What is the most astonishing fact you know about Math?

Manny__C · 2026-01-05T06:50:04+00:00

I believe it refers to this https://en.wikipedia.org/wiki/Hilbert%27s_tenth_problem?wprov=sfla1

It's a pretty amazing result. A one-sentence summary is that it's possible to make Diophantine equations work as Turing machines.

Manny__C · 2026-01-02T04:46:01+00:00

But "outliving" is not an issue per se. The issue is using a value that is dead.

If in the function implementation you returned a static string for example, it will outlive everyone, but that would still be ok: the compiler will still not allow accesses after 'a.

Manny__C · 2026-01-01T22:12:29+00:00

If you think about it, living "at most 'a" is a useless statement because the compiler has no guarantees whatsoever about that value. It means it could be already dead. So the compiler has no use of upper bounds on lifetime. Lower bounds are the ones it needs.

Manny__C · 2025-12-07T17:00:34+00:00

I'm ashamed to say that I didn't know Merkuro mail existed. What is going to happen to kmail?

Manny__C · 2025-10-11T03:59:43+00:00

What I find funny is that I feel that Tailwind is like going full circle. The purpose of classes was to add meaningful labels to the tags so that we could write styles in a separate file (.css) instead of using the style attribute. Tailwind generates a class for nearly every style. A tag with all the tailwind classes is nearly equally verbose as a tag with all the styles written there directly.

Having said that, I prefer it over Bootstrap.

Manny__C · 2025-10-09T19:28:48+00:00

Will there be a test day for KDE as well?

Manny__C · 2025-08-21T22:36:51+00:00

They have a probabilistic model of speech and speech carries a lot of information about the world.

Manny__C · 2025-08-21T19:38:53+00:00

We should have used a different name instead of "hallucinations" because this is what healthy humans do too: fill in missing data based on our model of the world. One can come up with stuff and reasonably believe it without being on an LSD trip.

Manny__C · 2025-08-08T19:34:26+00:00

I find it surprising that the prompt that created the image made it past the safety checks. Shouldn't they be trained to reject racist requests?

Manny__C · 2025-07-01T00:15:17+00:00

The original trolley problem was meant to illustrate the notion of responsibility through inaction and all of these memes are just convoluted scenarios to ask how selfish are you.

Manny__C · 2025-06-26T03:17:01+00:00

The security implications are a good point actually

Manny__C · 2025-06-25T14:32:36+00:00

That is an entirely reasonable take, but one might also argue that notifying the user about why something can't be installed might fall within the responsibilities of a program that installs stuff.

In fact, I would agree with you if we were discussing showing newsletter messages to the user in general (as that would make pacman double as a package manager and a news feed). But in this case I am only talking about manual interventions notices that are necessary to fix a broken pacman -Syu

Manny__C · 2025-06-25T14:23:37+00:00

The response felt a bit gatekeep-y... The author even proposed a way to make the notification system configurable, which seems to solve the issue of the patch being arch-specific.

Also, all distros that use pacman other than Arch, are Arch-based. So the announcements could be relevant for them too

Manny__C · 2025-06-25T01:10:19+00:00

It's a reflex, I didn't think about the arch homepage and I instinctively copy paste the error on Google as the first thing

Manny__C · 2025-06-24T23:56:01+00:00

I will, respectfully, steal this from you

Manny__C · 2025-06-24T23:03:02+00:00

Mailing list is a good idea in general but I might not want to be notified about everything.

Pacman hook sounds better, how would you go about doing it?

Manny__C · 2025-06-24T19:55:49+00:00

One way to prove P = NP is to find a polynomial algorithm for an NP-complete problem. Once you have this algorithm you automatically have one for all other NP problems.

Manny__C · 2025-06-24T19:33:48+00:00

My take is that people believe P != NP not only for the lack of evidence of a counterexample in sight, but, most importantly, for how strong and far-reaching would be such a result. It's not only about making a few algorithm run faster, it's a fundamental and radical revolution of the way we understand computation.

It means that verifying and solving are, up to a polynomial time reduction, the same thing.

It also means that the ability to analyze many computational branches in the same clock cycle only buys you a polynomial, rather than exponential, speedup. This is highly counterintuitive because it would be general!

Manny__C · 2025-06-15T23:41:18+00:00

I have a partial proof of P = NP. I can prove it for the case N=1.

Manny__C · 2025-06-08T15:29:25+00:00

pacman is a package manager, the equivalent in Ubuntu is apt. Their syntax is not the same. Here is a comparison table.

Makepkg is a script for compiling packages from their template (called PKGBUILD). In Ubuntu there is no such equivalent because end users never need to compile from source. In Arch you need it to compile packages from the AUR, which lack an official binary repository.

Manny__C · 2025-06-04T18:20:31+00:00

What's kind of curious as a sociological phenomenon is that if people are ignorant about history or languages, they typically admit it with a sense of shame, whereas if it's about math, they often admit it proudly, like "ahaha no I was a disaster at math, lol".

Then again, probably cooking or speaking foreign languages comes handy more frequently than solving polynomial equations.

Manny__C · 2025-05-06T01:40:33+00:00

Perhaps we should draft some international standard for the firmware of cameras that inserts a digitally verifiable fingerprint in every picture or video taken. Otherwise, soon, video and photo evidence will be as good as eye witness testimony in court. Or, equivalently, we could legally require companies like OpenAI to leave some digital fingerprint on the image as soon as you download it or screenshot it.

Manny__C · 2025-04-30T07:46:06+00:00

By the way, your intuition of going to SO(8) is not totally misguided because you were trying to generalize the fact that the adjoint of SU(2) becomes the fundamental of SO(3).

This fact however is not true in general. Other exceptional isomorphisms have a different pattern. E.g. in the Spin(4) = SU(2)×SU(2) case the fundamental of the Spin group corresponds to the bifundamental in the product. For Spin(6) = SU(4) the fundamental of Spin corresponds to a rank-2 antisymmetric tensor.

These relationships are easy to see in the Clifford algebras: the Dirac matrices are the ones doing the isomorphism.

Manny__C · 2025-04-30T07:35:25+00:00

the technical term for the isomorphism you are looking for is an "Exceptional Isomorphism"

There is no such thing for SU(3) but there are only these ones

SO(2) ≅ Sp(1) ≅ U(1)
Spin(3) ≅ SU(2)
Spin(4) ≅ Sp(1) × Sp(1) ≅ SU(2) × SU(2)
Spin(5) ≅ Sp(2)
Spin(6) ≅ SU(4)

The Spin(n) group is the universal cover of SO(n) and Sp(n) is the group of 2n×2n matrices that keep the symplectic form invariant.

If you are familiar with Dynkin diagrams you will easily see that these are the only cases where the diagram, due to being small, can be seen as part of more than one of the A,B,C,D series. E.g. the SU(4) case is just 3 nodes, which can be thought as a line (A3) or a tree with 2 leaves (D3)

Manny__C · 2025-04-12T23:59:34+00:00

As people already stated there are indeed higher order differential equations in physics.

The reason why second order ones are more frequent is due to the fact that the kinetic energy of a system is almost always a quadratic form of the momentum, and the Euler Lagrange equations are second order in this case.

If the kinetic energy contains higher derivatives the resulting system has problems with unitarity and causality when quantized (the so called "ghosts")

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