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Dry rocks on a beach
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Wet rocks on a beach
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Reminds me of lots of beaches in Nova Scotia where I grew up ♥️
Huge tides so we'd see a lot of wet rocks!
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Replying to @WeftOfSoul
Meanwhile I grew up a literal stone's throw from the bay with the highest tides in the world, so when I go anywhere with ordinary 2-4m tides it basically feels like there's no tides.
Image below is not my hometown but I had to look for a couple seconds to be certain.
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Tides is something I've been meaning to look into
How can the moon be so far away and be pulling such a huge amount of water this way and that?
Something doesn't add up
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here’s another thing that confuses me: in most places the tides are roughly in a 12-hour cycle, meaning 2 high tides and 2 low tides a day (“semi-diurnal”). the naive analysis using the fact that the moon orbits about once a day would suggest that it ought to be about 24 hours
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We've been doing some more digging but it's still not that clear
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That doesn't, intuitively, to me, explain why high tide is twice a day though, moon-side and far-side. Something I've been looking at in this quest today said something about inertia for that though. Hmm…
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i came across a pdf that claims the key is to account for the centrifugal force of the earth’s rotation but i still don’t grok it and now i’m super confused about wtf an inertial reference frame even is
whoi.edu/cms/files/lect
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Incidentally, I watched this video a week ago and now I think I understand inertial reference frames better.
Centrifugal forces appear when you have a rotating frame of reference (around 8mins in the video).
(featuring Terry Tao & MathOverflow)
youtube.com/watch?v=1VPfZ_
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okay this video was cooler than i expected. i also found a physics.SE answer that looks like it gives an explanation of why the tidal forcing function has period ~12 hrs and not ~24 hrs:
physics.stackexchange.com/questions/1184
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what i was missing is that when the moon is on the opposite side of the earth from you it's pulling on the earth more strongly than on the ocean because the earth is now closer to it, so the ocean still experiences a net upward force relative to the earth
but now i don't understand the other claim in the pdf i found that if the earth weren't spinning the tides would be diurnal 🤔🤔🤔
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