All Questions
21
questions
0
votes
0
answers
28
views
When we are on the ground do we still accelerate with 9.8 m/s²? [duplicate]
Do we accelerate with 9.8 m/s² when we are on the ground , if so why we do not fall inside the eart . How is the net force is zero , how many real forces acts on the body ?
- 1
2
votes
2
answers
2k
views
What kind of coordinate change is needed to make gravity disappear?
I understand that the Christoffel symbols associated with the metric will vanish locally once you perform the appropiate change of coordinates. These new coordinates correspond to an observer in free-...
- 391
2
votes
2
answers
119
views
Does a linearly accelerated observer inside an inertial spherical charged shell detect an electric field?
The electric field inside a charged spherical shell moving inertially is, per Gauss's law, zero.
If the spherical shell is accelerated, the field inside is not zero anymore, but it gains a non-null ...
- 133
2
votes
0
answers
58
views
Is there a way to know if you accelerate in empty space or in a uniform gravitational field?
If I'm in a room that accelerates through empty space uniformly I won't measure tidal forces. The situation is the same as standing on an infinite massive plane. So I could think, while looking ...
0
votes
1
answer
283
views
How can a person inside from a veiled and free-falling elevator distinguish whether he is in an inertial or non-inertial frame?
From wikipedia: "A non-inertial reference frame is a frame of reference that undergoes acceleration with respect to an inertial frame", according to that statement, I would say that an ...
- 339
3
votes
2
answers
247
views
Quantum gravity in an accelerated frame of reference
It is said that we can't study quantum gravity because gravity is a weak force. But gravity and acceleration are the same. Why can't we study quantum gravity in a strongly accelerated frame of ...
- 31
1
vote
3
answers
115
views
Newtonian physics and equivalence principle: a doubt on acceleration and gravity
First of all, the famous Einstein's elevator experiment is quite clear in my head, both of versions.
But now, consider the following:
Suppose then you wake up inside a car that is traveling in ...
20
votes
14
answers
6k
views
Why don't you feel gravity the same way you feel a car's acceleration? [closed]
If you are in an accelerating car or spaceship you feel an apparent force pushing you backwards, which as I understand is due to your own body's inertia (it wants to keep its current velocity but the ...
- 317
1
vote
1
answer
110
views
Strong gravitational field equivalent to accelerated frame
I have recently learned about the equivalence principle and what it says is that( If I have understood it properly) the trajectory of the particles will be the same irrespective of the properties of ...
- 135
1
vote
1
answer
78
views
Can one identify the presence of a gravitational field?
This is a slight modification to the Einstein's relativity thought experiment that I have not been able to find a discussion on.
Suppose that you are in a spaceship with no windows. Is there any ...
- 11
1
vote
5
answers
264
views
Einstein's Elevator - Constant acceleration eventually reaches $c$. Can't that be used to detect gravity vs acceleration?
Objects with mass that continuously accelerate will eventually approach $c$, but cannot exceed it. So if I find myself in an elevator, unable to determine if I'm in a uniform gravitational field or ...
- 111
1
vote
4
answers
159
views
Gravity, falling bodies, and the equivalence principle
Why is that bodies in a box accelerating uniformally in space that is sufficiently removed from gravitational fields fall identically to bodies in a box located in a homogeneous gravitational field (e....
- 85
9
votes
3
answers
1k
views
Can we determine an absolute frame of reference taking into account general relativity?
Given that acceleration induces measurable physical effects, would it be correct to say that there should be an absolute inertial frame of reference? I know that one cannot distinguish a priori ...
- 127
2
votes
1
answer
117
views
Can a free electron accelerating in a gravitational field absorb photons? [duplicate]
An 'free' electron accelerated in an electromagnetic field can both absorb and emit a photon. What about an election accelerating in a gravitational field?
Edit:
Some users have suggested that the ...
0
votes
3
answers
998
views
Artificial gravity in movie Interstellar
Cooper Station is somewhat like a hollow cylinder. Buildings are attached on the surface.
It has artificial gravity to hold on buildings and people.
If, a person needs to fly in this spot
Will the ...
- 113