Search found 15 matches

by rpresser
Wed Feb 10, 2016 10:09 pm UTC
Forum: What If?
Topic: What-If 0145: "Fire From Moonlight"
Replies: 157
Views: 72356

Re: What-If 0145: "Fire From Moonlight"

Cover the moon with photovoltaics. Hook them up to a microwave beamer, aimed at a satellite in L5 orbit. Put a microwave receiver in the L5 satellite, and an X-ray laser aimed at a spot on the earth. There's your fire. No lenses or mirrors; lots of heat loss (and required device cooling); but you ca...
by rpresser
Sat Jan 17, 2015 9:15 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1474: "Screws"
Replies: 96
Views: 39108

Re: 1474: "Screws"

Actual uranium screws -- i.e., screws actually composed of non-enriched uranium -- were used in the construction of nuclear weapons during the twentieth century. See http://blog.nuclearsecrecy.com/2014/11/ ... s-uranium/ and other links from http://www.explainxkcd.com/wiki/index.php/1474:_Screws
by rpresser
Tue Mar 25, 2014 6:37 pm UTC
Forum: What If?
Topic: What-If 0089: "Tungsten Countertop"
Replies: 77
Views: 23005

Re: What-If 0089: "Tungsten Countertop"

So what IS with the Tungsten Countertop itself? I'm guessing the person saw/heard of a countertop with a tungsten color finish and thought the countertop was made of tungsten. Kitchens with seizure-inducing countertops TOTALLY sell houses now. Tungsten EV seems to be a color pattern name used to se...
by rpresser
Tue Mar 12, 2013 5:42 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1184: "Circumference Formula"
Replies: 102
Views: 37054

Re: 1184: "Circumference Formula"

Ryan's a few dozen years late with this. See "Mathmanship" by Nicholas Vanserg (1958): The other side of the asterisk gambit is to use a superscript as a key to a real footnote. The knowledge‐seeker reads that S is –36.7 14 calories and thinks "Gee what a whale of a lot of calories&q...
by rpresser
Mon Mar 11, 2013 4:56 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1184: "Circumference Formula"
Replies: 102
Views: 37054

Re: 1184: "Circumference Formula"

Ryan's a few dozen years late with this. See "Mathmanship" by Nicholas Vanserg (1958): The other side of the asterisk gambit is to use a superscript as a key to a real footnote. The knowledge‐seeker reads that S is –36.7 14 calories and thinks "Gee what a whale of a lot of calories&qu...
by rpresser
Thu Sep 15, 2011 4:47 am UTC
Forum: Individual XKCD Comic Threads
Topic: 0951: "Working"
Replies: 165
Views: 34951

Re: 0951: "Working"

I haven't read every post in this thread, but I think the point still needs to be made that your choice about gasoline purchase is not made in a vacuum. Your choice to drive further in order to buy cheaper gas means that you burn more gas in the process, increasing your carbon footprint. Your choice...
by rpresser
Sat Oct 30, 2010 3:36 am UTC
Forum: Individual XKCD Comic Threads
Topic: 0812: "Glass"
Replies: 119
Views: 30510

Re: 0812: Glass

I did read a short science-fiction story where the laws of science were ill-defined, until repeated experiment fixed the results. Can't remember who it is by, or what it was called. If only there was a world-wide communication network/information repository I could search to find out. :? I vaguely ...
by rpresser
Fri Oct 29, 2010 4:21 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0812: "Glass"
Replies: 119
Views: 30510

Re: 0812: Glass

I wonder if this is the article. The probability that your soul and spirit transitions to another set of numbers; is because of meta-mathematics and fractal numbers. Using fractal numbers is at least some of the electroweak force set of existence. Then you would not have to worry about decompositio...
by rpresser
Wed Jan 13, 2010 9:57 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0688: "Self-Description"
Replies: 200
Views: 100698

Re: "Self-Description" Discussion

All right, clearly in panel 3 of the mini-comic in panel 3 there's another comic...and you can make it out well enough in that mini-comic...but what's in that mini-comic? We're getting close to the resolution, so is it just an approximation? It looks like kind of a grey smudge... two hundred and fo...
by rpresser
Wed Jan 13, 2010 9:23 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0688: "Self-Description"
Replies: 200
Views: 100698

Re: "Self-Description" Discussion

I would very much like to see a version of this comic where panel 3 shows "Location of WHITE ink in this image"
by rpresser
Wed Sep 10, 2008 1:10 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0474: "Turn-On"
Replies: 178
Views: 33792

Re: "Turn-On" Discussion

She's pretty agressive -- I'll bet that if there were a fifth panel, she'd have lepton him.
by rpresser
Wed Aug 27, 2008 4:59 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0468: "Fetishes"
Replies: 163
Views: 46608

Re: "Fetishes" discussion

I'm not so happy about this. Certainly it's a ticklish idea to try to apply the first Incompleteness Theorem to a list of fetishes ... but to make it really work, you'd need a Goedel encoding that represents statements about fetishes WITH fetishes. You need an isomorphism from symbolic logic -> feti...
by rpresser
Mon Aug 11, 2008 2:35 pm UTC
Forum: Science
Topic: Physics Tattoo Ideas
Replies: 63
Views: 17422

Re: Physics Tattoo Ideas

I would use this proof of the pythagorean theorem: http://jwilson.coe.uga.edu/EMT668/emt668.student.folders/HeadAngela/essay1/image1.gif (But without the lettering.) It's simple, can be demonstrated to anyone, should be very easy for the tattoo artist to execute, and if you're not committed to UV, c...
by rpresser
Mon Aug 11, 2008 2:22 pm UTC
Forum: Mathematics
Topic: Show us your articles! Or what's your Erdos number?
Replies: 185
Views: 269003

Re:

I just realized that one of my profs last year had an Erdos number of 2. I had the opportunity to proofread a book he was writing (and be credited in the published version for as much), but I didn't do it! Curses! I don't know how close I'll get to a 3 again. Just spend the next decade obsessively ...
by rpresser
Wed Oct 11, 2006 8:55 pm UTC
Forum: Logic Puzzles
Topic: Three Dots
Replies: 1
Views: 5706

This is very old.

This is the problem that is the usual introduction to the class of problems like the Blue Eyes problem. I first saw it at around age 9 -- but it took me a few years before I could understand it. First, think of 2 people. If there were 2 people, then if you saw a green dot and your neighbor saw a gre...

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