All Questions
Tagged with particle-physics general-relativity
68
questions
36
votes
7
answers
4k
views
Why can’t gravitons distinguish gravity and inertial acceleration?
If gravitons mediate the gravitational force, couldn’t the detection of gravitons by an observer be used to distinguish whether they are experiencing gravitational acceleration vs. inertial ...
- 481
19
votes
5
answers
2k
views
Are elementary particles ultimate fate of black holes?
From the "no hair theorem" we know that black holes have only 3 characteristic external observables, mass, electric charge and angular momentum (except the possible exceptions in the higher ...
user1355
17
votes
6
answers
7k
views
How can a grain of sand be "spaghettified" when nearing a black hole?
I have a hard time wrapping my head around this "spaghettification" process that apparently takes places when getting close to a black hole.
Gravity is proportional to the distance of the ...
- 439
13
votes
2
answers
1k
views
Do photons generate gravitational waves since they affect with their energy the stress tensor? [duplicate]
The gravitational waves are fact. They are produced in a way predicted 100 years before by Einstein. Anything with energy affecting stress tensor of space time produces them. What does it happen with ...
- 314
11
votes
4
answers
3k
views
What is the difference between a black hole and a point particle?
Theoretically, what is the difference between a black hole and a point particle of certain nonzero mass? Of course, the former exists while it's not clear whether the latter exists or not, but both ...
- 2,152
11
votes
1
answer
758
views
Justification for new theories of Particle Physics and General Relativity
In reference to arxiv:1212.4893v3 and arxiv:1206.5078v2 papers of Ma and Wang, they have proposed new theories in particle physics, the weakton model where quarks and leptons are formed using these ...
- 637
9
votes
2
answers
2k
views
Was the Higgs mass correctly predicted by asymptotic safety of gravity?
This paper was published in Phys Lett B in 2009, and predicted the Higgs mass to be 126 GeV based on the asymptotic safety of gravity. Is this prediction taken seriously by the theory community, or is ...
- 7,398
9
votes
2
answers
1k
views
Why does gravity need a graviton? [duplicate]
Einstein theorized that gravity is a phenomena manifested by the curvature of spacetime, in effect it IS the curvature of spacetime. If this is so, why do we need a graviton to convey the force of ...
- 115
8
votes
2
answers
2k
views
Does the equivalence between inertial and gravitational mass imply anything about the Higgs mechanism?
For example: the role it might play in a theory of quantum gravity (ie causing space-time curvature)?
I realize that inertial mass can result from binding energy alone. Has the equivalence principle ...
- 7,398
7
votes
1
answer
307
views
Are there any additional fundamentals of physics in addition to space-time, energy, mass, and charge?
What do you consider the fundamental quantities in physics to be? By fundamentals, I mean quantities that cannot be described by a combination of other quantities. Fundamentals are things that just ...
- 249
7
votes
3
answers
858
views
Can the Unruh effect be confirmed by the LHC?
Two short questions regarding the Unruh effect. There are related answers on this forum and on wikipedia, but I am looking for confirmation of my own intuitive assumptions, so a straightfoward yes or ...
user74893
7
votes
2
answers
424
views
$L^{1}$ energy-momentum tensors in general relativity; semi-classical gravity
I was unsure whether to pose this question in a physics or mathematics forum, but it is an interesting idea I have been thinking about for some time.
In any (semi-)classical field theory it is often ...
- 1,525
6
votes
1
answer
205
views
Spin statistical theorem in curved spacetime
In Wikipedia
https://en.wikipedia.org/wiki/Spin%E2%80%93statistics_theorem?wprov=sfti1
It states that
“The proof requires the following assumptions:
The theory has a Lorentz-invariant Lagrangian.
...
- 341
5
votes
1
answer
342
views
Why did Dirac say that atomic time is different from relativistic time, and that gravity is becoming weaker? What is the relation between the two?
In this gem of an interview in 1982 with Friedrich Hund, Dirac says at 09:17 that there is some theoretical basis and observational evidence that atomic time and distances are different from ...
- 1,421
5
votes
1
answer
283
views
The Explosive Force of the Braking Alcubierre Drive - What would this look like? [closed]
The Alcubierre Drive and faster than light travel more generally may be locked away in the realm of fiction forever. That might be depressing to some people but I think their impossibility is really ...
- 51