Solid light is changing how we think about energy. Lights can be bent through many forms, one of them being the manipulation of photons, which is what light is made of. When an electron is charged to its full capacity, it explodes, expelling photons, and the levels of energy in these atoms are translated into the colors we see. It can also be used to communicate anything if the quantum entanglement is strong enough to make a trip across the universe. Recently, scientists have found an intriguing format for the universe’s strongest characteristic— something called solid light.
The photons’ impact when studying light
Scientists and researchers are often discovering new things about light, but for people who don’t study this subject, light can be interpreted as a wave, or, if someone has more in-depth knowledge, as a stream of photons. Under the right conditions, the atoms can behave almost like different states of matter. The Bose-Einstein Condensate (BEC) of light is a great example of how photons behave under different situations. This research laid the foundation for modern discoveries like solid light, where photons show unexpected behavior.
In the early 1920s, Satyendra Nath Bose and Albert Einstein discovered a new state of matter, one in which particles called bosons (which have an integer spin) can all occupy the same energy state in suitable situations. At very low temperatures, the particles collapse into the lowest energy state, and they lose their powers as individuals, but act like one giant quantum wave—millions of atoms acting as one— is related to what we now observe in experiments involving solid light.
Scientists create ‘solid light’ and it’s awe-inspiring
For years, teams of engineers and physicists developed a way to turn light into a state where it behaves like something that has matter. Scientists from the Institute of Nanotechnology of Lecce, in Italy, shot a laser through a crystal, and inside it, the photons got mixed with atoms, forming polaritons, which can behave like particles with mass, creating a super-solid light state of matter.
In this state, photons behave like particles and can reflect and emit light with an intensity and order that it appears almost ‘brighter than white’—not only in brightness, but in how precisely the light is structured. Inside the polaritons, the particles arrange themselves in a crystalline structure (solid) while also flowing without friction (fluid). This was the first time researchers were able to bend light into a super-solid formation, where particles exhibit properties of both states simultaneously.
Super-solid liquids are stabilized at absolute zero
Just like the state of matter invented by Bose and Einstein, solid light and super-solids require very low temperatures, close to absolute zero (-273.15°C or -459.67°F), which allows the quantum effects to control their behavior.
This is important for scientists to be able to study the material. At normal or high temperatures, the particles have a higher level of energy, and researchers cannot analyze the individual components because they do not sit still. With the behavior of light being stabilized under these extreme conditions, they can map out how atoms and particles interact when put together.
More tangible than ever
What was once considered pure energy without mass can behave like matter. If photons had mass, the universe would be a very different place. Einstein’s theory of relativity shows that matter bends space-time, creating its own gravity and gravitational field, and even the speed of light would be affected by its weight. Even without mass, light cannot escape from black holes. But solid light, despite not having true mass, opens a new window into understanding how light interacts with matter and gravity in exotic environments.