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* 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 ?
@@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.
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!!
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.
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.
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!
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.
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
@@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.
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.
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.
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.
@@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
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!
5:35 my brother, I love watching these type of videos, although I may not understand 90% of it. Let me just say it 5:30 mark, the way you broke down the apple falling towards the ground versus the ground, moving in the path of where the Apple was going just blew my mind. I never make comments on pages, but I’m taking time to tell you, bravo. I’ll be following your page for a long time!
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 ❤
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 RUclips video is promoting misinformation. read more nonfiction. Dictionary. Encyclopedia. put down the pseudoscience and study linguistics. silly Human!
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 😂
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.
Mahesh Sir, I'm a big fan of yours. I have 2 physics questions. 1. A piece of ice is floating in a glass full of water. After the ice melts, will the height of the water increase or be equal? 2. Suppose I'm carrying a large stone in a small boat in a swimming pool. If I throw the stone in the pool, will the height increase or be the same as before? By the way, I learned the Archimedes law from your video in Khan Academy. Absolutely amazing!
I absolutely LOVE the way you explore these concepts as a conversation with the physicists who elucidated them. I feel like this lays a foundation for true understanding of the processes rather than simply learning the principles and memorizing them. I’m about to complete a physics II course, likely the last of physics I’ll ever take because I’m studying biology, but I will continue to watch these videos because I think chasing a deeper understanding of our world as a whole is very valuable! Thank you!❤️
Okay the explanation is cristal clear and I love it. Question from previous video for the context to the current question. - But why time gets curved by mass in the first place? Why does Earth's mass equal more time at the ground? Edit 1: I've just watched this video and I will reformulate my question: Why do accelerated frames of reference (like the ones created by masses's accelerations towards each other) create time dilation in the first place? Edit 2: And why space also expands with mass?
It’s because we move at light speed through space time. If we move faster through space there is less speed to go through time, and vice versa. Usually most of our speed is through time. But if you go very fast it reverses.
The qualiry of your contect is way abouve channels even like vertasium. Thats what I feel. I had cofnisons on relativity for many years. Thanks to you that things are getting clear
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.
"..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.
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.
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.
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* 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 ?
@@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?
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.
Brilliant is exactly the right word to describe you. That explanation was so clear and to the point. Please keep making videos like these they are marvelous.
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 ❤❤
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;)
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.
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!
I like that you essentially derived the underlying mechanism for WHY time ticks at different rates, essentially using photon clocks. However, I find the model much easier to understand where we are always moving through spacetime at the speed of light, so moving faster through space causes us to move slower through time, and vice-versa. Add to the curvature of space under gravity and objects not under acceleration always moving in straight lines through curved spacetime.
I think comparing gravity (which is not a force) with a centripetal force (which is a force; the electromagnetic force to be exact) will only help as an intuition for what is actually happening and only muddles the water from there on out. The difference is that the centripetal force is actually accelerating the observers where as it's the space-time curvature itself that is responsible, which is definitely not an acceleration. Problem now is that we are back at the question from the beginning of this video. You should have sticked with your older explanation, which I'm glad you mentioned so that other people can learn it the proper way. 2 objects falling onto earth at different altitudes with the same initial speed will have different moving clocks although they don't accelerate; they are just moving in a straight line trough curved spacetime, meaning no acceleration and no change in their speed; and yet time dilation still happens.
I can't get enough of the intuitive explanations. The model is inverted in respect to the observer to simulate gravity so the direction of the simulated gravity is also inverted in respect to the observer. I almost got hung up on the difference between the planet or black whole from the ring model and which way the arrows point.
17:27 That depends. If you are near a supermassive black hole, the gravitational gradient is not so extreme, so the smaller the black hole, the larger the difference between distances. Clocks will tick similar near a supermassive black hole, but will tick wildly different near a stellar mass black hole.
@Mahesh, hi. I just happened to watch the video about gravity and the curvature of time first, and that video makes more sense and explains the gravitational effect better, so much so that it contradicts this one (in my opinion). Let's see. I can understand the concept of gravity being caused by centripetal force as demonstrated in this video, but this doesn't apply to our planet, because we don't walk surrounded by an external wall, on the other hand, this would mean that those living at the equator would feel the maximum attraction and those at the poles would feel its absence. Question 2: If gravity is a rotational consequence, what would happen to 2 objects with the same mass, but one rotating on its axis and the other stationary relative to its own axis? Would the gravitational force be different? In any case, the way in which the explanations are presented is really intuitive and explanatory, and makes us reason in a scientific way.
@@CCave-wj6xy So do you expect Mahesh to alter his explanations to accommodate for every possible misinterpretation? What are you even complaining about?
This is by far the video of the millennium to me.. for someone who studied physics during non youtube times..👍 Pls continue to make these videos .....dont stop.
In my opinion this explanation is an elusion as usual. It is true that both speed and gravity slows down time keeping but as it has never been explained how a big mass bends space time more than a small mass without having some kind of influence (force) from the mass I can't see why we might not as well use the old explanation. If you have an oscillating (like a pendulum) electro magnetic signal in any cell, atom or even the smallest particle then if it moves it will take longer for the signal to go from one side to the other and back for the oscillation. This will slow down time keeping. The faster the slower but it is not linear. It is there fore no big deal that if gravity influences light (as I believe has been found although I am still skeptical)) and light is an electro magnetic emission then time should be measured slower in a strong gravitational field. Mahesh is very smooth and fast in his explanations just like a magician. One must take it very slowly, stop often to think about it and then verify and I must admit it is difficult. Albert Einstein must have been the same as many of his explanations supposedly where not even his own.
WRT the person at the center of the spaceship, the person at the far end isn't moving and remains at rest (assuming both are standing). If their relative velocity is the same but their time flows differently due to varying acceleration and increased gravity, it would be strange. The person at the center would see the one at the far end waving their hand in slow motion... your explanation just made another of reason of time dilation more clear to me!
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.
"The speed of light is the same in all reference frames, that is why [we have the time dilation effect we call gravity]. Do you now have a better understanding [...]?" No. Like you said, it's like explaining why an apple is red by saying it's a red apple. How does mass cause the path to extend?
Thank you. Terrific video. I've been saying for some time that spacetime curvature is, in fact simply time dilation. When light travels through space it is always travelling in a straight line from its own point of view and what makes it lens and bend to an observer is in fact time dilation, to keep the velocity of light constant and dilate time to another frame it also passes you effectively curve the distance between them. It's an illusion, spacetime curvature is just a topography of time dilated frames of reference. But this revision of Einstein's explanation using relativistic acceleration explains it much better than I do. Time dilated frames of acceleration reference as topographical gravitation is the term I'll use from now on.
you are the best teacher by far ! I love your videos ! I have another way to explain this but I am not sure if its correct or not. the big mass of the star (or blackhole) creates curvature in space time, which make the space around it more dense. for example 100 meters in empty space will dense into 20 meters around the star. so when I travel 20 meter near the star I actually traveled 100 meter at the same time. which means I moved faster by a factor of 5. thus creates the time dilatation due to faster speed.
Gravity in general relativity is due to the curvature of space-time caused by mass, not rotation nor velocity like in special relativity. The concept of how much "effort" spent in which dimension, spacial or time, is apt though. The analogy of stopping the rotation to stop simulated gravity does not correspond to how gravity works in reality. General relativity explains that near a massive object, space-time is curved, and this curvature causes time to slow down, a phenomenon known as gravitational time dilation. Gravity is not a force but a curvature of space-time caused by the presence of mass. Objects in a gravitational field follow curved paths, and time passes differently depending on the strength of the gravitational field. Near a massive object, space-time is strongly curved, causing objects in this region to experience a slower passage of time because they are in a stronger gravitational field. Conversely, far from a massive object, space-time is less curved, and objects experience faster passage of time due to the weaker gravitational field. This occurs because, near a massive object, more effort is spent moving through the spatial dimension, leaving less time to tick by in the time dimension. This is similar to special relativity, where increased velocity results in more effort spent in the spatial dimension, causing time to slow down for the moving object relative to a stationary observer. Being stationary near a black hole with no velocity further demonstrates that it is the curvature of space-time, not velocity, that slows time.
I thought I understood "why the clocks tick slower", but after this video, I realise I only "knew that clocks tick slower" without fully understanding why. This explanation helps me see why...
Didn’t realize the Feynman technique was called that! Whenever I learn something or am doing homework, I try to pretend like I'm the teacher explaining the homework problem to students and it helps me learn a lot more. So yeah, that technique is applicable not just for youtube videos. Try it out if you're struggling in a class
Damn! Even though I knew that time is relative, subconciously I still believed in the newtonian model of Gravity and time. Your approach broke my entire concept of time and you won't believe how happy I am right now! Thank you for shattering my concepts and bringing me into the new realm of relative time.
The speed of light isn't a constant; it's more likely that it's the amount of time it takes for a given area of space to process all the things that need to happen. A black hole isn't an infinite dense point in space, it's a powerful energy conversion machine. With more matter/energy you have slower time, which is effectively the frame rate of the universe. The reason light can't escape it isn't due to gravity, it's due to the way energy currents function in space. These energy currents hold the galaxy together, but if there is more energy than can be converted and sent into the galaxy, you'll get a pulsar, which is the method it uses to dump energy. These would be equal to the auroras on the planets. Hope this helps! edit: Aging slower is just a matter of each frame taking longer to process. Going fast means more processing per frame. It's a lot simpler than this mathematical model being described.
Duse, you have such a fresh way of explaining things! I've watched hundreds of science videos, and so many of them repeat the same words as each other, but I'm always thrilled to find a fresh perspective~
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! :-)
Just don't stop to keep building up the intuition videos And I'll ask to even make videos about some other physics topics like i am very in statistical mechanics and quantum mechanics Although I am enjoying the series 😊
I don't like that you describe gravity with the parallel to the centrifugal force. Gravity is because space moves towards mass (spacetime curvature) and the ground stops you from moving with space to the center of the planet, Star, black hole. This also means that you are moving relativ to space, not because you are moving but because space is moving and moving objects are time dilated. This is how i understand it and im pretty sure it's true.
Food for thought: If gravity slows down time, and affects space-time curvature, near black holes, it's so intense that light practically stops. Why does it stop if light speed is a constant? Well, the space value of light speed remains constant, but time is slowed down to a stop. That means that inside a black hole's event horizon, time is so slow that light from the start of the universe is still there. That's why a black hole is black. Because light from it never came out, yet. So, does that mean that the black hole is really a hole, or a deformation on space-time? Or is it maybe a star similar to a neutron star, with such a massive gravity that slows time to a stop? And the measurement of distance of stars? Is it really that viable, when we know that light when near a massive star can move slower than it should? What about light coming from another galaxy? Is light's time factor moving faster in the empty space between galaxies where it's not affected by gravity? Because, time as we perceive on earth maybe very well be already very compressed, compared to the void between galaxies.
Time itself cannot be manipulated,only energy such as light can bend. Also the same mass cannot occupy different space no matter how fast you travel. If you can travel faster than an image can travel than you can see yourself starting a journey but that ofcourse is only an image
The way I imagine it: the center of the circle is the black hole or point or intense gravity, and any circle you draw around the center is a timeline. So, to draw a complete circle, even though it may seem like line physical lines take the same amount of time to be drawn, the "length" of time (the circle) is longer.
I constantly have the problem with this sentence: "imagine you see someone who is moving very fast". I can't imagine this "physically". Because now it's all pure "mathematic" - not "biology", not "reality". If something is moving very fast - you can't see it - because it's always "running away" from you point of view. But in your example with rotating spaceship - the object and the obesrver are "still" in relative to each others. So we see the object constantly. So it seems? But, what does it means "to see" something? That means the photon reflected from that object hit our eye, right? Only at this moment we could use word "I see it". But it takes time for photon to move from the object to our eye. So maybe, all this time dilatation is just simply an "optical illusion"? We don't see the real state of that object in THAT MOMENT - we just see "a picture" of that object, that came to us - delayed. At the time we get the picture - the object moved and he is at different "state" than we see on the picture at that moment? You should draw a path on which photon moves from object to our eye (in your rotating spaceship example).Is it straight line? Is it curved line? So right now it's just an "optical illusion", we see him "slower" because we get "delayed pictures" of his state. But it doesn't explain, why this "illusion" doesn't work when the object observe us! :) Why he don't get "delayed pictures" :) An also, it all seems like "optilac illusion" but then all stops and we call the object "hey, come to us to the center". He comes to us and then we see that he is really younger than us!? So it's no more "optical illusion" it's a biological reality! Something must happend during the time he was going back to us? Sorry. I still don't get it :) I mean I understand the consequences of 'mathematic rules' that provide that theorethical conclusions. But I CAN'T imagine this in reality.
The model using centrifugal force to describe gravity is very clever, but this model only holds true when the person holding the apple is already standing on the ground and all three body have been combined into one object beforehand, It does not explain the formation of the system. The video you described space-time curvature is what really blew my mind. Even now, I still feel it’s beyond my comprehension.
This one gets me the speed of light is constant for all observers... time dilation means seconds pass differently so light has to slow down in gravitational field in order to match time dilation so that speed remains the same. And vice versa.
I have seen it explained like this as well. If we accept that time slows down closer to large masses, then gravity becomes like motion in a river. In a river, sometimes one side is flowing faster than the other. If you place a boat on the river, the faster flowing side puts more force on the boat, causing it to turn and move towards the slower side. So, if time flows faster out in space than it does on the surface of a planet, then we are all just being pushed towards the surface by the differential flow of time
@@kylelochlann5053first of all, not my idea. Second, it’s not meant to be a detailed mathematical explanation. It’s meant to help people intuitively understand the concept. And it does that.
There are so many unaddressed realities making the notion of a ship on a surface experiencing slowed time compared to almost normal just a few hundred miles above in an orbit. Even accounting for orbital plane of the craft vs orbital plane of the planet, the planet could never exist experience such a massive shearing of time and space across its own spinning diameter. Plus the was gargantua which had a very gentle event horizon due to its massive size making it more survivable of a black hole to fall into. Assuming it even was a black hole instead of something similar and artificially created for us by future us? The physics of Interstellar were recklessly abusive to physics and did not even try to address these enormous flaws. Still a great movie.
it seems so small, but the relativistic effects on GPS satellites are actually HUGE! they would fail so fast without extremely precise programming based on their altitude
Hi, and what about moving faster? If we have strong gravity/acceleration time ticks slower. But if you move fast without any acceleration you won't feel and gravity/force but you still should age slower than someone who is not. What's the difference?
16:45 the gravitational field decreases below the surface and is zero at the center. If you assume a uniform density, then the decrease is linear. So the centrifuge model is not that differnt, just the direction is reversed.
Yeah, it's the "Shell model", and Isaac Newton himself figured out that your weight will decrease as you go deeper and deeper into the Earth's crust. Eventually at the Earth's center of mass you would be weightless. And, this has been experimentally verified in caves and well shafts. The core of the Earth feels weightless and in an inertial orbit around the Sun. It is at a million atmosphere of pressure of course, from the 3000 miles of compressed rock and metal above it. That's the pressure you feel as 9.8m/s² of acceleration at the Earth's rocky surface.
Now, when I think about it, the rotating spaceship experiment is actually a bit deeper and creepier. If the person at the center of the ship could see the other person with his eyes throughout this whole time, not only that other person would age slower, but all his movements and everything around him would be in slow motion. And vice versa, the guy at the middle will appear in fast-motion. 🤔 But what would happen if one starts going to the other person's direction?
I've had a question I'm hoping you'll address about approaching the speed of light or the event horizon of a black hole. The science communicator channels all seem to agree that when your ship exceeds the speed of light you disappear but they don't ever mention red shifting during the process. It seems to me that it wouldn't be an instantaneous switch from visible to gone, and that after the boundary is reached(supposing it were possible) you would red shift into invisibility as your ship accelerated further. From the point of view of the the ship going into the black hole it would look like the rest of the universe was moving on and aging more and more quickly, I think, and an outside observer would see time slow down and stop for the ship then it would appear to fade into infrared until it became undetectable. What are your thoughts? Edited for clarity*
The first part is unclear, specifically, what you're talking about when referencing matter moving at or faster than the speed of light. A ship approaches the horizon, the distant observer will observe the luminosity and frequency to sharply decrease and the ship vanishes.
Yeah, the red-shift happens exactly in proportion to the time dilation _because they are exactly the same thing_ A lot of pop-sci entertainment explanations of relativity are bad because their sources are other pop-sci explanations, and it's a big game of telephone and no one ever bothers to actually read a physics textbook.
This is beautifully explained; but I take issue with the aging piece in interstellar. Because the human body would still age at the same rate regardless of how fast the clock is ticking unless we’re inferring that gravity also slows down the aging process. Sure 1 day may be longer further away from earth, but I don’t see how that would change the rate at which a human ages. I also can’t fathom, how “1 hour” 200,000 miles away from earth would differ from 1 hour on earth. Because to me, 1 hour is still 60 minutes regardless of how far from earth you are.
First, the effect is relative. (Hence, why all this is called relativity). That is, each person wherever they are located in space, doesn't notice any change. The change is noticed when people at different locations COMPARE to each other. Secondly, instead of using some type of man-made device to measure how much time has passed, it is just as valid as using your heartbeat. Typically, a healthy individual's heart beats 60 times a second. Thus, anything relativity has to say about ticking clocks, it says the same thing about beating hearts.
I would love a video about time dilation and quantum entanglement. Maybe that's just a special case of the relativity of simultaneity, which you've already covered. Anyway, I'd love to see one of your incredibly explanations on that topic! And just in case I do actually have your attention, I'll take the opportunity to say thanks for all the great videos. I agree with all the innumerable praises I've read in the comments section on all of your videos. Keep up the great work, whatever topics you choose to pursue!
Wouldnt it be easier to simply say that the speed of light is not constant and that light is acted upon by the force of gravity, such that the higher the gravitational pull the slower the speed of light. That would explain the desyncronization of the clocks in a similar way as the displacement model. In other words, the clocks are measuring the time it takes for a particle to go from point a to point b, to make the clock tick slower either increase the distance or decrease the speed of the particle. Relativity posits that we increase the distance, nuetonian physics suggests that we slow the particle.
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Hello mahesh sir, nice explanation. Does time dilate more inside the earth compared to that on the surface?
Can you please make a video on polarization of light.
* 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 ?
@@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.
Thank you
Never stop making videos even if u get less views,some channels r really good and this is one of it
Fewer views...
TO EVERYONE IN THIS CHAT:
*THE JUDGEMENT OF GOD IS DRAWING NIGH.*
REPENT TODAY AND GIVE YOUR LIFE TO JESUS TO ESCAPE ETERNAL DAMNATION!,..
@@JesusPlsSaveMe 😆
@@JesusPlsSaveMeWow I became christian after reading your comment
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!!
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.
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.
Every. Single. Video. I am BLOWN AWAY
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!
@@JusticeLeGrand10101 there’s no way your aren’t trolling 😭
I am really close to a brown hole within 3 feet and I am still getting older
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.
I am more confused than before watching this video
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
So the key To eternal life is moving fast 😄
@@genghiskhan9200Or maybe don't get a nosebleed...that's what finished Genghis apparently 😁
@@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.
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.
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.
I am really close to a brown hole within 3 feet and I am still getting older
Without motion there is no time*
Age dilation isn’t real only time dilation. Aka the clock count
@@Peoplearedumb47 But without motion, why so much commotion? Conjunction, junction what's your function?
@@alexshatner3907 and?
This is by far one of the best Physiscs explantion channel that I have ever seen...
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.
Fun fact: Watching this video on Miller's planet would cost you ~2.2 Earth years.
What?? 1 hour on Millers planet was 7 years… this video is 19:17 minutes long.
@@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
@@wlockuz4467maybe you are Millerian. Your math is impeccable.
@@wlockuz4467 awhhhhh I see I see
TO EVERYONE IN THIS CHAT:
*THE JUDGEMENT OF GOD IS DRAWING NIGH.*
REPENT TODAY AND GIVE YOUR LIFE TO JESUS TO ESCAPE ETERNAL DAMNATION!,..
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!
Watch closely there are cuts and he is looking towards the side most probably at his notes, still it's good video
Listen to me, you sir are the best RUclipsr, period. Please never stop making videos
5:35 my brother, I love watching these type of videos, although I may not understand 90% of it.
Let me just say it 5:30 mark, the way you broke down the apple falling towards the ground versus the ground, moving in the path of where the Apple was going just blew my mind.
I never make comments on pages, but I’m taking time to tell you, bravo. I’ll be following your page for a long time!
he is a gem to the world we need to protect it!!!💖💖
Having an instructor that truly want the pupil to understand the subject makes all the difference.
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 ❤
Love your vids that breakdown complicated topics into easily understandable chunks!
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 RUclips video is promoting misinformation. read more nonfiction. Dictionary. Encyclopedia. put down the pseudoscience and study linguistics. silly Human!
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 😂
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.
Mahesh Sir, I'm a big fan of yours. I have 2 physics questions.
1. A piece of ice is floating in a glass full of water. After the ice melts, will the height of the water increase or be equal?
2. Suppose I'm carrying a large stone in a small boat in a swimming pool. If I throw the stone in the pool, will the height increase or be the same as before?
By the way, I learned the Archimedes law from your video in Khan Academy. Absolutely amazing!
This is amazing intuition into a very hard problem. Great job
I absolutely LOVE the way you explore these concepts as a conversation with the physicists who elucidated them. I feel like this lays a foundation for true understanding of the processes rather than simply learning the principles and memorizing them.
I’m about to complete a physics II course, likely the last of physics I’ll ever take because I’m studying biology, but I will continue to watch these videos because I think chasing a deeper understanding of our world as a whole is very valuable! Thank you!❤️
I think Einstein would be proud of you.
This playlist was way beyond excellent, thanks. I’ll have to watch it again so the concepts become easier, then I’ll explain it to others
Mind blowing animation sir
Okay the explanation is cristal clear and I love it. Question from previous video for the context to the current question.
- But why time gets curved by mass in the first place? Why does Earth's mass equal more time at the ground?
Edit 1: I've just watched this video and I will reformulate my question: Why do accelerated frames of reference (like the ones created by masses's accelerations towards each other) create time dilation in the first place?
Edit 2: And why space also expands with mass?
It’s because we move at light speed through space time. If we move faster through space there is less speed to go through time, and vice versa. Usually most of our speed is through time. But if you go very fast it reverses.
Amazing content as always!
The qualiry of your contect is way abouve channels even like vertasium. Thats what I feel. I had cofnisons on relativity for many years. Thanks to you that things are getting clear
Thank you. You are an amazing teacher.
Thank you so much for this. I just watched it with my 10 year old and she now has a much better grasp of gravity and time. I do now as well. ❤
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.
"..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.
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.
Wow I came here to write _exactly this_.
Wait, are you me?
@@shrivatsa8604
this is a much more intuitive rationale than perpetuating the absurdity that all mass is under constant acceleration outward.
@@youngguns2121 👍🏻
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.
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!
Yes, you are right! I'll address this in the pinned comment.
Time dilates slowly at the centre than on the surface? But how?
@@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 ?
@@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?
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.
Brilliant is exactly the right word to describe you. That explanation was so clear and to the point. Please keep making videos like these they are marvelous.
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 ❤❤
g is down because if you drop something, it falls down.
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;)
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.
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!
@@varunvaswani4562 No, that's no right at all. Time dilation has nothing, per se, to do with acceleration.
I like that you essentially derived the underlying mechanism for WHY time ticks at different rates, essentially using photon clocks. However, I find the model much easier to understand where we are always moving through spacetime at the speed of light, so moving faster through space causes us to move slower through time, and vice-versa. Add to the curvature of space under gravity and objects not under acceleration always moving in straight lines through curved spacetime.
I think comparing gravity (which is not a force) with a centripetal force (which is a force; the electromagnetic force to be exact) will only help as an intuition for what is actually happening and only muddles the water from there on out. The difference is that the centripetal force is actually accelerating the observers where as it's the space-time curvature itself that is responsible, which is definitely not an acceleration. Problem now is that we are back at the question from the beginning of this video. You should have sticked with your older explanation, which I'm glad you mentioned so that other people can learn it the proper way.
2 objects falling onto earth at different altitudes with the same initial speed will have different moving clocks although they don't accelerate; they are just moving in a straight line trough curved spacetime, meaning no acceleration and no change in their speed; and yet time dilation still happens.
I can't get enough of the intuitive explanations. The model is inverted in respect to the observer to simulate gravity so the direction of the simulated gravity is also inverted in respect to the observer. I almost got hung up on the difference between the planet or black whole from the ring model and which way the arrows point.
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😁
17:27 That depends. If you are near a supermassive black hole, the gravitational gradient is not so extreme, so the smaller the black hole, the larger the difference between distances. Clocks will tick similar near a supermassive black hole, but will tick wildly different near a stellar mass black hole.
This is one of the best I have heard when it comes to explaining these complex concepts
Your visual representation is wrong. The two land surface should be outward and the force that pull in is centripetal
I also thought about that
Can you prove it and make a video , dont just give bullshit opinion
This was the explanation Einstein gave in the book…So let me get this straight, you’re implying that you’re smarter than Albert Einstein?
@@NoubelShimulyou bullshit. What a thing to say
@@NoubelShimulyou bullshit. What a thing to say
@Mahesh, hi. I just happened to watch the video about gravity and the curvature of time first, and that video makes more sense and explains the gravitational effect better, so much so that it contradicts this one (in my opinion). Let's see. I can understand the concept of gravity being caused by centripetal force as demonstrated in this video, but this doesn't apply to our planet, because we don't walk surrounded by an external wall, on the other hand, this would mean that those living at the equator would feel the maximum attraction and those at the poles would feel its absence.
Question 2: If gravity is a rotational consequence, what would happen to 2 objects with the same mass, but one rotating on its axis and the other stationary relative to its own axis? Would the gravitational force be different?
In any case, the way in which the explanations are presented is really intuitive and explanatory, and makes us reason in a scientific way.
Congratulations, you have just convinced people that the rotation of the Earth causes gravity.
He clearly said the opposite at the start.
@@logicianbones But that is not the part people will remember.
@@ShawnHCoreyNot his problem that stupid people exist.
What an absurd comment
@@CCave-wj6xy So do you expect Mahesh to alter his explanations to accommodate for every possible misinterpretation? What are you even complaining about?
I love that you ask yourself the same "natural" questions i ask myself as the video progresses and you answer them one by one.
Early comments give more likes...😊😊😊
I’ve heard other explanations about this stuff…but yours seems the best..thank you!!
Hey Mahesh - today I understood how the ground accelerates to meet the apple! Wow man! Check point 4:20
This is by far the video of the millennium to me.. for someone who studied physics during non youtube times..👍
Pls continue to make these videos .....dont stop.
i love your teaching style and general vibe & i'll be binge watching all your videos probably
In my opinion this explanation is an elusion as usual. It is true that both speed and gravity slows down time keeping but as it has never been explained how a big mass bends space time more than a small mass without having some kind of influence (force) from the mass I can't see why we might not as well use the old explanation.
If you have an oscillating (like a pendulum) electro magnetic signal in any cell, atom or even the smallest particle then if it moves it will take longer for the signal to go from one side to the other and back for the oscillation. This will slow down time keeping. The faster the slower but it is not linear.
It is there fore no big deal that if gravity influences light (as I believe has been found although I am still skeptical)) and light is an electro magnetic emission then time should be measured slower in a strong gravitational field.
Mahesh is very smooth and fast in his explanations just like a magician. One must take it very slowly, stop often to think about it and then verify and I must admit it is difficult. Albert Einstein must have been the same as many of his explanations supposedly where not even his own.
I love how you explain and use physical examples to explain such complex topic for my finance brain. Love astronomy as a hobby
WRT the person at the center of the spaceship, the person at the far end isn't moving and remains at rest (assuming both are standing). If their relative velocity is the same but their time flows differently due to varying acceleration and increased gravity, it would be strange. The person at the center would see the one at the far end waving their hand in slow motion... your explanation just made another of reason of time dilation more clear to me!
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.
Please don’t stop making videos, You cure depression.
My village in Uganda is poor. We enjoy your videos. Thank you.
I may have already wrote it but you’re as good as 3blur1btown yet in a totally different way when it comes to pedagogy. Bravo monsieur !
"The speed of light is the same in all reference frames, that is why [we have the time dilation effect we call gravity]. Do you now have a better understanding [...]?"
No. Like you said, it's like explaining why an apple is red by saying it's a red apple. How does mass cause the path to extend?
Thank you. Terrific video. I've been saying for some time that spacetime curvature is, in fact simply time dilation. When light travels through space it is always travelling in a straight line from its own point of view and what makes it lens and bend to an observer is in fact time dilation, to keep the velocity of light constant and dilate time to another frame it also passes you effectively curve the distance between them. It's an illusion, spacetime curvature is just a topography of time dilated frames of reference.
But this revision of Einstein's explanation using relativistic acceleration explains it much better than I do. Time dilated frames of acceleration reference as topographical gravitation is the term I'll use from now on.
you are the best teacher by far ! I love your videos !
I have another way to explain this but I am not sure if its correct or not.
the big mass of the star (or blackhole) creates curvature in space time, which make the space around it more dense. for example 100 meters in empty space will dense into 20 meters around the star. so when I travel 20 meter near the star I actually traveled 100 meter at the same time. which means I moved faster by a factor of 5.
thus creates the time dilatation due to faster speed.
Gravity in general relativity is due to the curvature of space-time caused by mass, not rotation nor velocity like in special relativity. The concept of how much "effort" spent in which dimension, spacial or time, is apt though. The analogy of stopping the rotation to stop simulated gravity does not correspond to how gravity works in reality. General relativity explains that near a massive object, space-time is curved, and this curvature causes time to slow down, a phenomenon known as gravitational time dilation. Gravity is not a force but a curvature of space-time caused by the presence of mass. Objects in a gravitational field follow curved paths, and time passes differently depending on the strength of the gravitational field. Near a massive object, space-time is strongly curved, causing objects in this region to experience a slower passage of time because they are in a stronger gravitational field. Conversely, far from a massive object, space-time is less curved, and objects experience faster passage of time due to the weaker gravitational field. This occurs because, near a massive object, more effort is spent moving through the spatial dimension, leaving less time to tick by in the time dimension. This is similar to special relativity, where increased velocity results in more effort spent in the spatial dimension, causing time to slow down for the moving object relative to a stationary observer. Being stationary near a black hole with no velocity further demonstrates that it is the curvature of space-time, not velocity, that slows time.
I thought I understood "why the clocks tick slower", but after this video, I realise I only "knew that clocks tick slower" without fully understanding why. This explanation helps me see why...
Didn’t realize the Feynman technique was called that! Whenever I learn something or am doing homework, I try to pretend like I'm the teacher explaining the homework problem to students and it helps me learn a lot more.
So yeah, that technique is applicable not just for youtube videos. Try it out if you're struggling in a class
Damn! Even though I knew that time is relative, subconciously I still believed in the newtonian model of Gravity and time. Your approach broke my entire concept of time and you won't believe how happy I am right now! Thank you for shattering my concepts and bringing me into the new realm of relative time.
Never seen such an intuitive video!
And with so much passion!
Please never stop!!
The speed of light isn't a constant; it's more likely that it's the amount of time it takes for a given area of space to process all the things that need to happen. A black hole isn't an infinite dense point in space, it's a powerful energy conversion machine. With more matter/energy you have slower time, which is effectively the frame rate of the universe.
The reason light can't escape it isn't due to gravity, it's due to the way energy currents function in space. These energy currents hold the galaxy together, but if there is more energy than can be converted and sent into the galaxy, you'll get a pulsar, which is the method it uses to dump energy. These would be equal to the auroras on the planets.
Hope this helps!
edit: Aging slower is just a matter of each frame taking longer to process. Going fast means more processing per frame. It's a lot simpler than this mathematical model being described.
I enjoy your work and your enthusiastic teaching style - you have a bright future ahead of you, my friend... Thanks for the content!
Love how passionate and engaging you are! Your visuals and explanations helped me understand this at a deeper level so thanks🤙
Duse, you have such a fresh way of explaining things! I've watched hundreds of science videos, and so many of them repeat the same words as each other, but I'm always thrilled to find a fresh perspective~
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! :-)
Bruh... That ad transition was straight up devious... Bravo... Bravo
Just don't stop to keep building up the intuition videos
And I'll ask to even make videos about some other physics topics like i am very in statistical mechanics and quantum mechanics
Although I am enjoying the series 😊
We need more videos like this and less mindless nonsense on this platform. Good on you sir.
I don't like that you describe gravity with the parallel to the centrifugal force.
Gravity is because space moves towards mass (spacetime curvature) and the ground stops you from moving with space to the center of the planet, Star, black hole.
This also means that you are moving relativ to space, not because you are moving but because space is moving and moving objects are time dilated.
This is how i understand it and im pretty sure it's true.
Food for thought:
If gravity slows down time, and affects space-time curvature, near black holes, it's so intense that light practically stops. Why does it stop if light speed is a constant? Well, the space value of light speed remains constant, but time is slowed down to a stop. That means that inside a black hole's event horizon, time is so slow that light from the start of the universe is still there. That's why a black hole is black. Because light from it never came out, yet.
So, does that mean that the black hole is really a hole, or a deformation on space-time? Or is it maybe a star similar to a neutron star, with such a massive gravity that slows time to a stop?
And the measurement of distance of stars? Is it really that viable, when we know that light when near a massive star can move slower than it should?
What about light coming from another galaxy? Is light's time factor moving faster in the empty space between galaxies where it's not affected by gravity? Because, time as we perceive on earth maybe very well be already very compressed, compared to the void between galaxies.
Thanks now I have a better understanding for what time is.
Bro I left engineering for physics but I am amazed how you have lernt so much physics even being an engineering graduate 😊❤
One of the best explanations of special relativity
Time itself cannot be manipulated,only energy such as light can bend. Also the same mass cannot occupy different space no matter how fast you travel. If you can travel faster than an image can travel than you can see yourself starting a journey but that ofcourse is only an image
The way I imagine it: the center of the circle is the black hole or point or intense gravity, and any circle you draw around the center is a timeline. So, to draw a complete circle, even though it may seem like line physical lines take the same amount of time to be drawn, the "length" of time (the circle) is longer.
Beautiful illustrations! You make this complex subject layperson-friendly!
You are now my favorite human. Brilliant explanation. Great video.
I constantly have the problem with this sentence: "imagine you see someone who is moving very fast".
I can't imagine this "physically". Because now it's all pure "mathematic" - not "biology", not "reality".
If something is moving very fast - you can't see it - because it's always "running away" from you point of view.
But in your example with rotating spaceship - the object and the obesrver are "still" in relative to each others. So we see the object constantly. So it seems?
But, what does it means "to see" something? That means the photon reflected from that object hit our eye, right? Only at this moment we could use word "I see it".
But it takes time for photon to move from the object to our eye.
So maybe, all this time dilatation is just simply an "optical illusion"? We don't see the real state of that object in THAT MOMENT - we just see "a picture" of that object, that came to us - delayed. At the time we get the picture - the object moved and he is at different "state" than we see on the picture at that moment?
You should draw a path on which photon moves from object to our eye (in your rotating spaceship example).Is it straight line? Is it curved line?
So right now it's just an "optical illusion", we see him "slower" because we get "delayed pictures" of his state.
But it doesn't explain, why this "illusion" doesn't work when the object observe us! :) Why he don't get "delayed pictures" :)
An also, it all seems like "optilac illusion" but then all stops and we call the object "hey, come to us to the center". He comes to us and then we see that he is really younger than us!? So it's no more "optical illusion" it's a biological reality!
Something must happend during the time he was going back to us?
Sorry. I still don't get it :)
I mean I understand the consequences of 'mathematic rules' that provide that theorethical conclusions.
But I CAN'T imagine this in reality.
The model using centrifugal force to describe gravity is very clever, but this model only holds true when the person holding the apple is already standing on the ground and all three body have been combined into one object beforehand, It does not explain the formation of the system. The video you described space-time curvature is what really blew my mind. Even now, I still feel it’s beyond my comprehension.
Watched this a second time as you explained this better than most creators do…so…I wanted to remember it💪
I kind of want to support you by subscribing to brilliant, but don't need to because you and your videos are brilliant. Catch 22.
Best science explainer on RUclips!
This one gets me the speed of light is constant for all observers... time dilation means seconds pass differently so light has to slow down in gravitational field in order to match time dilation so that speed remains the same. And vice versa.
But then in the same breath you cannot say it slows down because it moves same distance per second although the second has taken longer
You're the best Physics educator on RUclips, period
I have seen it explained like this as well. If we accept that time slows down closer to large masses, then gravity becomes like motion in a river. In a river, sometimes one side is flowing faster than the other. If you place a boat on the river, the faster flowing side puts more force on the boat, causing it to turn and move towards the slower side. So, if time flows faster out in space than it does on the surface of a planet, then we are all just being pushed towards the surface by the differential flow of time
Your idea won't work in detail anywhere and not work at all where gravity is strong.
@@kylelochlann5053first of all, not my idea. Second, it’s not meant to be a detailed mathematical explanation. It’s meant to help people intuitively understand the concept. And it does that.
@@spaz1002 Except that it doesn't work and doesn't make sense in the context of relativity.
@@kylelochlann5053 except it does work. You just don’t understand it. Feel free to move on now. I don’t really care to see your comments anymore.
@@spaz1002 So in your pet theory you believe point particles are unaffected by gravity?
Wow sir,🙏👏 in our Vedic Puranas, there is mention of time dilation. 1 second in brahmaloka is equal to millions of years on earth.
There are so many unaddressed realities making the notion of a ship on a surface experiencing slowed time compared to almost normal just a few hundred miles above in an orbit. Even accounting for orbital plane of the craft vs orbital plane of the planet, the planet could never exist experience such a massive shearing of time and space across its own spinning diameter. Plus the was gargantua which had a very gentle event horizon due to its massive size making it more survivable of a black hole to fall into. Assuming it even was a black hole instead of something similar and artificially created for us by future us?
The physics of Interstellar were recklessly abusive to physics and did not even try to address these enormous flaws.
Still a great movie.
it seems so small, but the relativistic effects on GPS satellites are actually HUGE! they would fail so fast without extremely precise programming based on their altitude
Hi, and what about moving faster? If we have strong gravity/acceleration time ticks slower. But if you move fast without any acceleration you won't feel and gravity/force but you still should age slower than someone who is not. What's the difference?
16:45 the gravitational field decreases below the surface and is zero at the center. If you assume a uniform density, then the decrease is linear. So the centrifuge model is not that differnt, just the direction is reversed.
and since earth's surface is covered in oceans, the real gravitational field is actually highest a few kilometers below the surface.
Yeah, it's the "Shell model", and Isaac Newton himself figured out that your weight will decrease as you go deeper and deeper into the Earth's crust. Eventually at the Earth's center of mass you would be weightless. And, this has been experimentally verified in caves and well shafts. The core of the Earth feels weightless and in an inertial orbit around the Sun. It is at a million atmosphere of pressure of course, from the 3000 miles of compressed rock and metal above it. That's the pressure you feel as 9.8m/s² of acceleration at the Earth's rocky surface.
Dude I love this guy.
Now, when I think about it, the rotating spaceship experiment is actually a bit deeper and creepier. If the person at the center of the ship could see the other person with his eyes throughout this whole time, not only that other person would age slower, but all his movements and everything around him would be in slow motion. And vice versa, the guy at the middle will appear in fast-motion. 🤔 But what would happen if one starts going to the other person's direction?
I've had a question I'm hoping you'll address about approaching the speed of light or the event horizon of a black hole. The science communicator channels all seem to agree that when your ship exceeds the speed of light you disappear but they don't ever mention red shifting during the process. It seems to me that it wouldn't be an instantaneous switch from visible to gone, and that after the boundary is reached(supposing it were possible) you would red shift into invisibility as your ship accelerated further. From the point of view of the the ship going into the black hole it would look like the rest of the universe was moving on and aging more and more quickly, I think, and an outside observer would see time slow down and stop for the ship then it would appear to fade into infrared until it became undetectable. What are your thoughts?
Edited for clarity*
The first part is unclear, specifically, what you're talking about when referencing matter moving at or faster than the speed of light.
A ship approaches the horizon, the distant observer will observe the luminosity and frequency to sharply decrease and the ship vanishes.
Yeah, the red-shift happens exactly in proportion to the time dilation _because they are exactly the same thing_ A lot of pop-sci entertainment explanations of relativity are bad because their sources are other pop-sci explanations, and it's a big game of telephone and no one ever bothers to actually read a physics textbook.
@juliavixen176 thanks for the input! It helped me feel like I wasn’t crazy.
This is beautifully explained; but I take issue with the aging piece in interstellar. Because the human body would still age at the same rate regardless of how fast the clock is ticking unless we’re inferring that gravity also slows down the aging process.
Sure 1 day may be longer further away from earth, but I don’t see how that would change the rate at which a human ages. I also can’t fathom, how “1 hour” 200,000 miles away from earth would differ from 1 hour on earth. Because to me, 1 hour is still 60 minutes regardless of how far from earth you are.
First, the effect is relative. (Hence, why all this is called relativity). That is, each person wherever they are located in space, doesn't notice any change. The change is noticed when people at different locations COMPARE to each other. Secondly, instead of using some type of man-made device to measure how much time has passed, it is just as valid as using your heartbeat. Typically, a healthy individual's heart beats 60 times a second. Thus, anything relativity has to say about ticking clocks, it says the same thing about beating hearts.
I would love a video about time dilation and quantum entanglement. Maybe that's just a special case of the relativity of simultaneity, which you've already covered. Anyway, I'd love to see one of your incredibly explanations on that topic! And just in case I do actually have your attention, I'll take the opportunity to say thanks for all the great videos. I agree with all the innumerable praises I've read in the comments section on all of your videos. Keep up the great work, whatever topics you choose to pursue!
Wouldnt it be easier to simply say that the speed of light is not constant and that light is acted upon by the force of gravity, such that the higher the gravitational pull the slower the speed of light. That would explain the desyncronization of the clocks in a similar way as the displacement model. In other words, the clocks are measuring the time it takes for a particle to go from point a to point b, to make the clock tick slower either increase the distance or decrease the speed of the particle. Relativity posits that we increase the distance, nuetonian physics suggests that we slow the particle.
Nope, because it’s constant, gravity simply changes its direction