The 16-year experiment was conducted to challenge Einstein's theory of general relativity. The international team looked to the stars through seven radio telescopes across the globe. The Max Planck Institute for Radio Astronomy is a credit.
Researchers at the University of East Anglia and the University of Manchester helped conduct a 16-year long experiment to challenge Einstein's theory of general relativity.
The international team looked to the stars through seven radio telescopes.
They challenged Einstein's most famous theory with some of the most rigorous tests yet.
The study, published today in the journal Physical Review X, reveals new relativistic effects that have not been observed before.
Dr. Robert Ferdman, from UEA's School of Physics, said that Einstein's theory of general relativity is not the final word in gravitational theory.
Scientists around the world are still trying to find flaws in his theory more than 100 years later.
General relativity is not compatible with quantum mechanics. To find out how and when the theory breaks down, it is important to place the most stringent tests on general relativity.
Any deviation from general relativity would be a major discovery that would open a window on new physics.
It may help us discover a unified theory of nature.
The international team of researchers from ten countries put Einstein's theory to the most rigorous tests yet, led by Michael Kramer from the Max Planck Institute for Radio Astronomy in Bonn, Germany.
A rotating compact star called a pulsar emits beams of radiation out of its magnetic poles.
They are so dense that they produce radio beams that sweep the sky like a lighthouse because they are only 15 miles across.
The most precise laboratory we currently have to test Einstein's theory was studied by the team, which discovered a double pulsar. His theory was conceived when the techniques used to study them were not possible to imagine.
The double pulsar is a pair of pulsars which are in motion in just over an hour. A pulsar is spinning fast. The companion is young and has a short rotation period. It is their motion around each other that can be used as a gravity laboratory.
In Australia, the US, France, Germany, the Netherlands, and the UK, seven radio telescopes were used to observe this double pulsar.
The 16-year experiment was conducted to challenge Einstein's theory of general relativity. The international team looked to the stars through seven radio telescopes across the globe. The Max Planck Institute for Radio Astronomy is a credit.
The system of compact stars was studied to see if gravity theories could be tested in the presence of strong fields.
We were able to test a cornerstone of Einstein's theory, the energy carried by gravitational waves, with a precision that is 25 times better than with the prize winning Hulse-Taylor pulsar, and 1000 times better than currently possible with the detectors.
He said that the observations are in agreement with the theory and that they were able to see effects that could not be studied before.
Prof Benjamin Stappers, from the University of Manchester, said that the double pulsar system was discovered as part of a survey and presented with the only known instance of two cosmic clocks which allow precise measurement of the structure and evolution of the system.
The Jodrell Bank Observatory has been watching it for a couple of weeks. An excellent data set was provided by this long baseline of high quality and frequent observations.
Prof Ingrid Stairs from the University of British Columbia at Vancouver said that they follow the propagation of radio photons emitted from a Cosmic lighthouse, a pulsar, and track their motion in the strong gravitational field of a companion pulsar.
The 16-year experiment was conducted to challenge Einstein's theory of general relativity. The international team looked to the stars through seven radio telescopes across the globe. The Max Planck Institute for Radio Astronomy is a credit.
The light is delayed due to a strong curvature of spacetime around the companion, but also that the light is diverted by a small angle of 0.04 degrees that we can detect. This is the first time that an experiment has been conducted at such a high spacetime curve.
Prof Dick Manchester from Australia's national science agency, the Commonwealth Scientific and Industrial Research Organisation, said: "These objects are 30 percent more massive than the Sun but only 24 km across, and they allow us to test many different predictions of general relativity!"
Our precision allows us to measure the effect of time dilation that makes the clock run slower in a field of gravity.
Einstein's famous equation E = mc2 needs to be taken into account when considering the effect of the radiation on the motion of the pulsar.
This radiation is equivalent to a mass loss of 8 million tonnes per second. It is only a tiny fraction of the mass of the pulsar per second.
The researchers measured the effect of the orbit changing its orientation with a precision of 1 part in a million.
They realized that at this level of precision they need to consider the impact of the rotation on the surrounding spacetime.
The main author of the study said that physicists call it the Lense-Thirring effect or frame-dragging. In our experiment, we need to consider the internal structure of a pulsar as a neutron star.
For the first time, we can use the precision tracking of the rotation of the neutron star, a technique called pulsar timing, to provide constraints on the extension of a neutron star.
A value of 2400 light years was achieved with the combination of the technique of pulsar timing and interferometric measurement of the system.
Prof Adam Deller, a member of the team, said that the combination of different observing techniques adds to the extreme value of the experiment. The studies were often hampered by the lack of knowledge of the systems.
This is not the case, where the information gained from effects due to the interstellar medium were taken into account.
The University of California San Diego's Prof Bill Coles said that they gathered all possible information on the system and created a consistent picture using physics from many different areas. This is extraordinary.
The results of our study are in line with other experimental studies which test gravity in other conditions or see different effects.
The timing experiment with the pulsar in a stellar triple system has provided an independent and superb test of the universality of free fall.
"We have reached a level of precision that is unprecedented," said Prof. Kramer. Future experiments with even bigger telescopes will go further.
Our work shows the way such experiments need to be conducted and which effects need to be taken into account. One day, we might find a deviation from general relativity.
The Physical Review X has a paper titled "strong-field Gravity Tests with the Double Pulsar".
The Double Pulsar, Physical Review X has more information.
The Physical Review X is in the journal.
Challenging Einstein's greatest theory with extreme stars was retrieved fromphys.org on December 13, 2021.
The document is copyrighted. Any fair dealing for the purpose of private study or research cannot be reproduced without written permission. The content is not intended to be used for anything other than information purposes.
