Galileo's free-falling objects experiment passes space test further proving equivalence principle

December 5, 2017 by Bob Yirka, Phys.org report
Galileo's free-falling objects experiment passes space test further proving equivalence principle
Credit: CNES/D. Ducros

A team of researchers from the French Aerospace Lab and at the Côte d'Azur Observatory working on France's MICROSCOPE satellite project has further confirmed the equivalence principle by recreating Galileo's free-falling objects experiment in a satellite. In their paper published in the journal Physical Review Letters, the group describes their experiment and why it was carried out.

Approximately 450 years ago, Galileo, as some have reported, dropped cannonballs of different sizes from the Leaning Tower of Pisa to prove that they would hit the ground at the same time. 350 years later, Einstein published his Theory Of General Relativity, which included the equivalence principle, and as Galileo demonstrated, stated that objects with different masses fall at the same rate due to gravity. In this new effort, the researchers have performed roughly the same experiment as Galileo, except they have done it in space and measured the results with far more precision.

Scientists continue to test the because they believe that if they can find a violation, it could reconcile the impasse regarding quantum theory and .

The experimental equipment aboard the MICROSCOPE consisted of one cylindrical shell set inside of another larger cylindrical shell. The cylinders were small, of course, just a few centimeters long, and were made of different materials—the inner one of platinum and rhodium, the outer from much less dense titanium and aluminum. Running the experiment in space removes factors that can disrupt gravitational force, such as water moving underground. The cylinders free fall as they move through space with an electric field present to keep them from veering from a straight downward path. Their fall is measured very precisely. Any deviations in acceleration would be seen as a change in the electrical field. The team reports that none were found. The researchers report their experiment offered 10 times the precision of previous experiments meant to do the same thing. They note that they believe it will be possible in the future to conduct the same experiment with even more precision by better controlling the temperature inside the satellite.

Explore further: Satellite to test universality of freefall

More information: Pierre Touboul et al. MICROSCOPE Mission: First Results of a Space Test of the Equivalence Principle, Physical Review Letters (2017). DOI: 10.1103/PhysRevLett.119.231101

ABSTRACT
According to the weak equivalence principle, all bodies should fall at the same rate in a gravitational field. The MICROSCOPE satellite, launched in April 2016, aims to test its validity at the 10−15 precision level, by measuring the force required to maintain two test masses (of titanium and platinum alloys) exactly in the same orbit. A nonvanishing result would correspond to a violation of the equivalence principle, or to the discovery of a new long-range force. Analysis of the first data gives
δ(Ti,Pt)=[−1±9(stat)±9(syst)]×10−15 (1σ statistical uncertainty) for the titanium-platinum Eötvös parameter characterizing the relative difference in their free-fall accelerations.

Related Stories

Satellite to test universality of freefall

April 27, 2016

France's Microscope satellite, carrying a set of ESA high-tech thrusters, lifted off last night from Europe's Spaceport in Kourou, French Guiana, taking advantage of the same Soyuz launch that took the EU's Sentinel-1B into ...

Equivalence principle in space test

May 11, 2009

Since Galileo Galilei and Newton, the assumption is valid that inert and heavy mass are equivalent. This is, however, questioned by new physical theories such as the String theory. Now, the equivalence principle is put to ...

Moonbeams Shine on Einstein, Galileo and Newton

March 6, 2005

Thirty-five years after Moon-walking astronauts placed special reflectors on the lunar surface, scientists have used these devices to test general theory of relativity to unprecedented accuracy. The findings, which also ...

Recommended for you

Turning entanglement upside down

May 21, 2018

A team of physicists from ICTP-Trieste and IQOQI-Innsbruck has come up with a surprisingly simple idea to investigate quantum entanglement of many particles. Instead of digging deep into the properties of quantum wave functions, ...

Quantum effects observed in photosynthesis

May 21, 2018

Molecules that are involved in photosynthesis exhibit the same quantum effects as non-living matter, concludes an international team of scientists including University of Groningen theoretical physicist Thomas la Cour Jansen. ...

4 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

tgmeloche
1 / 5 (3) Dec 07, 2017
Canadian Innovation

Principles of atomic gravity also agree with the equivalence principle but rules explain how gravity works in the natural world about 100 times better then the outdated theory general relativity!

Discover the principles in the google links below.

Learn, innovate, and solve the problem outside the box. Only the motivated and talented needed to apply the principles to their specific area(s) of research.

Atomic Gravity Summary

1vRTa9BoY64I0KsYrM1y7aRMONd7OrFm5RGIgPGA7PolB8hIXjF66azQOTu2yHWpl3uzw614aX6Ks-9q/pub

Zero G flight at the Atomic Scale

https://docs.goog...AbzI/pub

Canadian Innovation
mackita
1 / 5 (2) Dec 07, 2017
There is anecdotal evidence, that magnets glued in repulsive (artificial monopole) arrangement are falling more slowly (1, 2, 3). The similar effect could apply to charged capacitors, superconductors (Tajmar/Podkletnov effect) and similar systems, where the electrons are constrained in their motion, so that they're forced to interact with vacuum fluctuations more (they cannot "avoid" them so easily).
mackita
1 / 5 (1) Dec 07, 2017
The Earth is also appears to be moving at 627±22 km/s relative to the reference frame of the CMB radiation, so that the vacuum around us should exhibit drag for magnets in repulsive arrangement. This experiment was also already done with positive result by David L. Cameron and it should be consistent with DAMA/LIBRA observations.

But I don't think he will get Nobel prize in foreseeable time..
mackita
1 / 5 (1) Dec 07, 2017
The Tajmar effect could also ruin famous Gravity B experiment, which utilized spherical quartz gyroscopes covered by neodymium superconductor inside large Deward flask (superconductor is supposed to interact strongly with vacuum fluctuations). Contrary to expectations, these poor balls changed their orientation wildly and despite all preliminary measures they also did react to Sun storms and stellar wind, which rendered the experimental results nearly unusable.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.