The general theory of relativity is, probably, Einstein’s most popular scientific finding. Since he found it in 1915, researchers have been trying to prove it right. So far, they could confirm it applied to our solar system, but nothing about the rest of the universe. Now, a team of researchers from the University of Portsmouth showed the theory was true even outside of the Milky Way.
Does general relativity apply to other galaxies outside the solar system?
Einstein brought one of the most revolutionary scientific theories when he explained general relativity. Through it, he made the understanding of gravity a lot easier, making it simpler for us to grasp the concept of the universe.
Soon after Einstein discovered this theory, researchers were able to test this theory and prove it true. However, this only applied to our solar system. The first experiment of the kind occurred in 1919, during a solar eclipse. Back then, scientist Arthur Eddington could measure the curvature made by our solar system near the sun.
However, there was no one who attempted to test the theory of relativity beyond our Milky Way. Now, researchers have decided to prove gravity obeys the general relativity principles even in a different galaxy. For this, they have used observations from two important telescopes, the Hubble Space Telescope and the Very Large Telescope.
The gravitational lensing effect proved Einstein true
To test gravity in this distant galaxy, researchers used another galaxy nearby and produced gravitational lensing. Through this phenomenon, the light coming this distant galaxy towards Earth first has to pass this second galaxy. Since it appears between the two, it works as a lens and distorts the light.
According to the theory of relativity, big objects, like galaxies, should distort space-time. Therefore, if its light passes another galaxy on its way, then it should suffer a deformation. This is precisely what gravitational lensing is.
Researchers were able to measure the mass of the galaxy that was closer to our planet. Then, they compared these results with their observations on gravitational lensing. In the end, they could measure how gravity acted in the distant galaxy, obtaining major results. This way, they proved that general relativity works everywhere in the universe.
The study on the theory of relativity was published in the journal Science.
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