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HNQ
5:09 AM
2
Q: What kind of coordinate change is needed to make gravity disappear?

K. PullI 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-fall. Now, if this transformation is dependent on the velocity and acceleration of the free-falli...

 
 
13 hours later…
HNQ
6:16 PM
2
Q: How does Einstein's paper actually prove atoms exist?

Pecan LimReading through Einstein's Brownian motion paper "On the Movement of Small Particles Suspended in Stationary Liquids Required by the Molecular-Kinetic Theory of Heat", it seems the final argument is that he can calculate the Avogadro's constant by using data on the diffusion rates, particle size ...

 
 
3 hours later…
HNQ
9:14 PM
2
Q: Is there a distance from a gravitational source where the influence of gravity and dark energy are balanced out?

vengaqWhile gravity is a force that attracts objects with mass, dark energy (or the accelerated expansion of the universe) is not. However, I have found numerous articles, forums, questions in the stack network... where people seem to say that if you get further from a gravitational source (e.g. a gala...

1
Q: Potential energy in an ideal spring compressed from both side

GuessMy query is that suppose an ideal spring is present and is compressed from both the sides with X1 distance from left and X2 distance from right. So what will be the potential energy stored in the spring at this moment. So using the formula $\frac12 kx²$ Should it be $\frac12 k (x1+x2)^2$ Or sum o...

 
 
2 hours later…
HNQ
10:56 PM
1
Q: Why are there no enormous galaxies near us?

Tony HägerRecently the James Webb space telescope detected six massive ancient galaxies. They are very old and very far away. But these galaxies must still exist today and be even heavier now. Why can't we see any such huge galaxies near us now?

 

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