Can black holes be created from pure light? The theory of new paper challenges.

Squeeze enough stuff into one place, space-time itself will collapse into a sweet cosmic kiss known as a black hole.

In terms of Einstein’s sums, this ‘thing’ involves the immeasurable radiance of electromagnetic radiation. Given E = mc²which describes the equivalence between mass and energy, the energy of light itself should – theoretically – be able to create a black hole if enough of it is concentrated in one point.

Before you fire up the big-gun lasers and poke some holes in the floorboards of the Universe, there’s one thing researchers from the Complutense University of Madrid in Spain and the University of Waterloo in Canada want you to know.

Something called the Schwinger effect can make all of this impossible before you even get started.

Einstein’s general theory of relativity is a description of the distortion of space and time in relation to the presence of energy, such as that contained in a mass. Put enough mass in one place and the distortion will become so extreme that nothing – not even light – will escape.

In the mid-1950s, the American theoretical physicist John Wheeler discovered that there was nothing in Einstein’s theory to rule out the possibility that the energy within a sufficient concentration of gravitational or electromagnetic waves could distort space-time enough to sustain the same waves. stuck in place. .

He called this exotic object a geon and considered it a type of hypothetical, highly unstable particle.

Today, geons are a relic of an era of scientific thought that also gave us wormholes and white holes; theoretical toys that tell us more about the limits of mathematical models than about physical reality.

However, a form of geon that Wheeler referred to as a “kugelblitz” occasionally appears in science fiction as a fantastic source of energy. German for ‘ball lightning’, these tiny proton-sized black holes were proposed to form in the intense focus of extremely energetic beams of light, such as a futuristic high-powered laser.

While general relativity gives the kugelblitz the green light, quantum physics has its doubts. Thus, theoretical physicist Álvaro Álvarez-Domínguez from the Complutense University of Madrid and his team determined the numbers on the behavior of electromagnetic fields as their energy increases to extreme levels.

The quantum landscape is like a casino where the waves of possibility constantly ripple like a non-stop roulette wheel. Small bets rarely pay, but accumulate enough money at any table, you are almost guaranteed a win.

Similarly, a strong electromagnetic field in an otherwise empty space almost guarantees that pairs of electrons and positrons will emerge from the quantum storm of infinite possibilities.

In a paper that has not yet been peer-reviewed, Álvarez-Domínguez and his team showed that this phenomenon known as the Schwinger effect would prevent the formation of kugelblitzes ranging in size from nearly twice the size of Jupiter to a fraction of the size of a proton.

In fact, cramming all that light into a single point would provide the energy needed for pairs of charged particles to pop into existence and fly near the speed of light, preventing the growing blob in spacetime from ever developing a hole. black. defining the event horizon.

“Our analysis strongly suggests that the formation of black holes from electromagnetic radiation alone is impossible, either by focusing light in a hypothetical laboratory setting or naturally occurring astrophysical phenomena,” the team wrote in their analysis.

This is not to completely rule out the possibility. The researchers admit that things may have been different in the “extremely extreme conditions” of the early Universe.

Other forms of geons, such as those based on gravitational waves, remain a curiosity that could also have existed in the nascent cosmos billions of years in the past.

Those who are using a kugelblitz powered spacecraft to launch them to the stars may now have to go back to the drawing board.

This document is available on the arXiv preprint server.