Telescopes through Time
The earliest know glasses for correcting vision date back to about the middle of the 1300’s in Europe. It was not until early in the 1600’s that glass technology enabled the earliest known optical telescopes and in 1610 science superstar Galileo constructed a 20 power telescope to study Earth’s moon, discover four of Jupiter’s moons and make other astounding discoveries about the heavens. Four hundred years later scientists are still building bigger and better telescopes and while there are several kinds of optical instruments now in use, the latest is based upon round reflective mirror technology not unlike Galileo’s. Opening in 2007, The Large Binocular Telescope (LBT) is positioned on a mountain top as part of the Mount Graham International Observatory in Arizona. It is a joint project of the United States, Italy and Germany. With dual mirrors connected by computers that, among other things, can continuously adjust for distortions caused by Earth’s atmosphere, the LBT may give humans the best view every of the universe. Key to its construction, like the construction of Galileo’s telescope, is glass technology. LBT has two of the largest single mirrors ever manufactured. Each measures 8.4 (XXXX inches) meters in diameter. Assuming each mirror is flat (in fact it is slightly concave), what is the surface area of each mirror? What is the surface area of the largest mirror in your home?
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