August 15, 2022

Physicists have devised a way to see the elusive 'abnormal effect' in the lab

Physicists have devised a way to see the elusive ‘abnormal effect’ in the lab

Image of the article titled Physicists Have Created a Way to See

Clarification: Carl Gustafson

A team of physicists say they did They discovered two properties of accelerating matter that they believe could make an unprecedented type of radiation visible. newly described The properties mean that monitoring the radiation – called the Unruh effect – can happen in a tabletop lab experiment.

The Unruh effect in nature theoretically requires an absurd amount of acceleration to be visibleand because it is only visible from the perspective of an object accelerating in a vacuum, it is essentially impossible to see. But thanks to recent advances, it may be possible to watch the Unruh effect in a lab experiment.

In the new research, a team of scientists describe two previously unknown aspects of the quantum field that may mean that the Unruh effect can be observed directly. The first is that the effect can be potentiated, which means that a typically weak effect can be tempted to become more pronounced under certain conditions. The second phenomenon is that a sufficiently accelerated atom can become transparent. The team’s research was published This spring in physical review letters.

The Unruh effect (or the Fulling-Davies-Unruh effect, so named for the physicists who first proposed its existence in the 1970s) is a phenomenon predicted by quantum field theory, which states that an entity (whether a particle or spacecraft) accelerating in a vacuum will Glow – though that glow won’tbe visibleyes Any external observer is also not accelerating in a vacuum.

“What the acceleration-induced transparency means is that it makes the Unruh Effect detector transparent to daily shifts, due to the nature of its motion,” Barbara Chuda, a physicist at the University of Waterloo and lead author of the study, said in a video call. with Gizmodo. Just as Hawking radiation is emitted by black holes while their gravity pulls particles, so the Unro effect is emitted by objects as they accelerate through space.

There are several reasons why the Unruh effect has not been directly observed. First, the effect requires a ridiculous amount of linear acceleration; To reach a temperature of 1 K, at which the accelerating observer sees the glow, the observer It must be acceleratedGV 100 quintillion meters per square second. Glow Thermal Unruh Effect; If the object is accelerating faster, the glow temperature It will be warmer.

Previous methods of observing the effect of Unruh suggested. but this The team believes they have a compelling chance of observing the effect, thanks to their findings About the properties of the quantum field.

“We want to build a customized experiment that can unambiguously reveal the Unruh effect, and then provide a platform for studying various relevant aspects,” said Viveshek Sudhir, a physicist at MIT and co-author of the latest work. “Unambiguously is the key characteristic here: in a particle accelerator, it is really groups of particles that are being accelerated, which means that inferring the very precise Unruh effect from the medium of the various interactions between particles in a group becomes very difficult.”

Sudhir concluded, “In a sense, we need to make a more precise measurement of the properties of a single, well-defined accelerating particle, which is not the purpose for which particle accelerators were made.”

Hawking radiation is expected to be emitted from black holes, such as these two imaged by the Event Horizon Telescope.

Hawking radiation is expected to be emitted from black holes, such as these two imaged by the Event Horizon Telescope.
picture: EHT Collaboration

The core of their proposed experiment is to induce the Unruh effect in a laboratory setting, using an atom as a detector for the Unruh effect. By blasting a single atom with photons, the team would raise the particle to a higher energy state, and its transparency caused by the acceleration would muffle the particle to any everyday noise that would muddle the presence of the Unruh effect.

By inducing the particle with a laser, “you will increase the probability of seeing the Unruh effect, and the probability will increase by the number of photons in the field,” Oda said. “And that number can be huge, depending on how powerful your laser is.” In other words, because the researchers could strike with particle quadrillion shotons, they increase the probability of an Unruh effect by 15 orders of magnitude.

Since the Unruh effect is similar to Hawking radiation in many ways, the researchers believe that the two quantum field properties they recently described can be used to excite Hawking radiation and imply a gravitational transparency. Since Hawking radiation has never been observed, the Unruh effect degassing may be a step towards that A better understanding of the theoretical glow around black holes.

Of course, these results don’t mean much if the Unruh effect is not directly observable in a lab setting – the researchers’ next step. exactly when This experiment will be conducted, however, remains to be seen.

MORE: Black Hole Lab Shows Stephen Hawking Was Right, Obviously