I Never Understood Why Black Holes Slow Down Time… Until Now!

[@Mahesh_Shenoy]

T shirt (Dark, promo price): floatheadphysics.com/products/paranormal-distribution-dark T shirt (Light, promo price): floatheadphysics.com/products/paranormal-distribution-light You get a cool T-shirt and you support me!

[@shrivatsa8604]

Hello mahesh sir, nice explanation. Does time dilate more inside the earth compared to that on the surface?

[@Happybro91]

* Ek X Banda h voh earth se 9000 light years dur h ... * Uske waha gravity Kam h * Humaare yaha zaada * Humare yaha usko 9000 saal baad dekhenge toh woh ... * 6-7 hr jeeke ... * Par uski aging fast hogi .... * kya yeh theory sahi h ?

[@balabuyew]

@@Happybro91 Earth sucks space, like a vacuum cleaner sucks air. And since sucking is omni-directional, the space speed (relative to Earth surface) is greater near Earth than the speed at high attitude. As a result, a body near the Earth and another body at high attidue moves with different speed through the sucking space. So, according to special relativity, time ticks differently for them. If you'll take a flat infinite surface with uniform gravitational field, there will be no difference in grativy at different attitudes. So, there will be no difference in time flow. In other words, time flows differently at different attitudes because Earth is round.

[@michaelccopelandsr7120]

Thank you

[@1stHuemanAmerican]

Albino don't try and leave Earth keep ur Rocket off 😊

[@johnmacmillan627]

If you as a human have an ounce of curiosity then you absolutely must tune into this fellow’s videos. His wonderfully clear and enthusiastically presented videos are real gems not to missed. I marvel at his intelligence. I am almost 82 years old and am so thankful that I discovered his channel. Thank you, Mahesh, keep up the good work

[@Hovss]

Happy almost 82nd birthday :)

[@SkotiM]

This is the second video I've watched on this channel. Both times I feel absolutely certain that I now understand this stuff, right up to the point that the video ends. As soon as the video ends I go straight back to not understanding it at all.

[@Ahoooooooo]

Thx . I'll stop the videos 2 minutes before the end 🫣

[@WistrelChianti]

I always find this stuff is like trying to insert a brick into one's brain, it's not a natural place for the brick to be, and as soon as you stop trying to force it in there, it just pops right out again. I've spoken to a friend who did Physical PhD about this he said this is normal and that conceptually it's just a hard thing to ram into our brains as it goes against so much that we think we know and take for granted in how we operate through life. The only way to do it is to keep coming back to it, keep thinking about it, keep watching videos etc. This is why there is the suggestion at the end of the video to try to explain it to someone else. That's a great way to check and re-enforce your understanding. It might end up messy where you make a fool of yourself because you didn't fully cement it into your head yet, but it's the only way to do it. At least for me anyhow and I'm still going with it.

[@camdoesitall]

You seem to be trying to grasp the idea the entire video than understanding it completely

[@bugsy742]

@@WistrelChiantithat’s absolutely bloody incredible mate! Thank you for conversing that so damn coherently! 🤝🤝🤝

[@nishantbhaskar7685]

Universe accelerates or decelerates time and contracts or expands space in order to keep the speed of light at c. Everything in our universe revolves around the speed of light. It is the only constant that exists.

[@Akagami2404]

Never stop making videos even if u get less views,some channels r really good and this is one of it

[@langleywallingford260]

Fewer views...

[@JesusPlsSaveMe]

TO EVERYONE IN THIS CHAT: *THE JUDGEMENT OF GOD IS DRAWING NIGH.* REPENT TODAY AND GIVE YOUR LIFE TO JESUS TO ESCAPE ETERNAL DAMNATION!,..

[@langleywallingford260]

@@JesusPlsSaveMe 😆

[@LostinMango]

​@@JesusPlsSaveMeWow I became christian after reading your comment

[@akashicrecords9]

Life's uncertainties 😂

[@Pat_Fenis69]

This man had more conversations with Einstein than everyone that had conversations with Einstein put together squared.

[@WistrelChianti]

I really like his conversations with Einstein and the arguments he speaks. He's asking all the things anyone else would (and indeed probably already did - I'm sure Einstien had his work cut out even once he figured this stuff out. trying to explain it to anyone else.

[@muditpant]

@pat that's what you took from this video?

[@Pat_Fenis69]

@ no not from the video but from his channel more so.

[@Andrew-hp1yj]

I understood every word you used, I just didn't understand how you used them.

[@tschakatschada]

I feel that

[@wlockuz4467]

Fun fact: Watching this video on Miller's planet would cost you ~2.2 Earth years.

[@warhead213]

What?? 1 hour on Millers planet was 7 years… this video is 19:17 minutes long.

[@wlockuz4467]

@@warhead213 60 minutes = 3600 seconds = 7 years on Miller's planet 7 years = 220752000 seconds This video is 19 min 17 sec = 1157 seconds So we can do simple math; 1157 / 3600 * 220752000 = 70947240 70947240 seconds = 2.25 years

[@louied.quijano2254]

​@@wlockuz4467maybe you are Millerian. Your math is impeccable.

[@warhead213]

@@wlockuz4467 awhhhhh I see I see

[@JesusPlsSaveMe]

TO EVERYONE IN THIS CHAT: *THE JUDGEMENT OF GOD IS DRAWING NIGH.* REPENT TODAY AND GIVE YOUR LIFE TO JESUS TO ESCAPE ETERNAL DAMNATION!,..

[@Hatemode_NJ]

This is the type of channel that should have 50 million subscribers. Don't stop what you're doing. You're one of the best at it. I've watched more videos on these subjects than I can count, but after watching only a few of yours, it all makes so much more sense. Not only that, I was able to easily connect other videos you made to related topics and they all come together in my mind seamlessly. It reminds me how my highschool chemistry teacher couldn't teach me something in a year that a college professor described in one sentence and I still remember it over twenty years later.

[@Hatemode_NJ]

I also want to add, the best part of your presentations is you ask out loud exactly what most of us are thinking in that moment and makes it seem as we are there with you.

[@abumansaray7]

Why? Not everyone is interested in these things. It has no effect on your life whatsoever

[@Hatemode_NJ]

@@abumansaray7 you must be interesting at parties.

[@abumansaray7]

@@Hatemode_NJ Ya, i am. Bc I don't talk about pointless topics.

[@Hatemode_NJ]

@@abumansaray7 such a weird thing to say.

[@sauravroy5737]

This is by far one of the best Physiscs explantion channel that I have ever seen...

[@JusticeLeGrand10101]

What? This video is horrible! You must be a fan. A fan of pseudoscience! Put down the pseudoscience and study astronomy. Read more nonfiction. Dictionary. Encyclopedia.

[@Verymusician193]

Science Clic English is really good too

[@rformigli]

What an amazing end-of-year gift it is to have found this channel! I absolutely loved how you presented the topic and explained it so clearly. Congratulations, and thank you for creating such valuable content!

[@BroadsideBob]

That may be how the math works, but one problem I have with interstellar is that Brand, Cooper, and crew needed a Saturn V rocket to leave the Earth at the start of their journey, but apparently a craft the size of a Winnebago was able to leave a more massive planet (with a deeper gravity well than Earth) and then escape Gargantua's even deeper gravity well later in the movie. I get that, "it's only a movie," but it seems inconsistent.

[@maxsamarin9002]

Maybe initially they needed the rocket to lift all the supplies for the journey?

[@DrRobot44]

Solid point… where was Kip Thorne on that one Nolan?

[@johndavidtackett]

Yeah def a movie with many issues, I appreciate how much they got right but def a lot of unknowns and some inconsistencies also which are to be expected since it’s a topic that we simply don’t know nearly enough about anyhow.

[@ulrichvonlichtenstein7880]

Strangely enough, it makes sense. The larger the object, the stronger its gravity is if you cross a certain point, i.e. the event horizon. The more massive an object, the less pull it has on objects in their orbit and escape velocity is actually way less than it would be if the object was smaller. Simply put, the smaller the black hole, the harder it is to escape it. If you want more on how this works, send a qustion to Neil Degrasse. He will do a better job of explaining

[@stephenperry9042]

​@@ulrichvonlichtenstein7880 Then why didn't the astronauts who landed on the moon need a bigger, more powerful rocket to escape from the moon since the moon is smaller than earth?

[@devankurkashyap1031]

10:02 "That's what I am talking about!" I can't stop smiling. Your explanations are always to the point and easily understable, but these subtle comments, they are in the next level!!

[@DM-jo5ko]

Every. Single. Video. I am BLOWN AWAY

[@JusticeLeGrand10101]

Blown away by his imagination? Other than that, you need to read more nonfiction. Dictionary. Encyclopedia. Put down the pseudoscience and study astronomy. This guy is a clown!

[@DM-jo5ko]

@@JusticeLeGrand10101 there’s no way your aren’t trolling 😭

[@alexshatner3907]

I am really close to a brown hole within 3 feet and I am still getting older

[@shivamkumarshrivastava5182]

@@JusticeLeGrand10101 Aren't you the genius huh?

[@UltimateTobi]

Much better science channels out there. This is the second video I tried of him and he explains it poorly.

[@rihamission487]

How do you explain everything in one sitting? I haven't noticed any cuts, it's just you talking straight for 20 minutes without missing any points and with accurate emotions and energy. How is it even possible? You are a great teacher. Keep doing what you do. I cannot thank you enough. Your love for physics is unmatched. And ahhh I can finally watch Interstellar and actually understand a few things!

[@kcprdp1522]

Watch closely there are cuts and he is looking towards the side most probably at his notes, still it's good video

[@MrSean03839]

He has ads for brilliant, that's a break. Anytime there is an animation is a break.

[@Ravynheart]

there are cuts

[@carlossaraiva8213]

It's called learning.

[@troyfoster6004]

The way his hat sits on his head changes, telling me it was shot over two days. Very good video nonetheless.

[@IC0NICK]

I understand how centrifugal force works on a spacestation, because we are standing inside of the rotating object, and our feet are being pressed in the direction that is away from the center. But how does that translate to gravity on earth? On earth we’re not standing inside, we’re standing on the surface. So how does centrifugal force become gravity and not throw us into space? I’m genuinely interested. Forgive me for not understanding.

[@Wannakatana2112]

You're not The only one

[@mubashirsoomro6]

It is throwing you into space but at the same time the ground is accelerating towards you. It's not so much that the centrifugal force is not acting on you , it is not a "real" force. Think of when you are spinning a ball tied to a string. The ball wants to leave the string and continue moving on its path, but the string doesn't let it unless it breaks or you let go. Now reverse the directions. The string wants to push the ball away, but the path that the ball wants to move towards is towards the string rather than away from it. I don't know if that made sense, but that's what I think of it in my mind. If someone knows better I would be happy to be corrected. Edit: typos

[@ThesGt]

@@mubashirsoomro6 i just read einstein relativity and he also thinks that big mass curves spacetime, is not a force like newton but it curves spacetime/4th dimention, is not a centrifugal force like what the video describe, im really baffle from what the video author is describing, both newton and einstein do think that big masses proces a "force" is just that newton is more like a grabbing force and einstein is a force that bends space time around it so thing "falls" in a straight line, or at leasts thats how i understood it.

[@ThesGt]

i think the centrifugal was just a way to describe a behaviour we can observe but thats not how big masses bends spacetime to create gravity, lets says the earth wouldnt be rotating or moving, it would still produce bending of the space time, same with the sun, gravity is not a centrifugal result...

[@JayMoreau]

6:32 in this example they are on the inside of the circle (orb), the outside would fling objects off. I’m honestly trying to understand

[@paulozavala3232]

Me to! I struggle with the same question! If you are standing on the globe from the outside (as we are) then the apple should just sky rocket itself out from earth or just spin around it as a moon!

[@sudhanshuaswal3113]

I am also confused here,

[@erikmin2625]

The point of the example is not to give an alternative explanation for earth's gravity, but to show that the effects of gravity and acceleration cannot be distinguished from each other. And therefore, the effect on other phenomena (such as the path of a light beam, or the passage of time) should be the same. In fact, an apple IS flung of the surface of the earth a bit by it's rotation - but the pull of gravity from the earth is much stronger. That is why gravity on the equator is a tiny bit less than on the poles - on the equator you have gravity minus a tiny bit of flinging off, on the poles just gravity.

[@UltimateTobi]

@@erikmin2625 But why bring this up if he doesn't proceed to explain how it works for Earth? As he said multiple times: there is no "gravity", gravity is merely the movement of objects towards each other. If you invert the images back and imagine them spinning, the apple would fly off into space if it maintains its respective velocity. So... it's a stretch to explain to the viewer something but then ask them to just "trust me" and not answer the question. He did mention another video where it's allegedly explained, but asks the viewer to stay and "not get distracted", but to be honest? He lost me there, because I need that question answered now, because he brought it up and it seems relevant to the rest of the video. If it isn't relevant, why bring this up at all?

[@CastAwayProduction]

@@UltimateTobi Has he explained in the video, the feel of gravity on earth is the fact that the ground is coming to you and pushing against you (the rotation of the earth has nothing to do with it). So it's kind of like if Earth was expanding at great speed, or like with his example, when you are in a car and you are pushed against the seat. But how can the ground expand without the earth getting bigger ? Well it's kind of an illusion, planet and stars warps space itself, like if space was elastic. So imagine you're standing on a carpet, and someone is pulling the carpet toward them. For you, you didn"t move, you are still on the exact same spot on this carpet so it's the other guy who is coming to you, even if he doesn't really move either. Replace the carpet with space itself and the other guy with Earth and voilà ! (Sorry for my english).

[@malvoliosf]

My question is, why would you think a planet so close to a black hole that time is slowed down 1000x might be inhabitable?

[@CheeseDanish85]

Because you want to spite the other scientist on your team who you think is being emotional.

[@Deezy_Ankh]

​@@CheeseDanish85that was for the other planet.

[@अपना_रोहित]

the gravity will crush you

[@malvoliosf]

@@अपना_रोहित “I WILL CRUSH YOU!”

[@ahmedyaseen5369]

But supposing that the gravity is tolerable, humans will live longer than on earth

[@flanker909]

The best way IMO to wrap your head around time dilation is to consider these facts: - Velocity: All celestial matter is travelling through spacetime (not floating) - all celestial matter do bend spacetime proportionally to their mass and density, the more massive and dense, the more bend their create - This bending combined with the velocity cause smaller/less dense bodies to orbit bigger/denser bodies - All is intertwined in this celestial trip (bodies ---> planets--->stars--->galaxies---->clusters--->super massive BHs---->....etc) - Speed of light is a constant (hard limit that applied to everything in this realm) So with the above intertwined parts, trapped in an endless race through universe, there must something that should be flexible enough to keep things moving in unison and that thing is TIME! Time can expand and dilate while speed of light can not! You can not touch or see time, its a variable that exists in the matrix source code that runs the cosmos. EDIT: I would also add that the way we have decided to measure time (days, hours, seconds..etc) and the way we got used to seeing time measured this way is the very thing that keeps us from understanding what time really is. I think that time does not exist, only spacetime (fabric of space) and the speed of light do. I would thereby join @liquidmagma and @mattgee4867 on this.

[@morgan5941]

Now tie your clock to a light year and it becomes a constant as well and not variable at all.

[@liquidmagma]

No. Time is essentially made up, or at the most a side effect of gravity and mass.

[@x-cluster]

Time is not in the source code because it doesn't exist without an observer.

[@azilgaard]

Thanks. I guess your second point explains why the apple travels in a straight horizontal line while the ground travels in a circle...

[@RahzZalinto]

seems we are just comparing light. Not "time"

[@esotsm54]

Listen to me, you sir are the best KZbinr, period. Please never stop making videos

[@qandak]

1:02 Apple is not an emmiter, it doesn't emmit any color. Instead, it absorbs all waves in visible spectrum except red, so you see reflected red color.

[@Ajunadeeps]

Oh 😳

[@romcom6617]

Reflection is the term!

[@philh42]

Go watch the dark matter video and others on that playlist.

[@YooooouKnowwwww]

if you're not a professor it would be a crime against humanity

[@dronetheworld4k67]

He is Indian we can all forgive him...

[@makius1400]

Bruh... That ad transition was straight up devious... Bravo... Bravo

[@beepbop6697]

Love your vids that breakdown complicated topics into easily understandable chunks!

[@JusticeLeGrand10101]

That’s sad because if you understood this video, the only thing you understood was his imagination. Put down the pseudoscience and study astronomy for yourself. This guy is a clown! this KZbin video is promoting misinformation. read more nonfiction. Dictionary. Encyclopedia. put down the pseudoscience and study linguistics. silly Human!

[@overtoke]

being on earth makes you age "slower" too. no matter how 'slow' it gets you will always experience a normal flow of time from your perspective. like the water planet in the movie interstellar. they experienced a normal flow of time from their perspective.

[@Bellatticakes]

I am more confused than before watching this video

[@DhruvRed]

For the individual the perception of time will always the same but for the observer the time changes based on time dilation caused by moving at extreme speeds or extreme gravity

[@genghiskhan9200]

So the key To eternal life is moving fast 😄

[@philproffitt8363]

​@@genghiskhan9200Or maybe don't get a nosebleed...that's what finished Genghis apparently 😁

[@prahardarji6147]

​@@genghiskhan9200Nope for you time will always tick at the same rate, but u will be moving slower through the time "compared" to other's at rest. That's what relative means.

[@Aweal7]

You're honestly one of the best science communicators on the platform. Your passion really comes through too!

[@TomJones-op9nj]

Man !!! I look forward to going over your other videos your enthusiasm is absolutely contagious!!!

[@Robinson8491]

Thank you Mahesh, for showing me the connection between the cycloid (a rolling, rotating circle) and gravity in General Relativity I was looking for for 4 years. And it turns out to come from the master himself, Einstein! I love it ❤

[@actionpoker7C2H]

Loved using your relativity series to expand my knowledge and then finally intuitively demonstrate the concept of gravity being a fictional force to my friends. I made the flat spacetime graph, made the cone graph, and a figure to show Einstein's clock in like 15 minutes in a late night discord call. Started with Galileo's transformations on a train to introduce relative velocities, then used a thought experiment about what happens when Galileo lets go of the ball from the leaning tower of Pisa in terms of Newtons first and second laws of motion first from Newton's classical perspective where the ball begins to accelerate due to an applied force, and Einstein's where the ball remains at rest. Using your graphs, I showed how the equivalency principle shows us Einstein's alternative explaination for our observations. It was incredibly fun for everyone and I thank you for your efforts. For the sake of time (pun intended) and my own limited intuition I asked them to accept time dilation and that we observe it now in many ways but I suppose ill be threading in an imaginary space station next time. Its still hard for me to take a leap in this demonstration from objects accelerating toward eachother with zero relative motion to the idea they could accelerate away from eachother without relative motion. Luckily, I live in an area with gravity so I'm confident it happens 😂

[@JusticeLeGrand10101]

Your whole comment was based on imagination just like this video. Science rebukes imagination. Science is humans observing nature. Time, light and sound works simultaneously as nature. for example, we experience time through our star, the sun. we are our star. your imagination like this video is irrelevant. silly pseudoscientists! put down the pseudoscience and study astronomy. read more nonfiction. Dictionary. Encyclopedia. put down the pseudoscience and study linguistics.

[@Himanshu_Kumar_Sahni]

Einstein says that earth is accelerating upwards from every direction then suddenly put us inwards in a ring to explain that we are are accelerating towards centre, I mean dude seriously?

[@renedekker9806]

It is a comparison to make your understand that experiencing acceleration while not moving is possible. Gravity does the same, just in the other direction.

[@UltimateTobi]

@@renedekker9806 But why bring this up if he doesn't proceed to explain how it works for Earth? As he said multiple times: there is no "gravity", gravity is merely the movement of objects towards each other. If you invert the images back and imagine them spinning, the apple would fly off into space if it maintains its respective velocity. So... it's a stretch to explain to the viewer something but then ask them to just "trust me" and not answer the question. He did mention another video where it's allegedly explained, but asks the viewer to stay and "not get distracted", but to be honest? He lost me there, because I need that question answered now, because he brought it up and it seems relevant to the rest of the video. If it isn't relevant, why bring this up at all?

[@renedekker9806]

@@UltimateTobi _"So... it's a stretch to explain to the viewer something but then ask them to just "trust me" and not answer the question."_ - I cannot answer for Mahesh why he presented it this way, but I can answer why I would. It is very hard, almost impossible, to imagine the curvature of spacetime that General Relativity describes. We simply don't have the mental capacity for it. But we can draw analogies with other situations that we can imagine and that our intuition can understand. How things behave on a spinning disc, is one such analogy. Imagine a small room in the ring of a spinning space station, with its floor pointed towards the outside, and its roof towards the hub. What you would experience sitting in that room is very comparably to what you experience in the same room standing on the surface of Earth. When you let go of a ball, it will fall to the floor. You can feel the floor pressing against your feet when you stand up. The centrifugal (pseudo) force acts almost exactly the same as gravity does, only forcing you away from the centre of the disc, while gravity forces you towards the centre of a mass. But sitting in the room, and not knowing whether you are in a space station or on Earth, you will have a hard time finding the difference. The Equivalence Principle that General Relativity is based on, proposes that there IS no difference between them. That inevitably means that all effects that are observable in association with the centrifugal force must also be present in the presence of gravity. The time dilation that Mahesh talks about, is one such effect. _"I need that question answered now"_ - if you are seeking a deeper answer to the question why gravity works in the way it does, you are going to be disappointed. GR says that mass bends spacetime, and that this leads to effects such as time dilation. You can get a deeper understanding on what the all the effects are, and build up a better intuition about it. But the answer to the question WHY it works, is ultimately just: "because that it how it happens to be".

[@renedekker9806]

@@UltimateTobi _"So... it's a stretch to explain to the viewer something but then ask them to just "trust me" and not answer the question."_ - I cannot answer for Mahesh why he presented it this way, but I can answer why I would. It is very hard, almost impossible, to imagine the curvature of spacetime that General Relativity describes. We simply don't have the mental capacity for it. But we can draw analogies with other situations that we can imagine and that our intuition can understand. How things behave on a spinning disc, is one such analogy. Imagine a small room in the ring of a spinning space station, with its floor pointed towards the outside, and its roof towards the hub. What you would experience sitting in that room is very comparably to what you experience in the same room standing on the surface of Earth. When you let go of a ball, it will fall to the floor. You can feel the floor pressing against your feet when you stand up. The centrifugal (pseudo) force acts almost exactly the same as gravity does, only forcing you away from the centre of the disc, while gravity forces you towards the centre of a mass. The Equivalence Principle that General Relativity is based on, proposes that there IS no difference between them, and all effects that are observable in association with centrifugal force are also present in the presence of gravity. The time dilation that Mahesh talks about, is one such effect. _"I need that question answered now"_ - if you are seeking a deeper answer to the question why gravity works in the way it does, you are going to be disappointed. GR says that mass bends spacetime, and that this leads to effects such as time dilation. You can get a deeper understanding on HOW it works, and get a better intuition about it. But the answer to the question WHY it works, is ultimately just: "because that is how it happens to be"

[@XanBcoo]

​@@UltimateTobiI dunno dog, maybe go and watch the other video if you want to understand it?

[@yotube1ful]

You’re great! The love (more like passion) for learning and teaching is strong with this one 😅

[@gregorybrazell5133]

I'm subscribing, just because I want to see more of your content. This is the first video, and the way you explain things, the personality, etc, makes me want to see further videos.

[@AtharvaBajpai-r5o]

he is a gem to the world we need to protect it!!!💖💖

[@austin3789]

The real answer is that the larger the amount of mass there is concentrated in a region the longer it takes the simulation to process and therefore time slows down.

[@vallabhdeshmukh79]

how do you know we are in a simulation😈

[@fridgeffs5662]

@austin3789 this is the best explanation that I have ever heard 😂😂

[@susanogranados5892]

Wow… you truly are one special kind of stpd!

[@DieBieneFranz]

😂

[@crooger3594]

Beautiful and complitely logical explenation, provided there are infinite nr. of sim. This argument is supported by math and history shows us that all natural phenomenas now seen as a facts, were initially theories supported by math.

[@RicardoGarcia-sd1xb]

Amazing content as always!

[@tmanwattsutube]

Your enthusiasm for science is both awesome and refreshing!

[@avendeep]

Concise and impactful I rarely comment online, but this video compelled me to. Had I seen such content a decade ago, my life might have taken a different course.

[@minimumphase]

Now redo the explanation at starting at 4:41 with the part of ground inverted - the way it is on earth. With this explanation, the apple should move away from earth not towards it.

[@notafraidofchange]

6:34 … and less than two minutes later, Mahesh explains how the inverse is also true, how a rotating motion (not changing speed over time, like “straight motion” acceleration, but rather maintaining constant velocity and changing DISTANCE over time, which is also a form of acceleration), doesn’t necessarily make two objects fall away from each other and be flung outward into space (General Relativity and spacetime curvature expand upon how this is possible from a mathematical perspective).

[@UltimateTobi]

@@notafraidofchange He claims that, yes. But he starts to explain and demonstrate the first half, but then goes "trust me bro" on the second. It's unsatisfying.

[@BalthasarGelt-x2d]

The explanation is just an example of how you can accelerate without experiencing motion. Gravity on earth has nothing to do with its rotation, just its mass bending spacetime.

[@sdal4926]

I think Einstein would be proud of you.

[@dankuchar6821]

I'm sure he IS.

[@atheist8220]

He is not because he is dead. ​@@dankuchar6821

[@erdrickk]

I'm trying to wrap my head around this, I understand being closer to a larger mass such as a blackhole, you physicaly slow down relative to others, being further out you're moving faster (assuming we are orbiting) what I don't understand is why there is a time difference and I realize its a real thing, proved with our GPS satelites and their clocks having to be very slightly offset. But from my perspective, if I'm seeing someone move faster, why are they physically aging ? I'm having an issue linking perspective of time and physically aging, are we saying the slower we move relative to others, the faster we move forward in time? I gotta eat some shrooms and rewatch this LOL

[@erdrickk]

Lets say Earth was 100x bigger and I was able to drill down near the core (super powers) and I setup a couch, my NES, Commodore 64 and Xbox 360 and gamed for 100 years living off of hot pockets and Redline, you're saying when I finally emerge, I will be younger than the people near the surface?

[@toxic7829]

@@erdrickk Yes. And also, you will have lived a good life.

[@toxic7829]

Yes. Think of it like this. There is maximum time OR maximum speed. So if you dead still, your time will go as fast as it possible can. And if you go at maximum speed (speed of light), the time will stand still. You cant have maximum speed and maximum time at the same time. It's one or the other. So lets change the speed with gravity and you get the same result. The higher the gravity, the less time moves. Higher gravity = faster acceleration. Now this isn't a scentific explaination, but it may help you wrap your head arround it.

[@rogacz962]

This video explains it poorly. For everyday experience we can separate space from time. We can do mental gymnastics of teleport an object from point a to point b without intervening space and in zero time. Or we can do the reverse, pretend something doesn't move in space, and only ages with time. Under special relativity, neither is possible. Space combines with time into one construct - spacetime. And everything moves through it constantly. There is no at rest. You're always moving. But there is a limit to that movement. 'C', speed of light. And from PRACTICAL experiments we know that that speed is constant, regardless of frame of reference. So as you accelerate towards speed of light, in order to keep your measurement of speed of light at c, something has to give. And it's your measurement of time. As you travel along light at speeds approaching 'c', light has less of a distance gain to you, but you still have to clock it at 'c', so the only way for that to happen is for your clock to slow down, meaning that for your measurement of speed of light there is 'more time', and light can travel 'larger' distance. Imagine there is someone walking 10 paces in 1 second. And that regardless of how fast you move, and which direction, you always have to determine that speed at 10 paces/sec. A stationary observer will see them move 10 paces in exactly 1 second. Now imagine there is a second person walking, one which the stationary observer sees at 5 paces/sec. But when that second person attempts to determine the speed of the first one something weird has to happen. They can see the relative distance travelled as 5 paces, but they have to clock the speed of the first person at 10 paces/second. And the only way for that to happen, is their measurement of time, ie how fast they move through time part of spacetime, slowed down, by half. You can think of this as that as you approach 'c' your movement through spacetime is getting more and more skewed towards space, and your time component is getting changed as well. And with the realization that spacetime is not homogenous, and is instead impacted by gravity (from either mass or energy), you can derive the exact same observations, except the dilatation will be caused by disagreement on distance travelled, not on time travelled. But it all comes back whether you can realign your expectation on reality to there being a constant speed, irrespective of frame of reference. It's a big mind hurdle, because it goes against everything your everyday experience has taught you.

[@cservonyec]

@@toxic7829 time is still an illusion. There would be no difference how fast time is between two individuals, one standing in the exact middle of the Earth on the centre spot, not moving in any direction, just spinning slowly with Earth's rotation and the other standing still in his bedroom. For both it takes Earth 24 hours to complete one circle, but for the one in the centre, it will be less perceptible then the one in his bedroom, where he can register the changes in daylight.

[@MyNameIsSonsky]

Wow, I'm so thankful that the algorithm showed your video to me. This is exactly how my professor discussed back in college and I missed it so much. Simple yet entertaining and the information is very easy to digest. Subbed!!!!

[@MrBoybergs]

Could never truly get my head around this......until now; excellent explanation

[@NewtonDKC]

What would happen if the people near the center of the rotating space station started recording 2 videos - one streaming live, the other a stand-alone space smartphone that begins recording everything live at the center of the ship and keeps recording continuously whilst traveling to the outer ring (and has storage and power that will not run out). The streaming signal is broadcast while the space smartphone is continuously recording live the entire trip (and is put in a little escape pod and ejected toward the outer edge or traveling inside the ship on a little delivery Robot if it’s all connected and can reach the outer edge people). When the outer edge people start receiving the streaming signal, what do they see? Are there gaps in the broadcast signal, or does it show the center ship people in fast forward gradually slowing down, or what exactly would it look like to the outer ring people seeing it? Now for the space smartphone: When they receive the space smartphone they stop the recording (which has been recording without stopping the entire trip from the center people to when it reaches the outer edge people). They now begin playing back the recorded trip…does the video, now playing in their reference frame but recorded from its point of view in its reference frame from the center to the edge, what would that video look like to them? Would it start out playing super fast and gradually slow down or just be a super long, super boring video of endless hallways and passing by in “normal speed”? And just to be extra complicated, what if there were 2 devices recording, one digital and one on an old analog film recorder with rotating gears and wheels and endless videotape - how would the digital video compare to the analog recorded video with both now playing in this outer ring reference frame but recording all the time between? Does digital recording have any difference to the analog recording that had gears/wheels while recording? From the recording device’s perspectives time has just always been the same, but when the people in the outer ring frame of reference watch the recorded videos,starting the playback of both devices at the same time and watch them side by side…do they see video and hear sound that runs at different speeds from the beginning to the end? Do the 2 devices vary compared to each other? Or is just a boring standard speed video on both devices? How does the recorded video compare to the streaming video (if it had been recorded by the outer ring people while streaming and now also played back starting at the same time as the devices that travelled from the center to the outer ring? Hopefully this is an interesting thought experiment and not so obvious that I dont later think “why did I even ask that?” :-) And thank you, love this sort of thing; thumbs up and Sub’d! :-)

[@Bleacher22]

For everyone local time is normal, universal limit of speed is speed of light it means for signals and travels.

[@steventreadway9966]

The concept of these physics are quite profound. Without time, motion becomes impossible. This also means that motion and speed are affected by gravity in crazy and unexpected ways. Simply being in strong gravitational field does indeed affect aging. So when we “measure” the age of our universe which is expanding, was a year really a year when the universe was more dense? It certainly seems that 1 year very soon after the Big Bang could have actually been thousands or even millions of years relative to a year that we perceive now due to the gravitational affect of so much matter being in a smaller volume of a more compact universe.

[@alexshatner3907]

I am really close to a brown hole within 3 feet and I am still getting older

[@MrMoose1347]

Without motion there is no time*

[@MrMoose1347]

Age dilation isn’t real only time dilation. Aka the clock count

[@alexshatner3907]

@@MrMoose1347 But without motion, why so much commotion? Conjunction, junction what's your function?

[@MrMoose1347]

@@alexshatner3907 and?

[@erdrickk]

referring up to the first 6:14 or so with your graphic of the two people in the ring, I don't quite understand, your graph is showing the people standing on the inside of the ring, so in this case your explanation makes sense but people don't stand on the inner crust of a planet, they are on the outside and when I imagine this same excercise, with the people on the outside, it doesn't make sense to me. Using your explanation of "no gravativy" they would be flung off.... Here's what I mean - Does anyone remember the Gravitron ride at country or state fairs? if you're inside the ride, as you should be, you're stuck to the wall - as described as per his graph - but we aren't on the inside, imagine riding Gravitron on the outside? obviously you would be tossed out lol, unless the atmosphere acts as a layer pressing us down? pressure? ok I'll watch the rest, I was just confused by this part and wanted to type some thoughts.

[@erdrickk]

ok, I shouldn't have watched this video high LOL but @FloatHeadPhysics explains it so well, I love it, now one of my fav channels and regarding my above comment, I am diving into space time curvature and sitting here starring into nothing just wrapping my head around this, makes sense and going back to about 10:30 he explains that so well, its common knowledge that GPS Sat clocks are offset due to the time difference but I loved his explanation. Anyway, high as fuck and loving this.

[@choomanfoo157]

I always wondered this, I even did research, but no one ever said it so clearly as you, your example of the red apple was what I kept finding in my research, this is the first time I seen or read something that was clear on the concept, amazing, thank you for breaking it down for us all!

[@AishaShaw-cl6wc]

I never thought of things this way. This explains so much I have never thought of. Thank you.

[@maximivanov8467]

I've stumbled across one gap in the explanation that bugs me. In the spaceship, what really caused the time dilation isn't acceleration as such, it's speed. So to understand why gravity “causes” time dilation, we have to show that massive bodies somehow make everything nearby “move” faster. You've hinted at a solution out by showing that motion is a way to combine acceleration with constant distances, but it would be great if there were a way to demonstrate it more directly.

[@Mahesh_Shenoy]

"..isn't acceleration as such, it's speed". That's from the inertial perspective. From the perspective of the people inside the ship, they will attribute it to the centrifugal force.

[@shrivatsa8604]

You can imagin it like space itself is flowing inward towards the center, like water into a sink hole. When you are not resisting the flow you are under a free fall. And you are moving with your local spacetime but when you are on a surface standing, then you feel the force down at your feet , here you are resisting the flow of space hence you are moving through space , also the faster you move through your spacial dimension the slower you move through the time dimension.

[@akaHarvesteR]

Wow I came here to write _exactly this_. Wait, are you me?

[@youngguns2121]

​@@shrivatsa8604 this is a much more intuitive rationale than perpetuating the absurdity that all mass is under constant acceleration outward.

[@shrivatsa8604]

@@youngguns2121 👍🏻

[@guruyaya]

This is amazing intuition into a very hard problem. Great job

[@Bpg2001bpg]

Thank you. You are an amazing teacher.

[@goorlando1]

So good at explaining this. Really appreciate your drawings, put this in the classrooms. Love you

[@raphael52]

I just order the book. Thanks. Definitely thumps up and subscribed.

[@PHIplaytesting]

These are the realizations that helped me understand relativistic gravity and time dilation: - The "speed of light" is not actually the speed of light but the speed of causality, or the rate at which things "change", which is what cannot be exceeded. - Energy is basically "change." - Matter (and therefore mass) is energy. The more mass, the more energy. - The time component of space-time is affected by the presence of energy, or "change," which creates 4-dimensional deformation and curvature in space-time. And finally, - Objects in motion (that aren't accelerating) move in straight lines, but _not_ in 3D space as we imagine. They move in straight lines in 4D space (which is space-time). When we project 4D space down to 3 dimensions, the way we perceive the universe, those straight lines appear curved. So basically, causality has a "budget" of how much "change" can occur over time. Change takes different forms, including velocity, mass, and other forms of energy. The more accumulation you have of any one of these things, the less you can have of the others (within the limits of causality). So we perceive an increase of mass or of velocity as a decrease in other changes which we perceive as a decrease in or slowing down of *time!* These changes in time cause space-time curvature which affects the paths objects travel, and that's how we get gravitational motion.

[@BigSylvester]

Half of your statements are kinda right and half of them are absurdly inaccurate and just not true.

[@PHIplaytesting]

@AnubisTheSonOfRa You didn't provide any corrections though, so relativistically they remain true from my reference frame. 😌

[@BigSylvester]

@@PHIplaytesting Did you just say “my truth-your truth” in other words? 😂

[@BigSylvester]

@@PHIplaytesting Just because you asked, I will correct one of your statements:- Speed of light IS in fact the speed of light! 🤯 Who would’ve known?!😬

[@pund]

@@BigSylvesterNot him😂

[@ManishKumar-ui8pf]

Mind blowing animation sir

[@Physicsislife07]

Sir I have an very complicated doubt in 16:22 mins that is Einstein tells that it is due to Gravity the time slows down but also saying it is nothing but an illusion so last time again can you tell what is Gravity and why it slows time and the g arrow why is downward not upward??? Please ❤❤

[@DrDeuteron]

g is down because if you drop something, it falls down.

[@varunvaswani4562]

If you may allow then I would like to give the possible explanation. At the heart of it, what we perceive to be gravity is the equivalent of experiencing an accelerated frame of reference. In any case, gravity is due to the acceleration of ground towards us, due to the curvature of spacetime. It slows down time because again, it's essentially an acceleration. As per the analogy described in the video, such an acceleration, due to time dilation and special relativity, slows down time. Lastly, the g arrow in the rotating spaceship must not be confused with it being a planet or black hole. It is the analogy used to show how greater acceleration induces greater time dilation. Since the outer parts have greater velocity, they have greater acceleration. Hope it helps;)

[@logicianbones]

Gravity is the ground pushing up on you more and more (ground is accelerating up -- ground is moving up and the rate at which it moves up is getting faster). Whether due to mass attraction causing more time (see his previous video that he linked) or due to a centrifuge.

[@jozincarnate]

So the arrows that follow Gravity, think of them as a accelerated velocity vector away from the center that linearly increases as the difference between it self and the constant velocity vector for the rest frame (I think I am near but something might have gone negative so can anyone help correct me?). But space is flowing to the center of mass as the earths expansion accelerates to meet it with a slight positive velocity? Pls help answer Adrito and correct any mistakes in any explanations!

[@kylelochlann5053]

@@varunvaswani4562 No, that's no right at all. Time dilation has nothing, per se, to do with acceleration.

[@iliyailiev962]

I got hundred percent better intuition of the whole time dilation. Crazy i aways knew the concept but never couldn't explain to someone as such that they can understand it. Crazy Videos man keep on going :)

[@shankar7435]

By far the best explanation for the time dealation till date I found. Thanks.

[@DrDeuteron]

Another Banger, but I am concerned that you're perpetuating a grave misconception: that time dilation between two locations depends on the difference in their local gravity field strengths...which is a natural conclusion from the rotating wheel "model" (it's not a model: it is real gravity, but an analysis gets into Ehrenfest's Paradox, which is hole nother video). Bear with me: Where in Earth does time run slowest? Dead Sea?, Challenger Deep? The Kola Super-Deep bore hole? No: THE CENTER! (iirc, it has accumulated a 2.5 year lag since "The Beginning"). OK: what is the local gravity at the center of the earth: ZERO, ofc, by symmetry, shell th'm, etc etc. Time dilation between two points depends on the difference in the gravitational potential energy between the two points, and is not related to the local field strength, which leads to a fun fact: with Newton's kinetic energy KE = 1/2 m v^2 and Newton's potential energy PE = GM/r time dilation is: gamma = 1/sqrt(1 - 2E/c^2). with KE (PE) for relative motion (gravitational potential). with the formulae diverging at v=c and the Schwarzschild radius, respectively. Don't trust me bro, Trust Albert!

[@Mahesh_Shenoy]

Yes, you are right! I'll address this in the pinned comment.

[@theknown1741]

Time dilates slowly at the centre than on the surface? But how?

[@Happybro91]

​@@Mahesh_Shenoy* Ek X Banda h voh earth se 9000 light years dur h ... * Uske waha gravity Kam h * Humaare yaha zaada * Humare yaha usko 9000 saal baad dekhenge toh woh ... * 6-7 hr jeeke ... * Par uski aging fast hogi .... * kya yeh theory sahi h ?

[@DrDeuteron]

@@theknown1741 image the frequency of a photon (or a neutrino, if the shielding bothers you) as it leaves the center of the Earth. Is it fighting gravity and losing energy (frequency) the whole way up and off into space, or does it fall from the center up to the surface, and then start its energy-losing climb?

[@kylelochlann5053]

The gravity at the center is not zero. Recall that it takes 20 numbers to specify the gravity at a spacetime point. The Newtonian gravitational field strength is zero at the center.

[@dsd2002]

if time dilation is because light photon moving larger distance at angles, then its just that photon clock is just measuring time wrong, but real time is not dilating, right? we are just measuring it wrong with photon distances at angles.

[@steventreadway9966]

@@dsd2002 something that is mind blowing is that every massive object in the universe is in different measurements of time due to both speed it is moving through the universe and through the gravitational field it happens to be in.

[@lj5190]

THIS. 100%. This is the exact thought I have whenever time dilation is discussed. Just because a clock is physically ticking slower doesn't mean time is passing more slowly. When the batteries in my kitchen clock start to die and the clock slows down, time isn't slowing down. A clock isn't time... it's just a tool for measuring it, and tools are affected by gravity. The same goes for aging. Time doesn't age us... multiple other factors do like nutrition, environment, stress, exercise, genetics, and yes, gravity. It's why some 60 year olds look 45, and some 45 year olds look 60. Time is a constant. It is only our perception of it that changes. A "slow" hour at work is the exact same length as a "fast" hour at play. Time itself is a dimension beyond gravity.

[@अपना_रोहित]

it is measured by decay... atomic clock...not by dial clocks

[@Bleacher22]

@@lj5190 Time itself doesn't exist, it's a derivative quality of a universe with its matter. Time is called a rate of changes, so if changes are slowing down it means time is slowing down. The speed of light is not just a limit of light, but of everything that exist including fundamental forces, so if those forces are slowing down in atoms then in chain reaction also in molecules and cells which controls aging processes, ultimately making us age slower.

[@lj5190]

@@Bleacher22 Time and rate of change are two different things.

[@scorpionking8661]

I struggle with this theory. Time does not really exist… we as humans made it up and track it with clocks, watches, calendars, etc. you can’t slow down something that does not really exist. Our body clocks age at our own paces.

[@scorpionking8661]

Hoping someone can explain this to me.

[@Kishore_537]

I have the same question for a long time. We made the time to track some actions. But it is not constant for every planets. For example in earth 1 day = 24 hours. Which means 12 hours day and 12 hours night and it takes 365 days(1 year) to revolve around the sun. But for planet like jupiter 1 day is not 24 hours and 1 year is not 365 days. It will be more than the Earth. Because it is far away from the sun. So the 1 minute, 1 hour, 1 day, and 1 year are not Constant for all planets. Even though time concept is not constant. But 1 SECOND is CONSTANT in everywhere. And it can be slowed. So I don't understand what they mean by time will be slow? It will be different but not slow right? I'm not good in English. Hope you understand what I mean. Finally I found person with my same mindset in this topic. I need your reply soon😅😅

[@Grysham]

Totally understandable to struggle with this topic. Culturally, what we think of as time as a concept is very different to the reality of it. Time doesn't in and of itself exist, like you said. Instead time is a measurement of change. So why would that be different near a vlack hole? It makes a lot more sense if we think that when we age, when our body ages, what is happening on a minute level is the cells, molecules and atoms of our body are changing. Time is just a measurement of that change. So if something affects your bodys atoms in such a way as to slow down how fast they can undergo a state of change, that is what is "slowing down". Gravity affects space and time, when know this because when we use that model we can plug in predictions and calculations and they work, matching what we expect. Because of that we model gravity as bending space/time around it, like a ball sitting on a blanket bends the blanket around it. Gravity slows things on a subatomic level, so that a things mass (your body) undergoes change at a slower rate. Because everything is slowed, including your brain functions, it SEEMS like the rate of change for you is normal, but in reality it is just that the rate of change for your body and brain are slower than for an outside observer far away from the black hole. Time doesn't exist. All that's slowing down is how fast mass is changing states. Gravity affects that rate of change. Therefore, a black hole affects if even more because of how dense the gravity is around it. Let me know if that makes sense or if I can explain anything more clearly.

[@scorpionking8661]

@@Gryshamthank you!

[@Grysham]

@scorpionking8661 hey, glad that helped. You know whats rad? This whole thing of time dilation isn't limited to black holes. Those ones just have the most extreme (and coolest) situations. But here on earth we have to account for time dilation too. GPS satellites also experience time dilation, due to their distance away from the center of mass of the earth plus their relatively higher velocities orbiting the earth. This means we have to adjust our clocks to sync with GPS, otherwise you get innacurate results and the GPS doesn't work right. Same thing for space probes too. This is real science that we have to use here on earth.

[@kinleybottle]

I LOVE THE WAY YOU EXPLAIN THINGS!!

[@DavidHockenberry-dn2gi]

Your explanation is the only way I’ve ever been able to understand this concept. Thank you so much

[@Jeremy-dy5zv]

My question is if the people in the ship had walkie-talkies would the person in the middle sound like a chipmunk with a high pitched voice because they are speed up?

[@Mr_Bones.]

No, the radio waves would also have to travel a further distance and thus come in at a slower rate

[@pleasejustlmb]

bro i looooooooooveeeeeeeeeeeee your videos. they are soo awesome and on top of that they teach me sooo much. i hope you heart my comment😁

[@michaelbuckers]

If you do the math on the Interstellar's black hole, it turns out to achieve this ratio of time dilation you need to be within 100 km of its event horizon, well within innermost stable orbit radius, so nothing except an accretion disk can even exist there, nevermind a planet.

[@jimsty7550]

Okay but the movies script was heavily critiqued by the world renowned theoretical physicist Kip Thorne. Nearly every part of it was heavily researched, critiqued and calculated by Kip Thorne. That said, I trust his opinion on Miller's planet being theoretically plausible more than your vague KZbin comment.

[@thehighway3695]

Wow bro you know a whole lot about something nobody's ever seen.

[@hansisbrucker813]

I just love your videos. They give me so much understanding 🤓👍

[@dishant_7]

Am glad i came across this video, enjoyed every bit of it. Thanks a lot Mahesh for the amazing explanation ❤

[@herculesicarus1518]

Clocks are machines used to measure time, sometimes machines malfunction when used in unsuitable operating conditions, apparently acceleration/gravity affected a ticking clock and the clock started running slow(malfunctioned), that doesn’t mean time ifself has slowed.

[@Deadgye]

What is time that matters, then? As humans, I would think the way our cells age and the way unstable matter emits energy is an application of time. If matter is technically expanding and accelerating, then that emission fits into this model of having to travel a larger distance and given the constant maximum speed cap it would emit / degrade slower, relatively. Likewise, I assume the cells of our body would experience something similar if they were robust enough to survive the difference.

[@bijoykrishnachakraborty3103]

Relativity doesn't talk about any mechanical clock to measure time. Assume , someone is in a train, stationary to platform, shines a light to the floor of the train and notes the time interval as a unit time. This unit time will be same for the person inside the train and the person in the platform. Now the train moves. For the person inside the train, the distance travelled by the light is same as before in that unit time. But the person in platform will see that the distance travelled by the light to reach the floor is longer than before. So to reach the floor in same unit time light has to travel faster in the moving train , isn't it? But speed of light is a constant to every observer, physics can't be different for different persons, right? So, if speed of light is same in the moving train , then the time in moving train must be slower, so that light can travel the longer distance with speed same as before - this will be observation of the person in the platform. From the perspective of the person in train , nothing has changed. The time dilatation here not absolute, it's not that the "time" inside the train has slowed. There's no such thing as "universal time", everyone infer it from observing the changes. A person in a different trian will infer a different time scenario for the previous train .

[@TazTalksYouListen]

I had to stop watching when you said 01:03 "apples emit red color" when they *_reflect_* red color.

[@atheist8220]

Bade hoshiyar ban rahe ho...?

[@kaltziferYT]

7:50 not ok yet. Not explained.

[@jaydavis4752]

I agree. I once I watched a video of astronauts in the space station. I remember seeing a big water droplet in their habitat with small droplets around the larger one. The smaller water droplets were attracted by the larger one. Straight away, I thought this was what gravity really is. I realised its mass was allowing the smaller water molecules fall into its own space time curvature. So I don't believe Einsteins theory that the floor moves upwards to meet you.

[@andrews6013]

Oh thank God I'm not the only one. Now, I'm not the best with math, but I'm not scared of it. Didn't shy away from them at in college, and philosophy was amongst my favorite subjects. The foundation blocks are the same. Up till this point in the video I would have looked Einstein in the face an said that intuitively makes absolutely no sense.

[@kaltziferYT]

I read few pop-science books about special theory of relativity, watched few videos. But it still haven't convinced me.

[@sandbach7195]

This was incredibly helpful, thank you!

[@frantri3246]

Wow! Now I understand how an active livestyle keeps you young. Running a lot simply let's your clock tick slower. Brilliant!

[@chaos6876]

Why does mass cause spacetime to be curved?

[@mathura08]

Space curvature is just theory, it's just assumption We really don't know how gravity works practically

[@mathura08]

If time is really higher dimensional thing then I think we can't really explain how it works practically

[@jimsty7550]

It's because of the gravity produced by the massive object that curves the path of light. By curving that path for photons to travel, it slows down the photons, whereas on a flatter grid that is not being influenced by the gravity of a massive object but rather a smaller object of less mass, the photons move faster in that straighter line due to the weaker gravitational pull of the smaller mass.

[@jimsty7550]

@mathura08 say that to the people who have to account for the time dilation that occurs on our man made satellites in space. They move through space a little faster relative to anything here on Earth due to gravitational time dilation and scientists have to constantly account for the small time slippage in the satellites internal clocks because if they don't, things like the GPS's you and I constantly use would be completely out of whack. So no, it's "not just a theory"...

[@chaos6876]

Relativity doesn't answer my question because general relativity is just a mathematical model, derived to fit an observation(s). It can explain what is happening, but can't explain how it is happening. IMO, spacetime is the means by which everything is entangled at a quantum level. Here is another question: when a high energy photon decays into an electron and positron, what's happened to the original photon? Has it ceased to exist?

[@agg735]

I still didn't get it intuitively 😢

[@carlossaraiva8213]

The universe doesnt care if we get it or not.

[@Clarence_Oddbody]

Gravity doesn’t slow down or speed up time, because time only exists as a unit of measurement. What gravity affects is relative resistance. More gravity, more resistance, so our metabolic processes slow down as everything on a subatomic level is slowed by increasing gravity. In low/no gravity things move faster, so we age slightly faster as everything is moving faster with the reduced resistance.

[@Grysham]

Exactly, well put. Gravity and interestingly speed both map together to affect time (which is just the rate of change of mass within an spacial area). All that's really happening is the rate that mass changes on a subatomic level within the sphere of infuence is reduced by the resistance that high gravity or high speed pose. Considering that as you approach the speed of light, time for the object travelling close to the speed of light appears to slow, this suggests that it's to do with the resistance to changing energy states that's affected and that time (the rate of change) must be tied to energy in some way. The less resistance to the rate of change, the faster mass can go through it's subatomic changes.

[@Turbomantom2]

You're talking about gravitational stress, not "age"

[@supermanny26]

That's the explanation of time dilation that I've come closest to understanding. Great way to explain it. Thanks!!

[@aronlisy6108]

Woow! This is an amazing video! TBH I was quite sceptical when I clicked on it, but it is so perfectly explained! Great job! I love it!

[@hv9260]

So u r saying a tomato will perish quickly if its placed in merry go round instead if its placed away from it? When i as a child used merry go round in parks, i felt the world is fast forwarded but in reality its just visually moving faster. It didnt make the other kids in the park age more when i finished it. I still dont understand this time dilation concept.

[@WildAnimalsUncut3]

If his explanation is true, time dilation exists then it has to be demonstrated/experienced within this world itself. No changes is seen like in a merry go round, g-force testing sites etc....Nothing has been changed.

[@atheist8220]

Check time dilation formula. The velocity of object needs to be very high, at least a few thousand kilometres per second then one can see the relativistic changes

[@ahmedyaseen5369]

But this explanation goes opposite to the fact that a guy in space would age slower than a guy on earth.

[@felixdempsey4919]

That's time dilation due to orbit speed, this is time dilation due to gravity

[@michaelsiggers1362]

​@felixdempsey4919 I'm with Ahmed. He 'said' the models were due to gravity and not speed, but I missed where it said why or how. All I heard was that time moves slower because we're rotating and we say it's gravity because it's simple, but its really just velocity. I know that's not right but this one was tough, unlike literally all of his other vids

[@michaelsiggers1362]

@NikkiTaLance Hold on.... So we're only experiencing dilation and gravity because the Earth is spinning at the speed is spinning?? So if there were no rotation or movement there'd be no gravity??? This goes against everything I thought I knew about vectors and centrifugal force! By no means am I saying you're wrong, I'm just dreading having to go back to the drawing board😭😭😭

[@ahmedyaseen5369]

@@felixdempsey4919 both occure at the same time.. If an object is orbiting around a mass then it must be affected by its gravity, right?

[@ahmedyaseen5369]

But the aging difference experienced by someone who travels in space away from earth and back is not explained here

[@JD-ow6sc]

Ok, none of this makes sense. Your example has the person closer to the middle of the object experience a faster clock and aging faster, while the person on the outside is traveling faster and experiencing MORE gravity but yet ages slower than the other person? Also the explanation of the earth pushing up instead of the apple falling down makes even less sense. In the example the apple continues to follow its trajectory until the earth rotates and stops it, giving the appearance of it falling, but if this were true then wouldn’t that mean if you were in the middle of the North Pole you would experience no gravity? Maybe I’m misunderstanding

[@Dirtynapkin]

1. Min 11:02 explains it, that the faster you move the longer light has to travel, because it's going a further distance. 2. That's because the earth is a sphere and not a disk. It's just perspective, you can't find the center on the outside of a sphere. I get it, it's confusing.😄

[@DkingE39]

Great insight ane great breakdown I have asked these questions for years n stared this as my hypothesis

[@spartanbanjo2118]

Omg someone finally explained time dilation and i finally understand it tysm bro ur truly the goat

[@bharathhm2215]

Hi Mahesh, Considering the image from the frame 10:15 of this video, We calculate Time = Distance/Speed. Having Speed as constant. We see the outer point can cover longer distance than the inner point as both points be on the same radius. So by doing maths we can see time with the inner point move slower than the time with the outer point. Which don’t accept Einstein’s theory?

[@themfu]

Great explanation and enthusiastically presented, well done!

[@Rich-r7f]

Excellent explanation, and funny as well! Great Job Mahesh!

[@Vitorgsd]

This is insane. One of the best explanations I've seen.

[@janosterz733]

Sir, you just blew my mind. Thank you for this

[@mouse2588]

Brilliant! I had the hardest time for so many years understanding this!

[@stevenpike7857]

So if I am on the edge of the event horizon of a black hole and look out at the planet far enough not affected by the black hole's gravity - time is going by faster than for me. If I had a telescope - for the sake of argument strong enough to see what's going on, on the surface = then they would be zipping around and I would perceive their time going faster than mine? What about the light I am using to see them with?

[@jnx2003]

This is the first video of yours that I have seen and it was very very good I will be watching more, thank you

[@20.keshavmore86]

I discovered this channel and oh my i am just binge watching every video. Your explanation are brilliant. Better then veritasiums explanation. Keep going 🏆

[@kenk5269]

surprised with the very clear explaination. its so digestable and easy to understand.

[@dawienel1142]

Great video, but I see you are mixing up the two a few times. I will add one example but there are atleast two times that I noticed. 13:50 (your visual was correct at 18:20) Closer to the centre you barely age (as in Intersteller) further from the centre you age more. With intesteller the space ship was further from the black hole than the planet they went onto. Furthermore there is a lot wrong scientifically with intersteller here, xray radation being one, the planet is also too close to sustain a stable orbit and would probably be ripped appart almost immediately. Lastly time dialation wouldn't be nearly as severe as portrayed in the movie. For anything close to the movie time wise you'd already be past the event horizon. Still one of the best movies based around this, would love to see more come out in this genre. Loved your explanation of angular momentum creating the illusion of gravity, still super hard to fully grasp though, but one day I will get this XD.

[@johnplaysgames3120]

I've seen a lot of people point out the same things that are "wrong" in Interstellar, but Kip Thorne explains in his book about the movie how it actually works. In fact, in his interview with NDT, he tells the story of Christopher Nolan coming to him and saying that he wanted to have a planet in the movie where 1 hour would equal 7 years back on Earth and Thorne told him it was impossible. His reasoning was the same as all the arguments about why it's "wrong" that you see in comments under YT videos (and let's be real: Many people are just repeating stuff they've read from other commenters or that they saw in another NDT video from before he interviewed Thorne and was corrected). Nolan told him, "Go run the numbers, bc I've learned that your first reaction is to always say no and I want you to check if it's actually impossible." Kip went and ran the numbers and found, to his surprise, that it actually was possible if the black hole was spinning fast enough. I don't remember his exact quote but he basically said that you could get pretty much any amount of time dilation you wanted if the black hole was spinning fast enough. When NDT talked about the other person who told him that the time dilation in the movie was bigger than it actually could be IRL, Thorne said his calculations showed differently. And he explains how in his book on Interstellar. He said the size of the waves were slightly exaggerated for visual effect but also based on actual math and science. The orbit also works and wouldn't shred the planet apart, also because of the size and the speed of the spin of the black hole. In fact, BECAUSE Gargantua is so big is why the orbit can be so close. It's counterintuitive to people who don't know much about the physics but that's actually how it works. In fact, the only thing that is straight up "wrong" about Miller's planet is the apparent size of Gargantua in the sky. IRL, it would take up half the sky but Nolan wanted to save the close-up shots for other parts of the movie, so he chose to make it look smaller from the surface of Miller's planet than it actually would. Rather than write a novel here, I'll just point you to two sources (other than Thorne's book) that sum up why Miller's planet is actually not "wrong": - www.reddit.com/r/interstellar/comments/2mt73w/faq_millers_world_spoilers/ This pretty much just states why/how it works in layman's terms (if you're not a math guy). - relativitydigest.com/2014/11/07/on-the-science-of-interstellar/ This gives the math, if you're a math guy. Or, y'know, read Thorne's book. Dude won a Nobel Prize in physics. I trust his word that it works WAY more than I trust any rando in any comment section, social media post, KZbin video, or podcast. And he can show the math to prove to you that it works.

[@dennisk5818]

New subscriber, BTW. The title caught my attention, because this is one topic that I've really got to focus on. Your discussion seems great. But, having only a novice level of knowledge regarding Relativity, as an engineering/technical person, I'll have to repeat this a couple of times in order to draw my own metaphors and explanations.

[@Aeneas137]

instead of thinking of time dilation in terms of acceleration, I find it is helpful to visualize the space-time near a black hole is more dense causing everything to slow down. traveling further within the same distance.

[@johngore3364]

I never thought I’d understand physics. But this easily explained things. Wow

[@PravaRusija]

Holy shit! As a humanitarian, I never thought of reality this way. Glad I found you, Mahesh!

[@jusore]

If the flow of time depends on fluctuations in space-time, it would be interesting to think that the higher the density of space-time (center of mass), the more viscous space-time becomes and has a lower ratio of fluctuations, resulting in a slowed temporal flow in reference to others outside the reference frame.

[@ACW3DDesigns]

Good Video man, love to learn this .

[@michaeljang320]

I really like your videos, and I think you have some great ways of breaking things down to make things feel intuitive. One thing I find is missing from this video, though, is a link between the model of the spinning space station, and the reality of our experience on a planet. It’s a great model if we look just at the effect of gravity, but with the space station model the acceleration causing the experience of gravity increases the farther away you get from the center, where is on an actual planet it’s the opposite, and someone standing at the top of a mountain is actually travelling faster through space than someone standing at sea level, and yet the experience less gravity, which is the opposite of the spinning space station model. Still having a hard time getting an intuitive understanding to bridge that gap

[@MrValentinho13]

Really really educating video. Thanks man, your way of teaching people is close to perfect 😊