Scientists Catch Schrödinger’s Cat on Camera

No cats were harmed in the making of this science

Cat in a box
Alive or dead? You'll won't know until you peek inside. Box Cat/Flickr CC

Quantum physics can be a weird world in which things behave in ways that may not initially make sense. The “Schrödinger’s Cat” thought experiment was designed to demonstrate some of these properties, namely that atoms and molecules can exist in two different states at the same time until someone takes a peek at them. Now, a group of researchers have used this quantum paradox to capture the complex inner workings of the insides of molecules in greater detail than ever before.

For years, Schrödinger’s Cat was thought to be a particularly gruesome thought experiment. As originally devised by Erwin Schrödinger, it involved putting a cat in a sealed box and giving it a 50/50 chance of being exposed to poison gas. Until the box is opened, the cat is considered both alive and dead. In recent years, however, researchers have shown that it is more than just a thought experiment—not only can particles exist in two states at once, but they can even exist in two places at the same time, Tia Ghose reports for LiveScience.

This fact has led to some interesting developments. Scientists at Stanford University’s SLAC National Accelerator Laboratory used a green optical laser to essentially split an iodine molecule into versions of itself—an excited state and a non-excited state. Then, by firing pulses of X-rays at the twin molecules, the so-called "cat state," they were able to capture both versions in an "X-ray hologram," writes Jennifer Ouelette for Gizmodo. By stringing together a series of these images, the researchers created a stop-motion video, she writes. They posted their results to on the arXiv pre-print server, a paper that has since been accepted for publication by the journal Physical Review Letters.

'Schroedinger's Cat' Molecules Give Rise to Exquisitely Detailed Movies

“We see it start to vibrate, with the two atoms veering toward and away from each other like they were joined by a spring,” Phil Bucksbaum, a SLAC researcher and Stanford professor says in a statement. “At the same time, we see the bond between the atoms break, and the atoms fly off into the void. Simultaneously we see them still connected, but hanging out for a while at some distance from each other before moving back in. As time goes on, we see the vibrations die down until the molecule is at rest again.”

This all happens in a trillionth of a second, but it could lead to new developments in quantum research. By stitching each snapshot taken by the x-ray pulses together, the scientists were able to create a highly-detailed movie showing both states at the same time. Researchers can even use this technique to create detailed sequences from data collected in past experiments with quantum physics to get another glimpse at what is going on inside the cat state, Ouelette reports.

“Our method is fundamental to quantum mechanics, so we are eager to try it on other small molecular systems, including systems involved in vision, photosynthesis, protecting DNA from UV damage and other important functions in living things,” Buckbaum says in a statement.

Using this technique, researchers could soon glean new insight into how quantum physics influences biological systems and processes.

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