If you vibrate furiously you'll statistically, eventually, be at the exact same position you were a small delta time ago. You won't know when that's gonna happen, but you know it will eventually, probably, happen.
I find the idea that I'm not eventually gonna be everywhere an infinite amount of times ridiculous. Sure the universe can be infinite, but then there's also infinite me's. It's inevitable.
Correction: systems do not _often_ rearrange themselves into a previously ordered state. It is neither impossible for them to end up by chance in their original configuration, nor is it true that it has never happened. It is merely true that it should not be _expected_ to. Likewise, in this case, I feel the argument here about how there is no location that is non-relative is merely an assumption based on the fact that we need to define relationships between where things are to determine location. I do not agree. If we had perfect knowledge of not only where everything is, but where it has ever been and will ever be, and when it will be there, you can use those dimensions of time and space to form a coordinate system, and while allowing for non-matching coordinates along the time axis, you can thus return to a spacial location. The location will be the same because it will have been defined as being the same according to the coordinate system, regardless of whether that location in any way currently resembles what it did previously in time. Even if we take into account the possibility that the coordinate system is itself changing over time, we can simply convert the change of the system itself as another axis like we did with time, and use the new system as our definition of location. We can continue to do this across infinite dimensions and axes to eliminate infinite variables that prevent may get in our way, and in the end what this means is that location and its subjectivity are things we have defined and have control over. We defined location as how some place is related to some other place, but that is not the only way to define location and it is not the only way we have ever defined location. The problem is to do entirely with the perception of location, which is an unnecessary variable. One does not need to know their location for it to be their location, and similarly one needs not be able to understand how to measure it for it to be true. There are many things we have measured that were previously impossible for us to measure, that we have done only because we changed how we define the process of measuring or understanding those measurements. Thus things that were "impossible" to us once, were all the same, still always true, in spite of our definition of it being that it is false, and so applies to location. Relativity is not the truth... it is a possible truth and is not the only possible truth, nor a purely mutually exclusive truth, as it inherently depends on us to define it as true.
There is a thing called momentum that you have to reverse if you wanted to travel back in time, like the momentum of everything. The thing that was moving forward you would have to apply a force to make it go backward and vice versa. That's a lot of work you would have to apply on a universal scale.
But momentum is relative like velocity, so momentum can only be reversed relative to some reference frame - a stationary object reversed relative to a moving one will be sent flying at twice the speed to catch up to it
The CMB Dipole suggests that there are absolute positions in space. We are moving about 600 kps relative to the CMB, which is only about 4 times the maximum speed reached by the Parker Solar Probe, meaning there's no theoretical reason we can't position something stationary relative to the universe, move away from that point, and return to it.
Thanks for this video @dialectphilosophy. For a long time now, I thought that motion in space (both backward and forward) was silly. Of coarse all matter only travels forward! I've been thinking about doing a video myself, but yours is very good. Thanks.
This is a common sense video. Because if you could genuinely travel back in time, it would exactly be like a video or song played backwards. All your thoughts, your breathing patterns your body chemistry would have to be acting in reverse. All of that is going on when you play a video backwards. But you can not see it because it is all internal and not visual. But that is exactly what is going on when you play content in reverse. There was an iconic rap group in the 90s called the Pharcyde. They had a video that they came out with called "Drop". That video is actually a timeless classic. If you watch that video and find out how it was composed, you will see how it correlates to this video about space and time
Well done, and great points. There's a saying that you can never step in the same river twice. The water flows, fish swim, gravel tumbles, branches float by, and so on. It is a close enough approximation of the same river, but it is not exactly the same. That's true of your house, too. You come home at the end of the day, and many things that you don't notice (or maybe do) have changed. Some paint chipped off there. A newspaper landed on a flower and smashed it. A window now has bird poop on it. The roof is hotter and some composite has come off and rolled into the rain gutter. Wasps started a nest in the eaves. And thousands of other details, mainly small -- but maybe big! The newspaper maybe broke a window, or a large tree branch landed on your roof. You can never return to the same exact house as it existed in the point in spacetime from where/when you left it.
I tried to explain this when talking about traveling backwards in time and how you would end up dead in space and not on Earth. People we're very confused.
@@robertbeaman5761 Traveling back in space-time, because they are linked, you would end up on earth at its previous state (coordinates in space-time). Traveling backwards in space, while the arrow of time isn't reversed, well, then you would end up dead in space. which is pretty much the point of this video - you can't, because space-time coordinates exist only in relation to initial inertial frame of reference, which must be at absolute rest where absolute rest is impossible for something that exist and also it's also relative...
Depends, if you use consensus science and pick any old constant in some made up equation and call it a "dimension" you can travel, maybe it won't happen like that.
Glad someone understands spacetime. Your logic hasn't fallen on deaf ears. One thing about AE's equation states forward motion isn't possible without breaking that light barrier. Tweaking it will allow forward motion. However, that breaks his law on time travel. Only conclusion: one speed one direction.
Watching your various videos has helped me a little to understand the differences between absolute and relative space and time. Would you do a video that in simple terms explains the debate between Newton and Leibniz about absolute and relative space and time? Maybe that was what you are talking about at 3:07 to 3:24. My mom wonders why Leibniz would say absolute rest is not possible, is that partially explained in the Newton's spinning bucket with water video you made?
No, actually, for any spacelike vector, an object's 4-velocity may be oriented with any inner product sign with respect to that vector (i.e. toward or against it), but for a timelike or lightlike vector, an object's 4-velocity may only be oriented one way with respect to that vector, depending on which way that timelike/lightlike vector points. You may travel against any space-directed 1-form, but not against forward-pointing time-directed 1-forms (which come from the exterior derivative of your "time" coordinate).
@@aaronmorris1513 acceleration isn't comparative, it's absolute, and can be detected with a set of scales. If you stand on the scales in your bathroom and it shows a "weight" (actually a force), your home is accelerating with respect to something.
If you and your spaceship were travelling across space in the left direction, at say 260,000 km/s, but you then fired your rocket engines while pointing toward the right direction, and for some time you had obtained a spatial velocity of say 130,000 km/s, where in space you were located a minute ago, is now ahead of you. Thus, you have travelled backwards in space.
Some of these ideas are down to language and definitions. To 'travel in space' suggests space is a 'thing' like a fabric that you move 'through', in other words with respect to. Space has to be a total featureless void (as you are in fact saying) for relativity to hold, there's nothing there to travel through in the first place. You can only move between objects so you're only altering the configuration of you and the objects. Then of course you can reconfigure things back to the original position. As for the mug even if you could put it back together exactly in absolutely every respect you're only making a perfect copy of the past in normal time, you're not going back in time. To go back in time you'd have to obliterate any evidence or memory that the mug broke from the universe or you'd have two pasts: one where it broke and another where it didn't, again we need to sort the semantics before delving into the physics.
This video makes less sense the more I think about it. I wonder if he's changed his mind on this given his newer videos. This one makes some of the same mistakes that he criticizes other videos making.
If you move from a point to the "next" point in any direction you change positions. Period. Local or not. Or if some object changes position with respect to you, it changes position. Who moved? Who should move to recover the previous "position". Also if you ignore other frames to turn around is irrelevant you still have to increase your distance from where you are to where you're going. You can't draw a line with a negative length.
Mark W That means Galileo could be wrong =)) . I think the solution for all of these is we have to figure out what truely fixed is in the whole universe.
Well, I guess a discussion about CTCs (van Stockum/Goedel 1937/1949) and the self-consistency principle by Novikov (mid-1980s) could be way more interesting.
Surely absolute spacial location is an ill defined concept. 'Where are you in space?' is not a sensible question, that is the whole idea of relativity no? All we need to do is define what ever coordinate system/reference frame is most useful and then there is nothing stopping us from returning to a prior location in those coordinates. Also if you want the most global reference frame possible choosing the cosmic microwave background seems like a pretty good shout. We'd need a pretty bad ass rocket to get us where we were yesterday but theres nothing in physics that would stop us. (maybe in biology haha, might involve some serious G force).
@@PulseCodeMusic I get that but it’s still interesting to think about. Also I think the main point of the video wasn’t really about going back to your old position but about that neat relationship between space and time
Doesn't this establish that time is an emergent property of matter moving through space, just as a shadow is an emergent property of light being blocked?
We don't know what space _is_ and how it works exactly (how it grows, or whether its parts rearrange for instance), we could even add the issues of ontology of time (eternalism, presentism, ...) and identity of objects. All in all, you should remain agnostic on whether you can or cannot travel to some point in space that you've occupied earlier (with a spaceship for instance).
This assumes that global space is not related to your temporal space and thus time dilation couldn’t exist, but it does. Otherwise we would experience different time dilation when the Earth’s spin move with the motion around the sun or against the sun. But the GPS satellites don’t have to take this into consideration. Because in reality local spacial frames of reference govern out total motion
If we are watching or moving relative to time. what kind of reference frame that time would use to see us if we travel approximately at the speed of light ? SOMEONE PLEASE ANSWER THIS FOR ME 🤔🤔🤔🤔
I think yes, it'd require you to put everything back in the state it was in the past, which would require energy you could take from the rest of the universe, kind of like putting in energy to cool down your fridge, but you'd have to know everything about the system
@@mementomori7160 You still can't because second law of thermodynamics still holds in any isolated system. Unless you are talking about quantum systems with very few particles. Then you may return to the exact state in the past.
@@MrNicePotato We're talking about reversing time locally, and I said you'd have to take the energy from the outside, therefore we don't consider it as an isolated system that reverses time on it's own, that's why I think it is possible, just like cooling inside of your fridge by heating up the outside of it
@@MrNicePotato You can, because as he says it "would require energy you could take from the rest of the universe". So long as the entropy created in the outer universe is equivalent or greater than the entropy that was reduced by resetting the objects locally, the total entropy still increased. Imagine having a hot meal on a cold plate. The meal slowly cools down until the heat of the warm meal is equally spread out across the meal and the plate (more entropy). Then you rewind time to when the meal was still hot and the plate was cold (less entropy). If this takes no energy at all, then you just reduced the total entropy in the universe and broke the second law of thermodynamics. But, if the action of rewinding time for the meal created an equal amount of entropy elsewhere (inside the device you used to perform the rewind?), then it's fine because the total amount of entropy in the universe did not go down. It decreased in one place, but increased by an equal (or greater) amount elsewhere. It's just that your _local-time-rewind-device_ needs to - _will_ - release enough heat (or other form of entropy) to compensate for the entropy reduction caused by the local time travel. I like to think that rather than heat, a local-time-travel-device would have to increase the passage of time on some other object. Just as an AC produces more heat than it removes from the air, a device that manipulates time could rewind one thing, but would have to fast-forward another, and by more than was rewound. Could be a neat science fiction plot. Like a little rewind gun with an "entropy battery": You aim and shoot to rewind an object which fills the entropy battery as the object is rewound more and more, but you can't go too far or the entropy battery will explode. Then if you want to rewind more, you must first release all entropy from the battery by fast-forwarding other objects.
I am so glad someone made a video about this because I've been thinking about this for a long long time. If you want to travel back in time you have to return all the matter back to where it used to be and also account for the space created or let's call it the expansion of space and contract that as well. I guess I'm not the only idiot who thinks about pointless stuff like this.
I feel the same. I’ve been thinking about this ever since I started to understand Relativity theories. I’m so glad I found this video. I’ve always wondered why high level physicists still talk about this incorrectly. This simple idea builds on and makes Einsteins theory of Spacetime. more easily digestible
looking in the hubble space telescope is technically watching a movie of that planet or sun in real time from the past as it happened 100 years ago if that planet is 100 light years away..so you are actually seeing the matter from 100 years ago interacting we can't go back but we can observe the past 😉 Einstein was wrong we can't go forward or back no matter what we do we can observe the past that's all and there is zero physical proof that time would stop for a person on a space ship traveling light speed our observation of that ship would appear to stop because the light can't travel to us. But there is no proof or logical reason why the person in the ship would age slower or there clock would magically tick slower .as spock would say that's illogical..lol
@@sailingmohican2767 You completely correct with looking in the past.. Though it is 'proven' by General Relativity that if you were traveling through spacetime at the speed of light ( which really nothing with mass can) your time / clock would stop..⌚ It's the same situation with GPS.. They have to always take General Relativity time dialation into account or GPS would never be distance accurate .. 🛰️GPS satellites are traveling around the earth, through 'space-time' faster than we on the ground are, so their time/ clocks tick a little slower ( tiniest difference, but enough to throw out distance accuracy )slower than ground clocks do, so the GR calculations adjust for the difference.. ( With this next bit it helps having a space-time axis diagram to picture what I mean.. ( An L shape, with time⬆️ & space➡️ ) & remembering that our movement / travel always adds up to the speed of light through 'space- time'.. Not thru space alone nor through time alone , but both added up ) So, now if we are traveling through spacetime at the Speed of light.. Because we ( with mass) don't go fast compared to the S.of L., nearly all of our movement through space-time is through time (We experience 1 sec/sec along the time axis) but not much movement through space ( stuck going slow on a planet, or on the space axis).. But.. If you travel fast, 🚀zooming through space-time so fast, at the speed of light, suddenly all of your movement is through space,🌠 or on the space axis, leaving no movement left over to experience time.. That's cos the speed of light is not about light, it's about the speed of causality.. The fastest that anything can happen.. I don't reckon we'll ever go back in time, but forward in time , or changing our time compared to someone else happens all the time.. 🤦♀️ Despite the crappy explanation it's true.. 🤯It so cool & freaking amazing how spacetime works.. Basically it's saying that the faster you go through spacetime, the slower your clocks tick/ run.. As in satellites clocks all run slower than any clocks on the ground.. The bigger the difference in speed, the bigger the clocks are out.. It is actually taken into account for so many things.. 🌏☮️♾️
Earth, sun, galaxy etc are moving in locked orbits. But what if you are traveling in a spaceship and do not experience any gravitational force so you can chose freely where to move. Then, unless you believe that space itself is moving, you can get back exactly where you were.
I agree. Notice how the spatial structure of the universe seems to mirror as it scales up or down. An atomic nucleus or particle is exceedingly small compared to the spatial size of the overall atom. Same with stellar systems. Same with large structures such as galactic clusters.
The equivalence is here bad presented: the question is not if you can return to the exactly point of departure, but if you can go back, or go laterally or go forward, in short: if you can choose a direction and a toward, yes, you can, even if you are transported by space flow. But with the time you haven't these freedom degrees, you can only eventually slow the time or accelerate it by moving you near to ou farer from a mass (scalar modification of the time speed), without vectorial degrees of freedom: direction and toward. So, not: the time and the space are not equivalent and are not "dimensions".
I agree with you. Space may be a dimension but time is not. Also, if to move in ''time'' which I consider as non-existent, one would change the surroundings and that would affect the cause and effect rule even on microscopic level. One can flow through space but not through time and time itself does not flow either. It's always always.
Under those philosophical conditions, time wouldn't allow being able to be in the same space even if you could physically go back there anyways. Entropy would ensure you wouldn't be the same you when you made it back. For instance, the last heard, which is admittedly a while back now, that the human body changes every cell in its body every seven years. So, if you did actually manage to get back to an exact point in space you existed in before, likely none of the atoms that made you up would make it back there with you, just your consciousness.
changing with every evaluation the system of reference and adding more and more movements, lead to video conclusion, of course. But if you don't change the reference system and you don't add new movements to the system, lead to the same conclusion?
Cf. Einstein's Hole argument, that bothered him for many years. Some locations may not be “locations” in the full sense of the word, i.e. be possible to assign coordinates to. That, or not fully covariant. As for traveling backward in space... in which theory? Such a theory requires, at the least, to define what is "traveling," "a location,” and a distinction between forward and backward (which you've noted so keenly). Incidentally, the theory does not require a notion of time; the “traveling” subsumes it, and simply time isn't enough. These prereqs are easy to satisfy, but it's helpful to keep in mind that they ain't givens. Very good point, thanks for bringing ti up!
We stole the idea for this video from a passage written in a textbook we came across once. Later, we discovered Einstein had written about the very same thing in the prefaces to a discourse he had written on relativity. It seems like he had borrowed it from elsewhere as well, so it is certainly not a new argument. It does raise the issue of the relationship between space and time, which, even from a classical standpoint, can be viewed as blended to a certain extent. We feel that was what was most compelling about the topic... also of course, that it hints at why both absolute space and absolute time are impossible, or at least unknowable.
Came thinking this would be the same argument as you can't have a negative speed (but you can have negative velocity). Which might be related to negative energy. Also interesting that in 2D random movement will certainly result in returning to the same location - maybe the 2nd law of thermodynamics isn't necessarily true in 2D (or especially 1D) due to the dimension itself.
If an event is marked by the emission or reflection of a photon, then an observer at a distance will view that Photon. If the light is in fact a wave, it expands in a spherical surface at c. If the observer wants to vies the event again, he would have to travel faster that the speed of the wave, c, but this is impossible. It doesn't matter how fast the observer travels, he can never go back to the emission or reflection of that photon or wave...
the CMB is different depending on where you observe it. Obviously as the biggest and farthest observable thing in the universe, it is impractical to get a significantly different perspective on it. But hypothetically, just as the constellations would look different in a different solar system, the CMB would look different from a different galaxy (especially very distant galaxies) hm.... actually the more I think about it this doesn't really dispute your point... I mean sailors use the stars to navigate. So to repeat your question, why can't a space traveler use the CMB to gauge their motion? I mean the entire CMB will be blue/red shifted hemispheres depending on your direction of travel. Maybe it is a dumb distinction but "relative to CMB is still relative". Relativity doesn't stop you from comparing reference frames, it just says that no reference frame is privileged or more authoritative than others.
So if space fllows as time do and we can localy go backward in space, what is the equivalence in time ? can we go backward in time "loacaly" ? Is it equivalent to just slow the time flow ?
As I understand, the going "locally" backwards is just defining that a forward state is the "same" as the backward one. And of course it is arbitrary, as you can define what you choose to ignore(your reference system). So it is possible to do it with time, but as in space you are not going backward in time, you are going forward to a state that is defined as "the same" under an arbitrary reference system. An example might be just fixing something, you didnt go backwards in time but you might say its the same as before in some arbitrary way like the case of going back home. So you can say it went backwards on time locally. Although I dont know If I understood correctly.
Your entire argument is predicated in the existence of absolute positions and motion through space. That’s obviously not what we mean. Since space and distance are intrinsically relative, we can absolutely “return” to a location in space. All we have to do is return to the same relative distance between objects of reference-a point you even acknowledge at the end of the video.
You don't get it. One can return to an object or place locally but not to the same position in space that object was when you left. That's what he acknowledges at the end... Everything is moving at once, you can only return "home" because both you and your house are moving at the same rate is relation to the planet, so it seems like everything is perfectly still, but the planet is moving through space, so you'll never get back to same position in space. get it now?
@@MultiVigarista No, YOU don't get it. Read my comment again. The reason you can't "return" to a point in space is because there was never a "point in space" to begin with. It is literally meaningless to think about space in this way. And since that's not what we mean when we say "point in space," the argument itself is a gigantic fallacy of equivocation built on a false premise.
@@AntiCitizenX we can call it "general region in space" then, if that makes you feel better I guess. For all it matters we can be talking about a region 5 m^3 in 3d space the argument still holds, you can't return to it... 😅
Position is defined in refence to a frame. So this is just being obtuse...we might as wll say we can't move in space at all since we are always at the origine of our own rest frame. Also you are refering to an inconvenience as an impossibility.
Dialect 2 objects in empty space. One steps on the gas, accelerates, moves away, turn's around, come's back and meets the 2nd object... No Earth, no fixed stars, no nothing else in the Universe... Are you still saying that even then - these 2 objects when they meet again, they will not be at the same point in space as they were before their separation? Is that because of the Universe expanding? And if not, then why? Is it because we assumed that the 2nd object is inertial when if fact we can't say for sure if it really is inertial? Is that the point of this video?
b4: Can you travel forwards through time tho? Aren't we just these long 4d snakes of existence of which only each individual 3d slice is an everyday object that appears to evolve over time
Hold up. This is an argument from ignorance (a common fallacy). Not knowing what direction in space the spot you were at some finite amount of time in the past was does not equate with it being impossible to move to that location. It only means that if you do it, you won't know it.
Good point, and bravo for bringing that up! Is it merely a sort of epistemological confusion to equate an inability to define a past place to ontological unreality of that place? If something cannot be known to truly exist, then empirically speaking does it really exist? These sorts of questions are the true fun of the philosophy of physics!
@@dialectphilosophy If there is a reality that exists independently of being observed or known about -- I hope we all agree on that -- then events, like an object returning to a prior location (whatever that means in expanding spacetime), occur with or without someone being able to determine whether they have happened. It is of course still entirely reasonable to take the view that one should not concern oneself with the unknownable. I agree with the latter but I don't see how the admissions of one's epistemological limitations would impact on the ontological state of affairs.
@@Blackpill149 Facts don't care about our knowledge. It is good to know about one's limitation to know things, but it is hybris to think things don't happen because we are unaware of them. The same nonsensical school of thought led some to believe that a wave collapse needs a conscious observer. To me, this is no better than people in the middle ages thinking the universe revolved around the earth.
This is the 4th video I watched on your channel. I already had a headache from not being able to stop my mind from thinking about physics, but now it’s worse because I can’t tell what you’re trying to prove with your videos or if you’re just messing around for the sake of being funny or if there’s a point you’re trying to make by being funny.
But hold on... there is a perfectly valid frame of reference in which I can go back to the exact same place I was earlier. What you're actually saying, is that there is no absolute frame to contradict me. Okay... fine! So, here I am ... inarguably back where I was : ) Of course, whether the "me" that goes back can be said to be the same "me" that left, is a far knottier problem : )
but not being able to travel backwards in space is not as absolute as not being able to travel backwards in time. Just because lets say the processes of entropy are reversed in a system it doesnt mean it has traveled to the past, it just reaarranged. The same is not the case with space, except space itself is moving inside another dimension or wtf idk
😂 Entropy fucks it up. It doesn't like us trying re-arranging things to a order we like, yet we are here and somehow we live in those small pockets of stability amidst a unforgiving universe that doesn't give a shit to us.
Well, one should understand that physics is local! There is no point in imposing global constraints in every conceivable scenario. You can move to and fro in space, but not in time. Period.
The point is that it’s the same as time. You can move through time at different rates relative to other matter, as you can move through 3D space at different speeds, but you can never move backwards in either.
I feel like there's some relation to Heisenberg's uncertainty principle in Quantum physics. IF (and that's a big if) you know exactly WHERE you are, you wouldn't know what time it is and the other way around.
@@dialectphilosophy Heisenberg's uncertainty principle is well-known regarding POSITION and MOMENTUM. Not so well-known is it also ties together TIME and ENERGY. Thus, a virtual particle's energy exists only in an exceedingly short time frame as limited by the uncertainty principle. So position (i.e. space) and time, naturally enough, are both subject to this principle.
From what I can tell, the earth's orbit around the sun, and the sun's orbit around the Milty Way, etc. are all inertial reference frames in GR. Therefore it is perfectly legal to define our coordinates such that the galaxy is moving around the sun, and the sun around the earth, and the earth is standing still. Under this coordinate system, it is possible and very easy to return to the same point in space. Every point in space is the center of the universe, so why not pretend that your house is the center of the universe?
Rather than it being impossible, it sounds like we have no definition for places in an absolute sense. You can travel back to your home if you define your home as being the place where your house is. The definition of the place is anchored to your house, so wherever the house is that's where we agree your home is. But what does it mean to go to where your house was 1 second ago? We don't have any definition of where that place is. We could say that since your house 1 second ago was in the past, that the place should also be 1 second in the past, in which case we can't go there and it would be impossible. Alternatively we could say that it's the position of your house relative to the earth that your house had 1 second ago (e.g. in latitude and longitude), in which case you could go to "the same place", despite the earth moving relative to the sun and so on. Whether it's possible or impossible depends on what we mean by going "back" or a place being "the same".
If you try to go back in time. You violate, (General Order 157: the temporal prime directive). For example, if you try to commit your own grandfather paradox, the universe will protect itself. Similar to how your body protect you from viruses useing, your whiteblood cells as a defense. If you commit your paradox, the universe will defend itself by creating a singularity a blackhole, at the spacetime coordinate of the paradox. If the space-time coordinate of the paradox is earth. Then earth and the moon will be destroyed by the blackhole the universe create for defense. The universe is saved, the milky-way is saved, life will continue without us in the milky-way. Don't, don't violate (general order 157: the temporal prime directive) 😎
Наука
So Heraclitus was right. "You can't step in the same river twice."
"For it’s not the same river and he’s not the same man.”
If you vibrate furiously you'll statistically, eventually, be at the exact same position you were a small delta time ago.
You won't know when that's gonna happen, but you know it will eventually, probably, happen.
sounds like a fun experiment for april 1st, for any science teachers reading
@@renedekker9806 no, that's interesting! thanks!
I find the idea that I'm not eventually gonna be everywhere an infinite amount of times ridiculous.
Sure the universe can be infinite, but then there's also infinite me's. It's inevitable.
No man ever steps in the same river twice, for it's not the same river and he's not the same man. Heraclitus
You cannot think the same thought or same emotion twice. You can only aproximate them.
“so what does this all mean?”
for the most part, absolutely nothing
Correction: systems do not _often_ rearrange themselves into a previously ordered state.
It is neither impossible for them to end up by chance in their original configuration, nor is it true that it has never happened. It is merely true that it should not be _expected_ to.
Likewise, in this case, I feel the argument here about how there is no location that is non-relative is merely an assumption based on the fact that we need to define relationships between where things are to determine location. I do not agree. If we had perfect knowledge of not only where everything is, but where it has ever been and will ever be, and when it will be there, you can use those dimensions of time and space to form a coordinate system, and while allowing for non-matching coordinates along the time axis, you can thus return to a spacial location. The location will be the same because it will have been defined as being the same according to the coordinate system, regardless of whether that location in any way currently resembles what it did previously in time. Even if we take into account the possibility that the coordinate system is itself changing over time, we can simply convert the change of the system itself as another axis like we did with time, and use the new system as our definition of location. We can continue to do this across infinite dimensions and axes to eliminate infinite variables that prevent may get in our way, and in the end what this means is that location and its subjectivity are things we have defined and have control over.
We defined location as how some place is related to some other place, but that is not the only way to define location and it is not the only way we have ever defined location.
The problem is to do entirely with the perception of location, which is an unnecessary variable. One does not need to know their location for it to be their location, and similarly one needs not be able to understand how to measure it for it to be true. There are many things we have measured that were previously impossible for us to measure, that we have done only because we changed how we define the process of measuring or understanding those measurements.
Thus things that were "impossible" to us once, were all the same, still always true, in spite of our definition of it being that it is false, and so applies to location.
Relativity is not the truth... it is a possible truth and is not the only possible truth, nor a purely mutually exclusive truth, as it inherently depends on us to define it as true.
Damn, this dude is taking no prisoners when comes to this science stuff.
Incredibly similar to the phrase said by Heraclitus of Ephesus: "You cannot step twice in the same river".
@@gamevalor He sakd that in referencde to how the river constantly flows and thus is never the "same". Think more plz
There is a thing called momentum that you have to reverse if you wanted to travel back in time, like the momentum of everything. The thing that was moving forward you would have to apply a force to make it go backward and vice versa. That's a lot of work you would have to apply on a universal scale.
But momentum is relative like velocity, so momentum can only be reversed relative to some reference frame - a stationary object reversed relative to a moving one will be sent flying at twice the speed to catch up to it
I travel back in time yesterday and I found I existed in different possible timelines .. Now I am dead .... writing this msg on 30th November 2020
Where are you now? Please reply
You're also gay
You’re quickly becoming my favorite RUclipsr, really informative yet there’s still a lot of style to your videos
The CMB Dipole suggests that there are absolute positions in space. We are moving about 600 kps relative to the CMB, which is only about 4 times the maximum speed reached by the Parker Solar Probe, meaning there's no theoretical reason we can't position something stationary relative to the universe, move away from that point, and return to it.
Thanks for this video @dialectphilosophy. For a long time now, I thought that motion in space (both backward and forward) was silly. Of coarse all matter only travels forward! I've been thinking about doing a video myself, but yours is very good. Thanks.
This is a common sense video. Because if you could genuinely travel back in time, it would exactly be like a video or song played backwards. All your thoughts, your breathing patterns your body chemistry would have to be acting in reverse. All of that is going on when you play a video backwards. But you can not see it because it is all internal and not visual. But that is exactly what is going on when you play content in reverse.
There was an iconic rap group in the 90s called the Pharcyde. They had a video that they came out with called "Drop". That video is actually a timeless classic. If you watch that video and find out how it was composed, you will see how it correlates to this video about space and time
This is really inspiring! Thank you.
Well done, and great points. There's a saying that you can never step in the same river twice. The water flows, fish swim, gravel tumbles, branches float by, and so on. It is a close enough approximation of the same river, but it is not exactly the same. That's true of your house, too. You come home at the end of the day, and many things that you don't notice (or maybe do) have changed. Some paint chipped off there. A newspaper landed on a flower and smashed it. A window now has bird poop on it. The roof is hotter and some composite has come off and rolled into the rain gutter. Wasps started a nest in the eaves. And thousands of other details, mainly small -- but maybe big! The newspaper maybe broke a window, or a large tree branch landed on your roof. You can never return to the same exact house as it existed in the point in spacetime from where/when you left it.
I tried to explain this when talking about traveling backwards in time and how you would end up dead in space and not on Earth. People we're very confused.
Yes we're.
@@danielsnyder4426 were
@@robertbeaman5761 Traveling back in space-time, because they are linked, you would end up on earth at its previous state (coordinates in space-time). Traveling backwards in space, while the arrow of time isn't reversed, well, then you would end up dead in space. which is pretty much the point of this video - you can't, because space-time coordinates exist only in relation to initial inertial frame of reference, which must be at absolute rest where absolute rest is impossible for something that exist and also it's also relative...
Depends, if you use consensus science and pick any old constant in some made up equation and call it a "dimension" you can travel, maybe it won't happen like that.
Glad someone understands spacetime. Your logic hasn't fallen on deaf ears. One thing about AE's equation states forward motion isn't possible without breaking that light barrier. Tweaking it will allow forward motion. However, that breaks his law on time travel. Only conclusion: one speed one direction.
Watching your various videos has helped me a little to understand the differences between absolute and relative space and time. Would you do a video that in simple terms explains the debate between Newton and Leibniz about absolute and relative space and time? Maybe that was what you are talking about at 3:07 to 3:24. My mom wonders why Leibniz would say absolute rest is not possible, is that partially explained in the Newton's spinning bucket with water video you made?
No, actually, for any spacelike vector, an object's 4-velocity may be oriented with any inner product sign with respect to that vector (i.e. toward or against it), but for a timelike or lightlike vector, an object's 4-velocity may only be oriented one way with respect to that vector, depending on which way that timelike/lightlike vector points. You may travel against any space-directed 1-form, but not against forward-pointing time-directed 1-forms (which come from the exterior derivative of your "time" coordinate).
@CEO of Unpopular Opinions Also my first thought, lol
Nice video and presentation.
OK we got the message. So what is the point to return to the previous location in space?
I just choose my coordinate system centered on my home.
Which is accelerating...
@@alexjohnward Not with respect to the origin of my coordinate system.
@@aaronmorris1513 your co-ordinate system is accelerating though, not ideal! Lots of fictitious forces to live with!
@@alexjohnward Accelerating with respect to what?
@@aaronmorris1513 acceleration isn't comparative, it's absolute, and can be detected with a set of scales. If you stand on the scales in your bathroom and it shows a "weight" (actually a force), your home is accelerating with respect to something.
LOVED your choice of aircraft, The T-38 TALON!
The important thing is that you can do, in space, things you cannot do in time. That is all that matters.
This argument won't work for you in a court, as for the judge and the evidence of you coming back to the crime scene later is in fact the same place.
Any position can only be defined in terms of where it is relative to another object. The court prefers to use the crime scene as reference point.
If you and your spaceship were travelling across space in the left direction, at say 260,000 km/s, but you then fired your rocket engines while pointing toward the right direction, and for some time you had obtained a spatial velocity of say 130,000 km/s, where in space you were located a minute ago, is now ahead of you. Thus, you have travelled backwards in space.
At your house dumb ass
Some of these ideas are down to language and definitions. To 'travel in space' suggests space is a 'thing' like a fabric that you move 'through', in other words with respect to.
Space has to be a total featureless void (as you are in fact saying) for relativity to hold, there's nothing there to travel through in the first place. You can only move between objects so you're only altering the configuration of you and the objects. Then of course you can reconfigure things back to the original position.
As for the mug even if you could put it back together exactly in absolutely every respect you're only making a perfect copy of the past in normal time, you're not going back in time.
To go back in time you'd have to obliterate any evidence or memory that the mug broke from the universe or you'd have two pasts: one where it broke and another where it didn't, again we need to sort the semantics before delving into the physics.
I thought so too.
Thanks for the existential crisis! 👍
Great Scott !
This is great! Any movement in space is relative to every other position in space.
This video makes less sense the more I think about it. I wonder if he's changed his mind on this given his newer videos. This one makes some of the same mistakes that he criticizes other videos making.
If you move from a point to the "next" point in any direction you change positions. Period. Local or not. Or if some object changes position with respect to you, it changes position. Who moved? Who should move to recover the previous "position". Also if you ignore other frames to turn around is irrelevant you still have to increase your distance from where you are to where you're going. You can't draw a line with a negative length.
I am always at the centre of my own inertial frame, so not only can I travel back in space, I never left in the first place.
Considering this makes it easy to understand what it means to always then be moving in space-time.
Or you are always in the same spot because we're the center of the universe and everything is moving relative to you :P
Mark W That means Galileo could be wrong =)) . I think the solution for all of these is we have to figure out what truely fixed is in the whole universe.
@@duytuannguyen98 speed of causality is fixed. Time and space are relative.
@@duytuannguyen98 Nothing is fixed, or everything is fixed. All frames of reference are equivalent.
If you are capable of instant travelling beyond the speed of light, then you would be able to travel back, in a local segment in time.
Well, I guess a discussion about CTCs (van Stockum/Goedel 1937/1949) and the self-consistency principle by Novikov (mid-1980s) could be way more interesting.
Super explain vro keep it up ❤
Does it not refer to absolute position in space?
Wow great channel, I like it.
Backwards relative to what?
Relative to your mom, obviously.
@@tyrjilvincef9507 oh well in that case going backwards is easy.
*hugs mom*
Surely absolute spacial location is an ill defined concept. 'Where are you in space?' is not a sensible question, that is the whole idea of relativity no?
All we need to do is define what ever coordinate system/reference frame is most useful and then there is nothing stopping us from returning to a prior location in those coordinates.
Also if you want the most global reference frame possible choosing the cosmic microwave background seems like a pretty good shout. We'd need a pretty bad ass rocket to get us where we were yesterday but theres nothing in physics that would stop us. (maybe in biology haha, might involve some serious G force).
@@LL-LLLL9 Yeah that is my point. There is no such thing as 'the same place' so to say I cant go there is meaningless.
@@PulseCodeMusic I get that but it’s still interesting to think about. Also I think the main point of the video wasn’t really about going back to your old position but about that neat relationship between space and time
Good point. Fundamentally because while most assume the physical space as a vector space, it is in fact only an affine space.
Just two videos, but already subbed
Doesn't this establish that time is an emergent property of matter moving through space, just as a shadow is an emergent property of light being blocked?
Those places where information theory bumps into physical reality always make my stomach drop
We don't know what space _is_ and how it works exactly (how it grows, or whether its parts rearrange for instance), we could even add the issues of ontology of time (eternalism, presentism, ...) and identity of objects. All in all, you should remain agnostic on whether you can or cannot travel to some point in space that you've occupied earlier (with a spaceship for instance).
The "co moving" reference frame is one way to look at it.
This assumes that global space is not related to your temporal space and thus time dilation couldn’t exist, but it does. Otherwise we would experience different time dilation when the Earth’s spin move with the motion around the sun or against the sun. But the GPS satellites don’t have to take this into consideration. Because in reality local spacial frames of reference govern out total motion
This reminds me of that pickup line, where that 900+ year old man was talking to that 17 year old...what show was that?
If you think position as a relative concept I think we can travel back in space .( Something similar : you cannot step back into a same river)
If we are watching or moving relative to time. what kind of reference frame that time would use to see us if we travel approximately at the speed of light ?
SOMEONE PLEASE ANSWER THIS FOR ME 🤔🤔🤔🤔
If we don't time travel we'll be stuck in the Era we don't like forever
Well said.
But can you travel backward in time "locally"?
I think yes, it'd require you to put everything back in the state it was in the past, which would require energy you could take from the rest of the universe, kind of like putting in energy to cool down your fridge, but you'd have to know everything about the system
@@mementomori7160 You still can't because second law of thermodynamics still holds in any isolated system. Unless you are talking about quantum systems with very few particles. Then you may return to the exact state in the past.
@@MrNicePotato We're talking about reversing time locally, and I said you'd have to take the energy from the outside, therefore we don't consider it as an isolated system that reverses time on it's own, that's why I think it is possible, just like cooling inside of your fridge by heating up the outside of it
@@MrNicePotato You can, because as he says it "would require energy you could take from the rest of the universe". So long as the entropy created in the outer universe is equivalent or greater than the entropy that was reduced by resetting the objects locally, the total entropy still increased.
Imagine having a hot meal on a cold plate. The meal slowly cools down until the heat of the warm meal is equally spread out across the meal and the plate (more entropy). Then you rewind time to when the meal was still hot and the plate was cold (less entropy). If this takes no energy at all, then you just reduced the total entropy in the universe and broke the second law of thermodynamics. But, if the action of rewinding time for the meal created an equal amount of entropy elsewhere (inside the device you used to perform the rewind?), then it's fine because the total amount of entropy in the universe did not go down. It decreased in one place, but increased by an equal (or greater) amount elsewhere. It's just that your _local-time-rewind-device_ needs to - _will_ - release enough heat (or other form of entropy) to compensate for the entropy reduction caused by the local time travel.
I like to think that rather than heat, a local-time-travel-device would have to increase the passage of time on some other object. Just as an AC produces more heat than it removes from the air, a device that manipulates time could rewind one thing, but would have to fast-forward another, and by more than was rewound. Could be a neat science fiction plot. Like a little rewind gun with an "entropy battery": You aim and shoot to rewind an object which fills the entropy battery as the object is rewound more and more, but you can't go too far or the entropy battery will explode. Then if you want to rewind more, you must first release all entropy from the battery by fast-forwarding other objects.
Yeah. Physically grab the hands of the clock, and turn then back.
It always wonder me that
The place where I was born is too far away from where am I now !
Brilliant!
I am so glad someone made a video about this because I've been thinking about this for a long long time. If you want to travel back in time you have to return all the matter back to where it used to be and also account for the space created or let's call it the expansion of space and contract that as well. I guess I'm not the only idiot who thinks about pointless stuff like this.
No it isn't pointless unfortunately the majority thinks the other way. And they are wrong you are correct.
I feel the same. I’ve been thinking about this ever since I started to understand Relativity theories. I’m so glad I found this video. I’ve always wondered why high level physicists still talk about this incorrectly. This simple idea builds on and makes Einsteins theory of Spacetime. more easily digestible
Nah, completely normal ( unless I'm not normal either😁)
looking in the hubble space telescope is technically watching a movie of that planet or sun in real time from the past as it happened 100 years ago if that planet is 100 light years away..so you are actually seeing the matter from 100 years ago interacting we can't go back but we can observe the past 😉 Einstein was wrong we can't go forward or back no matter what we do we can observe the past that's all and there is zero physical proof that time would stop for a person on a space ship traveling light speed our observation of that ship would appear to stop because the light can't travel to us. But there is no proof or logical reason why the person in the ship would age slower or there clock would magically tick slower .as spock would say that's illogical..lol
@@sailingmohican2767 You completely correct with looking in the past.. Though it is 'proven' by General Relativity that if you were traveling through spacetime at the speed of light ( which really nothing with mass can) your time / clock would stop..⌚
It's the same situation with GPS.. They have to always take General Relativity time dialation into account or GPS would never be distance accurate ..
🛰️GPS satellites are traveling around the earth, through 'space-time' faster than we on the ground are, so their time/ clocks tick a little slower ( tiniest difference, but enough to throw out distance accuracy )slower than ground clocks do, so the GR calculations adjust for the difference..
( With this next bit it helps having a space-time axis diagram to picture what I mean..
( An L shape, with time⬆️ & space➡️ )
& remembering that our movement / travel always adds up to the speed of light through 'space- time'.. Not thru space alone nor through time alone , but both added up )
So, now if we are traveling through spacetime at the Speed of light.. Because we ( with mass) don't go fast compared to the S.of L., nearly all of our movement through space-time is through time (We experience 1 sec/sec along the time axis) but not much movement through space ( stuck going slow on a planet, or on the space axis)..
But.. If you travel fast, 🚀zooming through space-time so fast, at the speed of light, suddenly all of your movement is through space,🌠 or on the space axis, leaving no movement left over to experience time..
That's cos the speed of light is not about light, it's about the speed of causality.. The fastest that anything can happen.. I don't reckon we'll ever go back in time, but forward in time , or changing our time compared to someone else happens all the time..
🤦♀️ Despite the crappy explanation it's true..
🤯It so cool & freaking amazing how spacetime works.. Basically it's saying that the faster you go through spacetime, the slower your clocks tick/ run.. As in satellites clocks all run slower than any clocks on the ground.. The bigger the difference in speed, the bigger the clocks are out.. It is actually taken into account for so many things..
🌏☮️♾️
Earth, sun, galaxy etc are moving in locked orbits. But what if you are traveling in a spaceship and do not experience any gravitational force so you can chose freely where to move. Then, unless you believe that space itself is moving, you can get back exactly where you were.
I want this question answered too!
@@-_Nuke_- It is impossible to not experience gravitational forces
I had thought of your idea over ten years ago. Nice that someone else agrees too.
I thought about this as a kid, in terms of the movies back to the future
This channel is a rare gem.
Our sun is a positron in another system lol
I agree. Notice how the spatial structure of the universe seems to mirror as it scales up or down. An atomic nucleus or particle is exceedingly small compared to the spatial size of the overall atom. Same with stellar systems. Same with large structures such as galactic clusters.
I really want to time travel so bad because everything used to be good. My childhood days the 2000s
But it's impossible
omg that hit so hard!
There's so much wrong with this.
Firstly you're following some kind of cringe presentism...
Great !
Why did I go overboard with my addictions!?
Him: "Much like trying to fit the pieces of a broken Teacup back together."
Me: "Hold my Teapot."
The equivalence is here bad presented: the question is not if you can return to the exactly point of departure, but if you can go back, or go laterally or go forward, in short: if you can choose a direction and a toward, yes, you can, even if you are transported by space flow. But with the time you haven't these freedom degrees, you can only eventually slow the time or accelerate it by moving you near to ou farer from a mass (scalar modification of the time speed), without vectorial degrees of freedom: direction and toward.
So, not: the time and the space are not equivalent and are not "dimensions".
I agree with you. Space may be a dimension but time is not. Also, if to move in ''time'' which I consider as non-existent, one would change the surroundings and that would affect the cause and effect rule even on microscopic level. One can flow through space but not through time and time itself does not flow either. It's always always.
Under those philosophical conditions, time wouldn't allow being able to be in the same space even if you could physically go back there anyways. Entropy would ensure you wouldn't be the same you when you made it back. For instance, the last heard, which is admittedly a while back now, that the human body changes every cell in its body every seven years. So, if you did actually manage to get back to an exact point in space you existed in before, likely none of the atoms that made you up would make it back there with you, just your consciousness.
I can't go back to the past to redo what wrong in whatever year I want
Yes, this is Exactly what I thought..The only thing that makes sense 💯
changing with every evaluation the system of reference and adding more and more movements, lead to video conclusion, of course. But if you don't change the reference system and you don't add new movements to the system, lead to the same conclusion?
Cf. Einstein's Hole argument, that bothered him for many years. Some locations may not be “locations” in the full sense of the word, i.e. be possible to assign coordinates to. That, or not fully covariant.
As for traveling backward in space... in which theory? Such a theory requires, at the least, to define what is "traveling," "a location,” and a distinction between forward and backward (which you've noted so keenly). Incidentally, the theory does not require a notion of time; the “traveling” subsumes it, and simply time isn't enough. These prereqs are easy to satisfy, but it's helpful to keep in mind that they ain't givens. Very good point, thanks for bringing ti up!
We stole the idea for this video from a passage written in a textbook we came across once. Later, we discovered Einstein had written about the very same thing in the prefaces to a discourse he had written on relativity. It seems like he had borrowed it from elsewhere as well, so it is certainly not a new argument. It does raise the issue of the relationship between space and time, which, even from a classical standpoint, can be viewed as blended to a certain extent. We feel that was what was most compelling about the topic... also of course, that it hints at why both absolute space and absolute time are impossible, or at least unknowable.
now, "progressing backwards" finally makes sense.
Came thinking this would be the same argument as you can't have a negative speed (but you can have negative velocity). Which might be related to negative energy.
Also interesting that in 2D random movement will certainly result in returning to the same location - maybe the 2nd law of thermodynamics isn't necessarily true in 2D (or especially 1D) due to the dimension itself.
Can you force particles to run in reverse, only on earth, with, say black hole energy
There is actually a mathematical path around 2 rotating black holes that woud let you end the path before you started it
Neat
what?
Dialect what about objects that are stationary in space? Why can't they move forward and backwards in space if they are just in empty space?
We are all moving at the speed of light.
If an event is marked by the emission or reflection of a photon, then an observer at a distance will view that Photon. If the light is in fact a wave, it expands in a spherical surface at c. If the observer wants to vies the event again, he would have to travel faster that the speed of the wave, c, but this is impossible. It doesn't matter how fast the observer travels, he can never go back to the emission or reflection of that photon or wave...
Isn't it possible to define an absolute frame of reference of motion relative to the cosmic microwave background?
the CMB is different depending on where you observe it.
Obviously as the biggest and farthest observable thing in the universe, it is impractical to get a significantly different perspective on it. But hypothetically, just as the constellations would look different in a different solar system, the CMB would look different from a different galaxy (especially very distant galaxies)
hm.... actually the more I think about it this doesn't really dispute your point... I mean sailors use the stars to navigate. So to repeat your question, why can't a space traveler use the CMB to gauge their motion? I mean the entire CMB will be blue/red shifted hemispheres depending on your direction of travel.
Maybe it is a dumb distinction but "relative to CMB is still relative". Relativity doesn't stop you from comparing reference frames, it just says that no reference frame is privileged or more authoritative than others.
So if space fllows as time do and we can localy go backward in space, what is the equivalence in time ? can we go backward in time "loacaly" ? Is it equivalent to just slow the time flow ?
That's a great question. Can we identify systems that can be reserved locally with respect to time? It may be possible
As I understand, the going "locally" backwards is just defining that a forward state is the "same" as the backward one. And of course it is arbitrary, as you can define what you choose to ignore(your reference system).
So it is possible to do it with time, but as in space you are not going backward in time, you are going forward to a state that is defined as "the same" under an arbitrary reference system. An example might be just fixing something, you didnt go backwards in time but you might say its the same as before in some arbitrary way like the case of going back home. So you can say it went backwards on time locally.
Although I dont know If I understood correctly.
Your entire argument is predicated in the existence of absolute positions and motion through space. That’s obviously not what we mean. Since space and distance are intrinsically relative, we can absolutely “return” to a location in space. All we have to do is return to the same relative distance between objects of reference-a point you even acknowledge at the end of the video.
You don't get it. One can return to an object or place locally but not to the same position in space that object was when you left. That's what he acknowledges at the end... Everything is moving at once, you can only return "home" because both you and your house are moving at the same rate is relation to the planet, so it seems like everything is perfectly still, but the planet is moving through space, so you'll never get back to same position in space. get it now?
@@MultiVigarista No, YOU don't get it. Read my comment again. The reason you can't "return" to a point in space is because there was never a "point in space" to begin with. It is literally meaningless to think about space in this way. And since that's not what we mean when we say "point in space," the argument itself is a gigantic fallacy of equivocation built on a false premise.
@@AntiCitizenX we can call it "general region in space" then, if that makes you feel better I guess. For all it matters we can be talking about a region 5 m^3 in 3d space the argument still holds, you can't return to it... 😅
@@AntiCitizenXthat doesn’t make sense by virtue of Pauli’s exclusion principle
Position is defined in refence to a frame. So this is just being obtuse...we might as wll say we can't move in space at all since we are always at the origine of our own rest frame.
Also you are refering to an inconvenience as an impossibility.
But a frame is defined via your position relative to other objects… so you still wind up with the same problem, the lack of a “global” frame
@@gman8563 exactly. The point of this video is that you cannot go back in space, cos space is ever changing.
Time travelling is going back in time not in going back to home suppose you can understand
Dialect
2 objects in empty space. One steps on the gas, accelerates, moves away, turn's around, come's back and meets the 2nd object... No Earth, no fixed stars, no nothing else in the Universe... Are you still saying that even then - these 2 objects when they meet again, they will not be at the same point in space as they were before their separation?
Is that because of the Universe expanding?
And if not, then why?
Is it because we assumed that the 2nd object is inertial when if fact we can't say for sure if it really is inertial? Is that the point of this video?
b4: Can you travel forwards through time tho? Aren't we just these long 4d snakes of existence of which only each individual 3d slice is an everyday object that appears to evolve over time
Hold up. This is an argument from ignorance (a common fallacy). Not knowing what direction in space the spot you were at some finite amount of time in the past was does not equate with it being impossible to move to that location. It only means that if you do it, you won't know it.
Good point, and bravo for bringing that up! Is it merely a sort of epistemological confusion to equate an inability to define a past place to ontological unreality of that place? If something cannot be known to truly exist, then empirically speaking does it really exist? These sorts of questions are the true fun of the philosophy of physics!
@@dialectphilosophy If there is a reality that exists independently of being observed or known about -- I hope we all agree on that -- then events, like an object returning to a prior location (whatever that means in expanding spacetime), occur with or without someone being able to determine whether they have happened. It is of course still entirely reasonable to take the view that one should not concern oneself with the unknownable. I agree with the latter but I don't see how the admissions of one's epistemological limitations would impact on the ontological state of affairs.
Agree.Without a direction,even with time,we will never know if we reached the place we were in
@@Blackpill149 Facts don't care about our knowledge. It is good to know about one's limitation to know things, but it is hybris to think things don't happen because we are unaware of them. The same nonsensical school of thought led some to believe that a wave collapse needs a conscious observer. To me, this is no better than people in the middle ages thinking the universe revolved around the earth.
This is the 4th video I watched on your channel. I already had a headache from not being able to stop my mind from thinking about physics, but now it’s worse because I can’t tell what you’re trying to prove with your videos or if you’re just messing around for the sake of being funny or if there’s a point you’re trying to make by being funny.
But hold on... there is a perfectly valid frame of reference in which I can go back to the exact same place I was earlier. What you're actually saying, is that there is no absolute frame to contradict me. Okay... fine! So, here I am ... inarguably back where I was : )
Of course, whether the "me" that goes back can be said to be the same "me" that left, is a far knottier problem : )
Take 1 shot when u hear SPACE 2 for TIME
but not being able to travel backwards in space is not as absolute as not being able to travel backwards in time. Just because lets say the processes of entropy are reversed in a system it doesnt mean it has traveled to the past, it just reaarranged. The same is not the case with space, except space itself is moving inside another dimension or wtf idk
😂 Entropy fucks it up. It doesn't like us trying re-arranging things to a order we like, yet we are here and somehow we live in those small pockets of stability amidst a unforgiving universe that doesn't give a shit to us.
That's true only for the person who is seeing us far away from the earth.But for us it will be same
Well, one should understand that physics is local! There is no point in imposing global constraints in every conceivable scenario. You can move to and fro in space, but not in time. Period.
The point is that it’s the same as time. You can move through time at different rates relative to other matter, as you can move through 3D space at different speeds, but you can never move backwards in either.
I feel like there's some relation to Heisenberg's uncertainty principle in Quantum physics. IF (and that's a big if) you know exactly WHERE you are, you wouldn't know what time it is and the other way around.
Definitely a good point!
@@dialectphilosophy Heisenberg's uncertainty principle is well-known regarding POSITION and MOMENTUM. Not so well-known is it also ties together TIME and ENERGY. Thus, a virtual particle's energy exists only in an exceedingly short time frame as limited by the uncertainty principle. So position (i.e. space) and time, naturally enough, are both subject to this principle.
This is only physically coherent assuming the existence of the Ether
From what I can tell, the earth's orbit around the sun, and the sun's orbit around the Milty Way, etc. are all inertial reference frames in GR. Therefore it is perfectly legal to define our coordinates such that the galaxy is moving around the sun, and the sun around the earth, and the earth is standing still. Under this coordinate system, it is possible and very easy to return to the same point in space.
Every point in space is the center of the universe, so why not pretend that your house is the center of the universe?
Reminder that if everyone can go back in time that could cause either a multiverse or could cause the destruction of the world
Super great video! Love your lack of hubris.
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Rather than it being impossible, it sounds like we have no definition for places in an absolute sense.
You can travel back to your home if you define your home as being the place where your house is. The definition of the place is anchored to your house, so wherever the house is that's where we agree your home is. But what does it mean to go to where your house was 1 second ago? We don't have any definition of where that place is.
We could say that since your house 1 second ago was in the past, that the place should also be 1 second in the past, in which case we can't go there and it would be impossible. Alternatively we could say that it's the position of your house relative to the earth that your house had 1 second ago (e.g. in latitude and longitude), in which case you could go to "the same place", despite the earth moving relative to the sun and so on. Whether it's possible or impossible depends on what we mean by going "back" or a place being "the same".
It's like Heraclitus said, you can't step in the same river twice.
If you try to go back in time. You violate, (General Order 157: the temporal prime directive). For example, if you try to commit your own grandfather paradox, the universe will protect itself. Similar to how your body protect you from viruses useing, your whiteblood cells as a defense. If you commit your paradox, the universe will defend itself by creating a singularity a blackhole, at the spacetime coordinate of the paradox. If the space-time coordinate of the paradox is earth. Then earth and the moon will be destroyed by the blackhole the universe create for defense. The universe is saved, the milky-way is saved, life will continue without us in the milky-way. Don't, don't violate (general order 157: the temporal prime directive) 😎