Physics-lovers, hear out! A new form of light has been discovered by scientists! The finding is documented in a paper published in Science Advances. This will revolutionise the current understanding of light, and might pave the way to a faster optical communication.
Light is what allows us to see, and is vital to our life – you would think scientists know everything that there is to know about it. You’re wrong. The new study proves yet again how little does humanity actually know. Much to the surprise of mostly everyone, a team of Irish researchers from Trinity College Dublin have demonstrated that light can exist in other forms that were previously unknown to the world of science.
The study is based on angular momentum: the constant that indicates the value at which light rotates. This is how a beam of light can be measured. We normally hear of colour and wavelength as the characteristics of light. Angular momentum, albeit a less common defining trait, is also used by scientists. One of the authors, Kyle Ballantine, explains that a beam of light can rotate on its own axis even if it travels in a straight line, such that light hitting one’s eye would involve the photons twisting the eye to some extent.
Scientists have assumed that the angular momentum is an integer multiple of Planck’s constant (the constant that governs quantum effects) for all forms of light. The results, however, show that light can exist at half the value of the known angular momentum – this is the reality of the new form of light. Light can actually be at an angular momentum that is not a whole number.
Lead author Paul Eastham attests to how exciting this finding is, saying in a statement that this very fundamental property of light that has long been thought to be constant can, in fact, change.
Eastham and his team discovered this phenomenon when they were attempting to find new light behaviours; their aim was to come up with ways of enhancing optical communications. They, thus, made light pass through crystals to result in light beams with twisted structures. When they analysed this beam of light as per the theory of quantum mechanics, they unexpectedly found that its angular movement would have to be half the number. Therefore, they tested this by developing a device to measure the flow angular momentum in the light beam. They were also able to decipher the variation in this flow that would result from quantum effects.
The results show that the angular momentum of each photon was different by a small amount – one-half of Planck’s constant. Otherwise, quantum variations would make the angular momentum shift by whole numbers.
Thus was the new form of light discovered.
One of the researchers, Stefano Sanvito, says that their discovery is a “breakthrough for the world of physics and science alike“.
Before this information is used to enhance fibre-optic cables, the results will have to be confirmed by another research team by reproducing the experiment.