It was a banner weekend for antimatter fans, as CERN announced that it trapped entire atoms of the feisty, elusive stuff for over 16 minutes.
That’s the longest time that anyone has managed to hold on to antimatter atoms – they are famously difficult to corral because antimatter annihilates whenever it encounters matter.
Geneva-based CERN made the usual proclamation that accompanies antimatter breakthroughs: we are now one step closer to solving the mega mysteries of nature and the universe. The Big Bang should have created an equal amount of matter and antimatter. But antimatter is scarce; so scientists hope to learn what happened to it and how it works. That in turn could shake up our fundamental understanding of ordinary matter.
“Half of the universe has gone missing, so some kind of rethink is apparently on the agenda,” said CERN’s Jeffrey Hangst in announcing the 16-minute achievement.
There’s no denying the profound possibilities of CERN’s advance, so I will leave that discussion to others.
Instead, I’ll take this opportunity to explore another side of antimatter: its practical or, even, everyday, side.
One thing for sure about antimatter is that it explodes when it meets matter. Harness that, and the possible uses are limitless.
Take hospital PET scans for example, which are probably the most common application of antimatter. The “P” in PET stands for positron, which is a subatomic, antimatter particle. The medical profession uses Positron Emission Tomography to inject positrons into a brain and watch for gamma rays that flash when the positrons encounter electrons of normal matter. The two destroy each other, giving off a light pattern that is different in an afflicted brain than in a normal one, thus revealing neurological aberrations.
Likewise, researchers around the world are trying to put positrons to work exposing weaknesses and abnormalities in all sorts of materials and things, ranging from metals and semiconductors to aspirin, ice cream and potato chips.
When I last spoke with experts on this subject – admittedly several years ago - I was intrigued by the possibilities. Physicist Paul Coleman at the University of Bath in England told me then that positrons naturally find the atom-sized holes in the crystal lattices that make up a metal. Gamma ray detectors, like in a PET scan, could note where the positrons settle, thus revealing weaknesses. As Coleman said, “a crack will always start in atomic scale, which turns into a bigger crack which leads to your airplane wing falling off.’’
That is an extreme example. But the point is that by discovering atomic level vulnerabilities, researchers can develop stronger materials for building electronic chips, planes, trains, automobiles, skyscrapers, bridges, roads and so on.
Coleman is no a one-off crackpot. Plenty of other physicists and engineers are looking into this.
Want proof? Go to the website of none other than the Positron Annihilation Community. That’s right, the Positron Annihilation Community. Everyone has to have a community these days, so you wouldn’t want to discriminate against positron annihilators, would you? The website invites you to “learn about the possibilities of practical application of Positron Annihilation” across all sorts of fields including metals, semiconductors, dielectrics and polymers.
Professor David Parker at the University of Birmingham is a physicist on the vanguard of positron research. His group is producing positron emitting isotopes “that are used to tag tracer particles both for studying real-time flow in industrial processes and for diagnosis in hospitals,” according to his web page. “By detecting the back-to-back emission of gamma-rays that follow the annihilation of a positron and electron pair, imaging with millimetre precision in applications ranging from the lubricant distribution in engines and dynamic studies of fluid flow through geological samples is possible,” the page states.
Today’s positrons tend to come from expensive cyclotrons that create isotopes of elements that in turn emit positrons as they decay.
Over the years companies as varied as Intel, Unilever, United Biscuits and Rolls Royce have investigated the use of antimatter in everything from making a stronger electronic chip to a crispier potato chip, and from a better aspirin coating to smoother engine oil.
And let’s not forget that antimatter, with all its explosiveness, was the fuel source that so effectively hurtled Star Trek’s Starship Enterprise across galaxies. Of course, Captain Kirk didn’t have to worry about the price of antimatter – in 1999, NASA estimated that it costs $62.5 trillion to produce one gram of antimatter. But perhaps it is food for thought for those who dare to boldly go to a post-electric, post hydrogen world of locomotion.
Do you have a good use for annihilating positrons? A good source of antimatter? Feel free to comment below…
Photo: CERN
