This is conceived as an informal and spontaneous annex to my more extensive blog, Grand Strategy: The View from Oregon.

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Discord Invitation

21st August 2017

Post

Happy Eclipse!

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I watched the eclipse from Portland, which was outside the path of totality. According to what I read, the sun was about 99.2 percent occluded in Portland. I took the photograph above by putting my eclipse viewing glasses over my camera – a dead simple approach to eclipse photography – some time after the near totality of Portland eclipse viewing. I took the picture below with the same camera, not putting the eclipse viewing glasses over the lens, very close to the time of maximum occlusion in Portland.

If the sun was 99.2 percent occluded at 10:19 am PDT, it is impressive to see how bright less than one percent of the sun’s light is. While it got noticeably darker, it wasn’t even close to being as dark as night in Portland. That one percent or less of sunlight was plenty of light to read by, and plenty of light to do any number of chores. I did notice that, as the moon moved off the sun that it felt noticeably warmer, though I hadn’t previously noted the chill of near totality. So it seemed to me (by unscientific, anecdotal measures) that 99.2 percent totality blocked a lot more IR radiation than visible spectrum radiation. 

This made me wonder about worlds with dimmer suns or stars shining on planets with different wavelengths of radiation. How different is one percent or less of a G-type star solar radiation from the full dose of radiation from a smaller, dimmer K or M type star? And how far away would one have to move away from the sun to receive only about one percent of the light we typically receive on Earth? Given that one percent is as bright as it is, the outer solar system may be quite cool, but not as dark as I have imagined.

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Tagged: Portland2017 eclipsetotality