What's a 'frustrated hysteron'? No, it's not someone on Mastodon who wishes it were more like Twitter.
'Hysteresis' is when a system's state depends on its history. Sometimes a system like this is made of many tiny pieces called 'hysterons', which each act like a switch. Whether a switch is on or off depends on what you did to it in the past, so that's a great example of hysteresis.
For example, if you put a chunk of iron in a strong magnetic field pointing one way, and then turn off the magnetic field, it will get magnetized with its north pole pointing up. If you put it in a strong magnetic field pointing the *other* way and turn off the field, it'll get magnetized with its north pole pointing down. So the current state of the magnet doesn't depend only on its current environment, but on its past! That's hysteresis.
But if you look very closely, the iron is made of tiny bits called 'domains', which each have a uniform magnetization, and which act like little switches. These are hysterons.
In iron, flipping one of these little switches makes it more likely that others will flip the same way. But in some other systems, flipping one system *reduces* the chance that others will get flipped. Then you have 'frustrated hysterons'.
A physics professor at Penn State explains:
"“A good example of frustration is a bendy straw, which has a series of little bellows that can be collapsed or popped open. If you pull on the ends of the straw a tiny amount and stop, one will pop open, and it being open means that the others do not. The change in one relieves the stress in the system."
(1/3)
https://www.psu.edu/news/eberly-college-science/story/materials-can-remember-sequence-events-unexpected-way
John Carlos Baez
npub1nf…3nqe4
2025-02-18 18:01:46 UTC
Author Public Key
npub1nf4p4rh06z6n6lsvje4txk7eqs23y3hs8vd7nraq6tgwady5qvsqy3nqe4Seen on
wss://relay.momostr.pinkPublished at
2025-02-18 18:01:46 UTCEvent JSON
{
"id": "92310d7911061c4fce20aac87c4639d6ed1c2c77c0da7bb4891a28bdf6cf3f34",
"pubkey": "9a6a1a8eefd0b53d7e0c966ab35bd904151246f03b1be98fa0d2d0eeb4940320",
"created_at": 1739901706,
"kind": 1,
"tags": [
[
"proxy",
"https://mathstodon.xyz/@johncarlosbaez/114026198254968548",
"web"
],
[
"proxy",
"https://mathstodon.xyz/users/johncarlosbaez/statuses/114026198254968548",
"activitypub"
],
[
"L",
"pink.momostr"
],
[
"l",
"pink.momostr.activitypub:https://mathstodon.xyz/users/johncarlosbaez/statuses/114026198254968548",
"pink.momostr"
],
[
"-"
]
],
"content": "What's a 'frustrated hysteron'? No, it's not someone on Mastodon who wishes it were more like Twitter.\n\n'Hysteresis' is when a system's state depends on its history. Sometimes a system like this is made of many tiny pieces called 'hysterons', which each act like a switch. Whether a switch is on or off depends on what you did to it in the past, so that's a great example of hysteresis.\n\nFor example, if you put a chunk of iron in a strong magnetic field pointing one way, and then turn off the magnetic field, it will get magnetized with its north pole pointing up. If you put it in a strong magnetic field pointing the *other* way and turn off the field, it'll get magnetized with its north pole pointing down. So the current state of the magnet doesn't depend only on its current environment, but on its past! That's hysteresis. \n\nBut if you look very closely, the iron is made of tiny bits called 'domains', which each have a uniform magnetization, and which act like little switches. These are hysterons. \n\nIn iron, flipping one of these little switches makes it more likely that others will flip the same way. But in some other systems, flipping one system *reduces* the chance that others will get flipped. Then you have 'frustrated hysterons'. \n\nA physics professor at Penn State explains:\n\n\"“A good example of frustration is a bendy straw, which has a series of little bellows that can be collapsed or popped open. If you pull on the ends of the straw a tiny amount and stop, one will pop open, and it being open means that the others do not. The change in one relieves the stress in the system.\"\n\n(1/3)\n\nhttps://www.psu.edu/news/eberly-college-science/story/materials-can-remember-sequence-events-unexpected-way",
"sig": "74655078c091582a7d0c9779453b11fa47420b2bcc461a097ec44a7202211ab24c2f94817dabd450e63ba233cdce293269d2248c093a6e63fc44e948aa8b630e"
}