* Astronomy

The Design of Extremely Large Telescopes
In the late 1970s, astronomers had a problem: the scale of their telescopes no longer matched the size of their ambitions. To see deeper and deeper into our universe's past, they needed a bigger telescope. To build a bigger telescope, they needed a larger mirror, but mirrors larger than five meters had the pesky habit of deforming, producing bad images and frustrating attempts to surpass the resolution of the 5-meter Hale Telescope, first built in 1948.

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