Wavelength- Distance covered by one full cycle of a wave- commonly measured crest to crest CU physics site animation shows wavelengths http://www.colorado.edu/physics/2000/waves_particles/index.ht mlhttp://www.colorado.edu/physics/2000/waves_particles/index.ht ml
VLA The very large array in Socorro New Mexico was built in the 1970s. It uses 27 radio telescopes all linked together in a Y shape. These telescopes simulate a large radio telescope 40 km in diameter.
The SETI Project SETI stands for the Search for Extraterrestrial Intelligence. SETI began using the Arecibo telescope to look for alien signals. In 1974 the Arecibo telescope sent a megawatt signal to outer space.
Spectra are created from excited electrons in atoms Valence electrons absorb energy from heat, electricity, other EM emissions Electrons jump up to a higher energy level When electrons fall back to ground state they give off EM emisions
Kinds of spectrum Continuous spectrum- like the rainbow Absorbtion Spectrum - has rainbow with black lines in it Emmission spectrum – just a line or two or three…………. Of colored light
Types of Galaxies- draw in Elliptical Spiral Irregular
Doppler Effect Red Shift-move away –Lengthen wavelength –Color shifts toward red end Blue shift-move toward –shorten wavelength –Color shifts toward blue end
Mass of the universe determines fate More than critical mass collapse Big Crunch another Big Bang? Does the universe occilate? Closed universe Less than critical mass expands forever Open universe
HR diagram Graphs stars Temp (color or spectral class) vs Absolute magnitude (Luminosity) Absolute magnitude – brightness based on being the same distance away from each star Apparent magnitude – brightness from Earth- all stars are different distances away
2 Famous Telescopes In the 1960 Robert Wilson & Arno Penzias won the Noble Prize for their discovery with the first large microwave telescope. COBE was a microwave / infra-red satellite in the 1980s.
The BTA Telescope Currently the largest single mirror telescope is the BTA, (Bolshoi Teleskop Azimutal) in Southern Russia. The BTA was built in 1975 and uses a single 230 inch mirror to collect light!
Multiple Mirror Telescopes After building the huge BTA telescope, astronomers realized that 200 inches is the maximum size for a telescope. Anything larger than 200 inches and the mirror becomes distorted under its own weight. The solution to this problem was to build multiple mirror telescopes.
Multiple Mirror Telescopes M.M.T. combine many mirrors to form one giant mirror. These mirrors are computer controlled to make a parabolic shape. The KECK telescope in Hawaii is currently the largest telescope in the world with a total of 400 inches of segmented mirrors!
3 Famous Observatories #1 Mauna Kea is Hawaiis tallest peak and home to the largest telescopes in the world. #2 Las Campanas Chile has some of the clearest seeing on the the planet. #3 Kitt Peak Observatory in Tucson Arizona has a large collection of telescopes.
The Hubble Space Telescope By placing a telescope in orbit you solve the problems of light pollution and atmospheric turbulence. In 1990 the space shuttle Discovery was launched with the 90 inch Hubble Space Telescope.
The Future of Optical Telescopes The NGT (Next Generation Telescope) will be a 300 inch multiple mirror orbiting space telescope. The ELT will be a 30 meter (3 times larger than the Keck) segmented mirror telescope.