urpriest

[urpriest]

Oh my god

[urpriest]

[urpriest]

just found out in medieval france, having a lion on your coat of arms was so prevalent that there was literally a colloquial proverb to clown on knights for being basic and not having a real coat of arms. the hate game was so strong back then. imagine medieval hate anons

[urpriest]

When he was three years old, God gave wondrous increase to his stature; and none was so indifferent to beauty as not, on seeing Moses, to be amazed at his comeliness.

"Damn bro, that three year old is comely"

[urpriest]

Detect evil but it becomes increasingly clear that whoever calibrated it had some really weird moral stances.

[urpriest]

[urpriest]

To link them, remember that the gravitational field is the metric, which is just the universe's accounting rules.

it's hard for me to reconcile the view of energy as a number associated with a state, which seems like just an accounting trick for tracking work, with energy as the source of the gravitational field. They seem like different concepts.

[urpriest]

Yeah, agreed on that point. I don't think there's a definite hint, apart from the occasional not-quite-a-paradox-but-weird observation like this one. Nothing guarantees that gravity needs to be unified with the other forces, maybe it isn't!

(I do feel like it's hard to imagine how a world without unification would work, on a certain level. Like, you have some parameters, and they could have been set otherwise, but they happen to be this way. So, how do we know they could have been otherwise? Maybe we're just missing some constraint that forces them to be that way. I don't think "physical unification" is inevitable, but a world where ultimately models don't unify feels like a world with something deeply wrong with it, though in a sense I can't really fully justify.)

18, 11

18. Is the physicists' sought-for "theory of everything" a chimera?

You really should ask a physicist about this! As I understand it, the basic fact that makes it debatable is that there is some technical issue which means you can't handle gravity in the same mathematical framework as the other forces. But what lesson should we draw from that? I guess we should be less confident that they got the description of the other forces right. But even before gravity people were unhappy with renormalization theory ("it is what I would call a dippy process"—Feynman), and meanwhile, supposedly there are formalisms like string theory that can accommodate gravity, it's just that it's impossible to make progress without a particle accelerator the size of the solar system. From my layman's point of view, it seems like there's not so much philosophical lessons to be drawn from the fact that renormalization failed. In some alternative history some other mathematical approach could have been popular, but everything would still be underconstrained just from lack of experimental data...

Conversely, I guess there were physicists in the 1980s who thought they would recognize the ToE just by its mathematical elegance and solve fundamental physics in their lifetime, and that hope seems very chimerical now.

11. Is hip-hop/rap more political than the Eurovision Song Contest?

This question feels like a throwback to 2015! Like, the reason hip-hop is considered political is that it's associated with Blackness, and hence with questions of race which (along with sexuality) is the most contested political issue; meanwhile the Eurovision is avowedly "apolitical", and as we all know "to be neutral is to be complicit". But now in the 2020 with wars in Ukraine and around Israel, nationalism seems less harmless, so maybe even the stupid Eurovision pop music can become controversial again.

I think ultimately rap is an artistic form, not an ideology or a movement, so you can't really say that it's politically significant in itself. Otherwis, we again end up in 2015 when everyone was briefly convinced that Hamilton had achieved the great unified theory of politics and music...

[urpriest]

A lot of laypeople get confused about this, and frankly, I think a decent number of physicists are as well, at least on a branding level.

Quantum gravity is not, inherently, about unification. You can have a quantum gravity theory that doesn't unify anything. Loop Quantum Gravity is an example, most practitioners argue it should have no implications for other forces.

String theory, specifically, is a theory that unifies gravity with the other forces. It does this both physically, in that all quantum fields are different oscillation modes of a common sort of physical object, such that under different conditions you can get the same physical stuff to behave like gravity or like electromagnetism, and as a model, in that the strengths of the different forces are controlled by one parameter, the string coupling constant, with all of their differences coming from physical phenomena that could in principle be adjusted by sufficiently advanced technology.

(M theory, in turn, is supposed to have zero adjustable parameters: all of distinctions come from the dynamics of the theory, all can in principle be adjusted by physical effort.)

It also, like electroweak unification, should have a corresponding period of time: there would be a string unification epoch, just as there would be an electroweak unification epoch. But I think this is kind of a distraction in both cases, an accident of the fact that our cosmology begins with a hot dense state. We might find out that that's wrong: for example, we may in fact be in a cyclic cosmology, so the electroweak era happened after a previous era when the two forces were separated again. The important point is that the difference between "unified" and "separate" is dynamical: two states you can move between by physics within the theory, not two different settings for parameters that you can only change outside of the theory if at all.

(Also, electroweak unification is kind of a fake unification because E&M and the weak force still come from two different forces: the SU(2) and U(1) have independent parameters associated with them. They just are mixed, so both E&M and the weak force contain some of the original SU(2) and some of the original U(1).)

Where this gets confusing is when you come to other quantum gravity theories, some of which describe themselves as unified, but mean something very different. I kind of suspect they do this to take advantage of string theory's "branding", and that if string theory weren't running around claiming to be a "theory of everything" they wouldn't bother.

Asymptotic safety is a weird edge case, because it does not unite the forces physically, but some practitioners claim it unifies them as a model. The claim is that perhaps there is only one set of values for parameters consistent with asymptotic safety, which would constrain all the forces, including gravity. This isn't something they'd say they've proved, more a speculation, but it does lead some to call it a unified theory/theory of everything.

Then you've got stuff like octonions and Garrett Lisi's thing, which as far as I can tell only unify the forces mathematically, by putting them all under the same formalism. Which really shouldn't count, for the reasons you seem to be leaning towards above.

18, 11

18. Is the physicists' sought-for "theory of everything" a chimera?

You really should ask a physicist about this! As I understand it, the basic fact that makes it debatable is that there is some technical issue which means you can't handle gravity in the same mathematical framework as the other forces. But what lesson should we draw from that? I guess we should be less confident that they got the description of the other forces right. But even before gravity people were unhappy with renormalization theory ("it is what I would call a dippy process"—Feynman), and meanwhile, supposedly there are formalisms like string theory that can accommodate gravity, it's just that it's impossible to make progress without a particle accelerator the size of the solar system. From my layman's point of view, it seems like there's not so much philosophical lessons to be drawn from the fact that renormalization failed. In some alternative history some other mathematical approach could have been popular, but everything would still be underconstrained just from lack of experimental data...

Conversely, I guess there were physicists in the 1980s who thought they would recognize the ToE just by its mathematical elegance and solve fundamental physics in their lifetime, and that hope seems very chimerical now.

11. Is hip-hop/rap more political than the Eurovision Song Contest?

This question feels like a throwback to 2015! Like, the reason hip-hop is considered political is that it's associated with Blackness, and hence with questions of race which (along with sexuality) is the most contested political issue; meanwhile the Eurovision is avowedly "apolitical", and as we all know "to be neutral is to be complicit". But now in the 2020 with wars in Ukraine and around Israel, nationalism seems less harmless, so maybe even the stupid Eurovision pop music can become controversial again.

I think ultimately rap is an artistic form, not an ideology or a movement, so you can't really say that it's politically significant in itself. Otherwis, we again end up in 2015 when everyone was briefly convinced that Hamilton had achieved the great unified theory of politics and music...

[urpriest]

Registering my Seek speculations

The most obvious possibility:

Winnifred is right, "the years" involves spending time as sleeper agents before a big attack. That attack releases a robot apocalypse which leads to Orion's plotline after a timeskip.

Intermediate possibility:

The machines in Orion's plotline are run by Basilisk, hence their basilisk-like capabilities.

Wackier possibility:

Orion's plotline is happening *right now*, because he is doing "the years". The reason he and the others with him seem like they were troublemakers and criminals and have only partial memories is that they are Grey-Frocked. In order to keep momentum and counteract the way cults fall apart without social pressure, all of the onboarded Grey-Frocked are kept in a simulated world by their onboards, who then manage them as if they were normal for the outside world. Orion is in that simulation, designed to keep its inhabitants radicalized against automation. Orion's in particular is also trying to radicalize him against A and Basilisk, hence all the A-related stuff and the way that the hunting machines have behavior evocative of mythological basilisks. When he emerges he will be put in position to assassinate A, and we'll see whether he was pissed off enough at the people who put him under to break that conditioning.

[urpriest]

urpriest said: Now think about what happens when someone needs to send a csv file with financial data.

death! fire and death! the thief that comes in the night, stops breath, steals souls, leaves nothing but ashes and dust

[urpriest]

Regarding Feynman diagrams, maybe! Before I looked at that link there I hadn't realized just how "outdated" Feynman's original setup was, I'd always seen the "cleaned-up" derivations by people like Weinberg. Apparently Feynman originally framed things with quantum-mechanical wave functions, not field theory operators? Wild.

And makes sense re: "adding up to normality". The holy grail for crackpots and phenomenologists alike is to have one difference you could in principle pick out in an experiment, so you can claim your idea is falsifiable. But the idea still has to pass the "does this match what we already know" test, and my impression tends to be that stochastic electrodynamics does this by having enough room to fudge things that they can end up with the right answer that way.

partway thorugh QED, which does seem to be what you guys advertised it to me as, which is a good pop sci book on quantum mechanics. I thought there was no such thing.

but today i gave into temptation and bought a quantum woo book... The Field by Lynne McTaggart.

this book is not like other quantum woo books. It wasn't written by a scientist like Capra's The Tao of Physics. But it's also not totally uninformed like Talbot's Mysticism and the New Physics. It's journalistic. It's put together out of a very large number of interviews. The appeal to me is who was interviewed.... flipping through, I see Hal Puthoff, who as a parapsychologist was tricked by Uri Geller and as an engineer became a legal case study in "inoperable inventions" in the patent system. An interesting crowd.

One of the fundamental motivations behind the book seems to be to dismiss materialistic dismissals of homeopathy etc.

[urpriest]

can anyone find me that mesopotamian clay tablet telling you to marry a party girl because she'll bring you joy

[urpriest]

i should wake up and automatically be restored to full health, that's how sleeping should work, what is this horseshit

[urpriest]

If you want a really quick treatment that gives you the basics, the beginning of Nakahara's Geometry, Topology, and Physics is pretty good. It's mostly concerned with things that will be unnecessary for you (and were dubiously relevant for me until quite late), but if you stick to Chapter 2 and Chapter 5 (and especially section 5.4) you'll find a pretty clean presentation of the basic ideas.

wait, so those total differentials you write in thermodynamics, is the field of math that makes those precise differential geometry ??

in a way that makes perfect sense, the equation of state defines a 2D surface in a 3D space (coordinates pressure, volume, temperature)

but it's surprising if so... i thought i wouldn't have to know any differential geometry unless i wanted to learn general relativity

[urpriest]

I have been on Tumblr just long enough to find this an extremely funny choice of business name.

The company caters to caring for babies and toddlers.