The Conceptual Flaw of a 'Curved Space'

Ryan

What do you know about time warp

Harry

abslutely nothing I wasn't even aware of it until they mentioned it on the science forums at hypography and I haven't gotten ahold of one of the books Eeintein's Legacy; Time Warps Euclidean geometry still may play a factor I do not know.

ryan Henningsgaard

Look into time warp.


In my opinion it does not exist.

Only the relative communication line.

If you are standing at the event horizon and trying to commincate. Relative to us your time would stand still.

Thats because you communcation line is zero.

Did I get that right.

I'm so tied I should go to bed.

Since space is warped curved that time will also be warped relative to the communication.

Too many people add more to it. Makes a good movie

Harry

I saw the example of a taught rope stretched between two satellites and though it seems conceptually simple, there are still some problems. I see physical space as warped <i>over time</i> by gravity.

A force would need to be applied to this rope. The rope itself would tend to orbit along the same path as the satellites, so you'd have to apply a force on the rope to deflect it into a constant straight line between the satellites but if you apply this force, does it still represent a "straight line"? If you bend a rubber band, it's no longer straight. Now a beam of light shining between the two satellites would be straight(er) because it would travel (less or not at all) through time and so have less interaction with gravity. Possibly a way to describe this is that a force takes time to generate a motion. Light doesn't experience time, so doesn't respond to forces that occur over time (acceleration) so it follows a path of non-acceleration. Whereas, the rope would exist continually in time and be warped by gravity during this time. The true spacetime would be the path light would take and the rope could only approximate this by an external force (you couldn't continually pull the rope taut between the satellites with the satellites themselves being moved so it's an unsustainable system).

In the example of gavity being a resonant concave cavity, the reflections of the rope would always appear biased toward the center of this, whereas light would travel along the surface of this cavity and experience less curvature (or none, depending on your view).

I guess the point is that though there seems to be an obvious need to have a reference view of space that isn't warped, it's difficult to find any physical method of defining this. Triangulating gravity sources might be good but it's not as easy to work with as light.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Harry</i>
<br />Look into time warp.


In my opinion it does not exist.

Only the relative communication line.

If you are standing at the event horizon and trying to commincate. Relative to us your time would stand still.

Thats because you communcation line is zero.

Did I get that right.

I'm so tied I should go to bed.

Since space is warped curved that time will also be warped relative to the communication.

Too many people add more to it. Makes a good movie

Harry
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Yes, it's all about perceived time for an observer. So in this case, it gets harder and harder for someone to communicate to others outside of this gravity well because they're effectively trying to communicate uphill - anything that gets received is slower and weaker (or at least more diffused). Perceived time to the person inside a gravity well is something altogether different though and could play a part in what an "uphill" observer might see. (If movement slows inside a gravity well, then this might add to the to effect also) In either event, a conscious observer would seem to have little way of determining what their absolute time rate was as it would seem to be perceptually a matter of relating rate of witnessed events per thought, though most thoughts appear tied to physical actions in the brain so likely a conscious subjective view of time remains rather constant, though observed events elsewhere could appear to occur faster or slower.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by SteveA</i>
<br />I see physical space as warped <i>over time</i> by gravity.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">That is not the case even in the geometric interpretation of general relativity. It is only "spacetime" (a form of proper time) and not space that is curved by gravity.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">The rope itself would tend to orbit along the same path as the satellites<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">There is no need to make the example complicated. Think of the rope as simply connecting two points along the orbit, not as attached to orbiting satellites. Better yet, think of the path of a thrown baseball (which is part of an orbit in a sense), and a fixed rope with ends attached to poles, with the rope connecting two points along the baseball's path.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">you'd have to apply a force on the rope to deflect it into a constant straight line between the satellites but if you apply this force, does it still represent a "straight line"?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Yes. What else would it represent? If the rope sags from gravity, just increase the tension until the sag is gone.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">a beam of light shining between the two satellites would be straight(er) because it would travel (less or not at all) through time and so have less interaction with gravity.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">It is just the reverse. Light is bent near a mass by refraction in a light-carrying medium (called "elysium"). A taut, motionless rope has no bending unless you deliberately allow it to sag, which would introduce a curvature in the opposite direction than the curvature of light. Clearly, a sag in a rope has nothing to do with space curvature.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Light doesn't experience time ...<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Light doesn't experience the passing of any <i>proper</i> time. But it experiences coordinate time, as everything does, which is all that really matters. Gravitational phenomena are normally described in terms of coordinate time. For example, it takes light 8.3 minutes to travel from Sun to Earth.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">so it follows a path of non-acceleration.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">That path is nonetheless curved by refraction in an optical medium, or in "the space-time medium" (as a relativist might say). No one claims the path of light is a straight line through the space near a mass.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">though there seems to be an obvious need to have a reference view of space that isn't warped, it's difficult to find any physical method of defining this.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">It's no problem. Astronomers use a Euclidean-flat-space, orthogonal set of x,y,z axes to measure space for almost all applications. Combine that with the local gravitational potential field defining a local preferred inertial frame, and we can describe all dynamical problems without ambiguity. -|Tom|-

P.S. "Harry" was a spambot. Ignore his posts.