APOD: Moon over Makemake (2016 Apr 30)

Comments and questions about the APOD on the main view screen.
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neufer
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Re: APOD: Moon over Makemake (2016 Apr 30)

Post by neufer » Tue May 10, 2016 4:51 pm

geckzilla wrote:
Jim Leff wrote:
Just intuitively, I'd have figured from that that the sun, at our distance, would present a viciously perilous threat to the eyes; that humans would have evolved a downward-looking face and we'd all be nocturnal. Etc.
Ever tried staring at the Sun? It's physically painful. That's evolution telling you to stop it.
  • However, solar beings would have evolved an upward-looking face (or they'd all be blind/nocturnal):
https://en.wikipedia.org/wiki/Conversations_on_the_Plurality_of_Worlds wrote:
Conversations on the Plurality of Worlds is a popular science book by French author Bernard le Bovier de Fontenelle, published in 1686. In the preface, Fontenelle addresses female readers and suggests that the offered explanation should be easily understood even by those without scientific knowledge. The book itself is presented as a series of conversations between a gallant philosopher and a marquise, who walk in the latter's garden at night and gaze at stars. The philosopher explains the heliocentric model and also muses on the possibility of extraterrestrial life:
  • Inhabitants of the sun would not see any thing : they would be either incapable of enduring so immoderate a light, or, their eyes sufficiently strong, of receiving it unless they were at some distance; therefore the sun could only be a habitation for people without sight. In short, we have abundant proofs that this luminary was not intended to be a dwelling-place ; and therefore we may as well continue our planetary journey.
Art Neuendorffer

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Chris Peterson
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Re: APOD: Moon over Makemake (2016 Apr 30)

Post by Chris Peterson » Tue May 10, 2016 6:38 pm

Jim Leff wrote:
Chris Peterson wrote: The Sun isn't much of a threat to our eyes at all.
....and yet if you go 1,000,000,000 miles further out, to where the sun is only 1% of its earthly brightness, you still can't safely stare at it.

Hence my perplexity.
Why the perplexity? We have no survival characteristics that require us to stare at the Sun, and staring at the Sun is trivially avoided at no survival cost. Are you similarly perplexed by the fact that we need to drink water, but easily drown if we find ourselves in the middle of the ocean... on a water world?
Chris

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