How Time Dilation Causes Gravity, and How Inertia Works
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- čas přidán 12. 06. 2021
- The thing that’s pulling you towards the ground right now isn’t the force of gravity, as it’s commonly understood. Instead, you’re being pulled downward because that’s your natural path through spacetime, which is warped by the immense mass of the Earth. This warping primarily takes the form of time passing faster further away from the Earth. Spacetime warping in general also accounts for an object’s inertia and momentum, and we’ll get to that later in the video. How does spacetime warping result in the thing we usually call gravity?
Here's a donation link if you'd like to support my channel- many thanks! donorbox.org/idea-list-youtub...
By the way, at about 3:40 in the video I talk in terms of "hours" that the clocks are ticking off, and I should've clarified that the time difference between clocks a few hundred feet apart on the surface of the Earth is on the order of picoseconds, not hours! Misleading on my part, my apologies.
Here are the other videos I reference about how time dilation causes gravity. They’re really good, but the analogy of a “flow gradient” in time is nonphysical and, I think, just confuses the picture. I’d encourage you to give these a watch and decide which explanation makes the most sense to you: PBS Space Time: Does Time Cause Gravity?:
• Does Time Cause Gravity?
Science Asylum: The REAL source of Gravity might SURPRISE you...:
• The REAL source of Gra...
Physics Videos by Eugene Khutoryansky: Gravitational Time Dilation causes gravitational “attraction:
• Gravitational Time Dil...
Here’s a video that presents an excellent way to visualize four-dimensional spacetime warping: ScienceClic English: A new way to visualize General Relativity:
• A new way to visualize...
By the way, the animation at 10:43 was made by ScienceClic as well.
Here are excellent CZcams videos to explain each of the four assumptions we start the video with. There are many others that you can also find to supplement your understanding.
1. The three dimensions of space and the one dimension of time are inextricably linked into one dynamic medium: spacetime. TED-ed: The fundamentals of space-time: • The fundamentals of sp...
2. Mass warps spacetime in well-defined ways, and warped spacetime moves mass in well-defined ways. PBS Space Time: The True Nature of Matter and Mass: • The True Nature of Mat...
3. In the absence of external forces, masses follow geodesics in spacetime; that is, they follow the path of least local distance through spacetime. Veritasium: Why Gravity is NOT a Force: • Why Gravity is NOT a F...
4. Part of the warping of spacetime by mass involves time moving more slowly as you get spatially closer to the mass, so that for example clocks on the surface of the Earth tick more slowly than clocks on the international space station. (This is known as time dilation). PBS Space Time: How Does Gravity Warp the Flow of Time?: • How Does Gravity Warp ...
Late in the process of making this video, I found this paper published in 2017 in the European Journal of Physics by Stannard et. al. that gives quite a similar graphical explanation of objects following spacetime geodesics in curved spacetime: iopscience.iop.org/article/10.... It also has some additional analysis, including deriving a solution to Einstein’s Field Equations (that was published by Karl Schwarzchild in 1916) from the geometrical picture given. I can’t say that I was inspired by this paper in the making of this video, but finding it did quite reassure me that what I’m putting forward is correct! - Věda a technologie
There is a point towards the end where you say, "There comes a point where the only way to increase the speed of the object is to turn the object into light." But, I believe a better way of saying that would be, "There comes a point where the only way to increase the speed of the object is to turn the object into something with no mass."
Good point! Agreed.
Yes, it's the ultimate trade-off! Either you are at "rest" with all motion through time, or have no mass so that all motion is through space (no time passes for you).
@@ALBINO1D
Song : "No time ( left for you [ luxons ] )" by "The Guess Who"
@@2hcobda2 Bot. Reported.
@@ALBINO1D for what?
Holy crap, I've had an amateur interest in relativity for 30 years but I've never understood gravity as a function of movement through spacetime like this before. Thanks so much, cool as hell.
I found Science Clic to be an amazing resource too. Similar descriptions: czcams.com/video/wrwgIjBUYVc/video.html czcams.com/video/GQZ3R81iyE0/video.html but there's a bunch of other videos there that are great. But I think this video indeed goes into even more detail.
I honestly think these are newer revelations. I too with 30 years of interest have never had it shown like videos these days now start to explain.
Indeed, this video is the best I found so far.
The presentation still left out issue of weight!!! He something are not very clear, but it should be accepted as their are till proof otherwise. Alright.
Because it's incorrect. Gravity is not a result of time dilation. This is a misinterpretation of correlating data.
The clearest explanation I have ever seen. I had the 'hang on - that's obvious when you say it like that' moment. More like this pretty please..
What is offered in this video is a different description than the usual one. This is due to your starting question: what causes gravity? Answer: time dilation. And this video does a fine job in answering that question. The usual starting question from a historical perspective was: what causes time dilation? Answer: gravity. Each of these descriptions are equivalent. And that was the genius of Albert Einstein.
best explanation of gravity I have seen so far
This video answered questions that I hadn’t thought to ask. I really like your description of the “rate” at which mass warps and unwarps spacetime.
Agreed, this explanation is better than the other time gradient based explanations I've seen. Thanks for taking the time to make this video.
Yes, but humans can see movement over time, we can’t see warped space.
the video belongs to another youtube channel Veritasium ... that channel just stole the video.
Disagree.
Great explanation, helped me a lot. Thank you very much for making this video!
Superbly explained.... Thanks for the effort and making things simpler to understand 👍😊
The best video about this subject I have ever seen. It's also the first time that I have the feeling that I start to understand it.
Thanks for this.
I found your explanation much easier to follow that the video Space Time did on this same topic. 👍
Simplicity is the key to understanding the notion of inertial reference frames and to understand euclidian space. Cool diagrams are important and you’ve nailed it here.
Pure gold. Brilliant way to explain it. And now I FINALLY am beginning to get it. Thanks!!
This is very beautiful. It has helped me a lot. Thank you so much.
I dont think any better video of explanation of Spacetime is available on internet. Its awesome. Very well and simplistically explained. Would like to see such videos on quantum mechanics too if by any chance u prefer to make. Thanks a lot
Thanks! Would love to make more physics-y videos, hopefully when I can find the time.
Outstanding video and excellent narration. Your explanation is easy to follow and very clear.
the video belongs to another youtube channel Veritasium ... that channel just stole the video.
@@Pastor_virtual_Robson Hmmm,.... and I love Derek from Veritasium. I'll look for his "original" version. thank you,
Excellent explanation of how gravity works. Much better than the three videos you mentioned in the beginning. I would love it if you expanded your examples of traveling through the geodesics to objects flying by a planet at different speeds. Explaining why speed matters and why traveling at different speeds determine the geodesic path of the object. At high speeds its path is slightly bent. At the right speed it winds up in orbit. At lower speeds it crashes into the planet.
Thanks! And agreed, that would be a useful illustration of how geodesics are tied to momentum.
@@IdeaListEye pls make this. there is very little research on the relation between inertial forces and geodesics.
Wow! Thank you so much for making this and explaining it so clearly. Please post more
Glad you liked it! I would like to post more, but I've been busy with other things lately. Hopefully soon- do you have any topics in mind you would like to see explored?
@@IdeaListEye I previously visualized the warping of curvature as static around the mass, rather than as a dynamic/continuous motion of being sucked in. I’ve been ruminating on.. where this spacetime goes for lack of a better phrase. It just keeps getting sucked in? Maybe not enough for a whole video but the illustrations you used were so helpful to see in 3d vs the more common 2d depiction. I also think length contract doesn’t get as much love on youtube as time dilation, been trying to understand that better.
This channel must rise up! This single video filled many gaps that I've been thinking about, even after all that very same great references (PBS, Eugene, Asylum and ScienceClic). I found it searching "gravity and entropy", and I hope I can find something about it around here. Thank you!
Thanks, Gino! I'm glad you found it helpful, that's exactly what I was hoping for in making this video.
the video belongs to another youtube channel Veritasium ... that channel just stole the video.
I 've been thinking why it is so difficult to understand these notions, and came to the conclusion that the problem is not only due to our experiences, the problem is also verbal. There are no words to describe situations that fall away from our experiences and senses, which is exactly what relativity theory is doing. OR ARE THERE? Plato (and Freud in is own words) say that simple statements (words) require deep understanding. I understood what the narrator is trying to commune when I realised that all objects near a big mass (like earth) have the same ANGULAR SPEED (two words) on the space time diagram. These two words crystalized the meaning of the theory and helped me remember all the details effortless.
Mind-bending video ! 😉
I have been looking for this visual explanation for a while, and I was not satisfied with the videos you list in your introduction.
Now I know why it takes effort to climb up stairs!
the video belongs to another youtube channel Veritasium ... that channel just stole the video.
Thank you! That was a very helpful explanation.
Wonderful and clear explanation. Thank you!!
I'm so impressed. This explains the equivalence principle. Movement due to gravity or normal acceleration impacts spacetime the same way.
Only the theory presented is supposed to do away with gravity as a force, as I understand it…
Also how is mass defined in the absence of gravity? As inertia? Sort of a resistance against acceleration?
It also seems to me that time would come out a space-vector - the path of least resistance between two locations in a three dimensional grid - which, to complicate matters further, is itself warped by all the masses in the vicinity in accordance with their masses.
Nevertheless, NASA must have precise, time proven methods by which to calculate these things. How else would they be able to slingshot objects around planetary bodies, as they often do? NASA can’t presumably rely on approximations, since last minute course-corrections would come too late, when their space probes is light-weeks away.
Couldn’t you start by covering how such calculations are done in real life before we let ourselves be overwhelmed by quantum conundrums?
Einstein described very well in the chapter "The Equality of Inertial and Gravitational Mass" of his popular book "Relativity: The Special and General Theory" the conundrum that experimentally it had been determined that inertial mass of an object is equal to its gravitational mass to a high degree of precision. Einstein's realization was that this equivalence might not be accidental. The fact that the gravitational "mass" exactly cancels out the inertial mass in the Newtonian equation for acceleration due to gravity indicates a purely geometric phenomenon behind gravitational acceleration. In other words, the "force" of gravity is fictitious, but the geometry is not what we thought it was.
@@IldarSagdejev I have the book and have read it a couple of times with great pleasure, so no!
That’s not what Einsteins says. He just states that there’s no way to discern gravitational acceleration from an equal acceleration by an equal force, unless you have some external reference, thus explaining why inertial mass and weighed mass must be one and the same.
The theory about distorting the space/time matrix came almost 20 years after Relativity was published and seems to treat time as a space-vector, which makes things more complicated to calculate, and as you know, a breakthrough usually means better and more generalized formulas.
But time, handled as a vector, must itself be distorted by mass, so how can NASA successfully calculate sling-shooting anyway?
@@Hallands.Interplanetary flight caculations use Newtonian gravity.
See "Mach's Theorem" for the possible nature of inertial mass.
I loved your description of the attraction of matter to space-time causing gravity.😀😍 Resistance to movement change from forces and gravity and geodesics. The graphic was good to imagine matter sucking in space time. It helps give an intuition for it. Your questions give us ways to think about it and your answers frame it well, for sure! (Why does it take energy to move an object from its geodesic, ie an asteroid in space.)
Amazing, I've never seen it described like this! It makes so much sense to think of my inertia as me being attached to spacetime due to the way my mass warps it. Bravo
Yea that’s so believable, seems super logical, as long as you forget all knowledge ever known! Disregard everything ever felt, seen, heard, learned….-all sensible perceptions. Totally plausible! If that was no feat to overcome, then this wont be any brain-buster either…. Here soon the democrats will quit destroying the country, by funding good police and defund the wef, un, Soros, and their malnourished skinny Jeaned antifa creeps!
Thank You so much for this video. This is the first video I have discovered so far that explains the reason of falling of objects in a proper way. 🙃👍
the video belongs to another youtube channel Veritasium ... that channel just stole the video.
I have spent so many pleasant hours thinking about this much like you have shown here. But the second part of it I hadn't thought about, more that I accepted that all objects follow the fastest path or the one of least resistance. Great video, thanks.
the video belongs to another youtube channel Veritasium ... that channel just stole the video.
The spokes on a wheel grid analogy were fantastic. Thanks
Beautiful, it shows a dynamic space product of the energetic presence (see the previous comment for the quantum approach), so gravity potential energy is equivalent to the kinetic energy of speed √[2GM/R], Schwarzschild time dilation is equivalent exact to Lorentz dilation. The relativistic view is the union of observable speed plus the equivalent gravitational speed! This and more can be read in a small amazon book "Space, main actor of quantum and relativistic theories". Thanks for your great videos
Wow! I was never satisfied with the time gradient. Thanks a lot
That's a great way to visualize it. Kudos on the explanation and illustrations. Very impressive.
way better and makes no room for arguments than Asylum
I was commenting on a video just yesterday on how the warped 2d net in so many videos give you an incorrect picture of what is actually happening, since the warpage of spacetime would take pace in all directions at once. I give you credit for showing this warpage in a more true to life model. Thanks!
Thanks! I'd like to add that the visualization at 10:43 is by the channel ScienceClic, I neglected to include a credit there (my bad!). (Their channel is superb)
Finally, I’ve been trying to understand the curvature of space time for a very long time and this explanation is beautiful, this is just so amazing to me and the fact that Einstein figured all of this out on his own is amazing to me. Best explanation I’ve seen, I finally understand, thank you so much. This is so cool and it is such an amazing way to think about gravity
Einstein's work here was absolutely astounding, but he didn't do it alone! The work of his advisor, Hermann Minkowski, and the work of Lorentz were indispensable in his development of special and general relativity.
The best explanation of how time dilation is a symptom of warped spacetime which itself causes gravity (i.e. why objects accelerate towards the earth. Thank you so much as have been trying to get for over a year now 😄
Really liked this explanation. Thanks!
You attempted to be clear and intuitive in detail at both your space and our time, the graph puzzle links a solution, IF those historical theories where snapped together as one. Allowing a healthy questioning, without any rightous declared says. We don't get much *mass* explanations, from those other channels you mentioned on this one.
Excellent video, thanks!
Remarkable work. Thank you.
Tanks you . Please do not stop making such vidéo.
This video should be included in the physics courses they teach in school. The best explanation of gravity on the internet.
Just 86k views?? This video deserves to be one of the best science videos I've ever seen, so much information in such a short time, and very well and easily explained as well. You are great sir.
One request for u, please explain delayed choice and delayed choice quantum eraser and other quantum related ideas sir since you'll be able to explain them simply as well I'm sure 🙂❤️❤️❤️
Sabine Hossenfelder did a great video on the subject recently. Basically, you need to combine the interference pattern from both detectors when interpreting the result. You can’t just show the pattern from one detector which a lot of other videos do.
@@eyesopencam Thanks bro, I'll look through it 🙂❤️
Wow, thanks, Umer! Very kind of you to say. I'd like to dig into those topics, thanks for the request. I have been reading about quantum computing recently, and it's monumentally complicated and confusing-- it might be a long time before I have anything valuable to say, but stay tuned!
@@IdeaListEye will be waiting sir no matter how long 🙂
No, because it is wrong, very wrong!
Best graphic interpretation. I got tired of the "tent and the ball" everyone else used. Its like half whats happening. Feet and hands thumbs up.
Thanks! I'd like to add that the visualization at 10:43 is by the channel ScienceClic, I neglected to include a credit there (my bad!). (Their channel is superb)
Interesting perspective on GR and inertia. Thanks
Thank you for pointing out that there is no generally agreed upon theory for why inertia exists. I have been trying to find the answer to that question for years and no one else has simply said that "we don't know". They always just talk around the subject. I have watched pbs space time, dr lemon, and many others. Arvin an gets closer than most, but only you have just come out and said it.
So this is the way to think about uniting the forces into one grand theory. So simple and elegant. Just as scientists envisioned since the Greeks. Bravo!
Very very nicely done! Thanks.
Awesome approach! I love finding new teachers like you. Keep it up
the video belongs to another youtube channel Veritasium ... that channel just stole the video.
@@Pastor_virtual_Robson I wrote this comment on a completely different video, not Derek's either. Weird
very interesting video. i always used to think of time as if it itself was flowing rather than matter travelling in the spacetime continuam
the video belongs to another youtube channel Veritasium ... that channel just stole the video.
It is funny that you think the purpose of the video is to simplify what others failed to explain regarding spacetime. 😋u actually made it even harder to understand😘
😂
I've had a life long obsession with this subject and have come to the same conclusion that you have. Your video however has deburred the rough edges of my thinking and really brings the idea into focus, in a way that, so far as I know, is unmatched. My only disappointment is that you didn't illustrate the mechanism in which mass causes this effect in spacetime but my forgiveness is gratuitous, being that it's a very difficult problem to solve.
@@GriuGriu64 I think its useful
"because things pass through time at different speeds at different elevations. " I have watched HOURS of gravity CZcams videos to finally find this sentence. THANK YOU!
This is probably the cleanest explanation I've seen in any medium. Bravo! (I had two GR courses in grad school. I've read most of the graduate-level GR textbooks, and read fairly recent research papers...and Kip Thorne's office is a few minute walk from mine). I would just point out that energy is the thing that causes time dilation somehow (energy density, more specifically). Mass just happens to be a compact form of energy. The deep connection between energy and time might be a hint pointing us toward understanding why energy density slows time.
Huge thanks, Dr. Stickley! Very much appreciated coming from you. Re. “The deep connection between energy and time might be a hint pointing us toward understanding why energy density slows time”, I’ve been playing around with the idea that spacetime warping is due to the density of particle interaction in a given region of spacetime alongside the need for relative positions and momenta needing to maintain a relativistic relationship to the speed of light. In other words, mass could be thought of as an emergent property (due to spacetime warping) that arises out of the interaction of e.g. fermions and bosons, and is not itself a fundamental property that particles (or energy) have. In simple terms, the more boson/fermion interactions, the more spacetime needs to be “knit” by those interactions into a web that maintains relative positions and momenta relative to the speed of light always being constant. The seed of this idea is the observation/hypothesis that only some interaction can define a particle’s location and trajectory in spacetime; absent these interactions, the particle exists as a spread-out “impulse” in the quantum fields, quantified in our framework by its probability amplitude.
I dug a little into particle physics to flesh this intuitive idea out and learned that I’m way out of my depth there. Something I’ll probably continue pondering, though.
@@IdeaListEye The current standard explanation for what creates mass is the Higgs mechanism; things acquire mass by interacting with the Higgs field, but this interaction is only responsible for a small part of a particle's mass; it's enough to keep the particle from moving around at c like a massless particle, but most of the measured mass of a particle comes from field energy (i.e., the swarm of virtual particles) around the particle. For an electron, most of the mass is due to energy in the electromagnetic field, since electrons have electric charge which binds to the electromagnetic field; for a quark, the mass is mostly due to the energy in the gluon field, since quarks have color charge which binds to the gluon field. The mass of composite particles, like protons is mostly due to the kinetic energy of the quarks it contains, plus the energy stored the gluon field and electromagnetic field.
Some people think that inertia may be due to the Unruh effect. I've been in favor of that general view since high school. This seems pretty similar to what you've been thinking about. Do a Google search for "is inertia due to the unruh effect?" to find out more.
I've also been playing with the idea that the rate of time passage in a region of space is somehow inversely related to the density of interactions in that region of space. I haven't been able to flesh it out into an actual theory, though. If it can be done, then gravity emerges as a direct consequence, so it would be a big deal.
You might also find "loop quantum gravity" to be interesting....there are some interesting ideas there, even if it doesn't turn out to be the way nature works.
omg this was a brilliant video i really understood this wow i can see why so many see the beauty in GR.
Great video!
i finally got it with your apple example. thank you.
I didn’t…
I was told many years ago that time closer to the centre of Earth runs faster , on the top of a mountain time runs slower . There are 5 levels or aspects of time .
Excellent explanation👍
the video belongs to another youtube channel Veritasium ... that channel just stole the video.
I look forward to when someone with insight understands why mass warps space-time.
Alas, I doubt I will live long enough.
Yep, I’m searching too!!!
Thanks for creating and posting this awesome video! I could never understand why an object released from a stationary position (like a tree branch) in a gravitational field would start moving if there is no force involved. What would give it the impetus to start moving? Now that I've seen your two-dimensional graph of warped space-time, I finally think I understand it. If I understand this correctly, the object is fixed on a geodesic position, but the geodesic fabric is changing with respect to time, thus causing the object to move through the space dimension. i hope that's more or less correct anyway.
Hey David, you're welcome! Glad it helped you out.
Re. "If I understand this correctly, the object is fixed on a geodesic position, but the geodesic fabric is changing with respect to time, thus causing the object to move through the space dimension."
I think that is more or less correct, but a better way to think about it would be to say that the object is fixed on a geodesic path, not position, because every object is always traveling through spacetime; there's no fixed position because even if it's somehow perfectly stationary in space, the object is still traveling forward through time.
Using the apple as an example, the geodesic path the apple seeks to take (its path of least energy through spacetime) has it traveling downwards due to the curvature of spacetime making every other path require more energy. It's only kept from following that path by the branch exerting a force on it away from that path (upwards). So, to be clear, it's not that the "geodesic fabric is changing with respect to time"; that geodesic is fixed by the interaction between the Earth's mass, the apple's mass, and spacetime. When attached to the branch, at every instant the apple is traveling further through spacetime than it would if it could follow its preferred downwards path because the branch is pulling it away from that path into a region where time passes more quickly (causing the apple to travel through more time than it would if it were in free fall along its geodesic). I hope that helps! Let me know if you have any questions.
@@IdeaListEye Thanks for clarifying that. I see what you mean by the object not being "fixed" on the geodesic. It is always moving through time. I hope I've got that correct now. I also think I see what you mean when you say the geodesic is fixed, not the object.
Thanks for this video. With such a grip on spacetime and matter/energy, you should take the next step into fleshing out how entropy and enthalpy further quantize the events of causality. Essentially, what I’m asking you to do is to connect relativistic mechanics to quantum mechanics via focusing on entropy/enthalpy and how they define the arrow of time (or as I put it, further quantize causality).
Neither the standard model nor relativity make enough sense to fully model the world without each other, which is why Einstein spent most his life seeking the bridge and it remains the holy grail of physics. From what I understand about relativity, to consider gravity/time a force mediated by spin-2 tensor bosons is… unintuitive, while to a particle physicist, it is intuitive to consider gravity/time a fundamental force mediated by force carrier particles, as included in most standard models.
It’s literally looking for a fundamental particle for time, which imo is like looking for fundamental force carriers for speed, momentum, or inertia. These all seem like composite, non-fundamental forces for which there wouldn’t be a bosonic force carrier. It seems to me like we already have all the fundamental particles we need, what we are missing is a better understanding of how they interact via enthalpy and realize entropy. That’s so far quantifiable via high level quantum mechanics that can model up to a sufficiently composite, classical degree.
Furthermore, I would interested to see if the right understanding of the connection between quantum mechanics and relativity via entropy/enthalpy could also shed a bright light on dark matter and more importantly dark energy.
Cheers, pls do this for me even if you manage to prove this all wrong
Hey JackBlackNinja, thanks for this suggestion. It's an interesting idea, but I'm not particularly qualified to confirm or deny it. I'd encourage you to flesh it out, and perhaps even make a video on your own to explore and express your idea! If you were interested in doing so and had questions, I'd be happy to help in that regard (re. video production, etc.).
@@IdeaListEye I would so much like to make a video myself but I feel like I don't have the physics prowess nor editing skills to pull it off. You did so well with this video, which itself deals with time, so was just thinkin you might be able to explore the so-called 'arrow of time' described by the 2nd law of thermodynamics, which is a macro composite of quantum phenomena called micro states. This connection between the arrow of time described by the quantum mechanics via the 2nd law and the gravity-time described by relativity seems interesting to explore. Anyway, I totally understand if it's out of your wheel house, it's certainly out of mine too!
Keep up the stellar work boss
Great Explanation .
The casimir effect is probably related to why mass warps spacetime, I tried making a very simple abstract model of it (probably terrible way to go about it) but it would make sense, an empty region of space exerts a certain amount of force, the force pushes equally on other empty space and it cancels out giving flat curvature, as soon as any mass occupies it, it "blocks out" the things the effect emerges from and the force is no longer fully balanced out on neighboring regions of spacetime.
like there is something that props up spacetime so it is flat, like if you had a trampoline with the skin of it levitated by something that is "obsured" by mass
One thing I wished you had explained regards the stumbling block I had when I first tried to understand time dilation. I could not get my mind around the fact that two old school mechanical clocks would show different times when one was moved away from the earth. It seemed like they made a mistake as the mechanical mechanism should give the same result. The glossing over the reason this happens at an atomic level is not usually explained and causes a headache when trying to put the whole picture together. Maybe a topic for a future video? André in Sydney
This has been a consideration from the start, and a lot of very smart people have taken great pains to address it (and to test what you proposed, whether it's just a mechanical accident or actually a consequence of fundamental physics). You can read more here: en.wikipedia.org/wiki/Experimental_testing_of_time_dilation
Thank you so much for this. I was screaming at the screen while viewing the other videos you mentioned because of their darn time-flow vector that didn't seem to have anything do with spacetime (or just space). If felt like a relativistic three-card monte. So well done.
But you've given me something new that just feels wrong (not saying it is, I'm just having trouble accepting it): If it takes extra energy to warp spacetime to get the asteroid to move over, (and this makes perfect sense), once it's up to speed it will keep going with no new energy added (at least no new external energy). But the asteroid is still warping spacetime anew as it moves along. That feels like this warping and unwarping should need energy too, just like it did to get the asteroid out of the well it had formed at rest. Or at the very least, the motion would run down as energy gets used up, and of course this doesn't happen.
The direction of travel length contraction item seemed a little shoe horned in there (bare with me here, this is not meant as a critique). So I wondered if the length contraction has something to do with the asteroid being "attracted" to the spacetime it is about to move into and warp, and I just missed that connection. Or is there a length contraction gradient which would translate to a mass gradient would translate to a time gradient and we're back to what causes gravity but this time, in direction of travel; once an object is moving, or once spacetime is unwarping, does the object create its own "straight" geodesic?
That the asteroid is "attracted" to the spacetime it is about to move into (in this example), feels similar to why mass (or probably better: energy) causes a dent in spacetime. I'm hoping the answer is not "because it does" as it currently is for why mass dents spacetime.
It also feels a little like something riding a wave. The displaced spacetime behind pushes the asteroid forward - but there is an equal ridge of spacetime in front that must be overcome, so the energy supplied to ride down the hill would be the same as the energy to climb the hill in front. (unless due to motion there is now a time gradient so there is a lag between when the energy is supplied and needed.) Or is it that spacetime itself has inertia?
Again, thank you, I've been chasing the "time causes gravity" for some time now and the veil has been lifted.
Thanks! And thank you for these insightful comments, I was hoping someone would raise some of these issues.
"If it takes extra energy to warp spacetime to get the asteroid to move over, (and this makes perfect sense), once it's up to speed it will keep going with no new energy added (at least no new external energy). But the asteroid is still warping spacetime anew as it moves along. That feels like this warping and unwarping should need energy too, just like it did to get the asteroid out of the well it had formed at rest."
This is a great question. To clarify the picture, it's better to say that it takes extra energy to change the rate at which the asteroid warps spacetime, not just that it takes energy to warp spacetime. When you speed up the asteroid in the x direction, the asteroid now needs to warp more space per time in the forward x direction, and unwarp more space per time in the backwards x direction. Because mass is attracted to spacetime, the object moving through more spacetime in the x direction is more strongly attracted to spacetime in the x direction. By the same token, the object moving away from more spacetime in the backwards x direction is more strongly attracted to spacetime in the backwards x direction; the influence of the extra warping in the forward x direction and the extra unwarping in the backwards x direction cancel out, leading to a constant velocity. This is the case in any inertial frame (even for a hypothetical object that's completely still in space), the object's attraction to spacetime in every direction cancels out, leaving the object moving at a constant velocity. It takes extra energy to upset this equilibrium by causing the object to warp/unwarp extra spacetime in any direction (which results in that object picking up velocity in that direction).
One way to say this would be that the extra attraction that the mass gains to the more rapidly approaching spacetime in the forward direction is "paid for" by an extra "drag" on the mass by the more rapidly receding spacetime (which is also attracted to and attracts the mass) in the reverse direction.
I like your idea of an object moving through spacetime as similar to something riding a wave, but I disagree with the way you have it stated ("The displaced spacetime behind pushes the asteroid forward - but there is an equal ridge of spacetime in front that must be overcome, so the energy supplied to ride down the hill would be the same as the energy to climb the hill in front."). Try to imagine this wave instead like an attractive field, maybe like a magnetic field. The approaching spacetime attracts the object forward, and the receding spacetime attracts the object backwards, and the two cancel out (for any constant velocity in the absence of other forces). The thing that applying a forward force does is cause the object to be attracted to more spacetime in both the forward and backward directions per time (and thereby to travel more distance in the forward direction per time).
You're right that the bit about length contraction was a bit shoehorned in; I included it in the video because length contraction and time dilation are correlated with increased velocity through spacetime, but not because that fact gives useful explanatory value in the case we're discussing. The space contraction and time dilation that occurs for objects moving relatively faster than others can be understood better in the context of light clocks (I'll assume you're familiar, let me know if you'd like any clarification). For a light clock traveling through space faster relative to another light clock, the photons must travel farther to tick off the same amount of time (resulting in time dilation), and space also contracts in the direction of motion to accommodate this effect. This is true not just for clocks, but for all physics: in order for the equivalence principle to hold, for an experimenter traveling at 99% the speed of light, the photons involved in the electrical currents in the experimenter's neurons, in the biochemical reactions keeping them alive, and in lighting their experiments would need to travel a ludicrously long distance in the forward direction if space contraction in that direction didn't compensate (alongside time dilation). Kinetic time dilation and space contraction are required to allow objects moving near the speed of light experience the same laws of physics that objects moving at 0 speed follow.
@@IdeaListEye Thanks for the in depth response and for the respectful tone (so many of these presenters get down right nasty when you ask something) I'd like to solve time travel just to go back before they knew these ideas and give them a taste. There was always a time before we all knew.
Anyway: The befuddlement around the inertia section comes from the warped spacetime resisting being unwarped and needing energy to do that. So far so good. But then one the unbalanced force is removed the asteroid continues to anger spacetime as it unwarps the space it is in and warps the space in front, and to my thinking, the asteroid would have to expend its kinetic energy to keep that up; the warpage acting kind of like friction. Why is a body in motion more slippery than a body at rest? (with respect to the spacetime it warps)
Regarding mass's attractiveness to spacetime, based on the inflow 3D representation of this it seems like that flow would empty the universe in short order. Is this the correct way to think of it? Is this better than the idea that mass just warps spacetime instead making a sink? (so a still from that animation instead of a constant flow?) Is it a flow or a stretch?
Assuming a spheroid asteroid of even mass distribution, time dilations would be consistent all the way round, spacetime warping would be the same all the way round, I'm having trouble understanding why spacetime would being willing to unwarp and warp in the direction of travel with no added energy since it took energy to to do it in the first place from rest.
Or is it better to look at it this way:
From a geodesic point of view, instead of saying it takes energy to unwarp the space, would it be better to say it takes energy to alter the geodesic? (I think you kind of said that) For the at-rest sphere, the geodesic is as you depicted. With a push, we are angling it's geodesic over a little bit (I think) where it stays once the push is removed. On this new geodesic it's free to continue on its merry way because that is the lowest possible energy state and it's warping spacetime as it goes because, well, that's what mass does inherently. (BTW, to be clear, it's not that I doubt this happens, it's the depiction that energy is required to unwarp and warp space anew that has me frowning) As you say, if inertia is still a shoulder-shrugger even for Kip Thorne et al then there may be no answer to this.
Whether the sphere is warping spacetime while it moves or is stationary probably doesn't matter - the energy to do that is built into the mass of the object doing the warping. Does the motion really matter at all? Spacetime is reacting to the proximity of a bundle of energy and I"m not sure that needs any help or incurs an energy debt.
I love your geodesics diagrams for time causing gravity. I have now found another video that finally visualizes time and length contractions and dilations by warping the graph grid itself with the lorentz tranforms, while the spacetime motion remains the same - light bulb moment! (I prefer to get the concept before digging into the math - I came form the shut up and calculate school - I get the right answers when doing the math but I'm queasy about why. I could be wrong on this but I think Einstein made bigger leaps in the field by conceptualizing than in doing the math)
Yep savvy with light clocks. I was just thinking perhaps length contraction had something to do with how the object would be attracted to spacetime (bit of a hail mary on my part) and thought that's why that segment was there. Can't-get-puzzle-peice-to-fit!
@@markrichards5630 _"But then one the unbalanced force is removed the asteroid continues to anger spacetime as it unwarps the space it is in and warps the space in front, and to my thinking, the asteroid would have to expend its kinetic energy to keep that up; the warpage acting kind of like friction."_
The thing that "angers spacetime" (lol) is not the fact of the extra spacetime warping, it's a change to the _rate_ of spacetime warping. This is why an object way out in space resists acceleration proportional to its mass, but moves at a constant velocity (no matter how fast, up to the speed of light) in the absence of other forces. Spacetime warping at any _constant_ rate offers no resistance to motion (so it's wrong to think of it as like friction). The thing that is "frictional" is changing the _rate_ at which an object warps spacetime (which corresponds to changing the object's velocity through spacetime, i.e., accelerating it). Once you remove the unbalanced force, you're no longer changing the rate at which the object is warping spacetime, and the object/spacetime happily continue on in their new, faster interaction.
_"Regarding mass's attractiveness to spacetime, based on the inflow 3D representation of this it seems like that flow would empty the universe in short order."_
I borrowed that video representation from a great youtube video, czcams.com/video/wrwgIjBUYVc/video.html. Be careful in your reading of it- it's an attempt to show both space _and_ time simultaneously, and it's not showing space warping as time passes; it's instead showing inertial spacetime frames (and is a bit of a confusing picture because of that). The warping of a mass at rest far out in space is constant, and the warping of time by that mass is also constant, so there's no inflow of spacetime. The inflow applies to other masses embedded in spacetime whose geodesics have been directed by the first mass's spacetime warp towards that first mass.
_"Whether the sphere is warping spacetime while it moves or is stationary probably doesn't matter - the energy to do that is built into the mass of the object doing the warping. Does the motion really matter at all?"_
The motion definitely matters, and the nature of the sphere's warping of spacetime while it moves or is stationary _defines_ that sphere's motion (in particular, its momentum). If you believe in the conservation of momentum, the motion definitely matters. Specifically, the rate at which spacetime is warped by a moving mass (with that rate highest in its direction of motion) _is equivalent to_ that mass's momentum.
@@IdeaListEye Thanks for taking the time. This makes sense now - any disturbing of a motionless object or a constantly moving object would be an acceleration and therefor you can either look at it as that energy is needed to change the rate of motion or change the rate of warping. For my noggin I think I like the idea that the energy used to change the object's motion is in fact changing its geodesic. Is this a reasonable way to look at it? Ignoring relativistic speeds, is it safe to say that because the mass of the object doesn't change, the local shape of the curve it produces in spacetime doesn't change, and the geodesic just moves over, or, does the angle of the geodesic change too at the new constant speed?
I love how spell check turns a mangled "geodesic" into "videodisc" - I guess that's the flat-earther solution to this problem)
@@markrichards5630 That's right, the energy used to change the object's motion is changing its geodesic. This is how satellites stay in orbit: by putting in the right momentum, they now travel along a geodesic more or less parallel to the surface of the Earth.
Love this explaination❤
Way better and more intuitive explanation than the referenced videos at the beginning 👏👏👏
I have always taken the views that a) spacetime emanates from every point in all directions, thus allowing for changes of direction and time and b) nucleons, which to me are almost condensed parts of spacetime with rest mass, warp it because they are impermeable and so spacetime cannot go through them, spacetime almost concertina’s up around them. Bearing in mind most solids are vacuum and when mass is really concentrated then their mass such as a black hole completely blocks spacetime as opposed to Earth which only blocks enough for us to weigh what we do at the surface. Would love to develop this further.
The constant emanation is probably what we call the dark force. The emanation is what non mass waves ride along, at the speed of c. So mass is to me proportional to the volume of spacetime it encapsulates.
Everything moves to the least resistance. Slow time needs less effort so everything moves in that direction.
What struck me was that you can imagine it time dialation ( or time contraction) as moving up the slope of the time curve, i.e. gravity is the result of the slope of the change in time dialation.
this is easy to understand than understanding how to code a program.
Phenomenal video.
It seems similar to how electrons around the nucleus of an atom always 'try' to minimise their energy state, but electrons jump from one shell to a higher or lower one, not following a continuous geodesic path like large-scale masses do.
I realize for the sake of explaining the principle of geodisks in space-time you have used a skyscraper extending to outer space and exaggerated the time dilation enormously between the bottom & top floors. But for an object on earth such as an apple the time difference between the top of the apple and the bottom of the apple is in nanoseconds or less. How does such a miniscule time difference translate to such a high acceleration due to gravity of 9.8m/sec^2 for the apple?
Hi Ravi, good question, and good observation (I should've made it more clear in the video that this was an extreme exaggeration, as you pointed out). It turns out that in this context, 9.8m/sec^2 is quite a modest acceleration. This is because it must be considered relative to the speed of light, 300km/sec; all objects at rest are considered as moving at the speed of light in time, and when they begin to accelerate relative to other objects, the accelerating object trades some of its speed through time for speed through space (i.e. it slows down in its motion through time). From this perspective, only a very small fraction of an object falling on Earth's speed through spacetime has been converted from the time dimension into the space dimension. Here's a great video on this point: czcams.com/video/au0QJYISe4c/video.html
Thanks-a-lot!
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MUY buen video.
Utmost didactic. THANK you ❗
Despite beeing an engineer, my understanding is still a bit nebulous.
But my intuition tells me that I am going to understand it way more intuitively now, more naturaly 👍.
Now, I can grasp at least, that the traditional way of learning/explaining gravity as a force, as an "attraction", is simply wrong 🤔.
Literally, what I learned here makes me feel lighter, enlightened.
Your video is really great ‼️‼️‼️
Saludos de
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Great video but I now really don't understand why some videos say we are not attracted to the Earth but rather pushed up from it...
Great question, this is a major point of confusion on this topic. The idea that "we are not attracted to the Earth but rather pushed up from it" comes from the "equivalence principle", a hypothesis dating back 1,500 years that guided Einstein's development of general relativity. Briefly, Einstein's equivalence principle holds that the mechanism for the force experienced by someone sitting on the surface of the Earth pulling them downward is indistinguishable from the mechanism for the force experienced by someone far out in space, accelerating at g. (This is similar to how, when you enter an elevator and start accelerating upward, you feel heavier while you're accelerating; in fact, if you stood on a scale, the scale would show you weighing more while you are accelerating upward). In this sense, there should be no difference between a framework in which the Earth is attracting you downwards at g versus a framework in which the Earth is accelerating you upwards at g.
That's all well and good, but the first case is immediately intuitive to us, whereas the latter case seems ludicrous (e.g. the Earth would have to be ever expanding in every direction for this to be the case, etc.). What gives? I think the right way to look at this is that neither case is exactly true, because they aren't looking at the underlying mechanism, which is spacetime warping and your mass's interaction with that spacetime warping. So, the real story underlying both cases is that the Earth's mass interacting with spacetime warps spacetime (especially the time component of space), so that the forward direction in time for any mass has a component in the direction of the Earth's center of mass (in a sense, time is bent into the "downward" spatial dimension, and spacetime "flows" in that direction). Your mass also interacts with spacetime, and is "attached" to spacetime by that interaction. When spacetime flows towards the center of the Earth, you're attached to that flowing spacetime, and therefore your mass also is pulled along with that spacetime. The confusing part here is that the relevant "flow" occurs in the time dimension, (i.e. where should a mass go over time given the nature of spacetime in the vicinity?), because it's nonintuitive to picture a geometrical aspect of time. I think it's fair to think of it as: the time aspect of spacetime answers "what should happen next?", and in this case the time aspect of spacetime says "masses should move towards the Earth's center of mass" or more broadly, "masses should move in the direction of the 'deepest spacetime well nearby' with the most urgency", and time says this because of the way masses warp spacetime.
I hope this helps, I'm not sure if it's more or less helpful written out like this.
@@IdeaListEye thanks so much for this clarification. My confusion now lies on why mass produces this effect in space-time. Thanks to you I start understanding the consequences instead. I will focus more on the equivalence principle possible interpretations.
@@alessioandreoli2145 Why does mass produce its effect on spacetime? Now that's a great question; turns out, no one knows why that is, really. The Higgs mechanism is something of an explanation, but that kicks the ball down the road to "why do massive particles interact with the Higgs field?", which I believe is unknown. Similarly, "why do electrons interact with the electromagnetic field?" is unknown: some things are known solely from our observations about them, and not due to a more fundamental theory from which we could predict those things.
Thanks for an illuminating video. I find this topic endlessly fascinating. Your explanation adds to my understanding and for that I am grateful. You simply can't do enough on this topic. More please!
I'll have a look at your other videos.
Great ideas! 👏👏
The curve you describe makes me think of a record player. The centre and the outer points seem to make one revolution at the same time but the outer edge point has a larger diameter and so moves faster through space time. Would this be an apt analogy? Great vid nice simple chunks to help a person learn the more complicated parts in the future. Take care keep well.
Hi Vincent, interesting comment. I think it's not exactly an apt analogy, because all objects always move at the same rate through spacetime (at the speed of light, which is a confusing point in itself, but I think this video's description contains a link to a good video that explains this). The thing that changes from point to point in space relative to other objects in space is whether that thing is traveling at the speed of light solely through time (i.e. not moving relative to those other objects) or having a component of its travel through a direction in space (while traveling less than the speed of light through time as a consequence).
@@IdeaListEye Cheers mate I knew I wasn't there completely with that analogy lol or at all. This will help no end, much appreciated. Thanks again and all the best, take care.
Hi! But why does the body choose the "shortest path" between the white lines? Does it have to do with minimizing the action (the length of the world line)?
Hi! Yes, as with all spontaneous actions in physics, it's a result of the system seeking the lowest energy state. Masses follow local geodesics because it requires the least amount of energy (i.e. the object would require extra energy to follow any of the non-geodesic paths; for example, a satellite in orbit is only able to maintain orbit because it has a lot of kinetic energy perpendicular to the geodesic provided by the Earth's mass).
Great video, thank you... just a question though... according to equivalence principle, an object in free fall is like a floating object moving freely through its geodesic in spacetime (like the space station)... so according to my understanding, time for the falling apple should be as fast as it is for the space station until it falls on earth, at which its time will move slower... am I missing something?
I’ve always learned about time dilation with the light clock stuff using the speed limit of massless objects like light as the starting point. This is interesting.
I think that is the best starting point!
Thank you so much..
Awesomeness video!
Mass is motion. Inward motion. Inward motion is motion in time. It's similar to the vortex in your bathtub drain. You can think of it as a void, and the spacetime "fabric" trying to fill that void due to a pressure gradient. When it succeeds a black hole is formed
Excellent video! I think I understand this concept much better than before! Hope to see more videos like this! Thanks!
the video belongs to another youtube channel Veritasium ... that channel just stole the video.
Good video.
I think Einstein's work is very straight forward in the sense of how the time causes that things fall down. Any way, i think your work is great.
"Why does mass warp spacetime?"
The simple answer to the question is: relative parallax causes infinitesimal particles moving at instantaneous velocities to "slow down" or "warp" in space. That may sound impossible, but read on. It solves a LOT of problems and makes more sense than any of the current speculations.
I have been working on this for a long time and finally figured out very recently that infinitesimal particles (no size) create mass because of a parallax effect as they pass each other in space. The particles "register" each other as moving at slower rates than themselves. The further away the other particle, the slower it appears to move.
This is exactly the same effect as two airplanes who think they are flying parallel, but within a few seconds, they quickly discover that they were on a collision course, but too late, they collide.
Now these infinitesimals can never collide (being infinitesimal), but as they pass the same point in space, each becomes attracted to the other because to both particles, their paths curve, even though neither has changed course. This relative curvature causes the particles to seek a straight line in relation to each other, forcing their paths through space to curve. As their paths diverge, they become locked by a gravitational pull as each slows down in relation to the other, shaping their path as a curve. This creates a sine wave.
Time itself emerges from the relative movement of infinitesimal particles. The particles are normally inclined to change in position without change in time (instantaneous movement through space), which is identical in appearance to a stationary particle that changes its time without changes in space (instantaneous movement through time). However, the particle moving through space instantaneously has a pathway, even though it does not trace out that pathway in time. The above-mentioned curvature occurs as two particles' paths cross in close priximity relative to the rest of the universe. But since they register a velocity of each other as slower, due to a hierarchical relationship to all other particles in the universe, their path curves together, warping space time, and both particles are slowed through spacetime, though both particles are technically moving at instantaneous velocity.
This is what I call relative parallax. Their angle in relation to each other creates a spiral wave we register as a sine wave. Any other particles in close proximity can alter the path of the first particle pair and so on, causing a change in frequency. (I believe these pairs are photons or that photons are pairs of pairs of these particles based on recent findings at the LHC and the mathematical model of a photon having two parts revealed in December, explaining their spin 1), and I am currently of the opinion that the more parallel the particles travel, the flatter the wave, while the more perpendicular they travel, the more trophs in the wave, based on how much energy is transferred by the other particles. However, I am willing to accept the opposite. I still have to model it properly.
I had found that the particles have to start out with a rest velocity of instantaneous movement, leading to causing time, spacial curvature, energy and all four forces. That does not happen with non-moving particles starting with instantaneous time. In that scenario energy has to be added, but in my scenario, time, energy, mass and gravity emerge naturally. It also satisfactorilly shows that the universe is classically deterministic without some underlying, inexplicable, spooky "quantumness". (Though this does not necessarily mean that consciousness is superdeterministic, as the parts can exceed the whole to allow conscious agency.) QM is still just probability based on group theory, not a fundamental quality of space.
Bound photons sharing and trading infinitesimals creates electromagnetism and other particles in effectively three-body systems, producing 1/2 spin. It is the destabilization of the gravitational monopoles of the bound infinitesimal particles that creates electromagnetism. The restabilization of the field with additional particles having a counter-stabilizing effect produces weak force, and the perfection of this balance produces the strong force.
Good video!
Cheers!!!, I finally found an explanation that an old engineer can understand 👍🙏🙏
We love this video! You’re right that the connection between time dilation and gravity is only made more confusing by the “gradient flow” analogies of other videos. And we like that you’re not afraid to tackle the big questions - “why does mass warp spacetime” is the essential mystery left behind in the wake of GR. Interesting to think, for instance, that an accelerating object, in consequence of the equivalence principle, must observe a gravitational field, i.e. warped spacetime, in the vicinity of itself, and that the strength of this field is independent of both its mass and velocity.
Great work, we look forward to your future videos!
Many thanks! I hadn't heard of your channel before, but there are some really interesting topics there; looking forward to checking them out.
@@IdeaListEye Hah, we’re not big, but hit us up anytime!
"... an accelerating object, in consequence of the equivalence principle, must observe a gravitational field, i.e. warped spacetime, in the vicinity of itself, and that the strength of this field is independent of both its mass and velocity."
Well, lets do some philosophy. The only two entities in your statement that pretend to be real are the accelerating object and the act of observation of some object which is different, i.e. on the outside, from this observing and accelerating object. In this case, one may say that the observed object is the exterior, should we say the outside, of observing object. However, according to GR equivalence principle nither the accelerating object nor the gravitational field are real, therefore "the strength of this field is independent of both mass and velocity". Actually the only two real entities in your statement are the change of the rate of change, which is real because of it"s actual limit /the speed of light/ and the continuity of the extension /or the duration/. Just forget about the force and strength.
Thanks so much
Mass causes gravity, the curvature of space. Gravitational dilation is often referred as time dilation. It is gravity that distorts space causing measurements of motion within a gravitational field as distorted in time. Time is the measurement of motion. It is a measurement. Things move at different speeds through space. We measure this speed by time.
That was so interesting and well-explained! I'm a 9th grader and managed to understand most of it
Awesome, I'm glad to hear it! Isn't it great how as you learn more, more and more cool ideas become accessible to you?
My favorite spinning top toy as a child had a pull string, and, that thing would spin for almost a minute.
I wonder if the warping of spacetime is a measure of interactions, a convergent phenomena where time dilation is relative to the number of particle interactions. E=mc² shows a higher energy system has greater mass, but from an information science perspective, a higher energy system means higher concentration of interactions, not necessarily higher energy interactions. "Time takes longer wherever more things are happening" kinda makes intuitive sense, and I see the flow of gravitation like air flowing from below a single spot in the desert; the sand is spacetime, and objects near it will tend to fall into the loose quicksand because it's shifting. I wonder if mass energy falling away from other mass energy light years away might cause dark energy, as gravity can't overcome other forces, the sum of all falling in one galaxy pulls at the spacetime between it and all others, like two quicksand pits pushing sand between them when an object falls inside.
This is an interesting brainstorm. I'm not sure how to "confirm or deny" this, but maybe an openminded theoretical physicist will chime in here at some point.
Hello. Thank you for that great video. It makes things very clear. I was nevertheless wondering why the trajectory you draw through spacetime is a portion of circle. Would n't has to be parabolic ? Or i miss something. (Which is certainly the case).
Having seen all those apples and clocks move about at different rates, one question that remains is "why do objects move through time in the first place, then?"
This is a great question. Ultimately, time passes because things change. Why do things change? Because they're following the laws of physics, which require things like momentum to be conserved. Why do the laws of physics make things move, and why do things follow the laws of physics? In some way, the things have their existence rooted in and defined by the laws of physics, so you fundamentally can't separate out the laws from the things. Why do the laws and the things exist? No one knows.