# Tag Info

Accepted

### Does cosmic inflation create potential energy?

Inflation does not quite work that way. The objects are not pinned to a point in space, so as space expands, they just move to maintain their relative potential energy. That being said, in Lagrangian ...
• 42.9k

### Is it possible to derive the Weyl tensor from the Ricci tensor or Ricci scalar? If so, how?

To add up to the above answer, even though the Weyl tensor contribution to the Riemann curvature tensor is naturally an independent degree of freedom from the Ricci tensor, it cannot be fully ...
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### Is it possible to derive the Weyl tensor from the Ricci tensor or Ricci scalar? If so, how?

No. The Weyl tensor and the Ricci tensor correspond to different "degrees of freedom" of the Riemann tensor. As an example, notice that there are many Ricci-flat solutions to the Einstein ...
• 7,986

### Would obliquity and precessional changes of Earth affect the accuracy of GPS-based measurement of tectonic movements?

I can't give you any precise answer, but the GPS takes some of such changes into account. Have a look at the IS-GPS-200 document, page 181 (30.3.3.5.1.1 User Algorithm for Application of the EOP). ...
• 101

### Free falling bodies in the absence of external forces

You are right that gravity pulls harder in the heavy object. You are forgetting that the heavy object is also harder to move. These two effects happen to perfectly balance each other out. An object ...
• 46.6k

### Free falling bodies in the absence of external forces

Neglecting any kind of resistance, and assuming the height from which balls are released is not very large (the height must be very small as compared to the radius of earth), THEN the answer is simple!...

### Free falling bodies in the absence of external forces

If the balls were dropped in a vacuum, both balls would experience the same acceleration, which if near the surface of the earth would be $g$. From Newton's 2nd law $a=F/m$. Since the force of gravity ...
• 56.2k

### Free falling bodies in the absence of external forces

Newton’s second law applied to each of the two masses yield the same acceleration $g$, them acceleration of free fall because even though the larger mass has the gravitational attractive force on it ...
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1 vote

### How exactly did Einstein check if his equation on general relativity was correct?

Various experiments can be done to prove einsteins theory correct. Einstein theory predicts the bending of light due to gravity. He took photos of a constellation of stars at night , when the sun is ...
• 4,461