PHYSICS 20A Lecture Notes - Lecture 12: Chromatic Aberration, Lick Observatory, George Ellery Hale
Document Summary
Physics 20a lecture 12 exploring the cosmos. Spacecraft: the farthest sent space probe has just reached the edge of the solar system. Launched in the 70s this lecture was given in 2013. Proxima centauri, the nearest known star, is 4. 2ly away 30,000 years till that probe reaches. Space and ground telescopes: space probes suck the universe is too enormous, everything else we know about the universe comes from telescopes their discoveries dwarf those of any probe, hubble, types of telescopes. Refracting bends light; uses a lens to gather light. Reflecting bounces light; uses a mirror to gather light: telescopes collect light in large quantities. Can see fainter objects: telescopes improve clarity angular resolution. Bigger mirror sharper focus: telescopes are essentially light buckets . Telescope"s primary mirror/lens area its ability to collect light. At/ae = [ (4m)2]/[ (4mm)2] = (4000mm)2/(4mm)2 = 106 i. e. a big telescope can see 106 times fainter in the same amount of time.
