Welcome to brain stuff from how stuff Works. Hey, brain stuff, it's Christian Sager. Scientists always seem to be finding new evidence of Albert Einstein being right. The latest example comes from astronomers using the European Southern Observatories very large telescope in Chile. Astronomers there have been studying the stars that orbit dangerously close to the supermassive black hole in the center of our galaxy. To find that you guessed it.
Einstein's landmark theory of general relativity is holding strong even at the doorstep of the most extreme gravitational field in our galaxy. Most galaxies are known to have super massive black holes lurking in their cores. In our galaxy, the
Milky Way is no different. Located approximately twenties six thousand light years from Earth, our black hole behemoth is called Agittarius A, and it has a mass four million times that of our Sun. Astrophysicists are hugely interested in black holes, as they're the most compact, gravitationally dominant objects known in
the universe, and therefore an extreme test for relativity. By tracking the motion of stars orbiting close to Sagittarius A, a team of German and Czech astronomers have analyzed twenty years of observations made by the Very Large Telescope and other telescopes using a new technique that pinpoints the positions
of these stars. One of the stars, called S two orbits Sagittarius A every sixteen years and zooms very close to the black hole, around four times the distance between Neptune and our Sun. Because of its racetrack orbit deep inside the black holes gravitational well S two is treated as a natural relativity probe into this mysterious strong gravity environment.
By precisely measuring its motion around the black hole, the researchers could compare its orbit with predictions laid out by classical Newtonian dynamics, and they found that the star's actual orbit deviated from Newtonian predictions exactly as predicted by Einstein's general relativity, although the effect was slight. Here's a quick example of Einsteinian gravity at work. If you have a massive object, it will bend spacetime, like the famous example
of the bowling ball suspended on a rubber sheet. If another object travels past the massive object, the curvature of space time will deflect its direction of motion like a
marble rolling past the bowling ball. Now in two thousand and eighteen, S two will swoop to its closest point in its orbit around Sagittarius A, and astronomers using the Very Large Telescope are preparing a new instrument to get an even more precise view of the extreme environment surrounding the black hole, called gravity and that's gravity in all caps.
The instrument is installed on the Very Large Telescopes Interferometer, and astronomers not only predict that it will get an even more precise gauge on Einstein's general relativity, it might even detect deviations away from relativity, possibly hinting at new physics beyond relativity. Today's episode was written by Ian O'Neill, produced by Dylan Fagan, and for more on this and other topics, don't forget to visit how Stuff Works dot com.