Even 100 years after Einstein elaborated on his general theory of relativity, new observations continue to confirm its predictions,media reported. Now, Australian astronomers have found some of the best evidence of an integral part of the theory — a pair of high-density stars appearing to drag and distort the structure of space-time themselves in close orbit.
The system, known as PSR J1141-6545, consists of two “dead” stars orbiting each other. One is a white dwarf, about the size of Earth, but 300,000 times denser than Earth, and the other is a pulsar, the equivalent of 100 billion Earth-mass material, crashing into a sphere only 20 kilometers in diameter. The pulsar orbits the white dwarf every five hours, and the other two pulsars rotate very quickly.
In general relativity, gravity is the result of a large number of mass bending space-time structures. A few years after Einstein published general theory of relativity, mathematicians Joseph Rance and Hans Thirring proposed the concept of “inertial drag.” In essence, general relativity holds that rotating objects should also pull space-time together.
In most cases, this effect is so small that it is difficult to detect, and it has not been proven for more than 100 years. But now, the researchers in the new study say they have found evidence of such long-sought side effects.
Given the enormous mass released by psR J1141-6545, it is not surprising that it has become a breakthrough point. Astronomers have been using Australia’s Parkes telescope for nearly 20 years to study these objects to see how they interact over time.
It is understood that pulsars are very regular and release energy like a bar. If these pulsars reach the telescope at different times, it indicates interference somewhere in the process of reaching the signal.
After unraveling the complex physical mechanisms surrounding the system, the team concluded that pulsar signals have drifted slowly over the past 20 years. This indicates that its orbital plane is tilted gradually, possibly because of inertial drag.
So even after 100 years, general relativity passed the test because its predictions were consistent with new observations. Just a few years ago, an important aspect was finally confirmed — gravitational waves, the ripples of space caused by catastrophic events such as the merger of black holes.