Search found 194 matches

by drachefly
Thu Sep 06, 2018 7:02 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 2042: "Rolle's Theorem"
Replies: 76
Views: 3436

Re: 2042: "Rolle's Theorem"

orthogon wrote:That was me with matrix multiplication. "But why do matrices multiply like that? Who says? It's stupid"


We started straight off with the applications, so it never seemed stupid. Not easy, but it was clear that there was a point to it all.
by drachefly
Fri Aug 24, 2018 8:45 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 2016: "OEIS Submissions"
Replies: 31
Views: 3718

Re: 2016: "OEIS Submissions"

psst… use a run-length encoder first. Backreferences are just as good as run-length encoding, the limit here is that common implementations (zip/gzip/deflate etc) have a fixed bit-size for the "length" parameter. For example, a backreference in DEFLATE is at least 24 bits long but has jus...
by drachefly
Fri Aug 24, 2018 8:40 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 2037: "Supreme Court Bracket
Replies: 15
Views: 1560

Re: 2037: "Supreme Court Bracket"

Trives wrote:I can't believe Scopes Tennessee didn't make it to the round of 32! Bracket busted.


That's in a different division - US Supreme court cases only, here.
by drachefly
Fri Jul 06, 2018 10:03 pm UTC
Forum: Science
Topic: Cooling gas by expansion
Replies: 17
Views: 2067

Re: Cooling gas by expansion

So I have a compressed gas in a tank. 1) I release it through a nozzle into an infinite vacuum, like say, space. Does the gas cool to absolute zero due to infinite expansion, or is there some limit to cooling? Does the mean-free-path have anything to do with this? Yes, it cools with no limit, and t...
by drachefly
Fri Jul 06, 2018 9:46 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 2016: "OEIS Submissions"
Replies: 31
Views: 3718

Re: 2016: "OEIS Submissions"

psst… use a run-length encoder first.
by drachefly
Fri Jun 08, 2018 6:20 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 2003: "Presidential Succession"
Replies: 72
Views: 8417

Re: 2003: "Presidential Succession"

Michael Torsten Kreuger (b. 1983) is possibly the first (or, at least, the first adult) natural-born US citizen in the line, somewhere in the 110s or thereabouts ("possibly" because there are some marriage-related problems in his ancestry, and the WARGS list does not, in fact, include him...
by drachefly
Mon Jan 29, 2018 10:26 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1948: "Campaign Fundraising Emails"
Replies: 34
Views: 5147

Re: 1948: "Campaign Fundraising Emails"

niauropsaka wrote:At first I just read the bolded text...


applause.
by drachefly
Tue Jul 11, 2017 1:25 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1861: "Quantum"
Replies: 69
Views: 8732

Re: 1861: "Quantum"

I never came close to understanding the Heisenberg Uncertainty Principle. You've got to put stuff in a place. You're trying to get it bunched up, and you're trying to get it to lie flat. These two things conflict - you can't do them both perfectly. The math is literally the same for that problem as...
by drachefly
Mon Jun 19, 2017 1:38 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1851: "Magnetohydrodynamics"
Replies: 30
Views: 6355

Re: 1851: Magnetohydrodynamics

What really gets me is "fucking electrostatic interaction, how does that work?" Mumble mumble sea of virtual photons somethingsomething? Photons are a thing in the interaction picture. The interaction picture is the worst way of understanding statics. The problem is, no one really works w...
by drachefly
Thu Jun 01, 2017 3:12 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1844: "Voting Systems"
Replies: 83
Views: 11175

Re: 1844: "Voting Systems"

It's not that unintuitive, really. You can vote at half strength in two races, but in the end it's going to come down to the two candidates with the highest score, so you might as well put all your voting strength into that race, if you can identify it in advance. If you can't identify it, I think i...
by drachefly
Thu Jun 01, 2017 2:26 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1844: "Voting Systems"
Replies: 83
Views: 11175

Re: 1844: "Voting Systems"

Star voting seems to be a marketing term for range voting (which strategically devolves to approval voting), followed by a runoff where the top candidate of the top two wins. I think this devolves into approval voting, perhaps with a bias favoring the most polarizing candidate. Star Voting uses Ran...
by drachefly
Wed May 31, 2017 7:21 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1844: "Voting Systems"
Replies: 83
Views: 11175

Re: 1844: "Voting Systems"

This comic describes my position very well. IRV is weak and unstable compared to Condorcet systems, and Approval is quite good. I also like Star Voting, described above… pending analysis. Ranking means that you only have X stars to go around on your ballot and have to budget them out. Not quite sure...
by drachefly
Wed Mar 22, 2017 2:02 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1813: "Vomiting Emoji"
Replies: 45
Views: 10573

Re: 1813: "Vomiting Emoji"

The Snide Sniper wrote:Would this combining character affect characters other than emoji? I want to see a "vomiting Greek letter P".


Vomiting tab character.

Vomiting carriage return?

Vomiting terminal bell!
by drachefly
Sat Jan 28, 2017 5:08 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1791: "Telescopes: Refractor vs Reflector"
Replies: 99
Views: 14279

Re: 1791: "Telescopes: Refractor vs Reflector"

Kalium_Puceon wrote:Looks like it's been fixed so there's no reflector in the refractor anymore.


Oh, good –I'd been wondering where the heck this mirror everyone's talking about is.
by drachefly
Fri Dec 30, 2016 7:17 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1776: "Reindeer"
Replies: 32
Views: 6514

Re: 1776: Reindeer

What I find interesting is that the opposite is true for quantum systems, where the object is more likely to be found at the bottom of the energy well where you'd think it would be going faster and spend less time. Only in the ground state. In any excited state, especially the higher excited states...
by drachefly
Fri Nov 18, 2016 9:03 pm UTC
Forum: Mathematics
Topic: Odd or Even?
Replies: 10
Views: 4496

Re: Odd or Even?

Only if this particular instance of 1 is also deep and crisp.
by drachefly
Fri Nov 18, 2016 9:02 pm UTC
Forum: Mathematics
Topic: Trying to figure out a thing in a video game.
Replies: 5
Views: 2514

Re: Trying to figure out a thing in a video game.

If you get life drain cards of unequal power (e.g. got only one epic shiny draining card), then you need to multiply the power by the sum of the best N cards. This will make the stronger swords with fewer slots better.
by drachefly
Sun Sep 18, 2016 3:40 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1404: Quantum Vacuum Virtual Plasma
Replies: 62
Views: 20339

Re: 1404: Quantum Vacuum Virtual Plasma

But to push off the Dirac Sea, you need to make the ones you're pushing off of not be virtual anymore. If you're pushing off of nothing, you're violating QM so hard that tweaks aren't going to do it - you need to just go make a new theory. That's how Coulomb's law works if you want to keep locality...
by drachefly
Mon Jun 20, 2016 7:25 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1696: "AI Research"
Replies: 12
Views: 3558

Re: 1696: "AI Research"

...and if some Captain-Kirk-esque fool tries to get you to prove a paradox logically, the answer is always "you're a poopyhead." Nah, the correct response is to pretend it makes sense and see if you can crash Kirk's mind... Alternately, pretend to break. Play it by ear from there. Perhaps...
by drachefly
Wed Apr 13, 2016 5:42 pm UTC
Forum: Science
Topic: Tazer rifle
Replies: 10
Views: 2374

Re: Tazer rifle

The mean free path of electrons in air is way too short to make a practical weapon on Earth.
by drachefly
Wed Mar 09, 2016 4:18 pm UTC
Forum: Science
Topic: is Chicago ever the "front" of the planet?
Replies: 30
Views: 5771

Re: is Chicago ever the "front" of the planet?

This question reminds me most of when Soul used a portal to the far side of the Earth to get a stream of projectiles moving at a relative velocity of the Earth's rotational speed times the sum of the axial radii of the Equator and Tokyo (i.e. took a column of material from the Equator on the far sid...
by drachefly
Tue Mar 01, 2016 12:22 am UTC
Forum: Science
Topic: Quantum Fluctuations questions
Replies: 21
Views: 6049

Re: Quantum Fluctuations questions

2) The basic idea behind fluctuations is the Uncertainty Principle. You can't have a unit of space with precisely zero energy; there is an intrinsic uncertainty. The "conjugate variable" of energy is time, so they have complementary (im)precisions/(un)certainties. To be slightly more spec...
by drachefly
Tue Mar 01, 2016 12:08 am UTC
Forum: Science
Topic: Should we consider string theory to be science? (Philosophy)
Replies: 32
Views: 5304

Re: Should we consider string theory to be science? (Philoso

As for point 1 - when you zoom out, you can't do all the math, so you just end up with Lakatos. It's like the difference between QM or GR and Newton. Fundamentally, it's all the complicated thing. At the high level, it's the simple thing. It is nice to know how the complicated thing works. 2 - Bayes...
by drachefly
Tue Feb 23, 2016 10:02 pm UTC
Forum: Science
Topic: Should we consider string theory to be science? (Philosophy)
Replies: 32
Views: 5304

Re: Should we consider string theory to be science? (Philoso

) It was interesting to me that the philosophers of science said the cutting edge model was this Bayesian confirmation. That seems stupid to me. They're trying to put a quantitative number on something that is not quantitative. And you can use anything for your priors.. I don't know. I find it very...
by drachefly
Tue Feb 23, 2016 4:51 pm UTC
Forum: Science
Topic: Engines big enough....
Replies: 28
Views: 5549

Re: Engines big enough....

If you have a space elevator (which we don't) then you can use chemical rockets attached to it at a high enough point that the exhaust can escape. That said, the mass of the earth is rather large compared to the reaction mass, so it's pretty insignificant. Or you can use rockets attached to asteroid...
by drachefly
Tue Jan 12, 2016 3:43 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1628: Magnus
Replies: 27
Views: 6117

Re: 1628: Magnus

Hmm. Age extremes.

Harry Potter vs Voldemort round 1 comes to mind, but that's not as extreme as the one I came up with first...

0.03-year-old Hercules beats a snake in wrestling. 200-year-old Hercules beats the local cluster in absolute luminosity.
by drachefly
Mon Dec 28, 2015 9:28 pm UTC
Forum: Science
Topic: Many, many worlds (no relation to QM)
Replies: 20
Views: 3409

Re: Many, many worlds (no relation to QM)

About the white sun - maybe it's a reasonably-sized star in tight orbit about a black hole that's sufficiently massive for the perturbations from other systems not to matter anymore?
by drachefly
Mon Dec 28, 2015 8:43 pm UTC
Forum: Logic Puzzles
Topic: Blue Eyes with Superrationality
Replies: 48
Views: 9872

Re: Blue Eyes with Superrationality

Going back to the previous thread for a moment - It's hard to define. I was in the middle of a post trying to justify my brilliant scheme. Also I was thinking about this post about iterating down to zero. I had got it in my mind that something changed at N=3, this being the case where everyone's mod...
by drachefly
Thu Dec 10, 2015 5:48 pm UTC
Forum: Science
Topic: Would it be possible to spot Alan Shepard's golf balls?
Replies: 11
Views: 2398

Re: Would it be possible to spot Alan Shepard's golf balls?

You'd need to spot the dimples to be at all confident. That's not just one order of magnitude of resolution increase.
by drachefly
Thu Dec 10, 2015 5:27 pm UTC
Forum: Science
Topic: A question about Dyson Spheres
Replies: 13
Views: 2454

Re: A question about Dyson Spheres

as fusion spreads throughout the star, the radiation pressure coming in toward the center (and being reflected from the Dyson sphere at the edge) becomes greater than the outward radiation pressure. With the star no longer able to sustain itself against its own weight, gravity will cause the core t...
by drachefly
Thu Dec 03, 2015 5:27 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1611: "Baking Soda and Vinegar"
Replies: 43
Views: 9745

Re: 1611: "Baking Soda and Vinegar"

I've judged many science fairs, and the vinegar & baking soda volcano is [...] not an "experiment" in the sense that you're testing a hypothesis. In the earth-science sense, no. It's not much of a model of volcanic activity. In the chemistry sense, yes. Everyone already knows what's g...
by drachefly
Tue Dec 01, 2015 10:55 pm UTC
Forum: Mathematics
Topic: How does changing a bet alter the odds?
Replies: 6
Views: 2340

Re: How does changing a bet alter the odds?

It's the odds you have to have in order that it be profitable to stick with that particular pot.
by drachefly
Wed Nov 25, 2015 2:14 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1608: "Hoverboard"
Replies: 140
Views: 66303

Re: 1608: "Hoverboard"

Pfhorrest wrote:Whatever this is, it doesn't seem to work on Safari.


Works fine for me on safari 9.0.1 on 10.11.1.
by drachefly
Wed Nov 18, 2015 11:40 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1604: "Snakes"
Replies: 66
Views: 11974

Re: 1604: "Snakes"

I'm reminded of the comic where someone did Snakes and Ladders where the snakes just killed you outright, and plotted the probability that you'd reach any given square, for all the squares on the board.

Now, THAT was a grim game. The probability of reaching 100 was very low.
by drachefly
Mon Nov 09, 2015 9:11 pm UTC
Forum: Science
Topic: Bad science jokes!
Replies: 100
Views: 33201

Re: Bad science jokes!

Shoot, that angular momentum is not going to be conserved, at all.
by drachefly
Fri Oct 02, 2015 6:45 pm UTC
Forum: Science
Topic: Why not colonize Ceres?
Replies: 228
Views: 38550

Re: Why not colonize Ceres?

commodorejohn wrote:Unless there are Tesla coils involved.


Or Van de Graaf generators?
by drachefly
Fri Oct 02, 2015 6:43 pm UTC
Forum: Science
Topic: Is velocity a limit?
Replies: 18
Views: 4221

Re: Is velocity a limit?

Yeah, that's the problem with being bright or otherwise talented - you don't understand what the hard part is.
by drachefly
Thu Oct 01, 2015 7:32 pm UTC
Forum: Science
Topic: Stationary ramjet
Replies: 45
Views: 7313

Re: Stationary ramjet

Merely cooling and compressing atmospheric air for use as working mass would be a lot easier, though still probably too difficult to be realizable. Nope, that's exactly what Skylon/SABRE will do, and the technical reviews have come back 👍 looks good. Well, Skylon/SABRE isn't cooling/compressing atm...
by drachefly
Thu Oct 01, 2015 7:15 pm UTC
Forum: Science
Topic: Is velocity a limit?
Replies: 18
Views: 4221

Re: Is velocity a limit?

Wow, and this was a physics teacher? The difference between instantaneous and average velocity deserves basically as much time as needed for the teacher to be sure it has soaked in, from a starting point of assuming it hasn't at all.
by drachefly
Wed Sep 23, 2015 6:36 pm UTC
Forum: Science
Topic: Pluto down, next stop...interstellar?
Replies: 30
Views: 5779

Re: Pluto down, next stop...interstellar?

... locally optimized may be globally pessimized.

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