Scientists proved that Einstein's gravitational principle applies even under the most extreme conditions. A neutron star and a white dwarf, 4,500 light-years from Earth, still fall at the same time, even with different masses. ( NRAO / AUI / NSF; S. Dagnello )
Dropping a bullet and bowling ball from the 44th floor of a Manhattan skyscraper falls at the same time. 1
This has long been demonstrated in celestial objects in the solar system. For example, the earth and Jupiter "fall" to the sun at the same speed, although they have very different masses. Astronomer Dave Scott demonstrated this with a hammer and a spring falling on the moon at the same speed.
Even under the most extreme conditions, the principle stands. This has been demonstrated by a team of international researchers after rigorous observations of the behavior of a rare star system only 4,200 light-years from Earth.
Rare Three-Star System Proves Equivalence Principle
The National Science Foundation's Green Bank Telescope In West Virginia, the star system first discovered only 4,200 light-years from Earth in the constellation of Taurus. Scientists have named it the PSR J0337 + 1715 star system, which consists of a neutron star in a 1.6-day orbit around a white dwarf. Both are also in a 327-day orbit around a second distant white dwarf.
A neutron star is the remnant of a star after it explodes and collapses. It's usually never bigger than a city on earth, but it contains the same amount of mass as the sun. A tablespoon of a neutron star is about as heavy as Mount Everest.
Due to its extreme density, a neutron star has a strong gravitational field, making it one of the most extreme environments for testing Einstein's gravitational principle. The existence of two white dwarfs is increased.
White dwarfs are small stars the size of a planet. A white dwarf is a star that has consumed all its fuel, leaving only a hot core. White dwarfs typically have one-fifth of the sun.
Because they do not have as much gravitational force as neutron stars, the researchers found it fascinating to find two white dwarfs near a neutron star. Not many objects can survive the explosive death of a star.
"This is a unique star system," says co-author Ryan Lynch of the Green Bank Observatory in West Virginia. "We do not know any others that are so similar, which makes it a unique laboratory to test Einstein's theories."
Studying the Radio Pulses of a Neutron Star
In a New Paper In the journal Nature, the researchers found that the inner stars are accelerated at the same speed, providing the most accurate proof of gravity, as Einstein described it. They also observed that the second White Dwarf in no way affected the movement of the inner stars.
The researchers came to this conclusion by studying the movements of the neutron star. When a neutron star rotates, it becomes a pulsar. This emits radio waves, X-rays and even visible light as it rotates.
This pulsar rotates in particular with a very fast speed of 366 revolutions per second. The Pulsar emits radio wave pulses with each rotation that can be detected on Earth using advanced radio equipment.
Over a period of six years, researchers using the Westerbork Synthesis Radio Telescope observed the movement of the pulsar in the Netherlands the Arecibo Observatory in Puerto Rico and the Green Bank Telescope
"We can detect every single momentum of the neutron star since the beginning our observations, "said author Anne Archibald of the University of Amsterdam and the Dutch Institute of Radio Astronomy. "We can pinpoint his position to a few hundred meters, which is really an accurate trace of where the neutron star was and where it is going."
When the pulsar rotates faster, it sends more impulses, which means a more precise tracking of its location. If it accelerates at a different speed than the White Dwarf, the researchers would have seen the pulses arrive at different times than they expected. This was not the case.
In fact, the difference in the rate of acceleration between the pulsar and the white dwarf is so small that it is almost impossible to detect. The researchers say the difference is no more than three parts in 1 million.
Alternative Theories of Gravity
Einstein described gravitation as a curve in space-time that follows objects as they "fall" on top of each other. This can be demonstrated in the curved orbit of the moon around the earth and the planets around the sun.
However, some experts are not convinced that gravity is a curve. For this reason, they have proposed alternative theories that could explain how gravity behaves under extreme conditions.
The latest research, however, makes it much harder to disprove Einstein's predictions. The researchers acknowledge that their results are not incontrovertible proof of Einstein's gravity. Objects on very, very small levels, for example, still have to reveal how they relate to gravity.
"We have achieved better results than previous tests by a factor of 10 with this system," says co-author and physicist David Kaplan of the University of Wisconsin-Milwaukee. "But it's not an iron answer, reconciling gravity with quantum mechanics is still unresolved."
Watch: 30 Gadgets and Technical Gifts for Father's Day 2018 This Father Will Think Are Rad
All Rights Reserved. Do not reproduce without permission.