A groundbreaking experiment in physics has for the first time provided a precise measurement of a force between electrons and protons called the weak nuclear force.
A groundbreaking experiment in physics has for the first time provided a precise measurement of a force between electrons and protons called the weak nuclear force.
The value 0.0719 (give or take 0.0045) won't mean much to most of us, but the way they did it makes way for some exciting possibilities for pushing physics beyond the scope of the Standard Model.
In an international effort between scientists called the Jefferson Lab Q-weak Collaboration, physicists took advantage of an odd quirk of particle physics to get a solid measure on one of the weakest of nature's four fundamental forces.
Interactions between particles come in four categories, which can also combine together at high enough energies.
Gravity might be the one that comes to mind first, keeping our coffee mugs from drifting towards the ceiling. It's also the weakest one, demanding virtually planet-sized chunks of matter before we personally pay much notice to its effects.
The other force we're well acquainted with is electromagnetism, which sees the opposing charges of protons and electrons attract through the mediation of light particles, called photons.
Then there's the strong nuclear force, acting over tiny distances to bind particles called quarks into protons and neutrons via the passing around of a particle called a gluon.
Lastly there's a strange little 'weak nuclear' force that transforms neutrons into protons (with an electron and electron antineutrino for spare change).
Though nowhere near as faint as gravity, the weak nuclear interaction represents just a fraction of the pull between a proton's and electron's charges.
"Measuring this effect has proven difficult because the weak force is so much weaker than the electromagnetic," says the University of Adelaide's Ross Young.
The trick was to take advantage of a strange discovery made back in the 1950s.
Most things in physics follow some kind of rule of balance or symmetry, where swapping certain features of the Universe would make zero difference. For charge, this would mean if we suddenly swapped all positives and negatives everything would look pretty much the same.
Likewise, if we rewind time, there's no indication that we'll ever notice.
Space is a little weirder. If we flipped the positions of everything in some giant Universal mirror, most things wouldn't change.
The value 0.0719 (give or take 0.0045) won't mean much to most of us, but the way they did it makes way for some exciting possibilities for pushing physics beyond the scope of the Standard Model.
In an international effort between scientists called the Jefferson Lab Q-weak Collaboration, physicists took advantage of an odd quirk of particle physics to get a solid measure on one of the weakest of nature's four fundamental forces.
Interactions between particles come in four categories, which can also combine together at high enough energies.
Gravity might be the one that comes to mind first, keeping our coffee mugs from drifting towards the ceiling. It's also the weakest one, demanding virtually planet-sized chunks of matter before we personally pay much notice to its effects.
The other force we're well acquainted with is electromagnetism, which sees the opposing charges of protons and electrons attract through the mediation of light particles, called photons.
Then there's the strong nuclear force, acting over tiny distances to bind particles called quarks into protons and neutrons via the passing around of a particle called a gluon.
Lastly there's a strange little 'weak nuclear' force that transforms neutrons into protons (with an electron and electron antineutrino for spare change).
Though nowhere near as faint as gravity, the weak nuclear interaction represents just a fraction of the pull between a proton's and electron's charges.
"Measuring this effect has proven difficult because the weak force is so much weaker than the electromagnetic," says the University of Adelaide's Ross Young.
The trick was to take advantage of a strange discovery made back in the 1950s.
Most things in physics follow some kind of rule of balance or symmetry, where swapping certain features of the Universe would make zero difference. For charge, this would mean if we suddenly swapped all positives and negatives everything would look pretty much the same.
Likewise, if we rewind time, there's no indication that we'll ever notice.
Space is a little weirder. If we flipped the positions of everything in some giant Universal mirror, most things wouldn't change.