Gravity & Curvature of Space

[HankSolo]

If gravity bends or curves space, then it stands to reason that on the surface of this planet we are standing in curved space. Therefore we should be curved along with it, right? So it follows that what appears as a perfect sphere on the surface of the earth would no longer be a perfect sphere in the zero gravity of space. Also a perfect sphere or wheel on earth cannot exist because as it rotates it gets warped more on the bottom than on the top due to the increasing curvature of space towards the bottom, however minute. I realize how hard this must be to test, but I'm wondering if this is in fact true.

Take the classic 2D flat rubber sheet model of gravity. If you draw a perfect circle on it while it is flat, it will appear perfect. Put a bowling ball in the vicinity, and it will no longer appear perfect as it gets stretched out. Now draw a new perfect circle while the bowling ball is there, and remove the bowling ball, and the new circle is no longer perfect.

Has something like this been tested on Earth and in space? I have a hard time accepting gravity curves space, but this would seem to prove it if true. I would think the observer would have to remain fixed so that he/she continues to have the same frame of reference.

[GrapesOfWrath]

Mindboggling, isn't it?

It's not space that is curved, it's spacetime.

Is that an important distinction? The first example that I found that demonstrated this was in the tome Gravitation by Misner, Thorne, and Wheeler.

Imagine throwing a ball up and away, and watching its arc as it falls back to the ground. Now, shoot a gun at the ball lying on the ground and notice the subtle arc made by the bullet as it flies towards the ball. Both arcs definately do not have the same curvature. But now plot the arcs in a mathematical four dimensional space, where the coordinates are x, y, z, and ct (t time of flight multiplied by the speed of light c). Since the ball took so much longer to fall, its arc is stretched out much farther in spacetime, and the curvature of its arc is then the same as the curvature of the bullet's arc.

Clearly, it is the time dimension that makes most of the difference. The effects in space alone result in differences that are virtually undetectable.

[Russ]

One of the other things you must keep in mind when doing a thought problem like this one, all of your measuring references are distorted by gravity as well. So, as you leave the gravity well and your "rubber sheet" becomes less distorted, so will your measuring instruments. You will, therefore, see no change in whatever reference object you are measuring.

It's crazy stuff, isn't it?? [img]/phpBB/images/smiles/icon_confused.gif[/img]

[HankSolo]

Exactly why the observers (and the observer's tools) need to remain fixed. If our eyeballs and lenses and whatever are being warped too, then we won't notice a difference unless we observe the object in zero gravity from the earth's surface. I realize the difficulties in doing a test like this, and what I'm really wondering is if my logic is faulty.

[JS Princeton]

GR formulations in the limit of "ourselves" is locally flat (that is Minkowski Spacetime). We can see on larger scales that there is curvature but locally the curvature present is trivial in comparison to other phenomena.

[Wiley]

In my own personal five-dimensional world, spacetime is flat.

[Silas]

On 2002-09-19 15:03, HankSolo wrote:
Exactly why the observers (and the observer's tools) need to remain fixed. If our eyeballs and lenses and whatever are being warped too, then we won't notice a difference unless we observe the object in zero gravity from the earth's surface. I realize the difficulties in doing a test like this, and what I'm really wondering is if my logic is faulty.

One solution is to send an object (a clock on a satellite, for instance) into a region where the curvature is different, and then, after a while, bring it back. It will have measured a different amount of time than we measure here on earth.

It isn't proof, exactly, but it's evidence. It's data. And all the data, taken together, support the notion that gravity bends space.

At very least, there has never been an experiment that strongly suggested otherwise, and quite a few experiments have been conducted which support the theory.

Silas

[GrapesOfWrath]

On 2002-09-19 15:03, HankSolo wrote:
what I'm really wondering is if my logic is faulty.

Yes. It's not space that is curved, it's spacetime.

On 2002-09-19 23:38, GrapesOfWrath wrote: To: HUb' as 486/100

On 2002-09-19 15:03, HankSolo wrote:
what I'm really wondering is if my logic is faulty.

Yes. It's not space that is curved, it's spacetime.

When? [in 58] <ASr7> crossed BEYOUND
and the crew took it back to oakland to be cut up
I ? saw the wooden deck piece hang about mate neck B4i got out in '60 {believe what U like}

[beskeptical]

On 2002-09-19 14:36, GrapesOfWrath wrote:
Mindboggling, isn't it?

It's not space that is curved, it's spacetime.

Clearly, it is the time dimension that makes most of the difference. The effects in space alone result in differences that are virtually undetectable.

Well there's another thought I hadn't really considered. I shall add that to my contemplation of the Universe the next time I get lost in such thoughts. Now if I can just remember what Tim T. said a while back that seemed like a new way of looking at things. I'll have to go back through some old threads.....

<a name="20020922.12:34"> page 20020922.12:34 aka ( 0 )
On 2002-09-19 14:36, GrapesOfWrath wrote: To: ( 0 )
Mindboggling, isn't it? // possibly? Anyway Assume its time :
As the Compression [is that correct?] of TIME ..
RADIATED AWAY from T_0 [the mushroom stem]
across the 4 miles to where WE [ASR-7] watched
http://www.badastronomy.com/phpBB/vi...um=3#LINK2.ASR
a moment in time, came & went {a second or 2, or 3 maybe 4}
where TWO stems where clearly visable. My guess was
it happened when the { compression of time } was 1/2 way [ 2 miles ] and at
the aproximate location of the SUB.. remember also
that the RATE of Travel from T_0 outwards is the same rate in the air and in the water and there's just one So called "Shock wave" probably more correct terms would be tempral compression?

<a name="JD2452540"> page JD2452540 aka JD2452540
On 2002-09-19 16:37, JS Princeton wrote: To? HUb's 386/20
trivial in comparison to other phenomena.
Well? maybe not? lets take the Gramps & the coffee sceene:
HUb' ride in a Gw.. My guess once in GW I was
actually some way {levateted} out of D3 (Clock3) and
attached some way to clock4[D2] .. anyway Time itself Slowed..
thing in D2 were extreamly tranquil {observations were enhanced}
However: the return (out of GW) {from C2 to C3} was also accompanied by
a tempral recompression [it was very violent] Time passed very Quickly and dV/dT forces were very high. 1:02 A.M. PST / 97209

[beskeptical]

On 2002-09-21 04:26, beskeptical wrote:

On 2002-09-19 14:36, GrapesOfWrath wrote:
Mindboggling, isn't it?

It's not space that is curved, it's spacetime.

Well there's another thought I hadn't really considered. I shall add that to my contemplation of the Universe the next time I get lost in such thoughts. Now if I can just remember what Tim T. said a while back that seemed like a new way of looking at things. I'll have to go back through some old threads....

I remembered, it was that light doesn't interact with dark matter.

In the shadows of some new skepticisms
I can no longer say with the prior certanity
that the two steams i viewed {briefly}
were purely the result of a curvature
at the time within space.. for i can now
concieve of an atmospheric compression
which in and of itself may have had optical
properties..
SO do i fall back to some other position?
probably.. an a moment ago it was clear
on this line not so {maybe it will return}
[letss see compressed atmosphere {possible}
OK OK the point came around again
IT THIS: the rate of travel
bothe in
the atmosphere ? and in the sea waters
WAS THE SAME RATE.. and that where I fall back to!

[Avatar28]

On 2002-09-19 17:59, Silas wrote:
One solution is to send an object (a clock on a satellite, for instance) into a region where the curvature is different, and then, after a while, bring it back. It will have measured a different amount of time than we measure here on earth.

It isn't proof, exactly, but it's evidence. It's data. And all the data, taken together, support the notion that gravity bends space.

At very least, there has never been an experiment that strongly suggested otherwise, and quite a few experiments have been conducted which support the theory.

Silas

That's been done, actually, I believe. They sent an atomic clock into orbit around the earth and had another here on earth. They were originally perfectly synchronized, yet after some time, the clock in orbit was ahead of the clock on the surface because of the greater curvature of spacetime on the surface.

[Wiley]

On 2002-09-23 12:29, Avatar28 wrote:

On 2002-09-19 17:59, Silas wrote:
One solution is to send an object (a clock on a satellite, for instance) into a region where the curvature is different, and then, after a while, bring it back. It will have measured a different amount of time than we measure here on earth.

It isn't proof, exactly, but it's evidence. It's data. And all the data, taken together, support the notion that gravity bends space.

At very least, there has never been an experiment that strongly suggested otherwise, and quite a few experiments have been conducted which support the theory.

Silas

That's been done, actually, I believe. They sent an atomic clock into orbit around the earth and had another here on earth. They were originally perfectly synchronized, yet after some time, the clock in orbit was ahead of the clock on the surface because of the greater curvature of spacetime on the surface.

An additional example is GPS. Contrary to what certain people may think, GPS uses corrections based on general relativity. See General relativity in the global positioning system.

Standard 486/100 {faster} disclaimer
[no page name No time stamp etc]
ok so UP goes GPS with onboard Xtal[or T_i] {time interval}
and its documented somewhere that A change
can be accounted for mathamatically
FINE
my questions this
are the answers positive ot negative?
by this question
I raise the question
in which direction
does the correction apply
-----to myself only listen
if it reported that orbital clocks
in GPS satalites going round &round
Earth have 4shortened time intervals[T_i]
and the corrections to where on Earth an
earthling stands{sits to take a reading
then the faster clock rate would sugest to me
a shift of frame ibto the direction of electron orbitals
and NOT out twards the Galactic centered time coOrdinates? hay do you see the line on tv that does not pass thru english greenwitch? hmm?

[Wiley]

For GPS, SR (velocity effects only) predicts that the satellites' clocks would lose about 7 microseconds per day. Gravity alone (GR) predicts the satellites' clocks gain 45 microseconds. The net results the clocks gain about 38 microseconds per day.

Is this what you're after, Hub?

<a name="JD2452542.yes"> page JD2452542.yes aka JD2452542.yes
On 2002-09-24 13:07, Wiley wrote: To: HUb' on 386/20
For GPS, SR (velocity effects only) predicts that the satellites' clocks would lose about 7 microseconds per day. Gravity alone (GR) predicts the satellites' clocks gain 45 microseconds. The net results the clocks gain about 38 microseconds per day.

Is this what you're after, Hub?
[/quote]
yep? but i must "FALL BACK" for a while and say CM
that said the next question will be to try to
state what four equations the onboard computers required to solve?
[?1] [?2] [?3] [?4] what are those about

[Wiley]

This may help, Hub. It does require Adobe Acrobat Reader.

Student Project on GPS


<font size=-1>[ This Message was edited by: Wiley on 2002-09-25 14:31 ]</font>

<a name="20021001.7"> POST 20021001.7 aka Virtual reality?
On 2002-09-19 14:36, GrapesOfWrath wrote: To? PDT
Mindboggling, isn't it?
7:34 A.M. PDT October 1, 2002
.1 i notice that these lines are double spaced? I have a double
space problem with my uploads on this 486/100
AND I SURE WOULD LIKE TO SOLVE IT? {Modem}?
.2 I have a red llight bulb
Imagine throwing a ball up and away, and watching its arc as it falls back to the ground. Now, shoot a gun at the ball lying on the ground and notice the subtle arc made by the bullet as it flies towards the ball. Both arcs definately do not have the same curvature. But now plot the arcs in a mathematical four dimensional space, where the coordinates are x, y, z, and ct (t time of flight multiplied by the speed of light c). Since the ball took so much longer to fall, its arc is stretched out much farther in spacetime, and the curvature of its arc is then the same as the curvature of the bullet's arc.
.2a in it i see a vertial image of the filiment
Clearly, it is the time dimension that makes most of the difference. The effects in space alone result in differences that are virtually undetectable.
.2q wHY DO i see a vertual? 3D image inside the bulb {below te filiment?