Physics laboratory in space

Einstein’s general relativity is amazingly durable – astrophysicists have now re-established with unprecedented precision

The physics laboratory, which michael kramer has chosen from the university of manchester and its domestic colleagues worldwide, is not tailored to public transport. Kramer will only be able to see his life from afar. And that’s a good thing, because the chance to survive on a neutron star, even in the optimistic case goes against zero. In addition, the arrival took unreasonably long – with lighting speed up to 2000 years. The study object, which the scientific team has chosen around kramer, is called psr j0737-3039. It was only three years ago discovered and is the first known star system, in which two pulses around each other.

That it is so well suited as a test laboratory for einstein’s general relativity (and in particular the detection of space-time crumminess caused by gravity, lies on the extreme conditions that prevail there. As special neutron stars have the two components of psr j0737-3039 despite about one and a half-fold solar masses only a diameter of 20 kilometers, they are superconducting and suprafluid and turn (at a distance, the approximately double earth moon distance corresponds) in just 2.4 hours around the common focus.

Artistic representation of the double pulse system psr j0737-3039. The picture is not mabstapsfreiter: if you introduce yourself to the two pulsars in the mumble groove, they had to be 225 meters apart from each other. Nevertheless, the massive objects turn into only 2.4 hours around each other – the earth needs for a rounding of the sun a whole year.

In the current ie of the science magazine science, kramer and colleagues now report on their quantities of the pulsar system carried out in recent years (doi: 10.1126 / science.1132305). To do this, they have the recorded movement data of the system to press them from the outset into a particular theory system, structured in kepler and einstein shares – and in fact, the einstein shares with a previously unrivaled accuracy of 0.05 percent of the theoretical predictions.

This has succeeded in scientists, although their knowledge is not even complete on the parameters of psr j0737-3039 – the exact masses of the two pulses do not know them, for example, only their mass ratio. If the researchers will succeed in the future, so hope to measure further rail parameters pracisse, even einstein shares of higher order could be further prove.

On the ground, however, the evidence of albert einstein published in 1916 is not so pracisse to drove. This is lacking, because otherwise the physicists have already noticed much rather that the connection between mass and exercise do not fully describe with newton and kepler. Relativistic effects such as the time at break play in our lives only in a subjective way (approximately when waiting for the s-bahn).

Already the first targeted checking of general relativity was therefore a solar eclipse – it enforced with a deviation of all 20 percent that the light of a star is distracted by massive objects (the sun). The timing caused by gravity, on the other hand, could be tested with aircraft, which carried extremely exact timepieces around the earth. In principle, it was also revealed to build a tower with two clocks on the basis and lace – as a surcharge calculation shows, the clock is at the top of a 1000 meter high tower on earth after a million years by 3.44 seconds.