sojournTime @sojournTime@qoto.org

I can't decide which of these is the most idiotic cliche in political journalism. You decide.

Mathematicians get annoyed at how physicists take beautiful formulas and clutter them up with 'useless' constants like

𝑐 - the speed of light
ℏ - Planck's constant
𝑘 - Boltzmann's constant
𝐺 - the gravitational constant

making it harder to see the essence of things. Most mathematicians prefer units where all these constants are set equal to 1.

I used to be like that too - but right now I'm doing a project where I 𝑛𝑒𝑒𝑑 these constants to see the essence of things!

(Of course it's good to keep these constants around to avoid making mistakes where you equate quantities with different dimensions: this is what computer scientists would call a 'typing discipline'. That's important, but it's NOT what I'm talking about now.)

When you're studying just one physical theory at a time, you can set dimensionful constants equal to 1 to simplify things. But often we like to study a whole 𝑓𝑎𝑚𝑖𝑙𝑦 of physical theories at once - a family where those constants take different values! We can't set them to 1 if we're interested in what happens when they approach 0. For example:

As 𝑐 → 0, special relativity reduces to Newtonian physics.
As ℏ → 0, quantum mechanics reduces to classical mechanics.
As 𝑘 → 0, statistical mechanics reduces to classical mechanics.
As 𝐺 → 0, general relativity reduces to special relativity.

And this is just the beginning of the story: various collections of constants can approach 0 at different rates, and so on.

When we do this, we're studying what mathematicians would call a 'moduli space' of theories - or even better, a moduli stack. We may want to do 'deformation theory', where we expand answers in powers of some constant. And so on.

So don't scorn those constants!

So... my son nerd sniped me! He saw a video on the Fold-and-Cut Theorem by Vsauce and said I should figure out how to fold a piece of paper to cut out the hat and spectre tiles with one cut. Mission accomplished! This blog post has downloadable PDFs: https://divisbyzero.com/2024/08/14/fold-and-cut-hat-and-spectre-tiles/

octahedral line dance

@hugoestr https://www.cdc.gov/nwss/rv/COVID19-currentlevels.html

Have you noticed that the entire premise of Pinocchio is impossible because it'd allow you to solve the Halting Problem?

Like, the Konigsberg conference where Godel whispered the deepest truth in mathematics and only Von Neumann understood? Tell me that story over and over. The time you went to a conference in San Diego, and the beaches were nice and there was an open bar? No one cares.

Child A's first wobbly tooth fell out yesterday at nursery, and they didn't even notice! We only spotted the gap in the evening when I was helping them brush their teeth. They were very upset they couldn't leave anything for the #toothfairy , or get a coin for it. But don't worry, #German paperwork to the rescue. I created a mini 'lost tooth' form that we've filled out and put under the pillow instead, I'm sure it'll work out 😉

#FediEltern #Parenting

I finally got it!
The game-changer clue on what I was getting wrong came by reading this old post https://www.physicsforums.com/threads/puzzling-roll-x-dice-choose-y-highest-problem.418161/#post-2813034 but it took some time to reconstruct all the missing steps in that explanation.
Will probably write down a (hopefully easier to digest) explanation as soon as I have time.

you've heard of sine and cosine

now get ready for uh squine and cosquare

It’s finally time to release my newest project: https://www.followthecrypto.org/

This website provides a real-time lens into the cryptocurrency industry’s efforts to influence 2024 elections in the United States.

#crypto #cryptocurrency #elections #USpol #lobbying

How can we train people in the art of learning to read scholarly research like a scientist?

Fascinated by this project that studied how biologists read papers, from undergrads to faculty, and why undergrads get so lost on things that experienced researchers find fast/easy.

More experienced readers focused on the data. More junior ones focused on the narrative.

https://www.tandfonline.com/doi/full/10.1080/21548455.2022.2078010

School Vouchers Were Supposed to Save Taxpayer Money. Instead They Blew a Massive Hole in Arizona’s Budget.
==

#Arizona, the model for voucher programs across the country, has spent so much money paying private schoolers’ tuition that it’s now facing hundreds of millions in budget cuts to critical state programs and projects.

#News #Education #Schools #Students #Politics #Government

https://www.propublica.org/article/arizona-school-vouchers-budget-meltdown

Given that I am surrounded by Mathematicians here, let me ask for help for what should be a simple problem I can't seem to be able to solve:
Assume you have n fair dice with m faces (i.e. each can roll an integer from 1 to m with a uniform probability). You roll all n, and keep the k (with 0<k<=n) highest results. What is the probability that the sum of the k dice you kept is X?
(If one keeps all the dice, probability-generating functions give the answer straightforwardly. If I roll 2 dice and keep 1 I can easily enumerate the outcomes and calculate the probabilities, but I am stumped by the general case).

#ProbabilityTheory #IShouldKnowHowToSolveThisButIDoNot 😞

As part of an ongoing research project, and also to learn how to create animated graphs, I decided to perform a literature review of zero density estimates \[N(\sigma,T) \ll T^{A(\sigma)(1-\sigma)+o(1)}\] for the Riemann zeta function, where \(1/2 < \sigma < 1\) and the game is to get the exponent \(A(\sigma)\), and particularly the supremum \(\sup_\sigma A(\sigma) \), as small as possible. The Riemann hypothesis basically asserts that this supremum is 0, while the weaker Density hypothesis asserts that this supremum is at most 2. By 1972, the work of Ingham and Huxley had pushed the supremum down to 12/5=2.4, but it then remained stuck for over fifty years, until the recent work of Guth and Maynard reduced this to 30/13=2.307...

I had always wondered why there did not seem to be a comprehensive survey of all the zero density theorems that had been established over the years, and now I know why: the literature is immensely complicated, especially in the region \(3/4 \leq \sigma < 1\) where there has been a lot of activity using a variety of methods. The bounds tend be piecewise in nature, mostly due to the fact that the methods rely on controlling integer moments rather than fractional moments. However, while these bounds are quite messy to state in human-readable form, they are quite digestible to a computer, and it was surprisingly routine to collate all the bounds into a single Python file, which I then used to create the attached animation. These zero density estimates are useful inputs to other analytic number theory problems, so when our project concludes we will be able to easily tweak the code to explore what could have been proven at different points in history of the subject.

@peterdrake
It's both, but I'd side a little more with 'it's rigged', because that's a more solveable problem.

Anyone living under a FPTP system endures a lot of distortion, but the fact that some places use STV show that it's quite possible to not have those problems.

Under Trump, the U.S. military spread lies, via social media (later picked up by "traditional" media) about China's covid vaccine to persuade Asians not to use it.

China's regime is a criminal organization, and it lied relentlessly about covid and the U.S.

That's no excuse for what we did.

https://www.reuters.com/investigates/special-report/usa-covid-propaganda/

And it's no excuse for what American anti-vaxxers did, and continue to do.

Conspirators in death.