@SvenGeier@mathstodon.xyz
@SvenGeier@mathstodon.xyz avatar

SvenGeier

@SvenGeier@mathstodon.xyz

Geometry, Physics, Art, Math.

https://scholar.google.com/citations?user=G0JsJQMAAAAJ

This profile is from a federated server and may be incomplete. Browse more on the original instance.

ProfKinyon, to random
@ProfKinyon@mathstodon.xyz avatar

dear god no

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@ProfKinyon of all the things the Internet has wrought, I didn't expect to see "having tea time chat with my grant proposal"...

SvenGeier, to random
@SvenGeier@mathstodon.xyz avatar

Math woes https://www.smbc-comics.com/comic/k

designthinkingcomic, to random
@designthinkingcomic@mastodon.cloud avatar

Just my surname and date of birth, right? That's totes secure...

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@designthinkingcomic surely you've seen the game, right? https://neal.fun/password-game/

cstross, (edited ) to random
@cstross@wandering.shop avatar

If the British government recovered fragments of the sword Excalibur and decided to have it re-forged for nation-building reasons, how would they go about it?

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@cstross The last two are not mutually exclusive

foone, to random
@foone@digipres.club avatar

for complicated tumblr reasons involving dreaming of classified CIA visual novels, I mocked up a Powerpoint 4.0 slide for government agents trying to seduce transfems.

I thought I'd share it here for retro nostalgia and trans shitposting reasons

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@foone I think "shenis" ... uh ... "rolls off the tongue" the best...

johncarlosbaez, (edited ) to random
@johncarlosbaez@mathstodon.xyz avatar

It looks like they've found protonium in the decay of a heavy particle! 🎉

Protonium is made of a proton and an antiproton orbiting each other. It lasts a very short time before they annihilate each other.

It's a bit like a hydrogen atom where the electron has been replaced with an antiproton! But unlike a hydrogen atom, which is held together by the electric force, protonium is mainly held together by the strong nuclear force. It's also much smaller than a hydrogen atom.

There are various ways to make protonium. One is to make a bunch of antiprotons and mix them with protons. This was done accidentally in 2002 during the first experiment that created antihydrogen. They only realized this upon carefully analyzing the data 4 years later.

This time, people were studying the decay of the J/psi particle. The J/psi is made of a heavy quark and its antiparticle. It's 3.3 times as heavy as a proton, so it's theoretically able to decay into protonium. And careful study showed that yes, it does this sometimes!

The new paper on this has over 550 authors, so I won't list them all. It also has a rather dry title - not "We found protonium!"

• Observation of the anomalous shape of X(1840) in J/ψ→γ3(π+π−), https://arxiv.org/abs/2310.17937

The idea here is that sometimes the J/ψ particle decays into a gamma ray and 3 pion-antipion pairs. When they examined this decay, they found evidence that an intermediate step involved a particle of mass 1880 MeV/c², a bit more than an already known intermediate of mass 1840 MeV/c².

This new particle is a bit lighter than twice the mass of a proton, 938 MeV/c². So, there's a good chance that it's protonium!

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@johncarlosbaez I think all your mass numbers are off by about 3 orders of magnitude - did you mean to write "MeV" instead of "GeV"?

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@johncarlosbaez ...and not to be too niggly at the hairy edge of detectability, but 2×938M𝑒V=1876M𝑒V, so 1882M𝑒V would be a little h𝑒𝑎𝑣𝑖𝑒𝑟 than 2 isolated protons which is not what I would naively expect...

bleuje, to random French
@bleuje@mastodon.social avatar

I'm currently working on some interactive realtime project, using the "36 Points" algorithm from Sage Jenson.
(https://www.sagejenson.com/36points/)
Github repo of this project: https://github.com/Bleuje/interactive-physarum

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@bleuje beautiful :)

ProfKinyon, to random
@ProfKinyon@mathstodon.xyz avatar

Theorem: If N is a positive integer and is not a perfect square, then (\sqrt{N}) is irrational.

Proof: Suppose (\sqrt{N} = a/b) for positive integers (a,b) with no common factor greater than 1. Then (b/a = \sqrt{N}/N), and so (a/b = (bN)/a). Since the first fraction is in lowest terms, the numerator and denominator of the second fraction must be a common integer multiple, say (c), of the numerator and denominator of the first. Hence (a = cb), and therefore, (\sqrt{N} = c), that is, (N) is a perfect square. QED

I learned this proof from a one paragraph insert in the American Mathematical Monthly (vol. 115, June-July 2008, p. 524) written by Geoffrey C. Berresford. I just love it.

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@ProfKinyon @bkim
on Android, at least, there's an app called "mathstodon" (not related to the instance itself) that renders the latex just fine. It has clear bugs, but it's what I use...

futurebird, to random
@futurebird@sauropods.win avatar

Thinking about world building & the consequences of “too much” history. In many sci-fi tales parts of history are forgotten— some cataclysm results in a society with about as much history as we have: some 20k years with the last 2000 being most referenced and the last 100 (living memory) of real consequence.

But what if you had a million years of detailed written history? What about a billion? I think there is a reason so many sci-fi stories have the trope “we forgot the location of earth”

SvenGeier, (edited )
@SvenGeier@mathstodon.xyz avatar

@futurebird I think the "forgetting the location of the earth" is just a natural extension of the current state of affairs: do you really know where your great-great-great-ancestors came from? Most people can only vaguely wave at a continent or two when you go four or five generations back - the exact, precise rock where those people of old lived on is not just forgotten, but largely unimportant. I would think in the same way future sci-fi people will have a rough idea of the general spiral arm of the galaxy where people came from, and there will be delta-quadrant-supremacists who have whole religions structured around the idea that they never came from that backwater Orion-arm ...

foone, to random
@foone@digipres.club avatar

linux question where I figure someone might have the answer on the top of their head:
I have like three microcontrollers plugged into one system and they're all acting as serial ports, so I get /dev/ttyACM0 and ttyACM1 and ttyACM2:
How can I tell which one is which? like, spelunk into /sys/ and figure out the pid/vid of each?

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@foone /proc/bus/input/devices ?

lowqualityfacts, to random
@lowqualityfacts@mstdn.social avatar

That blows my mind.
https://patreon.com/lowqualityfacts

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@lowqualityfacts And that's just in Belgium. Imagine what they might do elsewhere...

foone, to random
@foone@digipres.club avatar

I know I really should prefer ARM given that it was designed by My People, but I just can't help it:
My favorite processor is 32bit x86

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@foone Anything 32 bits was a mistake. 16bit is already sus af. Z80 was good enough for Pac Man, it's good enough for me...

SvenGeier, to random
@SvenGeier@mathstodon.xyz avatar

Of the pictures I took today, this is my favorite. It clearly shows sunspots 3628 (in the center) and 3633 (towards the upper left) and of course the shadow of the moon partially covering the sun.
Let's have another eclipse one of these days...

SvenGeier, to random
@SvenGeier@mathstodon.xyz avatar

Two sun spots and a moon -this is as much as I can do from Los Angeles with a setup made from cardboard and bricks... 🤷

markmccaughrean, to photography
@markmccaughrean@mastodon.social avatar

As the Sun slips towards the western horizon as seen from The Netherlands, it's fascinating to think that the Moon is also in this picture.

And that as seen from some points on Earth, the Moon is already partly covering the Sun, the path of totality sweeping across the Pacific towards the Mexican mainland to arrive in half an hour or so.

But our view here? Nada 🤷‍♂️

Celestial mechanics 🌞🌑

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@markmccaughrean
Basic projection onto a note pad here in Los Angeles - things are winding down...

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@markmccaughrean thanks to the sun for those two noticable sun spots that kept orientation straight while I was taking cell phone pictures and not maintaining angles for those 2 hours. Very considerate.

lowqualityfacts, to random
@lowqualityfacts@mstdn.social avatar

I'm with Abe on this one.
https://patreon.com/lowqualityfacts

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@lowqualityfacts ...but why would they want to?

monsieuricon, to random

I've been admining Linux systems for 25 years, and I still have to check which one it is every time.

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@corbet @monsieuricon "rename that doesn't remove the old file" is just a complicated way to say "cp", right?

batkaren, to random
@batkaren@mastodon.online avatar

I guess NYC should get more accustomed to earthquakes now that we’re apocalypsing.

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@batkaren but that's so west coast. How about we compromise on sea monsters swallowing Manhattan?

TodePond, to random
@TodePond@mas.to avatar

My gender

(setting the record straight for anyone confused these last few days)

https://www.todepond.com/wikiblogarden/my-name/gender

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@TodePond "Why pick just one? Specialization is for insects."

dpiponi, to random
@dpiponi@mathstodon.xyz avatar

Too much of my life spent wrangling build systems rather than writing actual software that does something.

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@dpiponi ... maybe you should write software that wrangles build systems for you?

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@pozorvlak @christianp @dpiponi No, no, obviously it would be a bad idea to write a makefile generator by hand. I'd suggest writing a piece of code that writes it FOR you. Ideally using copilot....

ideogram, to Autism
@ideogram@social.coop avatar

The reason autistic people identify as LGBTQI more than allistic people is a mystery still but the theory that we "just don't give a shit" is strongly endorsed in the comments.

https://youtube.com/shorts/Y2ufJMLzFUM?si=rdvnw_Mxz6hXDvxF

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@BernieDoesIt @olena @ideogram When my kid asked one of these questions around age ... 4? I just shrugged and told'em "why pick when you can have both"? I have no personal use for the "gender" notion, so why propagate it? I'm "male" in the same way I'm "a capricorn" - useless labels people stuck on me that have no bearing on who I actually am. I understand the words and where they come from and I understand that some people think they are 𝑟𝑒𝑎𝑙𝑙𝑦 𝑖𝑚𝑝𝑜𝑟𝑡𝑎𝑛𝑡 and as far as I can tell they bring no value to my table...

lowqualityfacts, to random
@lowqualityfacts@mstdn.social avatar

Wow, that's a lot of calories.
https://patreon.com/lowqualityfacts

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@lowqualityfacts And that's just in a day. In a night it could consume another 100 or 200 more!

  • All
  • Subscribed
  • Moderated
  • Favorites
  • •
  • megavids
  • rosin
  • thenastyranch
  • GTA5RPClips
  • tester
  • InstantRegret
  • DreamBathrooms
  • ngwrru68w68
  • magazineikmin
  • everett
  • Youngstown
  • mdbf
  • slotface
  • kavyap
  • JUstTest
  • cisconetworking
  • khanakhh
  • normalnudes
  • osvaldo12
  • cubers
  • tacticalgear
  • Durango
  • ethstaker
  • modclub
  • anitta
  • provamag3
  • Leos
  • lostlight
  • All magazines
    •