Nov. 4 – 2B03 04/11/2011 9:32:00 AM
Summary of LHC:
Running at ½ power.
Goal is to find Higg’s boson
o Why particles have mass
Point of experiment – to find those exotic particles that are the
result of the collision of the particles (colliding @ 99.999.. % C)
We may se evidence of extra dimensions and questions of dark
matters when it runs at full speed.
These are the basic concepts that will be tested -> refer to slide.
You need those superconducting magnets to bend the proton beam.
Beginning time - from hubble constant (1/H)
o We will narrow in that number
Filled w/ cool, low-energy microwave radiation
o discovery 1960s. Coming from everywhere (universe as a
whole). Same blackbody microwave radiation – CBR (CMBR).
Inflation – universe grows quickly in size, in a fraction of a second.
Past vs. Today
Today: Average temp is cold. Filled w/ microwave (low energy, not
hot) wavelength. Low density. Structures such as stars, galaxies,
groups of galaxies.
Past: Smaller, and back enough, there are no galaxies or stars ->
just a sea of elementary particles, radiation.
Structure in the universe grows hierarchically.
Big things out of small things.
2 galaxies make a bigger galaxy - structure in the universe always
o Subatomic particles, atoms, molecules, stars, galaxies,
clusters of galaxies. Subatomic particles – nuclei, atoms, then a period of a long time that you
make stars (dark ages), then it is bright. And then you form galaxies.
Before cosmic background radiation, and big bang, and some people that
this wasn not the picture at all (hierarchical growth).
Maybe big, then small things.
Evolution of structure – like biological evolution, but simpler.
After a few seconds after the Big bang, the temp. of the univerise is ~100
million degrees or so.
Nuclear fusion occurs throughout the universe after the big bang,
not just in stars like today.
Closer to the big bang -> more hotter, denser.
Free floating electrons – photons scatter off of free electrons.
Once a photon hits an electron, it scatters and changes direction.
Light cant travel far, and changes direction often.
H -> He
Temperatures high enough in early universe to fuse H into He.
o Only goes on while temp are high enough (Hubbles law -> the
more t passes, universe will get cooler (less dense).
Big bang nucleosynthes