Tagged Questions
10
votes
1answer
119 views
Have general relativistic effects of the sun's rotation been measured?
I was wondering if general relativistic effects of the sun's rotation have also been measured, like gravity probes A and B measured GR effects from the earth.
5
votes
4answers
299 views
What is the “foamy space” hypothesis that has been debunked recently?
In "Space-Time Is Smooth, Not Foamy", a Space.com article, it is stated:
In his general theory of relativity, Einstein described space-time as fundamentally smooth, warping only under the strain ...
2
votes
1answer
198 views
Experimental proof of gravitational redshift of light
Has the gravitational red shift been proven for electromagnetic waves only or also for a single photon?
6
votes
2answers
153 views
How do the LASERs in LIGO realize that space has expanded as a gravitational wave passes by?
I read an article on LIGO, and I heard it mentioned that it is a nontrivial argument to say that the effect can be measured by interferometry. What happens to space as the wave passes? Does the light ...
20
votes
2answers
83 views
experimental bounds on spacetime torsion
Did Gravity Probe B provide any bounds on Einstein-Cartan torsion? is a non-zero torsion value at odds with the results regarding frame-dragging and geodetic effects?
5
votes
1answer
96 views
What makes us think we can actually detect gravitational waves?
This refers to the discussion about gravitational waves for the YouTube video LIGO Gravitational Wave Observatory.
I have two questions:
When the gravitational wave passes through the space where ...
4
votes
2answers
405 views
What experimental proof has been found of Einstein's theory?
As a casual science reader, I've always found the implications of relativity (inconsistent clocks after near-light-speed travel and various space-time paradoxes) to be confusing and magical-sounding. ...
1
vote
2answers
187 views
Question about gravity probe B
I have a question about the gravity probe B experiment.
According to this site:
http://science.nasa.gov/science-news/science-at-nasa/2011/04may_epic/
The measurements they made confirm Einsteins ...
2
votes
1answer
140 views
Does the recent Gravity Probe - B mission mean both the mass of an object and the spin of an object affect time?
I'm a non-engineer interested in the recent GP-B mission results: http://www.engadget.com/2011/05/06/nasa-concludes-gravity-probe-b-space-time-experiment-proves-e/#disqus_thread
Is it correct that ...
2
votes
1answer
156 views
Testing General Relativity
Ever since Einstein published his GR theory in 1916, there have been numerous experimental tests to confirm its correctness--and has passed with flying colors.
NASA and Stanford have just announced ...
5
votes
1answer
129 views
Which PPN parameters are least well determined?
There are by now (late 2010) many tests of GTR. GTR is holding up quite well! But, surely, we do not yet have it cornered in every possible way.
In terms of the PPN parameters used to ...
5
votes
5answers
2k views
What is the evidence for Inflation of the early universe?
The theory of Inflation explains the apparent consistency of the universe by proposing that the early universe grew exponentially for a 1E-36 seconds. Isn't a simpler explanation that the universe is ...
7
votes
6answers
983 views
What methods can astronomers use to find a black hole?
How can astronomers say, we know there are black holes at the centre of each galaxy?
What methods of indirect detection are there to know where and how big a black hole is?
2
votes
7answers
388 views
Can astronomers directly detect black holes?
Are there any methods of direct detection for black holes?
I'm not referring to gravitational lensing, or measuring the orbits of a star in a binary pair.
Is there any way of directly 'seeing' them? ...
