8 upvotes, 2 direct replies (showing 2)
View submission: Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science
IIRC, the sun has gradually but noticeably been brightening over its lifespan. So, during a partial solar eclipse, are we experiencing the same amount of daylight that a dinosaur, neanderthal, etc would have? Or is it too much/too little? Depending of course on how much of the sun is being eclipsed. Like if just the limb is blocked are we at Neanderthal/Cro-Magnon levels, is half blocked equivalent to Triassic, etc etc.
Comment by atomfullerene at 26/04/2023 at 18:05 UTC
33 upvotes, 0 direct replies
Figure 1 of this paper shows solar brightness over time
https://arxiv.org/pdf/1204.4449.pdf
As you can see, solar brightness seems to have started off at about 70% of today's levels 4.5 billion years ago and slowly increased to today's levels.
Going off the graph, a Neanderthal living a mere 100,000 years ago would see no difference at all. Solar levels in the Triassic, 225 million years ago, would have been 96/97% of what they are today. This is equivalent to the moon barely grazing the very edge of the sun's disc, and wouldn't be perceptibly different if you were to somehow look back in time.
Comment by CapWasRight at 26/04/2023 at 18:45 UTC
6 upvotes, 1 direct replies
Not what you asked, but note that eclipses change on geological timescales because the Moon's orbit is slowly shifting. Whoever talks about us like dinosaurs isn't going to have total solar eclipses any more, they'll be impossible by then!