Nostr notes by Roger Crew✅❌☑🗸❎✖✓✔

My autocorrect seems to be missing the word "horocycle". ...

2026-10-24T18:37:34Z

My autocorrect seems to be missing the word "horocycle".

I thought this shit was supposed to be intelligent (i.e. shouldn't the "AI" out there have figured out this is a word that I use). Or is this a good thing (as in: maybe I have successfully blocked the scrapers from seeing my stuff)?

So every time they beat back the White Walkers they left a ...

2026-10-16T03:41:55Z

In reply to nevent1q…yctv
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So every time they beat back the White Walkers they left a marker, sort of a,

"Hey guys: Just so you know, you're getting near our Wall, and even though we're not actually claiming this territory, we still do go out from time to time at least this far to randomly beat people up. FYI. kthanxbai."

Interesting.

I don't suppose anybody has yet checked whether these are ...

2026-10-07T21:24:58Z

In reply to nevent1q…lfjv
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I don't suppose anybody has yet checked whether these are indeed valid proofs as opposed to confident sequences of statements that look like proofs?

(or if anyone at OpenAI *did* check them before letting them out the door, are those folks getting credited?)

Meanwhile fwiw, here's my blog article with more on the ...

2026-10-01T21:09:19Z

In reply to nevent1q…qn5t
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Meanwhile fwiw, here's *my* blog article with more on the chariot warfare hypothesis,

(drawing mostly from Drews, caveats being it's 1996, and even though *I* found it pretty convincing, that doesn't necessarily mean anything...)

https://wrog.dreamwidth.org/57703.html

3/2

... eg., I had thought Robert Drews had thoroughly debunked the ...

2026-10-01T02:31:20Z

In reply to nevent1q…qcsx
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... eg., I had thought Robert Drews had thoroughly debunked the "Sea Peoples" hypothesis [tldr; a 19th century french archaeologist basically made them up out of whole cloth, mistranslated the Menerptah stele, there was never any real evidence for them in the first place, but people romanticized the idea so it caught on anyway, all attempts to track them down have fizzled,...]; his book is dated 1996 and yet I still see Sea Peoples in wikipedia 30+ years later...

Drews' own take is that it was people figuring out how to use infantry to defeat chariot armies -- a *different* case of centuries-established military tech becoming obsolete overnight -- that made the difference in 1200BC...

https://www.amazon.com/End-Bronze-Age-Robert-Drews/dp/0691025916/ref=sr_1_1?dib=eyJ2IjoiMSJ9.LpUAtAl_nlSvNrs4JJ9eBpFdUeEUdY-Qq-5nxDgCi5zGjHj071QN20LucGBJIEps.3hZJfHlsQ-ExWMYA6rZLgtKVxd_MyMiYWQBdeDeXhUM&dib_tag=se&qid=1790820943&sr=8-1

2/2

I thought the consensus was that the switch to iron happened over ...

2026-10-01T02:29:51Z

In reply to nevent1q…r47l
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I thought the consensus was that the switch to iron happened over the centuries **following** the collapse, but iron did NOT play much of a role in the collapse itself (we generally do not see iron weapons in the burn layers, etc... ).

So while this still can work as an explanation for why life was different in the centuries following the collapse and why new large empires did not replace the old ones, it's really not about the collapse itself.

Admittedly, I'm at the level of Random Layman Who Has Read A Book or two, so it's frustratingly hard for me to tell who's an actual expert working off of the latest information and who isn't

1/2

Seems like this is massively overestimating ...

2026-09-26T06:46:52Z

In reply to nevent1q…p5se
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Seems like this is massively overestimating Mastodon/Fediverse's reach.

wait why is this library being sold? Did something get defunded? ...

2025-10-16T22:08:30Z

In reply to nevent1q…flc9
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wait why is this library being sold?
Did something get defunded?

Seems to me there's a news item there.
Or should have been.

... and perhaps this is more of a sin of popularizers than ...

2025-05-07T21:00:19Z

In reply to nevent1q…vs63
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... and perhaps this *is* more of a sin of popularizers than actual physicists (a loop I'm mostly out of), though I've also seen actual physicists say some strange shit (*)...

... and I also get one has to be careful about how one says this in the current environment, given the idiots looking for excuses to Burn Down Everything.

(file under: Reasons I Don't Make You-Tube Videos, part 237)

(*) I particularly want to strangle the ones that keep trying to resurrect the Everett multiverse interpretation of quantum mechanics and implying this has anything to do with cosmology. "Mirror, mirror" was a great Star Trek episode, but that's all it ever was.

7/7 ?

... and yes that was 40+ years ago, the point at which I switched ...

2025-05-07T20:47:58Z

In reply to nevent1q…kacg
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... and yes that was 40+ years ago, the point at which I switched to computer science. It being basically impossible to keep up with everything, I've forgotten more than I would like, and have ZERO clue about the current state of the art,

but I do try to check in from time to time.

And age of the universe estimates keep bouncing around, It is NOT known to 2 or three significant figures.

which, to me, is COMPLETELY EXPECTED, but also suggests to me the fundamental character of cosmology really hasn't really changed that much. Assertions about the shape/history of the universe need to be taken with more of a grain of salt than they are

6/n

Astrophysicists do the best they can with what they have, and ...

2025-05-07T20:43:27Z

In reply to nevent1q…w9wq
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Astrophysicists do the best they can with what they have, and it's just that astronomical data is ABSOLUTE CRAP and probably always will be...

... at least as compared to THE DATA WE ACTUALLY NEED and may well never get if we can't get instruments out to interstellar/intergalactic distances to get the Really Long Baselines,

e.g., observations of black holes up close and personal, e.g., to distinguish Einstein's GR from the dozen or so viable competitors/attempts-at-quantum-gravity (or at least such was the state of things as I understood it as of my *last* phyics course (1984, Cambridge)

5/n

And I'm NOT saying that (1981-era) particle physicists ...

2025-05-07T20:40:26Z

In reply to nevent1q…e9hc
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And I'm **NOT** saying that (1981-era) particle physicists were Better at Science than the astrophysicists, or that Cosmology is Broken. It's just a reflection of the quality of the data available and the experiments/analyses one can do

(never mind that inverse square fields are a bit of a mathematical sweet spot: Stokes Theorem/Gauss's Law makes it possible to construct experiments to find the most ridiculously small deviations from 2, so this particular thing was kind of an unfair comparison anyway).

4/n

Contrast this to what was happening in my intro quantum class ...

2025-05-07T20:39:04Z

In reply to nevent1q…e4lg
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Contrast this to what was happening in my intro quantum class (taught by Happer) learning to calculate scattering cross sections and whatnot, how particle physicists could construct made-to-order experiments to verify arbitrary random aspects of QED/etc, and he would interject how the latest attempt to determine the Actual Exponent on the electrostatic inverse square law had nailed it out to something like 15 decimal places...

... it was quite clear to me and my classmates that the astrophysicists and particle physicists had quite different standards of "proof", as it were.

3/n

Gott (astrophyics) gave a lecture on galactic rotation curves, a ...

2025-05-07T20:36:46Z

In reply to nevent1q…hzud
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Gott (astrophyics) gave a lecture on galactic rotation curves, a hot new topic at the time (1981), showed calculations + how available data established that stellar velocities in nearby galaxies *were* within an order of magnitude of expected, so everything was okay so far.

Suffice it to say, this was Before Dark Matter, *long* before inflation was A Thing. People seemed mostly happy with Friedmann cosmology though there were clearly some warts that needed working out. Age of the universe was 15 billion years +/- a few billion, ... an annoying error bar but WAY, way better than Hubble's first estimate: 1 billion years (geologists: "Nope") which finally got fixed by better data on the Cepheids

2/n

"where did you get this idea?" From actual physics ...

2025-05-07T20:34:44Z

In reply to nevent1q…kw5m
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"where did you get this idea?"

From actual physics classes I took as an undergraduate. including *most* of prereqs for a physics major. But there weren't enough hours in the day to double-major physics *and* math at Princeton, ... and also algebraic topology was more fun, so I went with math.

And I get that undergraduate courses in many ways barely scratch the surface (my astro course *was* strictly intro: we did track-I of MTW) of what practitioners Actually Do. And I also get that it can take a while for the bleeding-edge stuff to trickle down,

... but they did try:

1/n

"haven't exactly been keeping up with Hossenfelder... ...

2025-05-06T23:30:21Z

In reply to nevent1q…fc96
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"haven't exactly been keeping up with Hossenfelder... "

essentially, I stopped watching her once I discovered Angela Collier, who then started using up all of the oxygen in my Physics-Video-Watching Room

https://www.youtube.com/@acollierastro

So... I'll admit I haven't exactly been keeping up with ...

2025-05-06T23:03:58Z

In reply to nevent1q…046q
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So... I'll admit I haven't exactly been keeping up with the Hossenfelder videos (life is too short), and I'll grant her transgender video was, at best, a huge misstep (from which it's going to take a LOT of work/apologizing to recover, and I haven't seen her doing that, unless she has and I missed those videos, because, again I haven't really been following her), but she otherwise/previously seemed mostly sane (*) to me.

Has there been been *other* batshit stuff from her that I missed?

(*) [read 2/2 before you jump on me]

1/2

"... a real working mathematician, not a self-educated ...

2025-05-06T06:26:37Z

In reply to nevent1q…x8v3
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"... a real working mathematician, not a self-educated crank."

It is unfortunately, quite possible for real working mathematicians (or physicists, etc...) -- even if it tends to happen less often than for self-educated/non-(working-whatever) folks -- to be cranks (or **become** cranks as they get older).

(cf. William Happer on climate science, Richard Dawkins on gender, James Watson on ... yeah... )

sorry I think your OP got disconnected (why I might not have been ...

2024-12-15T01:32:17Z

In reply to nevent1q…uq3p
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sorry I think your OP got disconnected (why I might not have been replying to the Right Things...); where is this BBC article?

(n.b. Even though they've got the Authoritative East-Anglian British Accents and they do tend to be better on average than US outlets, that's still kind of a low bar, and the BBC -- esp. more recent BBC after Tory funding cuts -- tends to suck more than Americans would expect on matters of scientific/historical accuracy.)

Ptolemy was essentially using Fourier series 1500 years before ...

2024-12-14T19:28:53Z

In reply to nevent1q…n7d0
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Ptolemy was essentially using Fourier series 1500 years before Fourier.

Even if you want to say something like "it's not real ...

2024-12-14T01:03:25Z

In reply to nevent1q…thvc
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Even if you want to say something like "it's not real gravity unless there's a tide", that doesn't work either; even with a uniformly spaced fleet of accelerating ships, the ones in the back have to be accelerating harder to keep up, so it's NOT really a uniform field the way you'd expect.

2/2

I think SF writers and TV producers have done us a disservice in ...

2024-12-14T01:01:41Z

In reply to nevent1q…fvs2
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I think SF writers and TV producers have done us a disservice in using "artificial gravity" everywhere (I get why they had to but it's still annoying) in that people now have this idea that "artificial gravity" is ever going to be A Thing.

Really, there's just Acceleration,

...which you'll either feel because you're accelerating/spinning or because you're near some massive body and somehow *not* accelerating when you're "supposed" to (due to ST curvature), -- say, because a planetary surface is getting in your way --

and that is all. Equivalence Principle says there's no difference.

1/2

a distant observer sees them all redshifted. But that says ...

2024-11-28T07:59:38Z

In reply to nevent1q…jzl9
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a distant observer sees them all redshifted. But that says nothing about how the ships see each other.

Consider: Even in the case of Captain #50 viewing the USS #1 crossing the event horizon, Captain #50 receiving the photon will also be on the event horizon when that happens. So the photon travels **along** the event horizon between a source and a destination that are both **on** the event horizon and that both have the same rate of time-dilation w.r.t. a distant observer. So I'm not seeing how there's red-shift.

and this also answers the red-shift question pretty quickly, ...

2024-11-28T07:27:40Z

In reply to nevent1q…ycax
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and this also answers the red-shift question pretty quickly, i.e., there **is no red-shift** (*) because the ships have no relative velocity.

(*) at least to first order. My gut tells me that the curvature will introduce a second-order effect, but I have no idea which way that goes. Tidal forces compress in the angular direction => ship-to-ship photons fighting that lose energy and hence (maybe) red-shift. But ships getting closer together => (maybe) blue shift. Or maybe the two effects cancel.

But what we can say is whatever the effect is, near the event horizon it's getting smaller/goes-to-zero as we consider larger and larger holes.

' imho, It's a lot easier to visualize if you use the ...

2024-11-28T05:19:31Z

In reply to nevent1q…mulr
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'

imho, It's a lot easier to visualize if you use the Kruskal-Szekeres coordinates.

You have 100 ships lined up along the x-axis, all proceding forwards in time just as if we were in vanilla-flat-Minkowski spacetime with everybody at rest w.r.t. each other (i,e., if they have zero relative velocity, we can just pick that reference frame).

Every ship captain sees what's in their past light-cone, as usual

So if the ships are spaced 1 light-sec apart, then Captain 50 sees what's happening on the USS 49 and the USS 51 one second ago, the USS 48+52 two seconds ago, etc..

And the **only** difference the black hole makes is you're drawing this 45° line across the picture and that's the event horizon.

I wonder what the status is, these days, of John Cramer's ...

2024-10-25T05:09:51Z

In reply to nevent1q…3nmx
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I wonder what the status is, these days, of John Cramer's Transactional Interpretation of quantum mechanics -- which, as I understand it, can be shown to be equivalent to the Copenhagen interpretation without needing any kind of "wave-function collapse' or reference to an "observer" (conscious or otherwise)

Seems to me this could stand to get more press if "wave-function collapse" is being used as an argument for *anything* (organized religion or otherwise)

https://en.wikipedia.org/wiki/Transactional_interpretation