Science cartoon based on Gravitational constant is universal constant.

Science cartoon based on Gravitational constant is universal constant.

Four fundamental forces are electromagnetic, strong nuclear, weak nuclear and gravitational. There was a century old question in cosmology: Is the force of gravity the same everywhere and at all times? According to Scott Ransom, an astronomer with the National Radio Astronomy Observatory in Charlottesville, Va. "Though it appears on Earth to be constant and universal, there are some theories in cosmology that suggest gravity may change over time or may be different in different corners of the Universe.".

Till now, astronomer were conforming the gravitational constant within our solar system. Astronomers used the National Science Foundation's (NSF) Green Bank Telescope (GBT) in West Virginia and its Arecibo Observatory in Puerto Rico and studied the pulsar PSR J1713+0747 for 21-years and measured various parameters very precisely. Study of the said pulsar and associated white dwarf star revealed that the gravitational constant is not changing. This is the first time that the conformity test of gravitational constant is tested out of our solar system. Thus it can be said Gravitational constant is universal constant.

Reference: http://www.sciencedaily.com/releases/2015/08/150806144557.htm