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?

I found Science Clic to be an amazing resource too. Similar descriptions: kzfaq.info/get/bejne/rdinmqybp7u9hpc.html kzfaq.info/get/bejne/fbeKZrVpls_ddWQ.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.

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.

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.

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.

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!

Thanks! Would love to make more physics-y videos, hopefully when I can find the time.

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.

the video belongs to another youtube channel Veritasium ... that channel just stole the video.

​@@GriuGriu64 I think its useful

the video belongs to another youtube channel Veritasium ... that channel just stole the video.

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,

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.

😂

the video belongs to another youtube channel Veritasium ... that channel just stole the video.

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)

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.

Yep, I’m searching too!!!

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!

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

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)

the video belongs to another youtube channel Veritasium ... that channel just stole the video.

The man, the myth, the legend himself! Thanks for watching, Tay. I like that analogy, I think of the formation of mass as basically just this, something like a knot tied into spacetime that pulls space inwards in all directions (at the speed of light), and which in some abstract way stretches out time as well.

atoms are mostly empty space. Matter does displace space, which pushes back against the matter as it passes through it. This causes a higher density region around the mass. Essentially, gravity is the effect of spatial pressure. We aren’t pulled towards the earth, we are pushed down onto it by space. So why time dilation? Time is just the rate of quantum vibration. In a high density special field, the vibration is slowed, ergo, time is slowed.

Oh wow it actually makes sense

@@lornenoland8098 define ‘quantum vibration’? How is that time?

E=MC2 is just a joke.., First off we live in a magnetic world. E=MD (Magnetic Density), All mater is magnetic all plants people everything we know exist is magnetic. The center of a magnet will prove all this to you!! Start working with the center of a magnet and you will see many things , Anti Gravity is one.. When Tesla tested his tower in Colorado for the first time he sent too much power from space into the local power plant and blew up one of the generators. FACT.. The north and south poles are the weakest part of a magnet, The energy in the middle once you learn how to use it will blow your mind!

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

I didn’t…

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.

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: kzfaq.info/get/bejne/l9tghK2KrrnJZJc.html

Thanks-a-lot!

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.

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.

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

the video belongs to another youtube channel Veritasium ... that channel just stole the video.

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! 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).

I think that is the best starting point!

Cool observation! I hadn't thought of it like that, but I see what you mean.

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, kzfaq.info/get/bejne/rdinmqybp7u9hpc.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.

the video belongs to another youtube channel Veritasium ... that channel just stole the video.

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.

the video belongs to another youtube channel Veritasium ... that channel just stole the video.

Bending of spacetime resists acceleration, not velocity. I think this is because of time. All objects must move in time and/or space. Increases in velocity is converting relative time velocity into space velocity. At the speed of light, time does not pass in your reference frame. Put another way, one might say that inertia or velocity is caused by the passage of time. More fundamentally, the constant speed of causality causes inertia.

@@bminerrolltide I realize that that's the common understanding based on the idea that everything travels at c through spacetime (which is perhaps equivalent to saying that c is the constant speed of causality, as you say). But he's trying to go deeper than that and explain exactly why spacetime resists acceleration, so I'm asking him to complete that explanation to account for the lack of resistance to constant velocity, if that makes sense. If you have any ideas, lmk.

@@GumbyTheGreen1 yeah I think I understand what you're saying. I think bending of spacetime does in fact resist any change in position, but this resistance is balanced by the object's inertia, which is caused by "the constant passage of time." Haha sounds kinda weird to say. Put another way, as the object passes through space, spacetime bending follows the object because time is passing at the same rate as the object's velocity through space. Or put another way, the object is moving on its geodesic.

This is kind of why you can say that "time" causes gravity. More precisely you can say that gravity is caused by all objects moving through spacetime at c. The mass bends spacetime, and its constant velocity in spacetime causes spacetime bending to follow the object in space. Thus, other nearby objects are pulled along these bends in spacetime, as well (gravity).

Hey Gumby, great question! I'm glad someone asked this. First off, I should state clearly that this is purely an intuitive description and understanding (in other words I don't have a derivation for this effect, but it makes sense to me (so it should of course be taken with a grain of salt)). In my view, constant motion is a case of "balanced" spacetime warping. In other words. as the object approaches spacetime in the forward direction (really, it should be ok to talk just about space in this case, since that's the relevant dimension, but I'll stick with spacetime), the spacetime's attractive influence on that object helps propel it forward. On the flip side, as the object recedes from spacetime in the backward direction, the spacetime's attractive influence on that object resists its forward motion. I see these two influences as balancing perfectly, leading to the observation summed up by Newton's first law (A body continues at rest or in motion in a straight line with a constant speed until acted on by an unbalanced force). In the case of an acceleration, to understand my perspective, look at it like this: the unbalanced force on the object is asking approaching spacetime and receding spacetime to warp at a different rate, upsetting the balance described above. For example, adding speed to the object in the direction it's already traveling requires spacetime to warp in the forward direction and unwarp in the reverse direction more rapidly, which takes energy to do (related to the inherent "stiffness" of spacetime ultimately defined by the permittivity and the permeability of spacetime). That energy is now considered part of the object's kinetic energy, but it's really contained in its modified relationship with spacetime (warping/unwarping spacetime more rapidly in its direction of motion).