@SvenGeier@mathstodon.xyz
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SvenGeier

@SvenGeier@mathstodon.xyz

Geometry, Physics, Art, Math.

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

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christianp, to random
@christianp@mathstodon.xyz avatar

I'm going to tell you two statements, each made by YouTube about a video I uploaded:

a) it was uploaded 1 year ago.
b) it was uploaded on 5th June 2022.

Could these statements both be about the same video?
If so, are they both accurate?

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@christianp Depends: "uploaded one year ago" on which planet?

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@christianp
Mars orbital period is 687 days.
687 days ago was Jun-23-2022. If we allow for 2 weeks slack, that fits quite well... 🤷‍♂️

j_bertolotti, to random
@j_bertolotti@mathstodon.xyz avatar

People studying brains: "We found no correlation between number of neurons and IQ."*

People talking about AI: "If we just add more nodes to our deep neural network we are surely going to create a super-mind!"

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@j_bertolotti @apodoxus Dunno - to within some range, surely there's some sort of trade between the number of neurons used and the cleverness of their arrangement. I highly doubt that LLMs are anywhere near as well-organized as the human brain, so they may well be in the realm where "more neurons" still gives huge advantages. 🤷‍♂️ At some point there's a diminishing return, and then we'll need to talk about "better structure" (which I, personally, would guess means "more complex structure" - I'm staggered by how 𝑝𝑟𝑖𝑚𝑖𝑡𝑖𝑣𝑒 the current crop of AI really are) but at any one time we might well be at a point where sheer quantitative growth can still beat out real advances...

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

Tolstoy: "Happy families are all alike; every unhappy family is unhappy in its own way."

Mathematics: "Real tori are all alike; every complex torus is complex in its own way."

To be precise, a 'n-dimensional real torus' is a real manifold of the form V/Λ where V is an n-dimensional real vector space and Λ ⊆ V is a lattice of rank n in this vector space. They are all isomorphic.

An 'n-dimensional complex torus' is a complex manifold of the form V/Λ where V is an n-dimensional complex vector space and Λ ⊆ V is a lattice of rank 2n in this vector space. These are not all isomorphic, because there are different ways the lattice can get along with multiplication by i. For example we might have iΛ = Λ or we might not.

And so, it's possible to write a whole book - and indeed a fascinating one - on complex tori. For example a 1-dimensional complex torus is an elliptic curve, and there are whole books just about those.

SvenGeier,
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@johncarlosbaez
@wnj
I may not have learned much in my years on this planet, but I have learned this: if John Carlos Baez says "not easy", there is no point for me to even look at it... 🤷🏽‍♂️

SvenGeier, to random
@SvenGeier@mathstodon.xyz avatar

i guess?

SvenGeier, to random
@SvenGeier@mathstodon.xyz avatar

In the beginning, god created the heavens and the earth. And then the dragons arrived...

whitequark, to random
@whitequark@mastodon.social avatar

please tell me the most obscure joke you know

(feel free to explain or not explain it, depending on what you find more amusing to think of me reading it)

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@SnoopJ @whitequark Bartender says "you guys just don't know your linits"

DavidKButler, to random
@DavidKButler@mathstodon.xyz avatar

I love those few minutes at sunrise when the tops of the trees are in sunlight but you are still in shadow.

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@DavidKButler If the tree can see the horizon and you know the height of the tree, then measuring the time for the sunlight to reach from the top to the bottom allows you to compute the circumference of the earth...

julesh, to random
@julesh@mathstodon.xyz avatar

Beware the pipeline

image/jpeg

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

@julesh
Wait, you have to go through a pipeline? I fear we completely skipped that part...

shadeow, to mathematics French
@shadeow@piaille.fr avatar

Alors la les matheux j'ai besoin de vous. Je suis tombé la dessus et je suis bouche bée 👀

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@shadeow
(Replying now to see what others come up with)

36 = 2×2×3×3 , so the 3 possible age distributions are

2, 2, 9
2, 3, 6 or
3, 3, 4

These add up to 13, 11, and 10, so I doubt the sum is going to tell us much here. Unless "passager" has a clever double meaning in French?

I'm assuming the "oldest loves sports" is supposed to tell us something about a minimum age a kid must be to love sports[?] My own kid was on a soccer team at age 6, so at most this might eliminate the 3rd option[?]

I'd love to hear what others make of this...

SvenGeier,
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@vacuumbubbles @shadeow (I'm not going to insult people by trying to write in French ;)

I had completely missed the "1" - that opens up the possibilities. Thanks.

Two kids can easily have the same age if they're twins, so 2,2,9 and such isn't excluded.

SvenGeier,
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@mcgoa @shadeow

Ah, brilliant!

And then "my oldest" means there is a single "oldest" so it's not 6,6,1.

cstross, to random
@cstross@wandering.shop avatar

TBH, putting "GIANT MURDER ____" in front of virtually any animal species' name makes it worse, except for Tyrannosaurs (where it's kind of redundant)

SvenGeier,
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@angusm @cstross

GIANT MURDER CAT ?

foone, to random
@foone@digipres.club avatar

The four most used operating systems:

  • windows
  • apple macos/ios
  • linux (legacy, deprecated, not for new projects)
  • systemd
SvenGeier,
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@foone I don't think android uses systemd (?) in which case android/Linux would be the first entry in the list, no?

SvenGeier,
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@foone

  • Emacs ?
ProfKinyon, to random
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"...the advanced type system helps catch silly and profound mistakes."

Took me quite a while to realize that the author of the sentence probably meant this to refer to two different kinds of mistakes.

SvenGeier,
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@ProfKinyon

Joemoeller, to random
@Joemoeller@mathstodon.xyz avatar

This summer I'm starting a postdoc at CalTech! I'm working with the roboticist/control theorist Aaron Ames on using category theory to study stability of dynamical systems.

I got verbal confirmation a month ago, but I've been holding back on saying anything until I got bureaucratic confirmation.

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@Joemoeller As a former Caltech postoc, congratulations.
Not sure if attitudes have changed from a couple decades ago, but beware of departments using you for their research and then dropping you on the floor - your career progress should be in the back of your head all the time. Write papers that YOU think are worthwhile (even if your collaborator/s don't think so). Attend conferences that are good for YOU (even if they're only marginally related to your 'official' research area). Make contacts that help YOUR networking (even if they don't help progress your project). You'll also do plenty of the other kind, ideally a lot of them. Ideally progressing your project/s and your career are symbiotic. But it's easy to lose sight of your own future in the hubbub and academic folks aren't the best managers that will look out for you...

j_bertolotti, to random
@j_bertolotti@mathstodon.xyz avatar

Business idea: A course teaching University Professors how to start their presentation from their own computer (with an advanced course on how to share your screen when online).

Not sure anyone would be willing to pay for it, but there is clearly a need for such a course.

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@j_bertolotti
Lesson 1: locating your "mute" buttons (you have multiple)

foldworks, to random
@foldworks@mathstodon.xyz avatar

Central panel from tessellated floor of a Roman Villa, Ancient Corinth, Greece

In the corners of the panel, kantharoi with ivy. In the center, the head of Dionysos with fruit and ivy in his hair. 2nd half of the 2nd c. 3rd c. A.C.

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@foldworks
Very cool, but I'm having trouble deciphering "2nd half of the 2nd c. 3rd c. A.C.": Second half of the ... second century[?] third century[?]
And what is "A.C."? ante ... something? I understand the move from BC and AD to BCE and CE, but I don't think I've heard "AC" before (except in the context of ⚡DC )

cstross, to random
@cstross@wandering.shop avatar

Optimistic interpretation.

MY takeaway from this is puppies are worth more than pregnant women to Republicans.
https://mstdn.social/@JamesWNeal/112343263700549374

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@cstross

pauldrye, to random
@pauldrye@spacey.space avatar

"The Panama Canal lies open and exposed to attack by modern bombers. Ships wait in line for their turns to thread its outgrown passage from sea to sea...WHY NOT BUILD A TUNNEL FOR SHIPS FROM ATLANTIC TO PACIFIC?"

Art for an article by Jorge Cortinez Delfino in June 1956's Popular Mechanics, signed "Weeks". I haven't been able to find the artist's full name.

I've been reading about Soviet mega-engineering visions, but happened across this New World one this morning.

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@pauldrye more interestingly, the locks for the current panama canal operate on fresh water - every transit requires millions of gallons of potable water to raise the ships to canal level, then the water gets dumped when the ship is lowered on the other side. A tunnel on sea level would do away with that.

cstross, to random
@cstross@wandering.shop avatar

This is not a software glitch, it's the Y1C problem: old mainframes were so storage-constrained that they only allocated two decimal digits for passenger age, and adding another digit would mean rewriting software that in some cases has been in use and constantly patched since the late 1950s.
https://press.coop/@BBCNews/112345996328670433

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@addressforbots @cstross my native name is from a rare Namibian !kung dialect and I demand that the bank store it in it's correct Western transliteration '; DROP Table customers; ...

ProfKinyon, to random
@ProfKinyon@mathstodon.xyz avatar

Saw an old paper of mine from 2012 and thought "oh yeah, I wrote that just a couple of years ago."

I'm sure you noticed the problem right away, but it took me nearly half a minute.

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@ProfKinyon An hour later I still don't see any problem with looking at a paper you wrote a couple years ago in 2012...

christianp, to random
@christianp@mathstodon.xyz avatar

Another entry in the annals of the Tyne and Wear Metro's difficulties with communicating statistics.
The current iteration of their stats poster has two statements about the number of trains arriving on time: "77% of trains arriving on time", and "on average, four out of five trains arrive on time".

I'd say 77% is more like three out of four than four out of five, wouldn't you? Is there any wiggle room with the phrase "on average"?

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@11011110 @christianp or it was like 77.8% and they just cut it of at the decimal (and it is in fact closer to 80% than to 75%)

batkaren, to random
@batkaren@mastodon.online avatar

That thing where you keep your eyes closed to stay asleep when peeing at 3am, but applying it to the whole work day.

SvenGeier,
@SvenGeier@mathstodon.xyz avatar

@batkaren
*work week

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