be 300 more miles away from your origin) you will be somewhere under that 200 mile point as the rate of expansion slows over time. So within the scale you're talking here, I'd say that while driving you would probably be knocking off anywhere between 10-20 miles in an hour in addition to your 100MPH speed. This being all to what she's said in the video, that the light will eventually reach the destination, same as you in your car would reach your next city. However; also with regard to this explanation, if your city's Cosmic Event Horizon was within that original 100Mile gap, you could drive at 100MPH for eternity and never reach that city. This also covers your example of expansion as by the second hour, when you've traveled 200 Miles, the end destination would be another 400Miles away (relative to origin city, AKA galaxy really far away) with it's given rate of expansion. But as aforementioned the expansions rate would slow down exponentially as you drive on, eventually leading to your car (photons) reaching the end city (our eyes)

[@r3ddp1l]

no discussion. she is monologizing. Only my grandpa was allowed to that and still be interesting.

[@edithdriver2094]

Simple version. In still water a boat travels towards you at say 10knots. If the water has a current going in the opposite direction to said boat at 5 knots, the boat is still travelling at 10 knots through the water but only proceeding towards you at 5 knots. Much simpler explanation. Still a very cool presentation 🤙

[@cyberwolf6667]

I’m watching this again after a year and my head still hurts trying to grasp Get better!! I miss your videos

[@PK-kj6zv]

So much passion and knowledge and so humble down to earth. M mesmerised by you. Science+good human being's = future saviours of earth

[@thursoberwick1948]

You make an important point there. "Science + good human beings" - science is nothing without morality. Unfortunately we see science being abused for political and economic gain right now...

[@eagleleft]

Science alone is insufficient. Economics, politics are way more important because good economics + politics enable good science and art to flourish and happen

[@thursoberwick1948]

@@eagleleft Science is nothing with morality. Recent events have proven that.... we are pretending to be kind while setting up a.repressive society that will exclude some people.

[@eagleleft]

@@thursoberwick1948 I think you meant morality and I agree. Science is just a method of discovery but the tech used from those discoveries can be used in a myriad of ways. Like tech is being used by huge corporations to increase the divide between the top and everyone else. People don't see any benefits. Workers don't get paid more even though they are more productive. And if we keep going down this road, it'll be a dystopia. But a better way exists where better tech can help make the lives of everyone better around the world. Maybe people don't have to work as much, enjoy more of their lives, spend it doing what they feel is worthwhile instead of going to work for fear of going hungry and homeless otherwise

[@thursoberwick1948]

@@eagleleft We already are living in a dystopia and what is happening just now is an attempt to create technocracy - force people to communicate mainly online (where it can be policed) and get tracking ID to prove they have had X number of jags. There is a lot of worship of science by people who don't seem to realise it is mainly a tool. Science can be used to cure malaria but it can also be used to create new nastier diseases. It just depends who's funding it and who's in charge.

[@adriangabrielgramada1016]

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

[@WayneSpivey-v2i]

They don't know that for sure space is it Expanding, it could just be things are getting further away in the space-time. Continue on Pratt fabric that you think is stretching is not stretching at all. Could just be that things are blasting. Still pushing further away from us. And it's just moving along that fabric. You have no way to know if the fabric of the space-time continuum is stretching. You don't know that the only way you can prove. That is, if you can show where it has tore and the only tear on the road that has happened, it is with t. Large head drawn Kalatter and that was not done because of stretching.

[@CannedFunkMusic]

So space is similar to calm water. You can move through it on your own motivation and affect things locally to you, but, you will still move with the overall flow of the water.

[@WingedShell82]

The reason I'm inspired to become an Astrophysicist, I love this, just crazy things that blow minds

[@joephysics5469]

Physics is the most amazing field of study and physicists tend to be the most brilliant people on the planet (not including myself). But it is not for everyone. My class at Xavier University started with 16 freshman undergraduate physics majors and we graduated 5. It takes very strong math skills to complete a physics degree. Most physics majors go to graduate school in some field of science, most for a doctorate. My friends went into 1. computer engineering where he is a university professor at the most prestigious program on the planet doing autonomous vehicle research, 2. optical physics and is teaching at a major university, 3. subatomic particle physics and is also a university professor. Others in my program went into engineering specialties. I went into medicine and became an anesthesiologist. I miss being around physicists. So the key to being good in physics is math. EVERYTHING in physics is described in mathematic terms, so get deep into calculus as much as you can before going to college. A physics education is something that few ever get to experience. It is an amazing journey. Best of luck.

[@ROBERTHOCKER]

For example,"halley's comet" moves evenly because it is an extraterrestrial device to monitor the space it surrounds. Look at a photo of halley's comet. You see a small object with a very long tail The questions,; of course, are how could a tiny comet have that much heat without disintegration? How can the comet contain that much fuel to continue so long? Unless specially dddignrd,designed, comet wh old run out of energy immediately then explode from so much energy. It could not retain that much nuclear energy to continue for so long How much fuel is contained to leave that much of a nuclear fire tail? And. For so long? A comet couldn't.

[@hagopakasparian7732]

What I want to add when we are looking at something let's say 13 billion light years away, actually we are seeing the past 13 billion light years ago, it's also possible what we might be seeing does not exist anymore and it might not be in the same position. Also the other way around if we can travel faster than light we can see our past without actually being in the past

[@CS--SambitKar]

That means light moves backwards with respect to the space expanding faster than the speed of light !

[@algladyou]

I was thinking of that. Does thiz mean light travel sideways?

[@metallicadragon8802]

Prior to this video I was watching a story on the exact sponsor of your video 3M they mentioned another company as well but there's 10 minutes of the story was how those companies over the past 40 years have dumped million of chemical into the lake and stream near their facility in their perspective state, Just kinda weird that that's your sponsors and I actually watched the videos kind of back to back .

[@guyanasun4361]

Two things are happening with this calculation we're not accounting for. The speed of light is measured with math illusion held up by current contrast and not all movement accounted for in original beginning. The speed of light is comparison we use to measure energy in time and distance. But how light moves now isn't how it always existed, nor how it will in all places. The speed changes but we haven't noticed because it's the current measurement of what was once moving faster but is now stabilizing. In other words, if I magically found a way to shrink all of existence at the same time in equal percentage, would we notice with nothing as contrast apart from what matters? No.. to us everything remains the same size even if it was millions times smaller or bigger based on perception with nothing to compare. If all light (matter) sped up or slowed down together, we wouldn't take it into account based on the formula measurements we use. Light travels at different speeds depending the state it exist in. The chamber- Prism or Atmosphere/Field determines energy magnified (released) or held. Where water/sound is echoed and concentrated into energy (density) or current waves, fire/ light is focused and reflected in spectrum dimensions.

[@eventhisidistaken]

I've asked this same question many times online, and no-one can really explain it to me. Imagine an explosion and some time has passed so that the explosive forces are no longer at play and things have reached steady state... and you have a device embedded in it measuring distance and rates of distance of debris from that device. Would it be possible for a closer debris object to be moving faster than a further debris object? No. Clearly, every debris object that is further away *must* be moving away faster than the close in stuff, and that's the reason it is further away. Yet, the fact that further objects are moving away faster than closer ones, is the evidence used to claim that space itself is expanding, when a simple explosion would do the exact same thing. What am I missing? We would not have to be at the center of the explosion for this to appear uniform in all directions. The explosion would simply have to be *big enough* for the asymmetry to be lost in the accuracy of our measurements.

[@michaelritchie5303]

To quote Neil DeGrasse-Tyson. The universe is under no obligation to make sense to us. I wonder the same thing.

[@Andy-o2f]

RE: "How far away is this galaxy" has another possible answer. The other correct answer is that it's possibly not even there any longer.

[@Beeterfish]

We might still see the crazy expansion of time and space in the first few seconds after the initialization in the distance. Things may be slowing down as in a regular explosion. Disclaimer: I have no mathematical or physical evidence of this whatsoever.

[@BartvandenDonk]

Redshift isn't going up or down, left or right as fast as the original light. That's what's missing in Einstein theory. If you look at the train experiment light-years away the light in the train is bouncing up and down slower than nearby.

[@Avatar_2025]

How is this presenter, has she recovered?

[@MrCubFan415]

Get well soon Diana!

[@JohnDrummondVA]

You are beloved and we pray for your health, PG!

[@legend9335]

My credit card is expanding faster than the speed of light.

[@Kevinardo]

Diana, life is so complicated for you. I wish for better times for you to do what you love and to be free from your ordeal. Best wishes and please get well soon.

[@jrremerable]

Are the galaxies moving away at the speed of light, or are we moving away from them at the speed of light? Or are we moving away at greater than half of the speed, and the other galaxies moving greater or equal than the speed of light?

[@pepperandzip]

Listening to you and watching your videos are just so captivating

[@barthvapour]

Question: is space itself actually expanding as suggested in this video, or is the universe expanding because galaxies are moving apart THROUGH space? Because surely if the former is correct, then that means the size of a metre is increasing over time, which would make it impossible to detect because the value of c would also be increasing in order to appear constant? If space was itself expanding, so everything was gradually getting bigger, but light continued moving at the same speed, then we would observe a gradual decrease in the value of c over time. But conversely, if light was getting faster as space gets larger, then we would see no redshift. So surely the only workable solution is that space is not itself expanding, things are just moving apart through it?

[@skagit58]

Soooooo, I watched this at 7:30 am which blew my mind much faster than had I watched this at 5:00 tonight. 😂

[@robertcramer9943]

I'm guessing the correct time it takes light to reach us is only relative for that moment in time. Every moment after that, it would take longer and longer.

[@jeffgorman2932]

I never realized how much I loved physics

[@Zino027]

Out Galaxy is guarantly moving (more like traveling) above lightspeed as well. Why should it not? The universe is expanding and we are not the center of the universe.

[@johnjacobjinglehimerschmid3555]

Well if you take into account total internal reflectance ( think fiberoptics ) the galaxy that they're looking at is behind us and it's taken light 32 billion years to bounce around the outside the universe.

[@skyryder2994]

I'm such a space geek! I'm curious about the Hubble sphere. How do we know that it's there? And how can we tell that it's moving away from us faster than the speed of light?

[@MrRatracing]

I was once told, when able to control neutrinos one can control everything, this is why the door must remain hidden

[@dmenace2003]

Not necessarily 32 Billion LY as there’s a current debate as to whether the Hubble constant is indeed the same in all direction, or in all region of the universe..

[@pedrosura]

This assumes that red shift is all caused by recessional velocity. We do not have an independent way of measuring or verifying this assumption. We do know that the greater the distance the greatee the rednshift. If that recessional velocity assumption was wrong then what is being said on this video would be wrong. A few scientists have pointed this out with evidence that puts this into question but they have been ignored because the majority do not agree. But in reality, it is an assumtion and in reality, we do not really know. I personally do not believe this until we get enough evidence. Also, towards the end of life Edwin Hubble also was skeptic of this interpretation of redshift which he made himself.

[@RealPersistences]

Based on how the Cosmic Event Horizon is described, it sounds the same as the observable universe. But this vid doesnt show it as having the same boundary

[@robertvirnig638]

Isn't the reason the light from things moving faster than light away from us will eventually start moving toward us because the Hubble Sphere expands encompassing that light and the light is then inside the Hubble Sphere and moving toward us.

[@nathanoxley4342]

This really cleared up a lot of stuff for me honestly. I always wondered how it’s possible our planet could get ahead of the light from the Big Bang. Now I know. Thanks!

[@willharlow607]

If we start calling it "the speed of causality", there wouldn't be so much confusion about what's going on.

[@benjaminlee-roche8772]

so does that mean the expansion of space is an unaccounted for force? strong nuclear force, weak force, gravity, etc?

[@RadiantFreeEnergyResearch]

Very interesting! I was recently watching a documentary on john searle and his seg engine. who would have known that spinning magnetic fields very quickly, could provide antigravity effects, as well as permit faster than light speed travel (theories). the rotating magnetic fields (circularly) encloses the craft within a gravitational sphere/bubble, permitting, theoretically, infinitely greater than light speed travel. which compared to the speed of light, can seem like the speed of a turtle traveling across country. it would not be practical, although theoretically, possible. there is also a speech given here on youtube, i mean, shared here on youtube, of russell anderson, the video is called “limitless energy from the vacuum” and its one hour of immense, joy and delight, of information. as it relates to the latest possibilities, of faster than light travel. thank you for sharing!

[@ADude-f3z]

I’ve often wondered if our self imposed planetary isolation stems from our refusal to acknowledge that regardless of our national heritage, we are all merely human? Extrasolar exploration would require global participation/partnership…

[@Diesal3]

@Physics Girl OK so if all galaxies (and everything else in the Ob. Universe) is moving away from us, then how is it possible that the Andromeda Galaxy and the Milky Way Galaxy will collide in roughly 5 billion year according to most estimates? Two things moving away from each other CANNOT collide. Unless the universe is a huge Pac-Man board and they each take the side tunnel and crash into each other.

[@ChristopherCowin]

I understand what she is saying clearly so the galaxy could be that old look at ours it is over that too and our galaxy is moving slower than the furthest ones are so speed is different but time is not

[@johncrumpley8702]

Nice video. I kinda, sorta, almost think I understand it. Amazing just to think about it. Thanks much!!!

[@Alkoholic666]

I’m so close to being to say, “ah, ok I get it!” But the truth is that these are some crazy concepts to wrap my brain around. I’m pretty sure that I will be able to grasp the theory after a couple bong rips and another viewing of the video! 🤘 Physics Girl Rules!!!

[@silentgamer666]

3M wants to improve quality of life? Apparently that included dumping toxic waste into the river (and the ocean )in my town.

[@amosdotl6892]

If there is a sphere of space around earth that allows matter to move faster than the speed of light then we are in the center of the universe. This is strong evidence for an intelligent creator. And even if this observation is an illusion it makes no difference because that's how it appears...being strong evidence for an intelligent creator.

[@ROBERTHOCKER]

The universe is never beginning and never ending in all directions. Think about it. If it ends, what is beyond thst?

[@TheLizardOfOz]

_"The universe is not only queerer than we suppose, but queerer than we can suppose."_ ~ J. B. S. Haldane

[@reddeadryan78]

Considering 1 light year is 6 trillion miles, 32 billion light years jyst blows my mind.

[@timbutts809]

It is clearly a tricky subject to wrap your head around. I think I’ve got it. We may want to pick it up again in a year or two and see how it fits into recently collected data.

[@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.

[@brecht1043]

Thanks for promoting 3M who basically poisoned half of my country..?

[@ketterknetter2525]

Belgium?

[@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.

[@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 ❔️❓️❔️

[@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.

[@TimothyOBrien1958]

Please get better. Please come back.

[@michaelcangelosi1684]

What

[@TimothyOBrien1958]

@@michaelcangelosi1684 You need clarification?

[@ronsleeter8222]

Here here. You are loved and missed.

[@jaygreer7430]

@@michaelcangelosi1684In case you didn’t know, since this video was made, Physics Girl has become very sick with a life threatening condition. We all hope she gets better soon.

[@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? .)

[@Jim-he4km]

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

[@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 :)

[@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.

[@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..

[@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.

[@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.

[@BlueSkyBonsai]

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