Techspeak translator required
We have a short text here which might be largely Greek to many but I’m sure there is some soul out there to whom it is as plain as day:
Unlike an electron or neutrino, which are fundamental particles that behave like points, a proton is a messy collection of quarks, gluons, and virtual particles that occupies what should be a measurable amount of space. And just how much space can be rather significant; as the authors of a new paper on the proton’s size put it, “The proton structure is important because an electron in an S [ground] state has a nonzero probability to be inside the proton.”
Within experimental error, various measurements of the proton’s size have all put it about 0.88 femtometers (an fm is 10-15 meters). But a team of researchers, working at a particle accelerator in Switzerland, has found a different way of measuring the proton’s size: put a muon—a heavy, unstable, relative of the electron—in orbit around a proton. The resulting atom, called muonic hydrogen, can be measured during the brief time it exists before the muon decays. Those measurements have produced a new, very high-precision value for the proton’s radius. Just one small problem: it differs from the other measurements by nearly seven standard deviations.
Now I understand proton and accelerator, even the words hydrogen and standard deviations and can guess what a muon is but it’s when it’s all put together that the strain on the braincells begins.
Chuckles hardly helped: “It’s just not the same, I’m positive.”
Filed under: Technology & ideas
It’s probably been almost forty years since I studied particle physics, so it took me a couple of readings of the article to make complete sense of it.
It’s easy. Substitute peanuts for electrons, currants for nutrino and clusters for protons. Now try again.
I find the text a model of clarity, or I did until Woodsy confused me… I always thought clusters were long known to be of variable size, and I did not realise that neutrinos were more wrinkly and squishy than electrons.
The text may essentially just be saying that replacing an electron with a muon may slightly alter the volume occupied by all the stuff going on inside and indeed around a proton. But all brief “explanations” or descriptions of this stuff contain huge over-simplifications, such as to make the validity of the effort rather questionable. The very idea of anything “in orbit” around a proton is a daft oversimplification anyway, just sustaining the false planetary model of the atom that is so far removed from reality it does almost as much damage to understanding as help…
Anyway, peanuts and currents eh… Off for a think.
Not my field but the upshot seems to be that two different methods of measuring the size of a proton give two very different results. The newer way is supposed to be the more acurate.
An electron is only somewhere when you find it, (the probability density function that describes where the elevtron might be collapses when you find it) and there is a chance that you find it inside the proton. The probability that you find it inside the proton depends on the size of the proton.
So this result is important if you want to know the probanility your electron might be inside the proton.
Aaahh!
It’s all so much clearer now!
Steve, I’ve quoted you directly in the current novella, Chapter 1.
“Unlike an electron or neutrino, which are fundamental particles that behave like points”: except when they behave like waves (in a dual-slit experiment, for example).
Does anyone still call them wavicles?
The Fundemental Question has not yet been asked, let alone answered: How many Angels can dance inside a proton.
the first comment to the linked article explains it
Phew, JD, glad I’ve someone who knows everything here to help out.
Dearieme – a matter which has been much on my mind.
Amfortas – and the answer is?
42, of course.