[Physics] Who does what?

I was listening to "Relativity: The Special and General Theory" by Albert Einstein and one question keeps popping into my attention, I don't know if it's a silly one but I just can't remember if I've ever heard it mentioned anywhere. Originally it is a question related to my own theory but after diving deep in Einstein's theories to my surprise it seems that I've actually come to many of the same conclusions and thus making the question related to that as well. Maybe more of a thought experiment than simply a question.

Who does what?
Movement through space can be measured in speed, celerity and velocity which all use a relative reference point and thus are far from absolute. If one object passes another we are able to describe it in countless ways but there are one elementary detail we (to my knowledge) have no way to get an absolute conclusion on, who does what?
This has become one of my obsessions. And since I'm far from a genius I thought I'd take advantage of the situation since some of you might be more educated on this particular theory than me and my DIY approach.

If there is a upper limit one would think there could possibly exist a state of absolute standstill right?. If two objects move in opposite directions, does one speed up and one slow down? How can we know if an object is moving at all and not only in relation to the current reference point? Did the comet hit us or did we hit it? ( hypothetical, and I am aware of gravity playing a major role )

Let's take a look at wormholes and how they could possibly work as an example, if such a thing should exist.
- Is it a shortcut/rip through space?
- Does it send matter shooting through space at incredible speed?
- Maybe it does the total opposite and grabs matter into a halt while actually space itself continues to move at amazing speeds and as a minuscule amount of time goes by and the wormhole starts to react with the matter and loses it's grip and as it "dematerializes" it ejaculates the matter back into space?

Could it be plausible that our best bet on intergalactic transportation technology is not going faster but rather "taking a break" and slowing down?
Just an entertaining little treat for thought.


Additional note:
I must have wrote five times more than I put in here with just off-topic material due to mind-wandering. And with physics being so full of possibilities it's hard as hell to focus on one subject matter. Just thought I'd mention to show my appreciation to those of you who manage to put it all down in words.

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ShadowBase

reply to post by ShadowBase

I think our best bet is finding shortcuts around the illusion of distance. You and I are miles apart only in one physical sense, seen from a three-dimensional standpoint. Ever heard of "tesseracts" like in A Wrinkle in Time? I think it should be possible to use one of those to link (in a higher-dimensional sense than we can perceive) wherever you're standing (point A) to wherever you want to go (point B), then just shut down its connection to point A, leaving point B as the only possible place you can be. "Travel without movement," as Dune put it, but - well, maybe Melange was a five-dimensional spice... I learned long ago not to doubt the wisdom of Frank Herbert.

If you were really really clever, you might be able to design a space ship engine that could go, say, twice the speed of light, but no more than that. It's not good enough. In Star Trek they worked around that (and time dilation) by putting the ship in a "subspace warp bubble" first. The laws of physics weren't the same in the bubble, so they could do almost anything they wanted... except travel without movement. I think Herbert beat Roddenberry on that one.

Yep; tesseracts. All hail Madeleine L'Engle. (And this thread deserves more attention than it's getting... just saying...)

Originally posted by ShadowBase
Who does what?
Movement through space can be measured in speed, celerity and velocity which all use a relative reference point and thus are far from absolute. If one object passes another we are able to describe it in countless ways but there are one elementary detail we (to my knowledge) have no way to get an absolute conclusion on, who does what?

Relativity states that no reference frame is preferred.

However, the CMB (Cosmic Microwave Background) does provide a reference frame, and since it's a single reference frame for the entire universe, while there's no requirement in relativity to prefer it, it is preferred in some respects. For example, we measure the velocity of our galaxy and our Solar system relative to the CMB.

Milky Way

In the general sense, the absolute velocity of any object through space is not a meaningful question according to Einstein's special theory of relativity, which declares that there is no "preferred" inertial frame of reference in space with which to compare the object's motion. (Motion must always be specified with respect to another object.)....

Another reference frame is provided by the cosmic microwave background (CMB). The Milky Way is moving at 552 ± 6 km/s[10] with respect to the photons of the CMB

Since we can measure the cosmic microwave background, that limits some of the ideas you suggested about wormholes. It's basically the leftover signature of the big bang, so it applies to the entire universe.

Interesting.

If the fastest object we made in space was 17.05 km/sec. (Centauri Dreams) Earth goes 30 km/sec, our solar system 220 km/sec, and our galaxy 1,000 km/sec. (StarrySkies) The speed of light is 299,792,458 m/sec to use as a reference. (Popular Science)

Now the math. (CalculateMe)

Fastest ship: 38,140 mph
Earth: 67,108 mph
Solar System: 492,126 mph
Galaxy: 2,236,936 mph
Speed of Light: 670,616,629 mph

How does this relate to what is being discussed? Well,if the power to stand still (cancel out the effects of gravity on the localized space craft), we increase our travel speed by orders of magnitude depending on how resistant to gravity we become. If we could nullify the effect of gravity entirely on the craft (perhaps with an inertia bubble or something), we could travel a light year in 300 hours (12.5 days).

Alpha Centauri is about 4 ly away, which equates to 50 days, or just under 3 months to get there.

This is a rather interesting idea, but boy would your calculations have to be exact. Once you activate the nullifier, the Earth would zip away from you or you could plow right into it.

reply to post by Thought Provoker


Thanks for mentioning dimensions, actually another good example of how I feel some scientists "conclude" to fast.
Now I understand that "tesseracts" in the context of A Wrinkle in Time refers to a wormhole like concept so I will focus on that first and tackle dimensions in section 2.

Section 1

Tesseracts (as used in A Wrinkle in Time)
Now from what I understand it could be thought of as a mirror that upon looking into it gives you the choice of which version of your surrounding you want to exist in (very simplified)?
I do see the attraction of such hypothesis' but I just can't shake the feeling that we make stuff more complex than it needs to be. Thus my attraction to "travel without movement" being just that, literally. Just slow down and wait for where you want to go.

The waiting problem
Now my "waiting for point B" hypothesis is not without it's holes. Main problem being that if the amount of reduction in movement through space gives an equal increase in exposure to time, then as a result everything else would moving incredibly fast and have less exposure to time than the waiting object who's exposure to time would increase exponentially and could actually for all practical purposes render the trip equal or even "longer" than the opposite solution.

Think of it like this (simplified)
Limit : C (constant)
Space : S = C - T
Time : T = C - S

Speed limit = S = C - ( T = 0 )
Absolute standstill = S = C - ( T = C )

To me it seems like the solution to space travel would essentially be stopping time. Maybe the solution could be combining "waiting for point B" with a Star Trek bubble kind of approach.

The bus shelter approach
To get around the waiting problem one could possibly apply a local movement in some sense, this would require a way to enclose a fast moving object withing a slow moving object. Now this might be tricky as any object enclosed within another object inherits it's parent's time & space properties and would have to reach incredible speeds within an confined space compared to the parent object.

Section 2

Dimensions
I've always had an issue with the "higher-dimension than we can perceive" because we never hear anybody say "lower-dimension than we can perceive". Last time I checked nobody has ever produced any proof that anything can exist only in the first or second dimension and thus if anything could exist we are not able to perceive it. But what about the higher dimensions?

Flatland
Let's look at Carl Sagan's flatland thought experiment as an example.
He assumes that a three-dimensional object may enter the second dimension, but doesn't a three-dimensional object exist in three dimensions, not in the third dimension?
How can a object that requires a set amount of dimensions exit one of it's lower dimensions?

They try to get around it by explaining how it may be perceived if it enters a lower dimension with "slicing" and that is all well and good and I agree but at this point it can be perceived by lower dimensions. The higher dimension argument falls flat once they try to remove it from a lower dimension.

The higher dimension hide & seek problem
A cube has these three dimensions;
1. Width
2. Height
3. Depth

- If we removed the depth (third dimension) everyone agrees that it becomes a two dimensional object.
- Then if we removed height it's suddenly still a three-dimensional object that's just not perceivable in the second dimension?

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ShadowBase

Ok, I'm going to recommend that you crack a physics textbook -- not a popularization, not a grey paper, and not a "lay science" book: a TEXTbook. Read the chapters on relativity. Learn how the math works (it's really not that complicated for Special Relativity which is what we're talking about here. Basic algebra with fractions and exponents. Nothing schmancy.).

For example, you talk about 'two objects moving in opposite directions' and what happens to them. Well, the simple answer is that yes, something's got to give, and what "gives" is Time. The times experienced in the two let's call them "spaceships" are different, the times they observe on the other ship are different from each other and the earlier self-measurements. In short, it always works out that when you do the calculation "observed distance/observed time" you get a figure less than c. Look up the concept 'proper time'.

Ultimately your question "Who does what?" is, in fact, unanswerable unless you include the phrase "as measured by an observer in situation X". That's the whole point of Relativity: the true and correct answer to the question _changes_ depends upon who's observing. I can say "A happened after B" and an alien swooping by at high speed can say "B happened at the same time as A" and, here's the key, WE'RE BOTH RIGHT. Truth in this world is not universal. As my Philosophy of Physics teacher put it, "Reality is Non-Transitive!".

Now, that doesn't mean facts don't exist, it just means that the word "real" is only locally defined. And while two observers might disagree about their relative speeds with each other, they will agree on the relative _difference_ in their energies. (That is, you can say I'm at .8c and I can say that YOU are at .5c and thus skewed, but when we run the math predicting just how hard we'd crash into each other, we'd come up with the same number. Energy DIFFERENCES have a deeper existential primacy than energy "itself".)

reply to post by Stunspot


Real textbook? I don't understand where you are going but I regard "Relativity: The Special and General Theory" as being quite an excellent book on the matter.
Could you be a bit more specific on the issue? I believe I brought up the time dilation issue in my previous post, did I get it that wrong?

As you said the "who does what?" is unanswerable. That's why it's an interesting problem. Even if we are not currently able to distinguish between an object going faster or slowing down in relation to a absolute stationary state without a satisfactory reference point it is still unsolved issue.

reply to post by ShadowBase


I meant more the kind of thing a physics undergrad course would have. As to what I was getting at, specifically, I was thinking of the Lorentz contraction/dilation factor and the math of applying it. If you just run the numbers on a few hyptotheticals, your question about two moving objects heading in opposite directions would answer itself, clearly.

And no, "Who does what?" IS a settled question. The answer is "That is a meaningless question, on the order of How many greens is 5? or how many cubes does a liquid form?." It's simply not how the universe works -- there is no single definitive answer that is capital-T True. It's not "We can't figure out which is doing what", it's that "Who does what really, actually depends upon who's perspective you take." It's not a disagreement where one is right and the other wrong -- it's that BOTH seemingly mutually exclusive realities obtain.

reply to post by Stunspot


I'm really sorry if I totally misunderstand here (it's late) but again isn't that what I did in my second post on "the waiting problem"? Yes I did not present the math.

I would have to disagree on the matter of the "who does what" problem being solved though. You are assuming that theory of relativity has gotten everything right and is a absolute solution. Within anything absolute there can exist a relative solution/context. I'm not saying there absolutely is a stationary state but it is worth giving it a try as the current view is so far unproven. Even Einstein suggested there where flaws. Special and General relativity is theories after all, not finished solutions.
And again, if there are no NULL, how can one ever reach a upper limit? The nature of pure relativity conflicts with the existence of a max velocity as the current velocity will always be regarded as NULL / stationary. Then there can not be a limit on achievable speed through space.

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ShadowBase