Thales’ circles

Shared thoughts and images from a mathematician-musician-theologian-aesthete

[shiverandqueeef]

how measurements work in canada (ie/ badly)

[your-dads-filing-cabinet]

@/teaboot

[teaboot]

This isn't even a joke it's just what we do

[qwantzfeed]

YES PROBABILITY DOES NOT WORK THIS WAY, BUT LOOK: IN THIS CASE, IT JUST DID

[bogleech]

I know it's unfair vilification and stuff but it's also a lot of fun to see old media and stuff where people were SO scared of big animals like lions, sharks, crocodiles and wolves were fully expected to just come and eat you the moment you stepped into their territory. In older media we also made that assumption about gorillas and in still older we thought it'd be whales. But some animals that will actually fuck you up got left behind. Boars will kill you and eat you. They're way more likely to do so than any of those other things actually. Hippos, obviously, got off like bandits always being depicted as cute and dopey. And then there's the squids. Not giant kraken size squids. The eight foot squids that hunt in packs and will fuck you up if you fall in the water at night. I can't BELIEVE people slept on that. It's like all they cared about were the huge deep sea ones we never see. The medium size wolf pack squids were right there.

[bogleech]

Oh some of you don't know about the squids. I talked about them in another thread that went kinda viral somewhere or other but one of the reasons you should not swim in the open ocean at night in many parts of the world is that the water starts teeming with these:

And as you can see it is not like instant death, they too are just animals and they are often just gently curious about the presence of humans! But people who study and dive with sharks will tell you you're safe as long as you stay calm and know what you're doing. The world's leading professional night divers and experts on these squids, specifically??? Stress in every interview and article and paper they write in that you simply do not fuck around with these squids. They know what they're doing and they still all have at least one story of being attacked, in some cases having to be hospitalized. Considering just how rarely anybody puts themselves in the pitch dark nighttime ocean on purpose, let alone during a squid feeding frenzy, it sounds like they're quite a bit more likely to consider you potential food than other marine predators. We also don't know how many fatal attacks might have ever happened, because what humboldt squid like to do with large prey is just drag it away into the darkness forever. The two worst attacks ever proven involved two or three squid at a time latching on to a diver (in BOTH cases they were professionals and knew the risk!) and jetting straight downward with enough force that both divers suffered injury from the sudden pressure change alone, including burst eardrums, nearly passed out and they probably would have died if they hadn't broken free. In general, people who die drowning in the dark open ocean are either never found, or they're found in pieces picked over by enough scavengers that the precise cause of death can only be narrowed down to "the sea." But now you know ONE of "the sea's" possible murder weapons :)

There's a short section on Humboldt squid in Wikipedia's entry for Cephalopod attacks on humans:

Cephalopod attack - Wikipedia

And if you can get past some of Animal Planet's hokey presentation style, this video includes a bit of interview with one of those professional experts who still got nearly squidded from existence:

There is of course some debate about all this, with some arguing that all proven documented attacks occurred on people with reflective diving equipment, which they say the squid must have mistaken for the shine of fish. However, there are lots and lots of people who have to fish around these squids to survive, who do not have access to that kind of equipment, and also have a consensus that if you fall in the water when big squids are out hunting you might disappear without a trace or perhaps just get your head bitten open. With many modern science guys agreeing with this sentiment, this is one case where the "they're just misunderstood sea friends" crowd is kind of outnumbered. The sea at night is theirs and not ours is all. It's not ours during the day either but since we are neither marine nor nocturnal animals we are double fools in the eyes of the squids, which by the way are these eyes:

No for real:

[my-ants-are-anxious]

Absolutely! Also, the Humboldt squid will hunt in packs, sometimes with one flashing brightly to draw attention while the others approach in near unseeable camoflage!

[bogleech]

Beautiful footage of the nefarious sea demons also :)

Also because I can't reblog every addition together:

Okay where's the other 1199

[spiralshellsreblogs]

I absolutely adore Humboldt squid. I saw a doc once where a scientist was cage diving to study them, and one of the squid squeezed it's entire massive body through the cage bars, bit the guy and squeezed right back out.

[bogleech]

Why isnt this an animal that's already long gone viral like honey badgers once did. This is the animal that actually gives no fucks. People really are just that obsessed with bigger squids I guess? But the bigger ones frankly come across as big softies in comparison. One big sea monster can never be as intimidating as a thousand coordinated man sized sea monsters.

This is why I thought that if mermaids had a cultural equivalent to lycanthropy it'd be weresquids. Fun fact nocturnal marine life increases activity on the brightest nights ie the full moon.

[lasrina]

This is all fascinating but I'm reblogging it exclusively for the phrase "got nearly squidded from existence."

[publicdomainreview]

Ajeeb the Wonderful, a chess-playing automaton made in 1865. Famous opponents incl. Houdini and Roosevelt though, of course, Ajeeb had a little help from the human hidden inside him making the moves. More from the Harvard Theatre Collection here: https://publicdomainreview.org/essay/cabinet-card-photographs-from-the-harvard-theatre-collection

[dajo42]

5001 being divisible by 3 doesnt feel right

[dajo42]

[shinyhappygoth]

Shortcuts to determine if an integer is divisible by:

This is a given.

If the last digit is divisible by 2 (a.k.a. even), then so is the whole number.

If the sum of the digits is divisible by 3, then so is the whole number. The recursivity of this means that if the sum has multiple digits, you can add them up again until you get a single digit and see if it's 3, 6, or 9.

Like the rule for 2, but check if the last two digits are divisible by 4.

If it ends in 5 or 0.

If the rules for both 2 and 3 apply.

No shortcut. Alas.

Like the rules for 2 and 4, but check if the last three digits are divisible by 8. (Yes, this pattern keeps going for 16, 32, etc.)

Like the rule for 3, but the sum of the digits (or the sum of the sum of the digits, etc.) must be 9.

If it ends in 0.

[noelements-setempty]

11. Put alternating + and - signs in front of each digit such that the last digit has a + sign (so for 5001 it's - 5 + 0 - 0 + 1). If the answer is divisible by 11, so is the original number. This is recursive like the 3 and 9 rules.

[unnatural-transformations]

7: Subtract twice the last digit of your number from the number you get by ignoring the last digit. If the result of that operation is divisible by 7, so is your original number (eg, 91 -> 9 - 2×1 = 7, so 91 is a multiple of 7). As with the rules for 3, 9 and 11 this rule is recursive (2261 -> 226 - 2×1 = 224; 224 -> 22 - 2×4 = 14; 14 -> 1 - 2×4 = -7 and so 2261 is divisible by 7).

It's not a fast way of checking if a number is a multiple of 7 (you honestly may as well just do the division), but it does work.

[nyxscave]

Learning used to be so much fun. I'd read encyclopedias during meals when I was a kid, solve math problems bc it felt good being the only one in my class who could do it, finish fiction books in a day.

Then academic trauma happened. Being 'the smart one' suddenly meant pressure to be better, be perfect, have the grades and the test scores and the medals to prove it. And now I'm an adult and doing a master's and still feel like the dumbest, most inferior person in this uni. Studying is so painful and I get fucking hives at the 20-min mark.

I hate seeing myself as the victim of all that shit bc all the procrastination and anxiety feels like it's only my fault. But what the fuck. Why would they do that to someone who somehow enjoyed learning. Was it worth it? If I put all my success in a can and hand it to them, weight it against that person's own shame and past trauma, will I ever be normal about this again?

[mathhombre]

Just got to talk to Francis Su, literally yesterday, and he shared how in grad school he went through something really similar. Everything was hard, and there were real problems. So he had to re-examine why he was doing mathematics.

Decades of thinking about that led him to his Math for Human Flourishing message.

Quick take:

Longer take:

So I don't know about being normal, but it can be better, and this is an opportunity to pursue virtues that will make all of life better. Gratitude and community, among other things Francis meditates on. It doesn't have to be math, but it certainly can be, and math is a great path if you're drawn to it.

I hope this doesn't sound preachy. Just had to say something because someone kind took the time to talk to us yesterday about it.

[janmisali]

oh I know how to make a poll's results look like the letter E watch this

what is the rightmost digit of the number of responses this poll has right now? (it should be visible before you vote.)

0, 1, or 2

3

4 or 5

6

7, 8, or 9

Voting ended onJun 13

[absenteism]

[melodramas]

photos by the artemis ii crew

[mckitterick]

NASA source for these and lots more Artemis Moon photos: X

[magicmooshka]

recently my friend's comics professor told her that it's acceptable to use gen AI for script-writing but not for art, since a machine can't generate meaningful artistic work. meanwhile, my sister's screenwriting professor said that they can use gen AI for concept art and visualization, but that it won't be able to generate a script that's any good. and at my job, it seems like each department says that AI can be useful in every field except the one that they know best.

It's only ever the jobs we're unfamiliar with that we assume can be replaced with automation. The more attuned we are with certain processes, crafts, and occupations, the more we realize that gen AI will never be able to provide a suitable replacement. The case for its existence lies on our ignorance of the work and skill required to do everything we don't.

[intosnarkness]

legit the best advice i can give you: feed your friends

any time someone is in any kind of crisis or upheaval, offer to feed them. tell them they don't have to choose what it is if they can't make decisions, just ask about allergies and preferences and tell them you're just gonna make food happen at their house.

friend having a baby? delivery gift certificate to order food to the hospital after the kid shows up.

someone's relative passes away? offer to make them dinner.

buddy gets laid off? ask if you can order them lunch.

pal stuck in a depressive episode? offer to drive them to fucking mcdonalds, if that's what they want.

people in crisis are tired and sad and angry and the last thing most of them are doing is thinking about feeding themselves. so if you have the ability or time or money, providing that is always, always a good move.

legit i do this all the time, and it is 100% always appreciated. i have taught all my friends that when something happens, we feed each other. it makes people feel extremely cared for, and I cannot recommend it enough.

[sandersstudies]

Right after I reblogged this I found out a friends’ mom was hospitalized — this is such a good reminder

If you can, provide disposable plates/utensils and save them from doing dishes — when my husband was diagnosed with cancer, bulk paper products were our most appreciated gift

[alagaisia]

Hey. Why isn’t the moon landing a national holiday in the US. Isn’t that fucked up? Does anyone else think that’s absurd?

[alagaisia]

It was a huge milestone of scientific and technological advancement. (Plus, at the time, politically significant). Humanity went to space! We set foot on a celestial body that was not earth for the first time in human history! That’s a big deal! I’ve never thought about it before but now that I have, it’s ridiculous to me that that’s not part of our everyday lives and the public consciousness anymore. Why don’t we have a public holiday and a family barbecue about it. Why have I never seen the original broadcast of the moon landing? It should be all over the news every year!

[alagaisia]

It’s July 20th. That’s the day of the moon landing. Next year is going to be the 54th anniversary. I’m ordering astronaut shaped cookie cutters on Etsy and I’m going to have a goddamn potluck. You’re all invited.

[watermelon-converse]

Hey. Hey. Tumblr. Ides of March ppl. We can do this

[emi--rose]

Hell yeah moon holiday

[hello-delicious-tea]

Ooh coming up we should celebrate

[ariaste]

PITCH: We call it Moon Day, and then every 7 years when it falls on a Monday, that's an even BIGGER deal and we call that Moon Day Monday and go absolutely apeshit about it (the next Moon Day Monday is in 2026 so we have a couple trial runs first)

[sarostheghostcat]

MOON DAY MOON DAY MOON DAY

[wafflebloggies]

moon day is 20th July!!!

[silly-jellyghoty]

Scheduling this a day earlier to remind you all and myself about the Moon Day tomorow!

[sashaforthewin]

Happy moon day to all who celebrate

[kitsuneofthemist]

This is your reminder to prep for Moon Day on July 20th.

[z-boson]

pro tip if you're ever stuck on a math problem you can try meowing at it. It wont help but you CAN try it.

[publicdomainreview]

Before Cousteau, way before @Octonauts, explorer Eugen von Ransonnet-Villez was bringing images of the undersea world to the surface, from his artist’s sketch pad inside a glass and steel diving bell: https://publicdomainreview.org/collection/underwater-landscapes-of-eugen-von-ransonnet-villez

[qwantzfeed]

and i don’t have to tell you this, but when that happens in a matter/antimatter intermix chamber it’s not great

[cwnerd12]

shit man this got me emotional

[mckitterick]

left: the Nebra sky disc, circa 1600 BCE, showing the Moon, Sun, and stars in gold on copper - the oldest depiction of the cosmos in the world

right: the Webb Space Telescope, July 2022, revealing thousands of baby galaxies forming in the early days of the universe - humankind’s deepest look into the sky

[thirdtimecharmed]

[codeearth]

Here’s some extra photos of the disc from when it was exhibited just in case

[stevishabitat]

Text from the images:

The Nebra Sky Disc

Found in Germany, the Nebra Sky Disc is the oldest known material depiction of cosmic phenomena in the world. It reveals the creativity and advanced astronomical knowledge of cultures without writing.

The distinctive rosette of seven stars represents the Pleiades. These stars play a key role in an ancient rule, known from a 2,700-year-old Babylonian text, that allowed the shorter lunar year to be kept in step with the solar year. A leap month should be added every third year if a crescent moon a few days old appears next to the Pleiades in the springtime sky.

The Nebra Sky Disc was made using gold from Cornwall and bronze from central Europe. It was remodelled as its meaning and use changed. Like Stonehenge’s alignment, the bands on either side marked the positions of the rising and setting sun over the course of the solar year.

Gold and bronze Nebra, Saxony-Anhalt, Germany about 1600 BC State Office for Heritage Management and Archaeology Saxony-Anhalt

[moishe-pipick]

Emma Kunz, 1892 - 1963