Levitation is a basic skill at Hogwarts but impossible in real life where the laws of physics hold true, scientists have found.
Physicists have long debated whether particles known as “antimatter” are sent upwards by gravity and experiments at CERN have now found, for the first time, that gravity pulls both matter and antimatter downwards in the same way.
There is as much antimatter in the world as normal matter but they have the opposite electrical charge. Normal matter makes up the world around us. It is what the laws of physics are built around and is easier to find and study than antimatter.
However, the discovery of antimatter around a century ago led scientists to speculate if it responds to forces in a different way due to its opposite charge.
To find out, University of California Berkeley experts worked at CERN to collect tubes of antihydrogen — an antiproton paired with a positron — and kept them at around -272°C in a magnetically controlled tube.
When the antihydrogen was released around 80 per cent dropped downwards instead of floating upwards, showing gravity works on antimatter in the same way as it does matter.
Therefore, if Isaac Newton was under an anti-apple tree when he discovered gravity in the 17th century, the anti-apple would have still fallen to the ground, just as a normal apple did in the apocryphal myth.
“The bottom line is that there’s no free lunch, and we’re not going to be able to levitate using antimatter,” said Prof Joel Fajans, a UC Berkeley professor of physics who has been trying to devise an experiment to solve this mystery for a decade.
The discovery proves Einstein right because his General Relativity theory, spawned in 1932, treats all matter identically. However, this is the first time since antimatter was first discovered that scientists have proven how gravity affects antimatter.
The team used antihydrogen as their measuring stick for the possibility of levitation because it is neutrally charged (its two components, an electron and proton, have the opposite charge to the conventional element but the overall charge is neutral) and therefore they could be contained using magnetism without experimental interference.
Less exciting result
The scientists acknowledge that finding antimatter does levitate would have been more exciting but say this is a landmark study nonetheless as it sheds more light on the mysteries of antimatter.
“If you walk down the halls of this department and ask the physicists, they would all say that this result is not the least bit surprising. That’s the reality,” Prof Jonathan Wurtele of UC Berkeley, who designed the initial study, said.
“The opposite result would have had big implications; it would be inconsistent with Einstein’s general theory of relativity.
“This experiment is the first time that a direct measurement of the force of gravity on neutral antimatter has been made. It’s another step in developing the field of neutral antimatter science.
“You don’t want to be the kind of stupid that you don’t do an experiment that explores possibly new physics because you thought you knew the answer, and then it ends up being something different.”
The study is published in Nature.