All Questions
9
questions
-2
votes
0
answers
53
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Does Mass Actually Displace Space-Time, or does Mass only Distort it?
1. Question
Given the plethora of space-time illustrations, there is a sense that space-time is actually being displaced by mass, (planets). But on its face, this doesn't really make sense because ...
- 93
0
votes
1
answer
66
views
Is the invariance of the 4-dim scalar product the fundamental law behind time dilatation and length contraction?
The Lorentz Group is defined as the group of all transformations that leaves the 4-dim. scalar product invariant. An implication of this definition is that the absolute value of the first matrix ...
- 189
2
votes
0
answers
419
views
Clock synchronization and definition of simultaneity along a curve or contour in general relativity
What I understand so far
Fix a point $A$ with coordinates $x^\alpha$ with respect to a frame $K$ with metric tensor $g_{\alpha\beta}$. Then take an arbitrary point $B$ infinitesimally close to it with ...
- 21
2
votes
2
answers
262
views
How do I deal with the radius-coordinate of the schwarzschild-metric in this numerical problem?
It is well known that if a black hole fulfills certain conditions, it's tidal forces will rip incoming objects apart even before they cross the event horizon. So at some point, the curvature of space ...
- 101
0
votes
2
answers
223
views
What is the physical interpretation of the equation for the invariant interval in general relativity?
In my GR lecture I was given the following equation for the spacetime interval (signature $(+,-,-,-)$):
$$ ds^2=(1+\frac{2\phi}{c^2})c^2 \, dt^2-(1-\frac{2\phi}{c^2})\delta_{ij}\, dx^{i}dx^{j} \tag{1}...
- 1,037
1
vote
1
answer
821
views
Spacetime interval calculation - What am I doing wrong?
I'm calculating spacetime intervals in standard setup with frames A and B
where t = t' = 0 and x = x' = 0, and all the motion is going only in x direction.
Objects A and B move in relative velocity ...
- 111
5
votes
2
answers
340
views
Spacetime diagrams and their interpretation
Recently started an introductory course of relativity, and started learning about space time diagrams.
I couldn’t figure out what are the uses of a spacetime diagram as an alternative to Lorentz ...
- 63
7
votes
1
answer
366
views
How does time behave inside a massive spherical shell?
According to General relativity the clocks in our satellites in the atmosphere tick faster than those on Earth, as they are farther from the gravitational well of Earth and are free falling.
...
- 5,568
0
votes
2
answers
82
views
If the measurements of a clock above the earth depend on orientation, then what measurements are correct?
Take a clock in space above the earth (assuming a Schwarzchild spacetime) that works by relaying a light signal a small distance radially; ticking each time the light signal returns. Compare this to ...
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