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Jan
9
reviewed Reviewed Space time expansion near galaxies
Jan
9
reviewed Close Acceleration of a static observer in Schwarzschild measured in locally inertial frame
Jan
9
reviewed Close is the expansion of the universe observable at a smaller scale?
Jan
9
reviewed Close Force required to move a stationary object
Jan
9
reviewed Leave Open If we forget which slit the photon goes through, does it interfere again?
Jan
9
comment If we forget which slit the photon goes through, does it interfere again?
I'm very confused why there are 4 votes to close a quantum eraser question as non-mainstream.
Jan
9
reviewed Close Point rolling on a ball
Jan
7
comment Black hole corona and bipolar outflows
@annav I do believe the chosen answer is off the mainstream. The cited paper is not quite wrong, but it uses language from 50 years ago that is misleading when put in a modern context. The only way you get a speed of light that is not $c$ is if you measure distance and time in different reference frames, and there's never a good reason to do that.
Jan
6
comment Is an x-ray maser possible?
Possible duplicate of Gamma Ray LASER Theory and Technology
Jan
6
comment Physics after a Theory of Everything
Something to ponder: what exactly do you think most physicists do with their careers? I assure you, the vast majority of professional physicists are not working on anything remotely like a theory of everything, despite the publicity such people might get. Most physicists study complex phenomena where we already know all the "fundamental" ingredients we need, but there are still plenty of problems to be solved. Having the fundamental theory in hand won't change their lives in the slightest.
Jan
5
comment How long ago, and how far away, could “A long time ago in a galaxy far, far away” have been?
The Pop III stuff is good, though a biologist might quibble that it took a few billion years for complex life to evolve once Earth formed. In any event, just to be pedantic, distances are somewhat tricky in cosmology. A galaxy at redshift 6 will appear to us as it looked 1 billion years after the Big Bang. When that light was emitted it would only have been 4 billion light years away. Its present position can be extrapolated to be 28 billion light years away, which is outside our event horizon (present-day light from that galaxy will never reach us).
Jan
5
answered What is the property which flows as described by the stress energy tensor in GR?
Jan
5
revised How is Earth orbit possible?
edited tags
Jan
5
comment How many frames can human eye see?
"Are new 144hz monitors just a marketing trick?" Yes, just like the absurd numbers of pixels you see today, far smaller than the angular resolution of most people's poor eyesight.
Jan
5
reviewed Edit How mass is determined in dynamics?
Jan
5
revised How mass is determined in dynamics?
removed unnecessary formatting and content
Jan
4
comment Can we consider light from the Sun during sunrise and nightfall as polarised?
Nothing to really worry about. Some users have voted to close this question as not conforming to our homework policy; others have voted to leave the question open. If is is closed, we can deal with how to improve the question.
Jan
2
reviewed Close What is an object made of?
Jan
2
comment Is causality a total order?
I kind of get what you're asking, but I'm curious as to the source of the first sentence. Spacetime is partially ordered, with timelike separated events being comparable and spacelike separated events not being comparable.
Jan
2
reviewed Leave Open Is causality a total order?