Find out the latest thinking about our universe.
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MargaritaMc
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by MargaritaMc » Mon Jul 24, 2017 7:35 pm
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!
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
— Dr Debra M. Elmegreen, Fellow of the AAAS
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neufer
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by neufer » Tue Jul 25, 2017 12:20 am
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.
Art Neuendorffer
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Ann
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by Ann » Tue Jul 25, 2017 5:56 am
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
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Chris Peterson
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by Chris Peterson » Tue Jul 25, 2017 1:24 pm
Ann wrote: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 10
34 years. Ten million billion billion billion years. I don't think it's going to matter to us one way or the other.
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neufer
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by neufer » Tue Jul 25, 2017 1:49 pm
Chris Peterson wrote:Ann wrote: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 10
34 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.
Art Neuendorffer
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Chris Peterson
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by Chris Peterson » Tue Jul 25, 2017 2:12 pm
neufer wrote:Chris Peterson wrote:Ann wrote: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 10
34 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.