Sep. 23 – 2B03 23/09/2011 9:23:00 AM
Recent research (last day or two):
Discovery -> neutrinos (small massed particles) observed to move
faster than light.
o Given the distance (Italy to Switzerland [between 2 particle
o Prof has spoken to other profs and they believe it can’t be
true (there has to be some error). The researchers said they
were really conservative and cant find any errors.
o Main criticism -> error of 10 nanoseconds (others believe it
should be bigger)
o Likely a systematic error, but if no one can explain this -> big
o 60-80 nanosecond difference between light and neutrino
speed (in the expt)
Everything in special relatively comes from the idea that
nothing can travel faster than c.
Main concept of last time – raisin bread shit.
Visible light is a tiny portion of all electromagnetic radiation in the universe.
Used in medical procedures
Still very energetic
Reason why UV light is damaging is because it is high energy.
Really long wave lengths -> radio waves -> transmitting communication.
Not expected to know the slide that has the vertical spectrum. Gamma ray bursts – first detected by cold war
Nuclear bomb also gives off high energy gamma rays.
Soviets were pissed that Americans were testing, but it was really
an astronomical event.
Things that emit x rays are hot gas, AGN (active galactic nuclei) –x
ray coming from the centre of galaxies, they are associated w/
Young hot stars
Infrared we detect stuff with dust in the universe.
We use all different cameras for all the spectrum wavelengths.
Radio - 21-cm radiation
Atomic (neutral) hydrogen dominates the universe, but we cant
normally see it. Only at this wavelength.
Back in the day, we only had the ability to detect it only at the visible
Now, we got the techn