### Why do measurements of the gravitational constant vary so much?

(Phys.org)—Newton's gravitational constant, G, has been measured about a dozen times over the last 40 years, but the results have varied by much more than would be expected due to random and systematic errors. Now scientists ...

### What is the value of G?

NIST has taken part in a new push to address a persistent and growing problem in physics: the value of G. The Newtonian constant of gravitation, used to calculate the attractive force of gravity between objects, is more than ...

### Physical constant is constant even in strong gravitational fields

An international team of physicists has shown that the mass ratio between protons and electrons is the same in weak and in very strong gravitational fields. Their study, which was partly funded by the FOM Foundation, is published ...

### Variables of nature

Within physics there are certain physical quantities that play a central role. These are things such as the mass of an electron, or the speed of light, or the universal constant of gravity. We aren't sure why these constants ...

### Test of equivalence principle searches for effects of spin-gravity coupling

(Phys.org) —Einstein's equivalence principle states that an object in gravitational free fall is physically equivalent to an object that is accelerating with the same amount of force in the absence of gravity. This principle ...

### Researchers use new method to calculate gravitational constant

(Phys.org) —A team of researchers in Europe has come up with a new way to determine the gravitational constant G. Rather than relying on using torque based techniques to measure gravitational pull, the researchers instead ...

### Exploding stars prove Newton's gravity unchanged over cosmic time

(Phys.org) —Australian astronomers have combined all observations of supernovae ever made to determine that the strength of gravity has remained unchanged over the last nine billion years.

### New measure of gravitational constant higher than expected

(Phys.org) —A trio of researchers working in France, along with a colleague from the U.K. has re-measured the gravitational constant using the same apparatus they built 12 years ago and have found a small change. In their ...

### Searching for dark energy with the whole world's supernova dataset

The international Supernova Cosmology Project (SCP), based at the U.S. Department of Energy's Lawrence Berkeley National Laboratory, has announced the Union2 compilation of hundreds of Type Ia supernovae, the largest collection ...