About curved space ...

I DO have a problem with curved spacetime. The term "curved" only has meaning in reference to the shape of an OBJECT that exists within a reference frame (SPACE?) that is taken to be uncurved. After all, if your reference frame is curved then it is not really a reference frame is it? But if our object is space itself then to what do we compare it to to state that it is curved? Physicists love to call space curved because they believe anything written as an equation on a piece of paper is true so long it is logically consistent. This "curvature" is a Humpty Dumpty redefining of a concept to mean what one wants it to mean rather than what it historically is supposed to mean. It is much like "spacetime", does the concept have conceptual validity if I merely type two words together without a space between them? How about "crowapple" or "greenhappy".

Gents,

On another note, for example, how does matter interact with space-time, which is inert and has no properties? This doesn't really "add up" ...

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Jeremy</i>
<br />I DO have a problem with curved spacetime. The term "curved" only has meaning in reference to the shape of an OBJECT that exists within a reference frame (SPACE?) that is taken to be uncurved. After all, if your reference frame is curved then it is not really a reference frame is it? But if our object is space itself then to what do we compare it to to state that it is curved? Physicists love to call space curved because they believe anything written as an equation on a piece of paper is true so long it is logically consistent. This "curvature" is a Humpty Dumpty redefining of a concept to mean what one wants it to mean rather than what it historically is supposed to mean. It is much like "spacetime", does the concept have conceptual validity if I merely type two words together without a space between them? How about "crowapple" or "greenhappy".
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">


Of course. You are exactly right.

What is “curved”, in my opinion, is the gravity fields, curved around spherical bodies.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">After all, if your reference frame is curved then it is not really a reference frame is it?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Yes, it is really a reference frame. I think you are thinking that a reference frame must be perfectly Euclidean. If there is a deviation from perfection you would be unable to explain a physical discrepancy, i.e. matter would not behave in the manner expected. The establishment of a reference frame for physical interactions is non-trivial and is established by nature independent of our expectations.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">But if our object is space itself then to what do we compare it to to state that it is curved?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
You compare it to your expectations in a Euclidean reference frame which is the logical default frame in 3 dimensions (isotropic and isomorphic). If space is curved around masses, a deviation could be seen in the behavior of matter ... provided that light is not significantly affected by the curvature. That is the case here. The curvature around the earth is too small to significantly affect the course of light so one can use the direction that light takes as coinciding with a Euclidean frame. To gauge the deviation of light in the earth's curved frame would require other methods to reveal discrepancies between observation and Euclidean expectation (like the light bending around galaxies to produce the gravitational lensing effect of which there are actual pictures now).

My opiniion is that direction in space is determined by matter which acts as a reference point ... and ... that each such reference point is the center of a spherical reference frame. Spreading baryons out uniformly would make a Euclidean reference frame on scales much larger than the spacing between two adjacent baryons ... but when the baryons are clumped into appreciable masses the non-Euclidean nature of their combined spherical reference frames becomes apparent.

I'm not a relativist, but I can understand how space and time are intertwined and how they're curved.

But then I understand matter, space, and time in the same sort of way Leibniz understood them, as opposed to Newton+Einstein.

All change in nature works one of four ways (the four forces) and it always involves two bodies at some distance mediated by another force carrying boson.

Matter, space, and time all exist as some type of analysis by one of the bodies in this change:

1. Matter is the analysis that there is something
(If you interacted you deduce that there is another body you interacted with)
2. Space is the analysis that there is some place
(If there is another body, it is at some other place)
3. Time is the analysis that something has changed
(If you change state, there is a past state in the context of the change)

So, if space is created because there is a distance traversed by a mediating boson, it would be simple to curve space: simply curve the path of the boson.

Second, how are space and time intertwined? They are both effects of a common cause. We see that matter is also an effect, so it might make more sense to say matter-space-time now.

I think you'll find this understanding of space and time to be particularly useful in understanding quantum mechanics, and removing the need for relativity.

(For example, special relativity predicts time dilation. This explanation also predicts time dilation. Time is created by change. If you have lots of change in a system you have lots of time. Time dilation. The interesting part is we can predict this without a speed limit in the universe. That should be appealing to any Tom van Flandern fans.)

mhelland@techmocracy.net

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">The establishment of a reference frame for physical interactions is non-trivial and is established by nature independent of our expectations.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Fair enough, but that applies to relativistic theorizing as well. So far observational evidence has found no smoking gun in the deepest galaxy maps that shows anything other than a Euclidean distribution of matter. If there was some other geometry then we should observe progressive distortion of solid angle as we map farther out. In fact these same relativists use Euclidean assumptions in making these maps and use the same positioning methods as any surveyor would (other than the Hubble relationship for getting the distance of course). Don't you think they should prove curved space before assuming it?

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">You compare it to your expectations in a Euclidean reference frame which is the logical default frame in 3 dimensions (isotropic and isomorphic). If space is curved around masses, a deviation could be seen in the behavior of matter ... provided that light is not significantly affected by the curvature. That is the case here.
The curvature around the earth is too small to significantly affect the course of light so one can use the direction that light takes as coinciding with a Euclidean frame. To gauge the deviation of light in the earth's curved frame would require other methods to reveal discrepancies between observation and Euclidean expectation (like the light bending around galaxies to produce the gravitational lensing effect of which there are actual pictures now).<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

If I throw a ball bearing past a powerful magnet I will observe it to deflect on its way by. Do I then declare that space is "curved" and that is why the ball bearing veered off? Light is affected by the gravity of the galaxy, not by curved space. I know that the relativists believe gravity is caused by curvature of space, but like most beliefs they have like dark matter, energy et al they assume it before they prove it and treat you like an ignoramus if you don't jump on the bandwagon.