Nuclear weapons have already shown that it is possible to convert matter into large amounts of heat and light, but doing it the other way around, converting heat and light into matter, is much more difficult — but this is exactly what laboratories in China and the UK hope to achieve.
If the intended objective is reached, it could open up a whole a new branch of physics, called nuclear photonics, full of technological potentialities still unimaginable.
According to a report by Explica.co, The Station of Extreme Light, which China has been developing in Shanghai since 2018, has made significant progress in its goal of manufacturing lasers so powerful by 2023 that they could break through empty space and create matter.
The Extreme Light Station (SEL) is a laser installation designed to produce a laser with 100 petawatts (PW) of maximum power (one petawatt equals one thousand trillion watts), a goal that is expected to be achieved within two years.
Once completed, the laser will be the most powerful on Earth, with a power 10,000 times greater than that of all the electrical networks in the world combined and with an intensity 10 trillion times greater than that of sunlight, the report said.
The laser will be powerful enough to produce matter and antimatter directly from the vacuum of space, allowing us to observe in a terrestrial laboratory the same process that supposedly gave rise to the universe.
This technology is based on the fact that a vacuum is never really empty: it is like a pond filled with pairs of electrons and positrons (particles of matter and antimatter) that occasionally emerge to the surface (existence), although they annihilate each other as soon as they are formed.
A laser could intervene in that process and separate the matter and antimatter particles before they collide, the report said.
You can then get both of them to emit gamma rays and generate more electrons and positrons. That barrage of new particles and radiation could be detected when it acquires sufficient density.
The laser would have thus succeeded in creating particles and antiparticles as if they had arisen out of nowhere: it would demonstrate that light can pull particles of matter and antimatter out of empty space, a phenomenon known as “breaking the vacuum.”
According to The Guardian, the original idea was written down by two US physicists, Gregory Breit and John Wheeler, in 1934.
They worked out that – very rarely – two particles of light, or photons, could combine to produce an electron and its antimatter equivalent, a positron.
Electrons are particles of matter that form the outer shells of atoms in the everyday objects around us.
But Breit and Wheeler had no expectations that their theory would be proved any time soon.
In their study, the physicists noted that the process was so rare and hard to produce that it would be “hopeless to try to observe the pair formation in laboratory experiments.”
If the operation is successful, it will directly create and measure the quantum properties of the vacuum, here on Earth.
It will also show that matter and energy are interchangeable in any direction, as Einstein had put forward in his famous equation.
Physicists at Imperial College London also claim to have cracked the problem using high-powered lasers and other equipment now available to scientists.
“We have shown in principle how you can make matter from light,” said Steven Rose at Imperial. “If you do this experiment, you will be taking light and turning it into matter.”
Writing in the journal Nature Photonics, the UK scientists describe how they could turn light into matter through a number of separate steps.
The first step fires electrons at a slab of gold to produce a beam of high-energy photons.
Next, they fire a high-energy laser into a tiny gold capsule called a hohlraum, from the German for “empty room.”
This produces light as bright as that emitted from stars.
In the final stage, they send the first beam of photons into the hohlraum where the two streams of photons collide.
The scientists’ calculations show that the setup squeezes enough particles of light with high enough energies into a small enough volume to create around 100,000 electron-positron pairs.
The process is one of the most spectacular predictions of a theory called quantum electrodynamics (QED) that was developed in the run up to the Second World War.
“You might call it the most dramatic consequence of QED and it clearly shows that light and matter are interchangeable,” Rose told the Guardian.
The UK scientists hope to demonstrate the process in the next 12 months.
In any case, both UK and Chinese scientific teams are not on the verge of a machine that can create everyday objects from a sudden blast of laser energy — so far, that reality only exists in science fiction.
Rather, the kind of matter they aim to make comes in the form of subatomic particles invisible to the naked eye.
Andrei Seryi, director of the John Adams Institute at Oxford University, said: “It’s breathtaking to think that things we thought are not connected, can in fact be converted to each other: matter and energy, particles and light. Would we be able in the future to convert energy into time and vice versa?”
Sources: Explica.co, The Guardian, Nature Photonics