[...] 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: 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