The Math Adds Up: How to Create and Manipulate Gravity

January 14, 2016 | Joanne Kennell

two sense white dwarf stars orbit each other as a result of general relativity, releasing gravitational waves
Photo credit: Tod Strohmayer/NASA (CC0)

Maybe this is how we can study Einstein’s gravitational waves.

There was a rumor going around this week that the world’s largest gravitational-wave observatory had, for the first time ever, directly detected gravity waves.  And it turns out, that’s exactly what is was.  A rumor.  

Gravitational waves are ripples in spacetime that are produced by massive objects or bodies accelerating through spacetime — such as a pair of neutron stars orbiting each other or the merging of two black holes.  These waves were predicted nearly a century ago as part of Einstein’s theory of general relativity, but have never been directly detected.

Gravity is the last of the four fundamental forces — weak, strong, electromagnetic and gravitational — that humans have not figured out how to produce and control.  But that may be about to change.  André Füzfa, a mathematician at the University of Namur in Belgium, recently published a paper proposing how we can do just that — but only in tiny, tiny amounts.

SEE ALSO: Wrinkles in Spacetime: The Quest to Detect Gravitational Waves

Nevertheless, the ability to produce even small gravitational fields is monumental from a scientific perspective, because it would allow researchers to really test Einstein’s general theory of relativity, including those elusive gravitational waves.

“Somehow, studying gravity is a contemplative activity: physicists restrict themselves to the study of natural, pre-existing, sources of gravitation,” writes Füzfa in his paper.  “Generating artificial gravitational fields, that could be switched on or off at will, is a question captured or left to science-fiction.”

Amazingly, Füzfa’s new theory uses technology already in use today.  Superconducting electromagnets, like those used in the Large Hadron Collider, generate controlled and very strong magnetic fields that would allow physicists to observe how they manipulate spacetime.

Although his method has not yet been tested, the math behind the theory appears to add up, and the calculations have been published in the journal Physical Review D.  It is based on something called the equivalence principle — at the center of Einstein’s general theory of relativity — which states that all types of mass and energy are affected by gravitational fields in the same way.  This means that electromagnetic fields should, theoretically, curve spacetime just like the sun or a black hole would.

SEE ALSO: Mysterious Radio Signals Now Used to Test Einstein’s Equivalence Principle

Although these fields would be very small here on Earth, superconducting electromagnets should be able to produce a very weak gravitational field that could be detected using very sensitive interferometers.  Interferometers work by superimposing gravitational fields on top of each other, allowing physicists to get information about them.

The only problem with this idea is that it would be extremely expensive and difficult to do.  However, it could lead to new technology based on gravity instead of electromagnetic waves.  “Until now, a scientific advance like this was a dream of science fiction, but it could open up many new applications, for example, in the field of telecommunications with gravitational waves,” said the University of Namur.  “Imagine calling the other side of the world without going through satellite or terrestrial relays.”

What do you think?  Is it worth spending a lot of money on something based only on mathematical proofs and the possibility of being able to create and manipulate the last of the fundamental forces?  I think so!

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