Lasers can have a cooling effect in quantum experimentsMike_shots/Shutterstock
In the strange world of quantum mechanics, nothing isn’t ever actually nothing — and now we have found that nothing, or the absence of a photon, can be used to cool things down.
One of the most common ways scientists cool things down is by using lasers. When particles of light, or photons, with a specific frequency hit an atom or molecule, it absorbs the photon and then fires out another photon with slightly higher energy, which cools the system overall.