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[...] In addition to the 9 percent of the proton's mass that comes from quarks' heft, 32 percent comes from the energy of the quarks zipping around inside the proton, Liu and colleagues found. (That's because energy and mass are two sides of the same coin, thanks to Einstein's famous equation, E=mc2.) Other occupants of the proton, massless particles called gluons that help hold quarks together, contribute another 36 percent via their energy.
The remaining 23 percent arises due to quantum effects that occur when quarks and gluons interact in complicated ways within the proton. Those interactions cause QCD to flout a principle called scale invariance. In scale invariant theories, stretching or shrinking space and time makes no difference to the theories' results. Massive particles provide the theory with a scale, so when QCD defies scale invariance, protons also gain mass.
The results of the study aren't surprising, says theoretical physicist Andreas Kronfeld of Fermilab in Batavia, Ill. Scientists have long suspected that the proton's mass was made up in this way. But, he says, "this kind of calculation replaces a belief with scientific knowledge."
(Score: 0) by Anonymous Coward on Monday November 26 2018, @06:45PM (19 children)
https://www.nature.com/news/2008/081120/full/news.2008.1246.html [nature.com]
(Score: 2) by takyon on Monday November 26 2018, @06:51PM (14 children)
Nope
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.212001 [aps.org]
Proton Mass Decomposition from the QCD Energy Momentum Tensor
Yi-Bo Yang, Jian Liang, Yu-Jiang Bi, Ying Chen, Terrence Draper, Keh-Fei Liu, and Zhaofeng Liu
Phys. Rev. Lett. 121, 212001 – Published 19 November 2018
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 1, Interesting) by Anonymous Coward on Monday November 26 2018, @07:19PM (11 children)
If they already proved the standard model correct by rigorously calculating the mass of the proton in 2008, then how did they only finally calclate the mass in 2018??
(Score: 1, Informative) by Anonymous Coward on Monday November 26 2018, @07:34PM (10 children)
There's a difference between calculating the mass of the whole proton, and figuring out how its internal components add up to make that mass. The latter is not explainable just with quark masses.
(Score: 1, Touché) by Anonymous Coward on Monday November 26 2018, @07:39PM (9 children)
How do you calculate the mass of a proton without adding up the components of a proton?
(Score: 0) by Anonymous Coward on Monday November 26 2018, @08:05PM (1 child)
The components are being added up, dumbass.
(Score: 1, Touché) by Anonymous Coward on Monday November 26 2018, @08:15PM
Uh-huh, did this happen for the first time in 2008 or 2018?
(Score: 0) by Anonymous Coward on Monday November 26 2018, @08:17PM (6 children)
How would you measure the mass of a cardboard box labeled "bathroom". Are there towels and first aid items in there? Or just big giant doodies? Does that uncertainty prevent you from putting the box on a scale?
(Score: 0) by Anonymous Coward on Monday November 26 2018, @08:24PM (5 children)
They didnt claim to have measured it in 2008, they claimed to have rigorously calculated it in a way that confirmed the standard model.
Not sure what kind of cognitive dissonance is going on in this thread, but I suspect the real answer is these are a couple of incorrect and hyped up press releases that no one should pay attention to.
(Score: 0) by Anonymous Coward on Monday November 26 2018, @08:40PM (3 children)
I did not research the 2008 assertion, just responding to "If they already proved the standard model correct by rigorously calculating the mass of the proton in 2008, then how did they only finally calclate the mass in 2018??"
You can measure the total mass of the proton without breaking down the individual components and how much they contribute. My analogy was meant to illustrate that, you can weigh a box and accurately determine the mass / weight without knowing anything about what is inside.
I think you need another cup of coffee.
(Score: 0) by Anonymous Coward on Monday November 26 2018, @08:51PM (2 children)
What research would you need to do? Read the sentence from 2008 I quoted.
And why are you repeating this stuff about measurement again? It is irrelevant to claims of calculating a value from the standard model. I mean, tell me this: Did you vote for Trump?
(Score: -1, Troll) by Anonymous Coward on Monday November 26 2018, @11:09PM (1 child)
Well you're an idiot.
However I will take the time to explain it for you.
"If they already proved the standard model correct by rigorously calculating the mass of the proton in 2008"
There was the original sentence about 2008. So, in 2008 they very accurately measured the TOTAL mass of the proton and it agreed with standard model predictions.
Now they have been able to figure out the SUB-ATOMIC PARTS that make up that TOTAL mass.
"And why are you repeating this stuff about measurement again? It is irrelevant to claims of calculating a value from the standard model. I mean, tell me this: Did you vote for Trump?"
Umm, you might be too stupid to post around here and that is one of the most damning insults I can come up with. You sure YOU didn't vote for Trump??
(Score: 1, Funny) by Anonymous Coward on Monday November 26 2018, @11:27PM
Measurement is different from deriving (calculating) a value from theory. In science you compare a measurement to the results of your calculations. These are two different things. You apparently think measuring is the same thing as calculating? Good lord we are fucked if people are this confused about science.
(Score: 0) by Anonymous Coward on Monday November 26 2018, @08:46PM
It's just somebody who's frustrated because we aren't covering electric universe theory instead.
(Score: 2) by JoeMerchant on Monday November 26 2018, @09:11PM (1 child)
That was original work, aka just "belief" - since another scientist has validated it it now becomes "scientific knowledge."
Actually, dupe studies like that happen all the time, where the author is convinced that they have something truly novel but someone knowledgeable in the field has seen it all many times before. Lots of those actually get published as novel in peer reviewed journals because the peers who do the reviewing aren't always the most knowledgeable people in the field, either.
🌻🌻 [google.com]
(Score: 0) by Anonymous Coward on Monday November 26 2018, @09:25PM
The 2008 article didnt mention anything about belief, they used the calculations as "vindication" for the standard model.
(Score: 2) by melikamp on Monday November 26 2018, @06:53PM (3 children)
The equation is off by a factor of c/2, utf to the rescue!
E=mc²
(Score: 2) by PartTimeZombie on Monday November 26 2018, @07:32PM
Actually don't bother. It's not like I'd understand it.
(Score: 2) by Bot on Monday November 26 2018, @09:44PM
The relation between energy mass and square of c was discovered, two years before Einstein published it, by an Italian self taught scientist, Olinto De Pretto, coming from basically the opposite POV of Einstein: no relativity, existence of ether. It's not even a coincidence, as Einstein and de Pretto had a common acquaintance who is likely to have talked with both.
Account abandoned.
(Score: 0) by Anonymous Coward on Tuesday November 27 2018, @05:41PM
☕ = ☃☔²