It's memorial day and it's freezing rain here. This is going to keep the trails closed for a bit longer. Sigh
RHZero
@rhzero
- 4 Followers
- 13 Following
- 75 Posts
Mathematics, Statistics and everything in between.
@jbz pinboard dot in is worth a try imo
So glad to be getting out of this arctic freeze. And out of this layering hell
@sebkrantz is there a recommended way to check if an existing package’s code is inefficiently written?
John Carlos BaezToday the Parker Solar Probe will get 7 times closer to the Sun than any spacecraft ever has, going faster than any spacecraft ever has - 690,000 kilometers per hour. WHEEEEEE!!!!!!!
But the really cool part is what the newspapers are barely talking about: what it's like down there. The Sun doesn't have a surface like the Earth does, since it's all just hot gas. But it has an "Alfvén surface" - and the probe has penetrated that.
What's the Alfvén surface? In simple terms, it's where the solar wind - the hot gas emitted by the Sun - breaks free of the Sun and shoots out into space. But to understand how cool it is, we need to dig a bit deeper.
After all, how can we say where the solar wind "breaks free of the Sun"?
Hot gas shoots up from the Sun, faster and faster due to its pressure, even though it's pulled down by gravity. At some point it goes faster than the speed of sound! This is the Alfvén surface. Above this surface, the solar wind becomes supersonic, so no disturbances in its flow can affect the Sun below.
But it's even cooler than that, because "sound" in the solar wind is very different from sound on Earth. Here we have air. The Sun has ions - atoms of gas so hot that electrons have been ripped off - interacting with powerful magnetic fields. You can visualize these fields as tight rubber bands, with the ions stuck to them. They vibrate back and forth together!
You could call these vibrations "sound", but the technical term is "Alfvén waves". Alfvén was the one who figured out how fast these waves move. Parker studied the surface where the solar wind's speed exceeds the speed of the Alfvén waves.
And now we've gone deep below that surface!
(1/n)
Check out the FBI's files on the mathematician Paul Erdős! You may know him as the author of 1500 math papers, endlessly traveling and collaborating. But to the FBI he seemed suspicious, because he came from behind the Iron Curtain, got caught poking around a secret radio tower in 1941, worked with a mathematician from China, and refused to take a loyalty oath.
In 1954 he was barred from re-entering US after going to Amsterdam to address the International Congress of Mathematics. But 5 years later he was granted a visa after Hubert Humphrey intervened on his behalf.
The FBI eventually decided he was ”purely a mathematician with typical atmospheric mind as related to factual things.... a genius type who lives within his own mental scope".
The FBI spent decades tracking mathematician Paul Erdős, only to conclude that the guy was just really into math
A Hungarian born in the early 20th century, Paul (Pal) Erdős, mathematician, was well-known and well-liked, the sort of eccentric scientist from the Soviet sphere that made Feds’ ears perk up in mid-century America. But, try as they might, the Federal Bureau of Investigation was never able to find much motivation behind his movements and acquaintances beyond the math of it all.
one #shortstory a day
All you zombies - https://www.baen.com/Chapters/9781982126032/9781982126032___5.htm
JD Long ✅Microsoft does so much so well these days. But this Microsoft Recall product is like watching a grown man carefully placing his hand in a door jamb and then repeatedly slamming the door on it. Obviously stupid from conception.
From: @SecurityWriter
https://infosec.exchange/@SecurityWriter/112558224281615019
Security Writer :verified: :donor: (@[email protected])
If you’re wondering how the Microsoft Recall scandal is going, I’ve just had a client tell me they’ve replaced their order for 10k Microsoft Surfaces with new MacBook Airs, at nearly twice the cost, and that we need to start the ongoing 6 month endpoint security project over.
David BauerMy children when I tell them to stop watching TV: «We will, in a just, orderly and equitable manner. By, before, or around dinnertime.» #COP28
lcamtuf 
My latest Substack post: the advent of robotic hall monitors.
https://lcamtuf.substack.com/p/the-next-frontier-for-llms-hall-monitors
