All Questions
8
questions
2
votes
3
answers
553
views
If I accelerate through space, can I say all stars gain kinetic energy?
Suppose I accelerate through empty space. Say all stars are small heavy marbles I can use to do work with by means of their velocity. Say I can let them smash into some generator that turns their ...
0
votes
2
answers
140
views
Is there any physical experiment that could tell us which object is moving to the other?
Imagine in empty space there are two objects in where one of them is moving to the other. How we can know which one is moving to the other? If there is an experiment that could tell us, would this ...
user319766
2
votes
1
answer
66
views
How would we know whether a object is moving in deep space?
In deep space, there isn't anything we can compare our position with (According to my knowledge). In other words, we won't be able to define an origin so how would we know whether we are in motion or ...
- 883
1
vote
1
answer
169
views
Acceleration and geodesics in General Relativity
Consider this situation:
A) An aeroplane travels a distance from point A to point B which are located on the opposite sides of the Earth. The aeroplane has taken the shortest possible distance to ...
- 159
1
vote
2
answers
122
views
Non-uniform relative motion between inertial reference frames?
I have the following doubt: let person A be in free fall being gravitationally attracted towards a massive body M. Suppose then that person B is completely isolated in space and in particular very far ...
- 193
3
votes
1
answer
56
views
Detecting external 'forces' in an inertial frame
Disclaimer: Science noob here, I may not use all terms correctly.
I've read somewhere of the following situation: An observer is inside a room (elevator) with no ...
- 137
1
vote
0
answers
118
views
Are there local coordinates for Schwarzchild spacetime?
In the Schwarzchild metric, $t$ is the time on the clock of an observer at infinity, and $r$ is the related to the area of a sphere by $A=4\pi r^2$. Are there more physical coordinates one could use, ...
- 1,647
11
votes
3
answers
7k
views
How can you accelerate without moving?
I know this question has been asked in other forms, generally regarding the balance of forces. This time I want to focus on motion. I've got a laser accelerometer on my desk. It tells me that I'm ...
user32023