gattr

No; instead, I use Maxima on Android (and on desktop Linux too).

This (unplanned loss of superconductivity) sometimes happens to accelerator magnets in LHC. To prevent stuff from melting/blowing up, there's an elaborate protection system integrated ([1]).

[1] LHC Magnet Quench Protection System https://cds.cern.ch/record/259538/files/P00021565.pdf

It's just visually jarring. Do you consider your use of spaces after commas and periods and capitalizing the first word in a sentence "pedantry"? To me it's at the same level.

@Omin, @mda, just a side note: I recommend using the (centuries old, I guess) established typography rule and putting a space between the number and the unit symbol. See [1] for additional info.

[1] SI Unit rules and style conventions, https://physics.nist.gov/cuu/Units/checklist.html

You're right, here are some numbers:

- photosphere temperature: 5870 K

- sunspot umbra temperature: 3000-4500 K

Per Stefan-Boltzmann law, this can make the photosphere up to (5870/3000)⁴ ≈ 15 times brighter.

I still do a playthrough of FC1 every two years of so (on highest difficulty). I love the game mechanics (though not the Trigen-heavy levels).

For photospheric observations/imaging like here (also called "white light") you only need the inexpensive Baader AstroSolar film fitted onto your existing instrument (telescope, binoculars, photographic lens).

...but beware the unrelenting "I need bigger aperture and to travel to better-seeing locations".

(For some more details, see also [1].) The bright boiling granules (comprising most of the image) show photosphere convection. There's also the inward movement of the tips of penumbral filaments (which surround the dark sunspot cores), though the material in them flows outwards ([2]). Note how granules get deformed in constrained areas before the two major sunspots.

All this can be seen in a "somewhat" higher resolution on time lapses from professional telescopes, e.g., [3] (from the 1 m diameter Swedish Solar Telescope).

[1] https://en.wikipedia.org/wiki/Sunspot

[2] https://en.wikipedia.org/wiki/Evershed_effect

[3] https://ttt.astro.su.se/isf/gallery/movies/2010/

Thanks! The horizontal FOV is around 5 arcminutes. The granules (the bright convection cells comprising most of the image around the sunspots) are about 1000 km across on average.

Captured with a 180 mm diameter telescope. The animation spans 20 minutes, with 20-second intervals between frames.

edit:

Also available as a smaller-sized H264 MP4 [1].

[1] https://www.cloudynights.com/gallery/image/182808-ar-3354-an...

Something also happens to regular polytopes. In 2D there are infinitely many regular polygons, in 3D there are 5 regular polyhedra, in 4D: 6, but for >=5D there are only 3.

[1] https://en.wikipedia.org/wiki/Regular_polytope

On my 24" 4K monitor TFA's font was indeed verging on unreadable. HN looks fine for me, though.

I'm an amateur astronomer and astrophotographer and it seems to me the market for this is very limited. Most beginners start with simple 'scopes to dip their toes into the waters and see if they're into astro at all. Most advanced amateurs assemble their setups themselves (going through many iterations/variants over the years).

This here is a turn-key, high-end solution (mostly for deep sky photography) for... whom? Very rich beginners wanting immediate results, maybe?

Hog hunting is a subplot in Neal Stephenson's novel "Termination Shock" (set in the near future).

Average Earth diameter = 2·6371 km ([1]). Size of glucose molecule ≈ 9 Å ([2]). Ratio = 7.06·10¹⁷.

[1] https://en.wikipedia.org/wiki/Earth_radius

[2] https://sphweb.bumc.bu.edu/otlt/mph-modules/ph/ph709_basicce...

Quite unlikely, but see e.g. [1]:

> Therefore, it is still possible that planets exist around main sequence stars in globular clusters, although at small numbers because of the low metallicity, and at orbital periods of >~10 days.

[1] Expected Planets in Globular Clusters (https://arxiv.org/abs/0704.1067)

> Inside a 'thick' nebula, obscuring all other entities in the sky except for their own star and planets.

Similarly to the alien planet in Eric Flint's "Mother of Demons"; there was a permanent thick cloud cover, and the the slowly moving sky illumination due to the unseen sun was called "the mother of pearl" by the locals.

I also like the idea of living in a dense globular cluster. Interstellar probes and, later, manned missions would be feasible quite early into civilization's technological development - since you're just a few light-weeks (or less) from another star, not a few light-years like us.

As of recently, my setup for backups consists of 2x4 TB HDDs (from different manufacturers) with BTRFS in RAID 1, plugged into a small 2-drive USB3 docking station. With both checksumming and mirroring, feels pretty safe from HW-failure/bit rot standpoint (if one disk fails, you can still mount the other in "degraded" mode).

Yes, you can see just fine (with a bit less contrast than in those images). Of course, flares and prominences will not move in front of your eyes, but they do change over a few minutes.

Shameless plug: I make time-lapse animations of solar flares (among other things) for fun, like this M-class [1] (46 min. of real time, 90 mm diameter telescope with narrow band Hydrogen-alpha filter).

[1] https://www.astrobin.com/289991/?nc=collection&nce=1468

Here's another take on "creating a person solely to do some work": I believe it can be done in a humane way. Say, generate (or use a mind scan of) a programmer who loves their craft (as in, used to dream "if I only didn't have to go to work, I'd use all the time for my hobby projects").

Solution: put them in a simulated environment running at a higher than normal rate. Then, from their standpoint, it would be e.g. two 8-hour workdays per week, with the remaining 5 spent on (simulated) sailing/hiking/DIY/having fun with virtual concubines, you name it. These conditions could be legally mandated.

I've read recently that dentists no longer need to get a physical imprint / make a form in order to produce a (anti-clenching etc.) mouth guard - they can just do some sort of 3D scan of the teeth (can't remember if it was video- or X-ray based). Couldn't similar technology be used for bra fitting? (Though I imagine it would be complicated by e.g. breast size depending on the menstrual cycle phase, etc.). A coarse-grained "structured-light" 3D body scan should be quick and convenient to do.

Indeed. Hmm, but what if I roll a D20 before each flight and take a bomb only if I get a "1"? Do I decrease the average two-bombs probability to 5·10⁻⁶?

I remember this one from a youth mathematics book. 10⁻⁴ chance of one bomb, and 10⁻⁸ of two (assuming the other one is an independent event — which it would be, as you're certainly not in collusion with any actual bomber).

On a similar note: bullshit detection script [1]. For some fun, try using it on some large well-known tech corp's homepage.

[1] https://mourner.github.io/bullshit.js/

I see it differently; I'd be OK with an upload if the alternative is death, but only under strong protections: the digital version is legally treated as a human, I have full autonomy, the compute resources to run me (and the simulated environment of my choice) indefinitely are assured, and I can still interact with the real world. I'd just go on doing my usual stuff, like writing software for fun, enthusing over new discoveries in astronomy...

I can recommend Greg Egan's novels that touch on this:

1) Permutation City (mind uploading tech in its infancy)

2) Diaspora (mind uploading well established)

Forgive my going off-topic, but what you wrote is basically my conclusion after reading the short story Lena [1] (mentioned some time ago on HN; strongly recommended). TL;DR: when mind uploading becomes possible, don't be an early adopter.

[1] https://qntm.org/mmacevedo

I strongly recommend Timothy Snyder's lecture [1] on this topic (and the whole series in general).

[1] The Making of Modern Ukraine. Class 15. Ukrainization, Famine, Terror: 1920s-1930s https://www.youtube.com/watch?v=1dy7Mrqy1AY&t=1s

Seconded.

Add to that the (insane?) early SIOP, a plan for an all-out attack on the USSR with waves of nuke-armed strategic bombers.

As for the Damascus accident, I'd love to watch a high-budget movie about it (preferably on the level of "Deepwater Horizon", with Mark Wahlberg to boot).

I was quite uncomfortable (but managed to get the business done) for the first week or so after arriving in the US (business trip) due to the inch-wide gaps around stall doors. When flying back, going to the toilet in the first European airport was very... moving.