Common Elementary Particles
Several estimates imply that practically all the matter, when measured by mass, in the visible universe (not including dark matter) is in the protons of hydrogen atoms, and that roughly 1080 protons exist in the visible universe (Eddington number), and roughly 1080 atoms exist in the visible universe. Each proton is, in turn, composed of 3 elementary particles: two up quarks and one down quark. Neutrons and other particles heavier than protons, as well as helium and other atoms with more than one proton, are so rare that their total mass in the visible universe is much less than the total mass of protons in hydrogen atoms. Lighter particles of matter, although equal (electrons) or vastly more (neutrinos) numerous than protons, are so much lighter than protons, that their total mass in the visible universe is again much less than the total mass of all protons.
Some estimates imply that practically all the matter, when measured by numbers of particles, in the visible universe (not including dark matter) is in the form of neutrinos, and that roughly 1086 elementary particles of matter exist in the visible universe, mostly neutrinos. Some estimates imply that roughly 1097 elementary particles exist in the visible universe (not including dark matter), mostly photons, gravitons, and other massless force carriers.
Read more about this topic: Elementary Particle
Famous quotes containing the words elementary particles, common, elementary and/or particles:
“Listen. We converse as we live—by repeating, by combining and recombining a few elements over and over again just as nature does when of elementary particles it builds a world.”
—William Gass (b. 1924)
“The common argument that crime is caused by poverty is a kind of slander on the poor.”
—H.L. (Henry Lewis)
“As if paralyzed by the national fear of ideas, the democratic distrust of whatever strikes beneath the prevailing platitudes, it evades all resolute and honest dealing with what, after all, must be every healthy literature’s elementary materials.”
—H.L. (Henry Lewis)
“In another’s sentences the thought, though it may be immortal, is as it were embalmed, and does not strike you, but here it is so freshly living, even the body of it not having passed through the ordeal of death, that it stirs in the very extremities, and the smallest particles and pronouns are all alive with it. It is not simply dictionary it, yours or mine, but IT.”
—Henry David Thoreau (1817–1862)