Title text:
They're up there with coral islands, lightning, and caterpillars turning into butterflies.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3135/
There are places in the solar system where the tide rips new mountains up every go around.
That’s metal AF
Io.
Been trying to learn about the tides around here so I can tell what I'm seeing on the water. Imagine my joy when I found a Casio, which I collect, with tide and moon phase indicators!
And that's when I learned the Gulf Coast is strange, has diurnal tides (twice a day) the watch can't predict. Took me an hour and a half to figure out it would never function. The moon phase works!
Huh. TIL that there are three common types of tidal cycles and which one you get depends on geography, location, ocean currents. https://beltoforion.de/en/tides/tidal_cycles.php
And yeah, dinural is apparently the most rare of the three. Wild.
Tidal prediction requires a harmonic analysis of observed tides, and its location specific. Not sure how a watch is supposed to do that other than holding a database of tidal coefficients.
This video contains a lot of interesting history of tidal analysis and prediction:
There are adjustments you can make on the watch. Requires tables and whatnot. That's why it took me so long to figure out it wouldn't work!
Tides go in, tides go out, you can’t explain that.
Casio can't!
the Gulf Coast is strange, has diurnal tides (twice a day)
Diurnal tides are once a day (semidiurnal is twice a day). By the Gulf Coast, I guess you must mean the Gulf of Mexico. I'm living on the other side of the world in the other diurnal region, so I assume our tides are synchronised!
No idea how I got that backwards. I even looked it up before posting!
I think lightning would be crazy to anyone who never experienced a planet with it. Like, "WTF, sometimes your sky does what?"
FlatEarthersSayWhat
They'll just say the moon pulls the water around as it circles above the flat disc or something idk
"Tide comes in, time goes out - you can't explain that!"
Everyone was taught the tides look like two giant water bulges going around the earth in line with the moon.
That representation is oversimplified and false.
This is how the tides look like at a global level. It’s messed up.
Ok, that clarifies things so much better for me. Thank you.
You understand it more after that?
I'm more confused, honestly. But that's hardly surprising.
And when Mercury is in retrograde, you can make an excuse for anything being kind of shitty or off.
I wonder if anyone has ever done the math on how much (in L or kg) water is moved by the moon each day. It's got to be something absurd.
Just wanted to mention I see your pfp on every post.
Thank you for keeping lemmy alive and making like 4% of the total posts. Seeing you post brightens up my day.
No homo.
Imagine being out exploring new islands, not realizing its low tide. You setup camp for the night on an island that's relatively flat and close to current sea-level. Then while you're sleeping the tide comes in and washes your whole camp out to sea...
Come to the beach here in Bordeaux (well, on the coast) and see tourists set up their stuff at low ebb but forgetting they have to watch out for the flood.
There's an island near me that has a pedestrian causeway at low tide. There are huge signs warning to check tide times or get cut off, but still people don't get it.
A community for a webcomic of romance, sarcasm, math, and language.