JAN 12, 2018 11:00 AM PST

Einstein Could've Given The Thumbs-up to This Space Version of Galileo's Classic Experiment

WRITTEN BY: Daniel Duan

The Micro-Satellite à traînée Compensée pour l'Observation du Principe d'Equivalence (MICROSCOPE) is a mini-satellite operated by French space agency CNES to test the universality of free fall. Credit: CNES/VIRTUAL-IT 2017

If Einstein is still alive today, he could have been delighted to know that his theory of general relativity (GR) has been proven right again. A European research satellite (the Micro-Satellite à traînée Compensée pour l'Observation du Principe d'Equivalence, a.k.a. MICROSCOPE) has conducted a version of the famous falling bodies experiment designed Galileo Galilei. The precise measurement from this study confirmed the so-called "equivalence principle" of Einstein’s theory.

According to the traditional account (which is heavily debated to these days), Galileo conducted the famous "free fall" experiment from the top of the leaning tower of Pisa, in order to refute the Aristotelian notion, which states that heavier objects fall faster than light ones. He dropped two balls of different weight and observed that both hit the ground at the same time. He concluded that no matter how heavy objects weigh, as long as they are attracted by the same gravity and start their descend at the same speed, they would reach the ground at the same time/speed. This unique property of gravity was one of the motivations for Einstein's general theory of relativity.

The CNES scientists have conducted experiments to verify the universality of free falls on the MICROSCOPE satellite. Instead of balls, the researchers used two hollow cylinders to perform free-falling inside the satellite. Their experiment lasted over 120 orbits of Earth, or eight days worth of time. The rates acceleration of the two cylinders matched so well that they were only a two-trillionths of a percent (that is 2*10^-15) in relative difference.

The MICROSCOPE study results verified the equivalence principle of GR. According to the equivalence principles, an object’s inertial mass, which determines the amount of force needed for acceleration, is equal to its gravitational mass—the characteristic of an object in the gravitational field. Things fall at the same rate in a vacuum, according to the principle, even if they have different masses.

Another objective of this seemingly simple experiment is to measure accelerations with high precision. There have been predictions that the equivalence principle could be violated to some extent under certain circumstance. Understanding if that’s true could hold the key to reconciling general relativity with quantum mechanics, which physicists have been working on for decades.

The findings of the MICROSCOPE experiments were published in Physical Review Letters last December.  

Equivalence Principle. Credit: Bozeman Science

Source: bigthink

About the Author
  • Graduated with a bachelor degree in Pharmaceutical Science and a master degree in neuropharmacology, Daniel is a radiopharmaceutical and radiobiology expert based in Ottawa, Canada. With years of experience in biomedical R&D, Daniel is very into writing. He is constantly fascinated by what's happening in the world of science. He hopes to capture the public's interest and promote scientific literacy with his trending news articles. The recurring topics in his Chemistry & Physics trending news section include alternative energy, material science, theoretical physics, medical imaging, and green chemistry.
You May Also Like
FEB 01, 2021
Chemistry & Physics
Presence of plasma inhibits ultra-relativistic energies in solar storms
FEB 01, 2021
Presence of plasma inhibits ultra-relativistic energies in solar storms
A study published in the journal Science Advances reports new measurements from NASA's Van Allen Probes spacecraft. ...
FEB 23, 2021
Chemistry & Physics
Converting methane in natural gas into liquid methanol at room temperature
FEB 23, 2021
Converting methane in natural gas into liquid methanol at room temperature
New research detailed in the journal Proceedings of the National Academy of Sciences describes a recent development ...
MAR 04, 2021
Chemistry & Physics
The magic vibrational powers of frog lungs
MAR 04, 2021
The magic vibrational powers of frog lungs
Ever tried picking someone up at a loud, crowded bar? It’s not easy – not only may they not hear your fabulo ...
MAR 10, 2021
Chemistry & Physics
Where does the energy go in singlet fission?
MAR 10, 2021
Where does the energy go in singlet fission?
New research from scientists at Linköping University, Sweden, describes a recent discovery revealing where the ener ...
MAR 31, 2021
Clinical & Molecular DX
A Non-Invasive Look at Fat Distribution in the Liver
MAR 31, 2021
A Non-Invasive Look at Fat Distribution in the Liver
The build-up of fat inside the liver is a worrying sign that points to the possibility of conditions such as nonalcoholi ...
JUN 11, 2021
Chemistry & Physics
Cutting-edge wearables: the next generation of electronics
JUN 11, 2021
Cutting-edge wearables: the next generation of electronics
New research published in Applied Physics Reviews from AIP Publishing considers the development of flexible supercapacit ...
Loading Comments...