Scientists reverse the arrow of time in quantum systems

A team of researchers reverses the arrow of time in quantum experiments.


It’s not quite time travel, but scientists appear to have reversed the arrow of time in quantum systems. The “arrow of time” is the concept that natural processes run forward, not in reverse. An international team of researchers was able to show that given specific conditions, heat can flow from a cold quantum particle to one that’s hotter. 

The arrow of time is derived from the second law of thermodynamics, which says that entropy increases over time. Entropy is the measure of disorder. The law explains why it’s hard to unbreak stuff or why a hot cup of tea will eventually turn cold. It just doesn’t usually work the other way. 

What the scientists found is that “the arrow of time is not an absolute concept, but a relative concept,” as says the study’s co-author Eric Lutz, a theoretical physicist at the University of Erlangen-Nürnberg in Germany. His lab was able to reverse the flow of heat in two quantum particles. They were correlated, meaning that their properties were linked, similarly to quantum entanglement but less strong. The special quality of correlated particles is that they share some information with each other. This property is not possible for bigger objects. 

The researchers, led by the physicist Roberto Serra from the Federal University of ABC in Santo André, Brazil, manipulated molecules of chloroform. These are made of carbon, hydrogen and chlorine atoms.

The scientists heated up the nucleus of the hydrogen atom more than the nucleus of the carbon and observed how the energy flowed. In an uncorrelated state, the heat flowed as expected, from hot to cold. But when the nuclei became correlated, heat flowed backwards with the hotter hydrogen nucleus getting hotter and the cooler carbon getting cooler. 

The significance of the experiment lies in demonstrating an exception to the second law of thermodynamics, which doesn’t take into account correlated particles.  

While odd behavior at the quantum level may be hard to grasp, what is more tangibly exciting is that the scientists are aiming to use these particle quirks to design super-small quantum engines.

You can read their study here.

 

 

Stand up against religious discrimination – even if it’s not your religion

As religious diversity increases in the United States, we must learn to channel religious identity into interfaith cooperation.

Sponsored by Charles Koch Foundation
  • Religious diversity is the norm in American life, and that diversity is only increasing, says Eboo Patel.
  • Using the most painful moment of his life as a lesson, Eboo Patel explains why it's crucial to be positive and proactive about engaging religious identity towards interfaith cooperation.
  • The opinions expressed in this video do not necessarily reflect the views of the Charles Koch Foundation, which encourages the expression of diverse viewpoints within a culture of civil discourse and mutual respect.
Keep reading Show less

Moon landing astronauts reveal they possibly infected Earth with space germs

Two Apollo 11 astronauts question NASA's planetary safety procedures.

Credit: Bettmann, Getty Images.
Surprising Science
  • Buzz Aldrin and Michael Collins revealed that there were deficiencies in NASA's safety procedures following the Apollo 11 mission.
  • Moon landing astronauts were quarantined for 21 days.
  • Earth could be contaminated with lunar bacteria.
Keep reading Show less

NASA's idea for making food from thin air just became a reality — it could feed billions

Here's why you might eat greenhouse gases in the future.

Jordane Mathieu on Unsplash
Technology & Innovation
  • The company's protein powder, "Solein," is similar in form and taste to wheat flour.
  • Based on a concept developed by NASA, the product has wide potential as a carbon-neutral source of protein.
  • The man-made "meat" industry just got even more interesting.
Keep reading Show less

Where the evidence of fake news is really hiding

When it comes to sniffing out whether a source is credible or not, even journalists can sometimes take the wrong approach.

Sponsored by Charles Koch Foundation
  • We all think that we're competent consumers of news media, but the research shows that even journalists struggle with identifying fact from fiction.
  • When judging whether a piece of media is true or not, most of us focus too much on the source itself. Knowledge has a context, and it's important to look at that context when trying to validate a source.
  • The opinions expressed in this video do not necessarily reflect the views of the Charles Koch Foundation, which encourages the expression of diverse viewpoints within a culture of civil discourse and mutual respect.
Keep reading Show less