Light is everywhere, and we believe that we know everything about it. More than 340 years back, Danish physicist Ole Rømer discovered that the speed of light was finite. Until this day, photons keep surprising us. Just last year, scientists identified a fundamentally new property of light.
And now Scientists from Trinity College Dublin have discovered a mode of light propagation that has never been observed. They have discovered a new form of light which is totally different from our existing rules regarding light and angular momentum and screening that light can take on new and unexpected forms.
This new discovery could shake up our understanding of electromagnetic radiation.
Kyle Ballantine, one of the researchers, explained, “A beam of light is characterized by its color or wavelength and a less familiar quantity known as angular momentum. Angular momentum measures how much something is rotating. For a beam of light, although travelling in a straight line, it can also be rotating around its own axis. So when light from the mirror hits your eye in the morning, every photon twists your eye a little, one way or another.”
To measure a beam of light, one way is through its angular momentum (a constant quantity that measures how much light is rotating). Until today, it was considered that the angular momentum would be a whole number multiple of Planck’s constant (a physical constant that sets the scale of quantum effects). However, this new research has demonstrated that a new form of light exists, where the angular momentum is only half of this value.
Assistant Professor Paul Eastham said, “What I think is so exciting about this result is that even this fundamental property of light, that physicists have always thought was fixed, can be changed.”
One of the researchers, Stefano Sanvito, added, “This discovery is a breakthrough for the world of physics and science alike.”