Tour guide very clear that the #uchicago announcement does not mean the observatory is closing. There are options still. Encourages ppl to bring more folks to visit the observatory for science education.
Worlds largest telescope in 1895.
Big crowd for today’s tour 
Nice slice of #UChicago history on this tour - Harper, Rockefeller, etc.
So much ornamentation on the building. Some Harper, Yerkes, Rockefeller, in addition to the usual gargoyles, etc.
Smaller dome has a 41 telescope used for edu outreach. International junior astronomers org.
Building a telescope was part of Hale’s agreement with #UChicago. He was a local from Kenwood on the south side.
Yerkes was a capitalist, he accepted Hale’s request to fund the observatory as a way to rehabilitate his image.
Yerkes one of the capitalists involved in building the loop El mass transit.
Yerkes put up 1/2 Million in 1890s money for the observatory.
(We’re doing the history part outside where I have reception; spotty on the inside with this big a group)
Telescopes are about collecting light. The larger the lens the more light can be collected. Size of a telescope is the diameter of the lens.
.@YerkesObs has the largest lens still, later telescopes use mirrors and other technologies.
Hale left to go to Mt. Wilson in California when it become the largest telescope. @YerkesObs had the largest telescope for about 20 years. Succeeded by Mt. Wilson and then Palomar.
Canary Islands current largest, to be succeeded by the Giant Magellan. 900 inch diameter (?) telescope. #uchicago part of the consortium that’s putting that together.
Hubble, Sagan, Hale, and others have all used the @YerkesObs telescope.
Telescope.
(Nice overview of refractors vs. reflectors. )
(Nice overview of photons, how light works)
Chromatic aberration is corrected by having two lens.
Hale was the father of the four largest telescopes in succession.
Spectroscopy, photography main functions of Yerkes
Grand Canary telescope has a diameter 10 times the size of Yerkes (400 vs 40)
Giant Magellen mirror will be the size of the entire floor/dome of Yerkes Obs
Giant Magellan is expected to open 2023.
Telescope weighs 82 tons. Cool hydraulic floor. Base of telescope below.
Didn’t open the shutter today, but rotated the dome.
This technology can see galaxies out to 50-65 million light-years.
The hydraulic floor and the motors that rotate the dome are original 1890s tech (and motors)
Some of the tech was made digital in the 60s/70s.
High quality gift shop.
One more!
unroll
Here’s one of the Telescope @YerkesObs
