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| DrCWho |
 Posted: Fri Apr 18, 2008 9:43 am Post subject: Just What is the Meaning of This? |
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Assuming we are not forming a geodetic structure at first, what would I be describing with:
ds2 = (cdt)2 - (dx)2 - (dy)2 - (dz)2
?
How would we relate this to F = Gm1m2/r2
?
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| william |
| Posted: Fri Apr 18, 2008 9:59 am Post subject: |
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Forum Ph.D.
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Ahah! Isn't that the line element of the metric tensor that describes a flat space-time? Looks like the Cartesian variety. I think it's called a Minkowski space-time.
Doesn't this relate gravity to curvature?
My GR is waaaaay rusty!
Cheers,
william
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About my avatar: This is a smoothed particle hydrodynamics (SPH) simulation of the merger of two galaxies. The code was written by Volker Springel of the Max Planck Institute for Astrophysics at Garching Germany. This simulation uses 20,000 disk particles (stars) and 40,000 halo particles (dark matter) per galaxy. The three views are, from left to right, the x-y plane, x-z plane, and y-z plane. |
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| Demon X01 |
| Posted: Fri Apr 18, 2008 11:17 pm Post subject: Google |
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Don't know but might as well try and give an ansewer does it have to do with Einstein's theory of relativity? Something to do with how space and time are related.  
F= Force G= Gravitational constant (6.67 x 10-11 N-m2/kg2) whatever the hell that means. m= mass of the object. Divided by r= volume or a cubic function.
So Force= the Universal Gravitational constant X the mass of an object X the mass of an object to the second power/ the volume of an object to the second power.
X= times /= divides.
I don't know but is supposed to relate to how an object can never overcome it's own mass and therefore not traval though time. Or maybe never reach the speed of light.
Okay that was proably way off maybe even extremely far off. Maybe what I just said was totaly useless but I thought I would give it a shot.
(Blindfold On.)
You can now commance fire. 
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| Selene |
| Posted: Sat Apr 19, 2008 6:31 am Post subject: |
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ds2 = (cdt)2 - (dx)2 - (dy)2 - (dz)2
is it general relativity and gravitational waves and the relation between space and time?
F = Gm1m2/r2 a black hole?
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| DrCWho |
| Posted: Sat Apr 19, 2008 6:33 am Post subject: |
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William is right on the money. It does allude to what Demon answered.
Can either of you spot the embedded error in one of the expressions?
(I do that to see how alert we are...  )
And I have to compensate for symbols and capabilities these editors lack... 
0[size=9]o|o[size=7]1
See what I mean?
Dr. CWho
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| Selene |
| Posted: Sat Apr 19, 2008 6:37 am Post subject: |
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Should it be - ds 2 = (dt)2 - (dx)2 - (dy)2 - (dz)2
?
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| KALSTER |
| Posted: Sat Apr 19, 2008 7:23 am Post subject: |
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(ds)2 = -(dct)2 + (dx)2 + (dy)2 + (dz)2
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Last edited by KALSTER on Sat Apr 19, 2008 8:54 am; edited 1 time in total |
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| Demon X01 |
| Posted: Sat Apr 19, 2008 8:22 am Post subject: |
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Hey, so that means I was somewhere close right. Hey Google really does work.
Should it be - ds2 = dt2 - dx12 - dx22 - dx32
See I am getting slowly smarter at least in useing Google.
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| Cosmo |
| Posted: Sun Apr 20, 2008 6:23 am Post subject: Re: Just What is the Meaning of This? |
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| DrCWho wrote: |
Assuming we are not forming a geodetic structure at first, what would I be describing with:
ds2 = (cdt)2 - (dx)2 - (dy)2 - (dz)2
?
How would we relate this to F = Gm1m2/r2
? |
I an not a math expert but the 1st formula seems like it represents Einsteins 'spacetime'
Newtons gravity formula has no relation to spacetime.
Cosmo |
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| DrCWho |
| Posted: Mon Apr 21, 2008 7:07 am Post subject: |
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1. Newton's expression uses -G in relativistic problems. It describes gravity as a pulling force.
2. The flat space time, although used as a basis for Minkowski space-time, it was Euclidean and even more precisely considered a Galilean system.
Selene,
The speed of light is a necessary element. Galileo knew this.
ALL of you are doing your homework.
As I'll be publishing soon (likely at my own site in MSN where I can use jpg.'s to build my equations...) gravity fields have always been the "crux corporus" of the steady state. Intersections of gravitational curvilinear fasiculations offers the same results as -G, but explains the process.
Thanx for the responses. All are intelligent.
Dr. CWho
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