A 10-year study has revealed that the electron is very spherical indeed.
To be precise, the electron differs from being perfectly round by less than 0.000000000000000000000000001 cm. To put that in context; if an electron was the size of the solar system, it would be out from being perfectly round by less than the width of a human hair. The Imperial College team behind the research, which was conducted on molecules of ytterbium flouride, used a laser to make measurements of the motion of electrons, and in particular the wobble they exhibit when spinning. They observed no such wobble, implying that the electron is perfectly round at the levels of precision available, reflected in the figure above.
The co-author of the report describing the research, Jony Hudson, said: “We’re really pleased that we’ve been able to improve our knowledge of one of the basic building blocks of matter. It’s been a very difficult measurement to make, but this knowledge will let us improve our theories of fundamental physics. People are often surprised to hear that our theories of physics aren’t ‘finished’, but in truth they get constantly refined and improved by making ever more accurate measurements like this one.”
The next step is to up that precision level even further, using new methods to cool the molecules to extremely low temperatures and control their motion. The results are important in the study of antimatter, and particularly the positron — which should behave identically to the electron but with an opposite electrical charge. If more differences can be found, it could help to explain why far less antimatter has been discovered in the universe than predicted by theory.
Image: Lawrence Rayner/Flickr