Microscope satellite proves that Galileo and Einstein are right

For a long time (like Galileo) we knew that one kilogram of lead falls at the speed of a feather – if no force other than gravity applies to it, for example air friction, what you get in a vacuum. However, between 2016 and 2018, a satellite, Microscope, in orbit at an altitude of 710 km, tested this four-hundred-year-old certainty by repeating object-fall experiments.

The verdict was issued on Wednesday, September 14, in twelve articles in Arabic physical review messages And the Classical and quantum gravityAnd the Obvious: Galileo was right.

The difference in acceleration between two objects in free fall is less than 10^-15th.

And not a little. His observation remains true, just as the researchers were able to verify: the difference in acceleration between two objects in free fall is less than 10^-15th. Keep in mind the accuracy with which one can detect weight“Half a microgram flies on a 500,000-ton supertanker”.

Manuel Rodrigues, project manager and member of the National Office for Aerospace Studies and Research (Onera), used the image, which came to salute an unprecedented record, during a press conference on Wednesday.

Galileo measured a difference of up to a thousand parts (10 .).^-3). The result obtained is also a hundred times better than that provided by other measurements made on Earth in 2007, and ten times better than the initial conclusions of Microscope in 2017.

Another victory for general relativity

With this accuracy, Albert Einstein was right. To develop his famous theory of general relativity, in 1915, he raised Galileo’s observation as a fundamental principle: a falling body is like an accelerating body. Gravity and acceleration are equivalent.

But the experiment was not dedicated to the history of science, but to its future. The researchers wanted to see if Einstein and others had overlooked microscopic forces, and whether they would slow or speed up the blocks. This contraption is not very reckless, as there is already evidence that general relativity does not explain everything, for example the abnormal rotation of galaxies or the acceleration of the expansion of the universe. The substitution theory would almost certainly be synonymous with new forces or particles.

Construction of a 300-kilogram satellite for the National Center for Space Studies (CNES), designed by Onera and whose data was analyzed by the Côte d’Azur observatory together with a large number of researchers from the National Center for Scientific Research (CNRS), twenty-five years ago, with the aim of finding an obstacle in the equivalence principle.

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