three speeds at once.

[YT2095]

an absolute location cannot exist.

 

you have no Absolute Motion with which to compare it with, and without a common frame of reference there can be no "absolute location".

[Severian]

Woah woah WOAH! I said the absolute frame was a POINT in space! Not a 3D region! You can't be IN a point!

 

Then you are simply measuring velocities relative to that point. It is still a relative measurement.

[dstebbins]

an absolute location cannot exist.

 

you have no Absolute Motion with which to compare it with, and without a common frame of reference there can be no "absolute location".

 

Well, I'm just saying that maybe we should make one! Designate a point in space as the origin of the Universal coordinate grid. Problem solved.

 

Somebody tell me what's so complicated about this. PLEASE!

[YT2095]

dude you CAN`T do that, it`s well known and Documented that the Universe is constantly expanding, and thus moving.

 

as I said, find the source of Absolute Motion, then you might be in with a chance, but since that`s not possible (because there isn`t one), it`ll never happen

[Norman Albers]

Yes we are free to define coordinate systems, and in GR we make convoluted coordinate transforms to solve the complicated system of differential equations. Do not fool yourself into thinking any other center wouldn't be as good or equivalent in terms of its physics. This is what we think we have observed.

[dstebbins]

Then you are simply measuring velocities relative to that point. It is still a relative measurement.

 

Dude, were you even paying attention? Absolute location is a relative location, yes, but it's relative to a universal, or absolute, frame. This makes this particular relative location absolute.

 

On a map of the earth, the global frame is the intersection of the Equator and the Prime Meridian. Of course, since all objects in the universe are in constant motion, our best bet for this absolute frame is a point in space.

 

SHEESH!

 

dude you CAN`T do that, it`s well known and Documented that the Universe is constantly expanding, and thus moving.

 

as I said, find the source of Absolute Motion, then you might be in with a chance, but since that`s not possible (because there isn`t one), it`ll never happen

 

You're forgetting one thing: The Multiverse. Our universe is not the only one. It says so in M-Theory. There are an infinite number of universes in the multiverse. THAT'S where the absolute frame is located!

[YT2095]

the universe is expanding, in all directions at the same time. how would you keep your "Absolute location" for more than the merest fraction of a femto second?

 

You're forgetting one thing: The Multiverse. Our universe is not the only one. It says so in M-Theory. There are an infinite number of universes in the multiverse. THAT'S where the absolute frame is located!

 

no no no! I`m NOT playing That game with you

[dstebbins]

Okay, time out! Time out! This is getting WAY out of hand! We all need to take a few breaths. Myself included, but you guys also.

 

Let's come back in a few hours, shall we? Maybe then we'll have calmed down, and we can talk, not e-scream.

[Norman Albers]

I agree that good puzzles and questions lie here in cosmology in the large. You seem to imply a finite ball of universe albeit with a receeding edge. I am still not up to speed in cosmology, but I don't think we can find cosmic real estate at the edge.

[YT2095]

I agree that good puzzles and questions lie here in cosmology in the large.

 

I dunno, quantum Physics holds quite a bit More mystery and "puzzels" to be solved than the Macro scale in my opinion.

 

I like both, so I`m not too picky, I just dont like 30 players put on the football field when it clearly started with 11 a side

[Severian]

Dude, were you even paying attention? Absolute location is a relative location, yes, but it's relative to a universal, or absolute, frame. This makes this particular relative location absolute.

 

On a map of the earth, the global frame is the intersection of the Equator and the Prime Meridian. Of course, since all objects in the universe are in constant motion, our best bet for this absolute frame is a point in space.

 

SHEESH!

 

Even if you have something to anchor your 'absolute' frame (and you don't), what makes it any more absolute than any other choice I can make? For example, you quote an 'absolute' frame for the Earth, but how did you choose your Prime Meridian? It was arbitrarily chosen by historical accident.

[Norman Albers]

"Properties available, lots with a back fence bordering on NOTHING... Not much to see, but serene".

[swansont]

It may be that there are two distinct uses of "absolute frame" being used here.

 

In physics, an absolute frame implies you can do a measurement to see if you are in that frame, i.e. you can tell if you are moving or not, but you can't do this. It is not some arbitrarily chosen frame used for convenience; we already do that to make the math easier. But the point is that we don't have to choose that frame — we'll get the right answer if we chose another frame. So designating a frame as an absolute one is a contradiction.

[Janus]

I had a feeling you'd say that.

 

 

However, the need for a material object to be the universal frame is bull. Who says we can't designate a point in space to be the universal frame? The "origin of the coordinate grid" if I may. Sure, even the vacuum of space has kinetic energy (about 3 degrees kelvin between galaxies), but there's no matter around for the enegy to affect. The vacuum would stay stationary.

 

So in a sense, absolute location (location relavent to the absolute frame) can be measured, and if we can measure absolute location, we can measure absolute speed.

 

But this would be a arbitrary choice for "absolute location and absolute speed." I could choose a completely different point in space, one that has a motion relative to yours, and claim it to be the origin of Absolute space and motion, and my choice would be just as valid as yours. There is no way to make a definite choice between the two. Neither can be prefered over the other. IOW, there is no objective test that can be performed that shows that my point is really moving and yours motionless or that mine is motionless and yours is really moving.

 

This is what is meant by there being no absolute motion; that any assignment of such is purely subjective and not objective.

[Norman Albers]

Here is a gedanken: we can perhaps perceive what to us is the light of first galaxy formation, as a light-radius of some 13 billion light-years, if I have it right. What does someone moving rapidly nearby perceive? (I don't yet know.)

[foodchain]

Ok then, I have a question. Is there any action in the universe that spawns or requires a certain speed or velocity in order to function. I mean I posed a question in the speculation section on this website over my thoughts on this. Such as how slow can something go? I mean it seems that the speed of light is the upper limit, which probably helps in calculations, but what about how slow something can go? It seems to be that if such a slowness was obtained that natural states of say particles could not exist? Am I simply making unreal or non rational connections here?

 

I understand that all things happen to be in motion, or at least at some level in a giving context, but it just seems that if there is an upper limit, there should also be a lower limit then, and at a point if something could not reach such a slow speed, would that then be some form of a more absolute reference frame?

 

Feel free to point out all the ways I am wrong I can use the education on such.

[Norman Albers]

People are theorizing that gravitation in the small-field limit goes as 1/r, not as 1/r^2.

[Klaynos]

I had a feeling you'd say that.

 

Is there really no such thing as absolute speed, or could absolute speed be a manifestation of a relative speed, relative merely to a universal frame? It is common knowledge that energy of motion and energy of heat are the same thing, so when an object reaches a temperature of absolute zero, it is absolutely stationary, therefore, this theoretical object would be the perfect universal frame. The only problem here is that matter as we know it cannot obtain a universal frame.

 

However, the need for a material object to be the universal frame is bull. Who says we can't designate a point in space to be the universal frame? The "origin of the coordinate grid" if I may. Sure, even the vacuum of space has kinetic energy (about 3 degrees kelvin between galaxies), but there's no matter around for the enegy to affect. The vacuum would stay stationary.

 

So in a sense, absolute location (location relavent to the absolute frame) can be measured, and if we can measure absolute location, we can measure absolute speed.

 

There is no absolute location, coordinate sets are arbitrary you can set them up however you like :'(

 

There have been several experiments to show there is no absolute rest frame

 

Which you can't do with temperature...

[Norman Albers]

Foodchain, interesting question on how slow can something go. I see quantum mechanics making a statement about indeterminacy of things in the small. Importantly, this also pertains to "zero temperature". You cannot actually get there from here.

[revthought]

Well first of all everything is relative, so no matter what your speed relative to "you" light well always be moving away from you at 299,792,458 m/s. Now from your perspective the light travels away from you at this speed because for every second that passes for you, no time has passed for the beam of light, the same for the people of the planet, this is why "c" is so important, it gives you something to compare everything else to.

 

revthought

 

Well first of all everything is relative, so no matter what your speed relative to "you" light well always be moving away from you at 299,792,458 m/s. Now from your perspective the light travels away from you at this speed because for every second that passes for you, no time has passed for the beam of light, the same for the people of the planet, this is why "c" is so important, it gives you something to compare everything else to.

 

revthought

[someguy]

I don't know, but if moving faster causes an object to create a more intense gravitational field then it would follow that all other things being equal there would be some vector where that gravitational field would be the smallest. and I would call that speed zero. and if i had to guess what speed that would be i would first try to plot the center point from which the universe is expanding and try to peg a speed to that. but apart for that then you can't really say how fast anything is moving or how slow because it's all relative. but still when you cause a body to move you basically inject energy into it and that changes it. you would think that you could find a speed where no part of the body's energy is allocated to motion of the whole body, and only of its parts. so if you could isolate the motion component of its energy and know that is the only thing changing about the body then personally i think it would be possible to find a slowest speed possible. but i could be wrong.

[Klaynos]

Moving faster relative to what?

 

There is no centre point from which the universe is expanding (or more correctly, that centre point is EVERYWHERE).

[foodchain]

Moving faster relative to what?

 

There is no centre point from which the universe is expanding (or more correctly, that centre point is EVERYWHERE).

 

 

What’s that say about time? I mean people talk about clocks, well those can come in various forms and happen to be some form of either matter or energy performing some function right? I mean if I am looking at light from a star that’s x light years away, I am looking at little more then the light which is simple enough of a concept, but the light itself is open to effects right? So more or less its sort of a smear of energy really?

 

I mean I hear that the expansion of the universe is faster then the speed of light, and this can be measured to a high degree of certainty, well, giving relativity, how can this be so thoroughly known then? I mean from sitting here on earth and looking at the heavens with a microscope, what I am looking at really is relativity in action, which to me seems to be a term that describes energy in action, but I don’t know where to sit exactly time into any of this let alone what an absolute description of time is. Does relativity basically begin a bridge to the unobservable universe then? Also, does matter have to be in bulk before relativity takes hold or applies or basically escapes the QM domain.

[Klaynos]

I'm a bit tired (I've had an average of 4h sleep the last 6 nights, and 3h last night) so I don't quite get your thread.

 

But, in special relativity time is part of the 4-vector the same as the 3 spacial dimensions.

 

SR and QM work fine together, and QM and GR do not disagree except around extream situations like black holes, which is probably due to the incompleteness of one or both of the theories. There is a good post on this by ajb that he made recently...

[someguy]

Moving faster relative to what?

 

There is no centre point from which the universe is expanding (or more correctly, that centre point is EVERYWHERE).

 

faster than it was before. relative to its previous speed.

 

if the center point was everywhere then it couldn't be moving away from the center point it would always be at the center point and therefore you could not conclude that the universe is expanding. no? it seems to me that if the universe is expanding then there must be a center point from which it all came or at least a center area and you could still take that center area and find the middle of that even if the universe was never just a single point. if the universe is at least somewhat spherical or rather some 3d globby shape and all the energy in it is expanding then by calculating the mass and velocities or vectors of all the energy it consists of you should be able to extrapolate a middle point. no?

 

I may be wrong but i think that what you mean is that the only thing that exists is universe and therefore it expanding must mean that it is just itself a middle point. it is a stretching thing rather that many tiny solids expanding in a void like marbles on a table. the actual centrepoint is sort of stretching and expanding so it is itself the middle point and you could never find it's origin in the universe because whatever spot you find used to be a smaller spot that was inside the universe when it was smaller. but still even at that i think you could calculate the middle of the universe from an energy point of view, the center of mass of the universe and you would do that by finding the "middlepoint" from which everything seems to be moving from, taking into account they speed direction and mass. but you couldn't say that that spot was the spot in the universe where the big bang took place because the point entity universe of big bang is the whole universe and therefore where it was located when the big bang banged cannot be located inside the universe. but you can still find the middle of the universe.