Nick has moved to Mathstodon @internic@qoto.org

How to catch the Geminids, one of the strongest meteor showers of the year.

@AssociatedPress reports: "The shower often produces meteors with a distinctly more yellow glow, likely due to the unusual origin material, said Sally Brummel, planetarium manager at the University of Minnesota’s Bell Museum."

https://flip.it/pvsIGt

#Geminids #Meteor #Space #Astronomy #Science

Just finished "A City on Mars" and it was SO GOOD. I learned so much and laughed so hard. Thank you for writing it, @ZachWeinersmith!

Required reading for anyone who thinks we're going to live in space anytime soon (especially the biology section, wowza). I kinda wish I had read the hilarious and informative space law section before SpaceX debris fell near my house...

Also fun to see @michael_w_busch (as well as a bunch of other research colleagues) in the acknowledgements

Euclid's original text on geometry is almost as hard to reconstruct as the Big Bang. All we have is echoes of echoes of echoes.

The oldest surviving copy of Euclid’s book, handwritten on parchment, dates back to 888 AD. That's old - but it's 1200 years after Euclid!

In 1897, some fragments of the book were found in an ancient garbage dump in Egypt. These date back to 300 AD. That's really old - but still about 600 years after Euclid.

How did we get Euclid's Elements? This 'family tree' created by the biochemist Herbert M. Sauro begins to answer that question. It's pretty damned interesting.

The earliest transmission of Euclid from Greece to western Europe went via Arabic, and I'm interested in this stage. At that time western Europe was like the barbarian boondocks, far from the center of the civilized world. Unfortunately Sauro just has one entry saying "Arabic (~800 AD)" for what is actually a complicated process. I'm not scolding him - I just want more!

Luckily more is known about Arabic translations of Euclid. There's a lot already in Heath's famous 1908 translation of the Elements. When I asked around on the History of Science and Mathematics Stackexhange, the nice folks there found two family trees besides Sauro's:

https://hsm.stackexchange.com/questions/18090/what-is-the-family-tree-of-translations-of-euclids-elements

If I had time, I might try to combine all these family trees into one huge beautiful chart.

For more by Herbert M. Sauro, go to his website:

https://euclid.analogmachine.org/early-history

I am super excited to share that my forthcoming book with @alex, THE AI CON: How to Fight Big Tech's Hype and Create the Future We Want, is now available for pre-order!

All the details here: https://thecon.ai/

"Hey, I discovered an amazing formula!"

"Wow, that looks implausible. Did you prove it?"

"No, but I checked it to 15 decimal places!"

"You should have checked it to 20 decimal places."

It's great to make guesses in math. But it really does pay to prove them. A story like this actually happened:

https://mathoverflow.net/questions/251636/numerical-coincidence-why-is-sumxk2-sumxk1-22-for-x-0-8

In fact the "coincidence" shown below not a coincidence at all!

It's a fact about the Jacobi theta functions θ₂ and θ₃, which I define below. These functions are important in the study of elliptic curves. It's not very hard to show that as x gets bigger and approaches 1, we have θ₂(x) - θ₃(x) → 0. But fact it goes to zero very fast, so

|θ₂(4/5) - θ₃(4/5)| ≈ 9.3 × 10⁻¹⁹

We can go on with this game:

|θ₂(9/10) - θ₃(9/10)| ≈ 4.5 × 10⁻⁴⁰

and so on.

My university is owned and operated by the US government, and I'm a govt employee. This means that all my research papers where I'm corresponding author are "US government work", and are in the public domain (according to US law). This means that I CAN'T grant scummy publishers the copyright for my work. Anyone can post it where ever they want since it's in the public domain.

This is an unexpectedly awesome perk of my job. I exist in the corner case of US copyright law that allows academic papers to be distributed as they should be.

@natematias @mako at least Wikipedia is a nonprofit with an open license, so there is a reasonable understanding that contributors are giving their time and effort truly for the commons. Openstreetmaps is similar. I do not do unpaid volunteer work for for-profit companies. There is a history of privatizing volunteer work and data; the first time I was conscious of this happening was with CDDB, which seems almost quaint now: https://www.eff.org/deeplinks/2021/05/outliving-outrage-public-interest-internet-cddb-story

**rubs forehead and mutters to self**: as if we don't have enough problems:

"the choice to burn up satellites in the atmosphere may pose a significant risk to the Earth’s climate and the ozone layer, through the resulting alteration of atmospheric chemistry. . . . with a typical satellite weighing of order 1,000 kg [2,200 lb], and being primarily metallic, the steady state injection of metals into the stratosphere by vaporization of satellites would be at least 8,000 tons per year."

https://buttondown.com/creativegood/archive/musks-space-junk-is-a-threat-to-us-all/

#space #SpaceJunk #starlink #climate #environment #pollution #garbage #trash #nature #air

Wow, Framework laptops look awesome!! Thank you for the multiple recommendations, Fediverse! I'll look at this more tomorrow when I (hopefully?) recover from decision fatigue.

Site blocking means the right to choose what websites you visit would be taken away from you and given to giant media companies and ISPs. And the very shape of the internet would have to be changed to allow it. https://www.eff.org/deeplinks/2024/04/mpa-doesnt-get-decide-who-first-amendment-protects

Mastodon isn't perfect.

But the fact a social network exists that is completely free to use

has no venture capital investors

has no shareholders to answer to

has no growth targets

with a web interface with zero tracking cookies

and mobile apps with zero trackers at all

with ten thousand server administrators who donate their time for user safety

is - in my opinion - mindbogglingly cool, given the state of the world we live in. Not everything has to be shit. People make things better.

i do have to give Haliey Welch some credit for comedic timing. intentional or not, she perfectly timed her rugpull to steal the spotlight from bitcoin hitting $100K, a moment coiners have been awaiting for years. masterful stuff

Michael Gottlieb (@feynmanlectures), editor of the new edition of the Feynman lectures, has written a letter strongly disagreeing with some things Collier says in her video. You can see it here:

https://www.feynmanlectures.caltech.edu/info/other/Letter_to_John_Baez_regarding_Angela_Colliers_sham_video.pdf

I was not implicitly endorsing all of @acollierastro's claims in my first post. I merely said what I wanted to say.

Nor am I implicitly endorsing Gottlieb's claims here. I hope Gottlieb and Collier can discuss this without using me as an intermediary.

(2/2)

New modeling study finds that if everyone in the United Kingdom had worn N95 or FFP2 masks from the start of the pandemic, the rate of COVID-19 transmission would have been 9 times lower.

Tusky 27 Beta is out on Google Play!! If you want to try it and tell us how it is going, remember: opt in into its beta program.

Tusky F-Droid users: don,t worry, you will have it also, but it will take a little more to be available.

@TonyVladusich @shuttersparks @dougmerritt - thanks! My uncle was a physics teacher, and he gave me the Feynman Lectures, so I've wanted to explain physics since I was a kid, and I had some good role models. But if I'm good at explaining stuff, it probably also helped that I had a teaching job for 35 years, and my main hobby is explaining math and physics online. I practice every day.

Explaining calculus to freshmen who are forced to take the course is much harder than explaining black holes to an interested audience online! I was probably pretty bad at teaching for the first 5 or 10 years. One of my first teaching evaluations simply said "Fire him." But I really wanted to get good.

And that seems to be how it works with everything. I can't find it now, but there's an article I really like that explained the differences between Olympic-level swimmers and the second and third tier of swimmers. And one difference is that the best swimmers really enjoy doing all the exercises and drills that lesser swimmers find boring... probably because they are not just idly repeating the drill, but thinking all the time about how to improve.

TL;DR: They tested the genome of all the bat viruses that were in the Wuhan labs in 2021 and found that none are related to the Covid-19 one. Meaning that we have one more proof that Covid-19 did not "escape from a lab".

(I assume the link is paywalled but can't check now)
https://www.nature.com/articles/d41586-024-03982-2

I am curious about how many people posting about insurance companies have ever emailed their employer to specifically request that the employer advocate for an expansion of something with an insurance provider (I have done this several times).

Beech parquet flooring? Or solid pine? Limestone counter tops? Or stainless steel? Architecture firm Henning Larsen has published an open-source catalogue of the carbon impacts of interior products. Download “Unboxing Carbon” at https://henninglarsen.com/publications #ClimateAction

In some previous posts, I’ve been chipping away at the question of how two objects falling into a black hole appear from each other’s vantage, and now I’ve put all the pieces together to answer a question @johncarlosbaez posed on his blog:

If a fleet of spaceships all fall into a black hole from different starting points along the same radial line, how would the other ships appear to one in the middle of the fleet?

https://johncarlosbaez.wordpress.com/2024/11/30/black-hole-puzzle/

The plot here shows the “apparent distance” of the other ships (as determined by the angle each ship subtends, if you know its size, or by its parallax if you view it from slightly different positions). It also shows where the ships were located, when the light now being received from them was emitted.

The details are quite different depending on whether we’re seeing a ship that is closer to the black hole than us, by means of “outgoing light” — light moving away from the hole — versus a ship further from the hole that we see by “incoming light”.

Because the event horizon itself is formed by the paths through spacetime traced by outgoing light rays, we see all the ships closer to the hole than us cross the event horizon just as we cross it ourself.

But the incoming light from ships that are further from the hole than us reaches us later, for any given r coordinate where it was emitted, and we hit the singularity at the centre of the hole before we see any light emitted from those ships when they crossed the horizon.

EDITED TO ADD: This diagram has some mistakes. I’ve given a correct version in a reply.