APS: Proton Loses Weight

[MargaritaMc]

Synopsis: Proton Loses Weight
https://physics.aps.org/synopsis-for/10 ... 119.033001
The most precise measurement to date of the proton mass finds a value that is 3 standard deviations lower than previous estimates.
Knowing the proton mass is crucial for analyzing atomic spectra as well as determining fundamental constants, like the Rydberg constant. A new proton mass measurement by Sven Sturm from the Max Planck Institute for Nuclear Physics, Germany, and colleagues is 3 times more precise than past observations. The team’s value—obtained by comparing a single proton’s motion in a magnetic field to that of a carbon ion—is significantly smaller than the current international-standard estimate.

https://phys.org/news/2017-07-higher-pr ... ought.html

https://journals.aps.org/prl/abstract/1 ... 119.033001

High-precision measurement of the proton's atomic mass
Fabian Heiße, Florian Köhler-Langes, Sascha Rau, Jamin Hou, Sven Junck, Anke Kracke, Andreas Mooser, Wolfgang Quint, Stefan Ulmer, Günter Werth, Klaus Blaum, Sven Sturm
(Submitted on 21 Jun 2017)
We report on the precise measurement of the atomic mass of a single proton with a purpose-built Penning-trap system. With a precision of 32 parts-per-trillion our result not only improves on the current CODATA literature value by a factor of three, but also disagrees with it at a level of about 3 standard deviations.

arXiv preprint: https://arxiv.org/abs/1706.06780

PS: yes - I know that we are speaking about mass not weight, but I'm directly quoting from the journal of the American Physical Society!

[neufer]

Code: Select all

Old proton mass = 1.007276466879 atomic mass units
New proton mass = 1.007276466583 atomic mass units

Much like saying that an Apatosaurus losses weight when a flea hops off.

[Ann]

Fascinating, Margarita!

I think - and I'm too lazy to google - that people have speculated that the proton might decay, which would be bad news for all of us, to be sure.

Of course, if it's going to happen, it won't happen for billions of years. I suppose.

But it's still a little scary to read about a proton being more emaciated than previously thought!

Ann

[Chris Peterson]

Fascinating, Margarita!

I think - and I'm too lazy to google - that people have speculated that the proton might decay, which would be bad news for all of us, to be sure. :ohno:

Of course, if it's going to happen, it won't happen for billions of years. I suppose.

If protons do decay (which is not likely), they do so with a half-life of not less than 10³⁴ years. Ten million billion billion billion years. I don't think it's going to matter to us one way or the other.

[neufer]

Fascinating, Margarita!

I think - and I'm too lazy to google - that people have speculated that the proton might decay,
which would be bad news for all of us, to be sure.

Of course, if it's going to happen, it won't happen for billions of years. I suppose.

If protons do decay (which is not likely), they do so with a half-life of not less than 10³⁴ years.
Ten million billion billion billion years. I don't think it's going to matter to us one way or the other.

Not to us personally, perhaps,...but one must consider posterity.

[Chris Peterson]

Fascinating, Margarita!

I think - and I'm too lazy to google - that people have speculated that the proton might decay,
which would be bad news for all of us, to be sure. :ohno:

Of course, if it's going to happen, it won't happen for billions of years. I suppose.

If protons do decay (which is not likely), they do so with a half-life of not less than 10³⁴ years.
Ten million billion billion billion years. I don't think it's going to matter to us one way or the other.

Not to us personally, perhaps,...but one must consider posterity.

Well, I guess our distant descendants will just have to get by with fewer protons. There will certainly be a lot less available energy, so downsizing will be a good thing.