New Property of Light Discovered

Toroid

Founding Member
https://phys.org/news/2019-06-property.html
A team of researchers affiliated with several institutions in Spain and the U.S. has announced that they have discovered a new property of light—self-torque. In their paper published in the journal Science, the group describes how they happened to spot the new property and possible uses for it.

Scientists have long known about such properties of light as wavelength. More recently, researchers have found that light can also be twisted, a property called angular momentum. Beams with highly structured angular momentum are said to have orbital angular momentum (OAM), and are called vortex beams. They appear as a helix surrounding a common center, and when they strike a flat surface, they appear as doughnut-shaped. In this new effort, the researchers were working with OAM beams when they found the light behaving in a way that had never been seen before.

The experiments involved firing two lasers at a cloud of argon gas—doing so forced the beams to overlap, and they joined and were emitted as a single beam from the other side of the argon cloud. The result was a type of vortex beam. The researchers then wondered what would happen if the lasers had different orbital angular momentum and if they were slightly out of sync. This resulted in a beam that looked like a corkscrew with a gradually changing twist. And when the beam struck a flat surface, it looked like a crescent moon. The researchers noted that looked at another way, a single photon at the front of the beam was orbiting around its center more slowly than a photon at the back of the beam. The researchers promptly dubbed the new property self-torque—and not only is it a newly discovered property of light, it is also one that has never even been predicted.
 

Sheltie

Fratty and out of touch.
Interesting, I wonder if this in any way alters the findings of the double slit experiment.
 

Shadowprophet

Truthiness
Amazing :D A new property of light. I guess I've got some study to do, I want to find out as much about this as possible. Being able to twist light in such ways this could be helpful for literally almost every application in which we use light, From the outside shed to holographic displays.
 

Dean

Adept Dabbler
Here is an abstract of the researchers' paper in Science (unfortunately, the paper itself is behind a paywall):
Generation of extreme-ultraviolet beams with time-varying orbital angular momentum | Science

Inside this news release, there is a link to a very interesting short video, in which the researchers explain their findings, with various visual aids:
https://phys.org/news/2019-06-property.html

(I tried posting a direct link to the video, which is .mp4, but for some reason I could not get the link to work on this site.)
 
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spacecase0

earth human
I keep waiting for them to discover that red shift is caused by light going long distances and not from primarily from doppler shift.
I wonder if this would be it
 

Shadowprophet

Truthiness
I keep waiting for them to discover that red shift is caused by light going long distances and not from primarily from doppler shift.
I wonder if this would be it
I thought redshift was caused by the exponential expansion of space stretching the wavelength of the light. Like a rubber band kind of thing. when stretched in such a way the blue and green are not as pronounced as such long wavelengths, so you tend to get a lot of red. I wonder if this new discovery can be used to benefit gravitational lensing?
 
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