A 21-year study of a distant pulsar is confirming that the gravitational constant is indeed constant, all throughout the universe. "Gravity is the force that binds stars, planets, and galaxies together," noted study co-author Scott Ransom from the National Radio Astronomy Observatory in Charlottesville, Va. in a statement, according to io9. "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."
Astronomers used the National Science Foundation's (NSF) Green Bank Telescope (GBT) in West Virginia and its Arecibo Observatory in Puerto Rico to conduct the study on the pulsar known as PSR J1713+0747.
The pulsar is estimated to be 3,750 light-years away from Earth. It is one of the brightest and most stable pulsars known to scientists.
It orbits a white dwarf star, and it was noted that it completes its orbit cycle for a constant 68 days. This means that the pulsar and the dwarf star share an uncommonly wide orbit, making it the perfect pulsar to use for the confirmation of the gravitational constant.
"The uncanny consistency of this stellar remnant offers intriguing evidence that the fundamental force of gravity - the big 'G' of physics - remains rock-solid throughout space. This is an observation that has important implications in cosmology and some of the fundamental forces of physics," said Weiwei Zhu, an astronomer formerly with the University of British Columbia in Canada, Astronomy Now reports.
"The gravitational constant is a fundamental constant of physics, so it is important to test this basic assumption using objects at different places, times, and gravitational conditions," added Zhu. "The fact that we see gravity perform the same in our solar system as it does in a distant star system helps to confirm that the gravitational constant truly is universal," Discovery News reports.
The study is published in Astrophysical Journal.
