- Gears – Bartosz Ciechanowski
- Cool gear animations and explanations of how they work.
(tags: animation engineering physics mechanics)
- How knitters got knotted in a purity spiral – UnHerd
- Yep, knitters. “Purity spiral” is a good name for the runaway effect of only rewarding people who call out others for not being pure enough.
(tags: ethics culture community purity social-justice)
- black holes – Why is information indestructible? – Physics Stack Exchange
- Top answer has a nice model using coloured squares and cellular automata rules.
(tags: physics black-holes universe entropy)
- The Science Behind “The Expanse” – 1/25/17 – YouTube
- A panel with Caltech scientists and people from the show.
(tags: tv the-expanse science science-fiction sci-fi physics astronomy)
- Abigail Nussbaum — Person of Interest – The Good Bits Version
- If you want just the SF bits of Person of Interest (which are great, see Peter Watts’s review) without the police procedural/victim of the week stuff, Abigail Nussbaum has a useful list of episodes to watch.
(tags: person-of-interest artificial-intelligence science-fiction television)
- What I learned as a hired consultant to autodidact physicists | Aeon Ideas
- “A typical problem is that, in the absence of equations, they project literal meanings onto words such as ‘grains’ of space-time or particles ‘popping’ in and out of existence. Science writers should be more careful to point out when we are using metaphors. My clients read way too much into pictures, measuring every angle, scrutinising every colour, counting every dash. Illustrators should be more careful to point out what is relevant information and what is artistic freedom. But the most important lesson I’ve learned is that journalists are so successful at making physics seem not so complicated that many readers come away with the impression that they can easily do it themselves. How can we blame them for not knowing what it takes if we never tell them?”
(tags: science physics culture pseudoscience)
- The Human Cost of Tech Debt – DaedTech
- BPS Research Digest: 10 of The Most Widely Believed Myths in Psychology
- Surprises of the Faraday Cage
- Something Feynman got wrong, apparently (and which was repeated in the electro-magnetism lectures at university, as I recall).
(tags: physics science feynman electromagnetism)
- What is this thing, called swing? | The Home of Happy Feet
- Daniel Newsome geeks out about music.
(tags: lindyhop swing music jazz beats dance)
- 19 Tips For Everyday Git Use
- Top tips for git
(tags: git software software-engineering tips)
- Scott Aaronson Answers Every Ridiculously Big Question I Throw at Him – Scientific American Blog Network
- A fascinating question and answer session with Aaronson.
(tags: physics quantum scott-aaronson philosophy computation mathematics)
A friend commented the other day that I don’t post much on here any more. I do occasionally write interesting stuff over on Reddit, so I thought I’d make some blog posts based on some of those comments. Here’s a little realisation I had about how we talk about the physics of lindy:
A follower was telling me how she always needs to create her own momentum or she won’t move anywhere, and I responded that if she does so, it breaks one of the most basic rules of following and causes confusion and miscommunication in the dance. — LindyEverywhere on Reddit
Followers aren’t on frictionless wheels. Naturally, they’d stop, but the game is for them to pretend to have a lot less friction than a body on legs actually does (and maybe a bit less mass, too, I think). They’re not just physically getting moved around by the leader without co-operating by playing that game. Shifting people who aren’t co-operating is martial arts, not lindy 🙂
What lindy teachers seem to be referring to when talking about keeping momentum and not injecting energy is that once you’re playing the game, you play it consistently. Maintaining that consistency is not a natural consequence of the physics of the situation, so the follower you were talking to was right to say physically, she’s actually moving herself a lot of the time, or, not having wheels, she’d just stop. Playing the game consistently is a learned skill.
Because this game is so engrained into the dance, a lot of experienced people abbreviate the description of what’s going on by speaking as if what followers do is just allow physics to take its course (when they’re not throwing in their own stuff, I mean), when what they’re actually doing is simulating being a different sort of body and allowing a simulated version of physics to take its course. I imagine this is a bit confusing for beginner follows. (The other thing is that I’ve heard balboa teachers talk about a different simulated physics for follows turning down a line, where they lose angular momentum and so curve in).
One good exercise I’ve seen for teaching this is to play “lindy tennis”: half of you get into a circle, half of you are the tennis balls. The people in the circle set the balls off across the circle with some direction and rotation, which the balls maintain (except for avoiding collisions with teach other). When the balls reach the edge of the circle, the people there catch them and re-direct them (gently!). Playing this fixed an awful lot of “followers stopping themselves” i.e. killing the momentum rather than continuing the line around beat 4 in swing-outs from open, because it teaches what the pretend physics is.
Edit: Thinking about it some more, it seems more “real” at high speeds and when the connection is transmitting an impulse, and more “faked” at low ones and when the leader isn’t exerting a force: in the first case, it may be that it feels like your upper body is being moved by the connection to the leader and you’re just keeping your legs under you so you don’t fall over (which is still kind of a choice, but a natural one), but the thing where follows are told to keep moving at a slow pace having been given a small impulse seems like something you learn to do so as to pretend you’re a frictionless follow moving in a vacuum.
Over on top cosmologist Sean Carroll’s blog, there’s a guest post by his fellow top cosmologist Don Page, who is a Christian. Page was responding to Carroll’s debate with William Lane Craig. Page does not find Craig’s Kalam Cosmological Argument persuasive, but has his own reasons for being a Christian, which you can read about over there (spoilers: maybe God is the simplest explanation for the fact that the universe is orderly; also the Resurrection happened).
The comment thread beneath the post is huge and goes off in all sorts of interesting directions. Page makes use of Bayes’ Theorem in his arguments. There are some people who use in their day jobs (rather than just reading Less Wrong and bullshitting, as I do) who respond to him, notably Bill Jefferys, staring here.
I’ve been commenting on and off. I reconstructed the threads I got involved in as the lack of threaded commenting over there makes it difficult to follow. I’ve been reading Peter Boghossian’s “A Manual For Creating Atheists” (which I hope to post about at some point) so I was trying for some Socratic dialogue and questioning of “faith” as a means of knowing. See how I got on:
- On Occam’s Razor and what we mean by “simple”.
- On whether the Fall of Man changed the whole universe and if it didn’t, where the boundary between Fallen and un-Fallen physics was.
- Of Miracles, with the ugly broad ditch and Hume, of course.
- Simon Packer’s claims to have done and seen faith healings.
- My response: why doesn’t God heal amputees and raise the dead these days?
- Simon Packer’s claims that Christians can raise dead people.
- My followup questioning whether he’d believe such claims about other religions, among other stuff.
- Simon’s followup telling me to trust in God and lean not on my own understanding (I used to know a song about that).
- My followup, asking if he’d obey a call to trust in another god without understanding it.
- Simon’s followup.
- My followup: Christianity seems to entail belief in demons, although it’s not clear whether Prof Page believes in them. Accusations of “ultra-rationalism” are Straw Vulcan arguments.
- Don’t worship science, feed it. I also ask what “faith” is.
- Simon attempts to define faith.
- My followup: how do we know when a strong feeling of being sure is legitimate? (Simon’s said it isn’t always)
- Simon’s followup: the Gospel is true and you need to respond to it.
- My followup: would you believe someone who said “The Koran is true and you need to respond to it”?
I was interested in Daniel Kerr’s comments (for example, here, here, and finally here, in response to one of mine). He says that simplicity depends on a choice of mathematical language, but I thought this was just a constant factor. However, the comments rapidly go off into model theory and stuff about the Axiom of Choice, so I got lost. Can anyone comment on what he’s saying and whether he’s right?