Where have all the Free Quarks Gone?
Prof. Heidi Newberg
Rensselaer Polytechnic Institute
This is the story of the
Universe. The details may not all be
true, but it’s what we tell our students.
Universe began as an
infinitely dense point in space. The
particles and the physics are exotic.
At 10-30 s, the Universe
expands by a factor of 1026, in a process
we call Inflation.
10-14 s later, baryons
and antibaryons annihilate and we are left with a quark-gluon plasma, in which quarks can exist by themselves,
outside of a hadron.
Where have all the free quarks gone?
Long time passing.
Where have all the free quarks gone?
Long time ago.
Where have all the free quarks gone?
Gone to protons every one.
When will it ever end?
When will it ever end?
Well, some are in neutrons
too, but not all the flowers were picked by young girls, either.
The protons and neutrons bind
together into nuclei of light elements, mostly hydrogen.
Where have all the protons gone?
Long time passing.
Where have all the protons gone?
Long time ago.
Where have all the protons gone?
Hydrogen atoms – 75% of them –
When will it ever end?
When will it ever end?
300,000 years after the Big
Bang, hydrogen atoms form, the CMBR is released, the dark ages begin, and last
until quasars and the first stars light up the Universe.
Where have hydrogen atoms gone?
Long time passing.
Where have hydrogen atoms gone?
Long time ago.
Where have hydrogen atoms gone?
Made the first stars every one.
When will it ever end?
When will it ever end?
Matter falls into black holes
that will eventually be the nuclei of galaxies, emitting light as quasars. Also, a generation of very massive and short
lived stars (Population III) is created.
These energetic events reionize the gas. Stars
are numbered in order of their discovery, which is the opposite of the order
they appeared. The Sun is Population I,
older stars are Population II, and the first stars, which have never been
directly observed, are Population III.
Where have all the first stars gone?
Long time passing.
Where have all the first stars gone?
Long time ago.
Where have all the first stars gone?
Supernovae every one.
When will it ever end?
When will it ever end?
The heavier elements of the
periodic table are created by fusion in the centers of massive stars, and then
released into the interstellar medium in supernova explosions, that end these
stars’ lives.
Where have supernovae gone?
Long time passing.
Where have supernovae gone?
Long time ago.
Where have supernovae gone?
Enriched the gas to make Pop II.
When will it ever end?
When will it ever end?
The enriched gas is made into
Pop II stars in small clusters.
Where have all Pop II stars gone?
Long time passing.
Where have all Pop II stars gone?
Long time ago.
Where have all Pop II stars gone?
Formed dwarf galaxies every one.
When will it ever end?
When will it ever end?
These clusters hierarchically
merge to make ever larger galaxies.
Where have the dwarf galaxies gone?
Long time passing.
Where have the dwarf galaxies gone?
Long time ago.
Where have the dwarf galaxies gone?
Merged to make the Milky Way.
And they are merging still.
And they are merging still.