In the beginning was the equation – and University of Michigan researchers say they’ve demonstrated mathematically that it’s possible to make something out of nothing.
Under just the right conditions, they say — which would involve an ultra-high-intensity laser beam and a two-mile-long particle accelerator — it could be possible to create matter and antimatter from a vacuum.
They’ve developed a tool to put their equations into practice – on a very small scale – using the Hercules laser at U-M. The work could potentially have applications in inertial confinement fusion.
The new equations show how a high-energy electron beam combined with an intense laser pulse could rip a vacuum apart into its fundamental matter and antimatter components, and set off a cascade of events that would generate additional pairs of particles and antiparticles.
“We can now calculate how, from a single electron, several hundred particles can be produced. We believe this happens in nature near pulsars and neutron stars,” said Igor Sokolov, an engineering research scientist.
At the heart of this work is the idea that a vacuum is not exactly nothing.
“It is better to say, following theoretical physicist Paul Dirac, that a vacuum, or nothing, is the combination of matter and antimatter — particles and antiparticles.Their density is tremendous, but we cannot perceive any of them because their observable effects entirely cancel each other out,” says Sokolov.
Matter and antimatter destroy each other when they come into contact under normal conditions.
“But in a strong electromagnetic field, this annihilation, which is typically a sink mechanism, can be the source of new particles,” says research scientist John Nees. “In the course of the annihilation, gamma photons appear, which can produce additional electrons and positrons.”
An experiment in the late ’90s managed to generate gamma photons and an occasional electron-positron pair from a vacuum. The new equations take this work a step further to model how a strong laser field could promote the creation of more particles than were initially injected.
“The basic question of what is a vacuum, and what is nothing, goes beyond science,” says Solokov. “It’s embedded deeply in the base not only of theoretical physics, but of our philosophical perception of everything — of reality, of life, even the religious question of could the world have come from nothing.”