Bibliolater 📚 📜 🖋 @bibliolater@qoto.org

A Gothic book of hours for the industrial age, the pages of this 1886 prayer book were not printed, but rather woven on the Jacquard loom — a proto-computer programmed with more than 100,000 punch cards: https://publicdomainreview.org/collection/lyon-woven-prayer-book

An unhealthy outlier...
https://ourworldindata.org/grapher/life-expectancy-vs-health-expenditure?time=earliest..latest

Here's the kind of thing you need to suffer through, to understand this "polarization flip" stuff. None of it gets close to the exciting physics - it's just preliminary junk.

People say the Earth's magnetic field points *up* in Antarctica. This is just an arbitrary convention. There's also an arbitrary right-hand rule we need to figure out how the magnetic field pushes on electrons and positrons as they shoot down through the air. But these two arbitrary conventions cancel out and give a non-arbitrary prediction about which way the electrons get pushed, and which way the positrons get pushed.

I'm used to that. But on top of that, people say stuff like this:

"A magnetic compass does not point to the geographic north pole. A magnetic compass points to the earth's magnetic poles, which are not the same as earth's geographic poles."

Okay, fine. But then:

"Furthermore, the magnetic pole near earth's geographic north pole is actually the south magnetic pole. When it comes to magnets, opposites attract. This fact means that the north end of a magnet in a compass is attracted to the south magnetic pole, which lies close to the geographic north pole."

Okay.... I was trying to learn about exciting new discoveries in particle physics, and I learned this. 🥴

Here's the new paper on the exciting stuff:

• Search for the anomalous events detected by ANITA using the Pierre Auger Observatory,
https://arxiv.org/abs/2502.04513

and here's the article I'm quoting about, explaining that the south magnetic poles is near the geographic north pole and vice versa:

• Christopher Baird, Why does a magnetic compass point to the Geographic North Pole?, https://www.wtamu.edu/~cbaird/sq/2013/11/15/why-does-a-magnetic-compass-point-to-the-geographic-north-pole/

Balloons carrying radio antennas over Antarctica have detected mysterious radio pulses coming up from the ice! Physicists can't yet explain them.

These balloons detect radio pulses when extraordinarily energetic particles from outer space smash into the Earth's atmosphere and create showers of electrons and positrons. People aren't sure where these particles come from. Most are probably atomic nuclei shot out of supernovae or quasars. That's one reason we've got these balloons over the Antarctic - to learn more. But I'm talking about a different mystery.

Some of these radio pulses come from above. Others come from below! But that's not a mystery: radio waves are reflected by the ice. And we can tell that's what's happening, because when radio waves are reflected, their polarization flips.

But a few pulses coming from below DON'T have their polarization flipped. And nobody knows what makes those! That's the mystery. Enough explanations have been ruled out that people are starting to talk about "new physics".

This "polarization flip" business confuses me, so I read about it. This is what I understand so far:

When a shower of electrons and positrons comes down through the air, they get pushed in opposite directions by the Earth's magnetic field. So you get an electrical current, and this makes radio waves. You can tell from these radio waves which way the shower came from, because the current is always at right angles to both the velocity of the shower and the Earth's magnetic field.

When the radio waves bounce off the ice, they should look different. But we're seeing some radio waves coming from below that don't look like that!

(1/2)

https://www.psu.edu/news/research/story/strange-radio-pulses-detected-coming-ice-antarctica