Edison’s “Tasimeter” and the Eclipse of 1878

Edison’s “Tasimeter” and the Eclipse of 1878

On July 29, 1878, Thomas Edison observed the total eclipse of the Sun as part of Henry Draper’s Expedition to Rawlins, Wyoming Territory. (Although this year’s total eclipse will pass through Wyoming, the City of Rawlins will be some distance south of the total path this time.) Edison was there to test a new invention that could detect infrared light and estimate the temperature of objects remotely, and he planned to try and estimate the heat of the Sun’s corona while the solar photosphere was blocked by the Moon.

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Equinox: The Big Dipper Star Clock

The pointer stars Merak and Dubhe point at Polaris and go once around per sidereal day, every 23 hours 56 minutes and 4 seconds.  By making a daily correction it is possible to estimate the time at night using these three stars. One point on this is pretty much...

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Fundraising for Digital Planetariums

Fundraising for Digital Planetariums

Planetarium technology isn’t the only thing that’s changed from the last heyday of planetarium installations in the '60s and '70s. 21st century fundraising is also a new concern for today’s educational planetariums. Today, a planetarium upgrade (or construction of a...

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