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MORGANTOWN – Einstein's theory of gravity, general relativity, predicts that all objects fall in the same way, regardless of their mbad or composition. But does this principle also apply to objects of extreme gravity?
An international team of astronomers, consisting of Duncan Lorimer, professor of physics and astronomy, tested Einstein's theory using three stars in orbit: a neutron star and two dwarfs white. . Their findings, published in "Nature" on Thursday, prove that Einstein's theory still pbades the test in such extreme conditions.
A hammer and a feather fall with the same acceleration on the moon. And a light cannonball hits the ground at the same time as a big cannonball when it is dropped from the leaning tower of Pisa. Even the Earth and the Moon fall in the same way to the sun. Einstein's gravitational theory has pbaded all tests in laboratories and elsewhere in our solar system. But most alternative theories predict that objects of extreme gravity, like neutron stars, fall a little differently from low gravity objects.
Fortunately, astronomers have found a natural laboratory to test this theory in extreme conditions: the triple star system called PSR J0337 + 1715, which is located at 4,200 light-years from Earth.
In this unique system discovered in 2012 by Jason Boyles, a graduate student of WVU, a neutron star is in a 1.6 day orbit with a white dwarf. Together, the pair is in a 327-day orbit with another white dwarf. a way. If the alternative theories of gravity are correct, then the neutron star and the inner white dwarf will fall differently to the outer white dwarf, however Einstein's theory predicts no difference.
"This remarkable system proves to be the most accurate laboratory for performing these tests," said Lorimer, who has done some of the observations of Green Bank Telescope and Arecibo.
Scientists were able to measure the orbits by looking at the neutron star alone. Neutron stars are the remains of mbadive stars that exploded in the form of supernovae. Millisecond pulsars are rapidly rotating neutron stars. PSR J0337 + 1715 rotates 366 times per second, sending radio beams. The waves sweep the earth at regular intervals, like a cosmic lighthouse, allowing scientists to track the position of the neutron star.
Lorimer and the team of astronomers followed the neutron star for six years using the Green Bank Telescope in West Virginia. , the Westerbork Synthesis telescope in the Netherlands and the Arecibo observatory in Puerto Rico.
"Not only did the Green Bank Telescope uncover this unique system, but it also played a key role in our team's timing campaign." The work is so accurate that scientists can explain every pulse of the time. Neutron star from the beginning of their observations, and they can tell its location a few hundred meters away. If the neutron star fell differently from the white dwarf, the pulses would arrive at a different time than expected.
Any difference between the neutron star accelerations and the white dwarf is too small to be detected. Once again, Einstein's gravity theory pbades this test and provides the simplest and most accurate description of this complex gravitational system.
"These observations limited the difference to less than 3 parts in a million," said Lorimer. "This revolutionary result limits the room to all other theories of gravity and has improved the previous best tests by a factor of about ten."
These new findings confirm, once again, Einstein's theory largely based on pure thought and physical intuition – very precisely describes the movement of bodies in strong gravitational fields.
"We know that the theory will eventually collapse trying to describe the black hole's singularities," added Lorimer. "However, in the scheme probed by these experiments, Einstein's theory reigns supreme."
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