Every time you take a step, the space itself glows with soft warmth.
Called Fulling-Davis-Unru effect (or sometimes just the Unru effect if you run out of time), it’s a horrible glow of radiation coming out of a vacuum, like a mysterious Hawking radiation what is thought to surround black holes.
Only then is it a product of acceleration, not gravity.
Don’t you feel it? There is a good reason for this. You will need to move at an impossible speed to feel even the faintest rays of Unru.
At the moment, the effect remains a purely theoretical phenomenon that is far beyond our ability to measure. But that may soon change with the discovery of researchers from the University of Waterloo in Canada and the Massachusetts Institute of Technology (MIT).
Returning to the basics, they demonstrated that there could be a way to stimulate the Unru effect so that it could be studied directly in less extreme conditions.
In an unexpected turn, they could also reveal the secret of turning matter into invisibility.
The real reward, however, would be the discovery of new ground in experiments that aim to combine two powerful but incompatible theories in physics – one that describes how particles behave and the other covers the curvature of space and time.
“Theory general theory of relativity and the theory of quantum mechanics is still somewhat divergent at the moment, but there must be a unifying theory that describes how things function in the universe. ” I say mathematician Achim Kempf of the University of Waterloo.
“We’ve been looking for a way to combine these two great theories, and this work is helping to come together, opening up opportunities to test new theories against experiments.”
The Unru effect is right on the border of quantum laws and general relativity.
According to quantum physics, an atom that is alone in a vacuum would have to wait for an incoming photon to slip through the electromagnetic field and give its electrons a jitter before it can consider itself illuminated.
If we consider the theory of relativity, there is a way to deceive. Simply accelerating, the atom can experience the slightest oscillations in the surrounding electromagnetic field in the form of low-energy photons converted by a kind of Doppler effect.
This interaction between the relative experience of waves in a quantum field and the oscillation of atomic electrons is based on the total time in their frequencies. Any time-independent quantum effects are usually ignored, on paper they tend to be balanced in the long run.
Together with colleagues Vivisek Sudhir and Barbara Soda, Kempf showed that when an atom accelerates, these usually insignificant conditions become much more significant and may in fact become dominant effects.
By tickling the atom in the right way, for example with a powerful laser, they showed that you can use these alternative interactions to make moving atoms feel the Unru effect without the need for large accelerations.
As a bonus, the team also found that with the right trajectory, the accelerating atom could become transparent to incoming light, effectively suppressing its ability to absorb or emit certain photons.
In addition to science fiction applications, by identifying ways to influence the ability of the accelerating atom to interact with ripples in a vacuum, we may be able to come up with new ways to find where quantum physics and general relativity give way to a new theoretical basis. .
“For more than 40 years, experiments have been hampered by the inability to explore the interface between quantum mechanics and gravity,” I say Sudhir, a physicist at the Massachusetts Institute of Technology.
“We have the opportunity to explore this interface in the lab. If we can figure out some of these big issues, it could change everything.”
This study was published in Physical review letters.