Search found 34 matches

by DaveMcW
Wed Jul 27, 2016 12:56 am UTC
Forum: What If?
Topic: What-If 0151: "Sun Bug"
Replies: 43
Views: 15536

Re: What-If 0151: "Sun Bug"

To make a measly 3.84E26 W like our Sun, the hole would weigh 968 kilograms. The Schwarzschild radius of a 968 kg black hole is 10 -24 meters, which is millions of times smaller than a proton. In Niagara Straw , we saw what happens when you try to squeeze 3000 tonnes of water through a 3.8 x 10 -5 ...
by DaveMcW
Thu Jul 21, 2016 1:13 am UTC
Forum: What If?
Topic: What-If 0151: "Sun Bug"
Replies: 43
Views: 15536

Re: What-If 0151: "Sun Bug"

I'm imagining the curve of increased output to run closer to the increase in mass of bioluminescent organs than to the increase in surface area. Am I wrong? As Randall metioned, there are 2 options. 1. "Arranging the fireflies in a hollow sphere, with their lanterns pointing outward." Thi...
by DaveMcW
Mon May 11, 2015 7:01 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1523: Microdrones
Replies: 30
Views: 6164

Re: 1523: Microdrones

It is rather inconvenient to stand around with a butterfly net all day. I think a better option would be a drone designed for hunting other drones. In heavily drone-infested areas, it could drain the battery packs of its prey to stay in the air indefinitely.
by DaveMcW
Fri Feb 20, 2015 4:32 am UTC
Forum: What If?
Topic: What-If 0129: "Black Hole Moon"
Replies: 63
Views: 21667

Re: What-If 129: "Black Hole Moon"

Could we put a space telescope in a tight orbit around the black hole in order to use it for better observations through gravitational lensing of some kind? As far as my inderstanding of this lensing goes: no. All the "reflections" near the event horizon are condensed (and darker/redshift...
by DaveMcW
Wed Oct 29, 2014 7:19 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1440: Geese
Replies: 52
Views: 10473

Re: 1440: Geese

Is this supposed to be a pun on G's?
by DaveMcW
Mon Oct 06, 2014 8:50 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1430: "Proteins"
Replies: 81
Views: 14617

Re: 1430: Proteins

Kit. wrote:Google:

"I write software that" - About 172,000 results
"I make software that" - About 27,400 results


172,000 programmers.
27,400 managers.
by DaveMcW
Thu Sep 18, 2014 11:13 am UTC
Forum: What If?
Topic: What-If 0112: "Balloon Car"
Replies: 31
Views: 8263

Re: What-If 0112: "Balloon Car"

armandoalvarez wrote:Wonder why he mixed metric and Imperial.


Thats what they do in the UK.
by DaveMcW
Mon Aug 25, 2014 4:32 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1412: "Teenage Mutant Ninja Turtles"
Replies: 150
Views: 36284

Re: 1412: "Teenage Mutant Ninja Turtles"

Randall's Trochee Phrase
FIXATION
by DaveMcW
Wed Jun 04, 2014 7:32 am UTC
Forum: What If?
Topic: What-If 0099: "Starlings"
Replies: 30
Views: 7834

What-If 0099: "Starlings"

What-If 0099: "Starlings" I was watching this video and was wondering: How many birds there would need to be for gravity to take over and force them into a gargantuan ball of birds? —Justin Basinger http://what-if.xkcd.com/imgs/a/99/collide.png While building your starling-star, you would...
by DaveMcW
Wed Apr 09, 2014 2:10 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1353: "Heartbleed"
Replies: 99
Views: 28338

Re: 1353: "Heartbleed"

forward4 wrote:I'm assuming because of the unique awareness that we have, the forums are secure...

The forums don't use SSL, so they are secure from the heartbleed bug.

Of course that means your forum password is available to anyone who wiretaps your internet connection...
by DaveMcW
Mon Mar 17, 2014 8:42 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1343: "Manuals"
Replies: 34
Views: 13855

Re: 1343: "Manuals"

The most ridiculous offender of all is the sudoers man page, which for 15 years has started with a 'quick guide' to EBNF, a system for defining the grammar of a language. 'Don't despair', it says, 'the definitions below are annotated. I prefer to think of it as a subtle reminder that you should let...
by DaveMcW
Thu Oct 24, 2013 9:37 pm UTC
Forum: What If?
Topic: What-If 0068: "Little Planet"
Replies: 70
Views: 14895

Re: What-If 0068: "Little Planet"

According to wikipedia the writer died in 1944, so he could just wait a year for copyright to expire in most countries (doesn't the USA also use a 70 year copyright after death period?). The copyright on stuff published after 1923 will probably never expire in the USA. http://en.wikipedia.org/wiki/...
by DaveMcW
Wed Oct 23, 2013 6:37 am UTC
Forum: What If?
Topic: What-If 0068: "Little Planet"
Replies: 70
Views: 14895

Re: What-If 0068: "Little Planet"

At 1/25 the mass and 1/5 the radius, the escape velocity at the surface would be sqrt(1/5) what it is on Earth, or about 5 km/s. That's proportionally about halfway between Earth's and the Moon's, so I don't know what it would really mean for holding onto an atmosphere. That is the Mars scenario, d...
by DaveMcW
Tue Oct 22, 2013 3:05 pm UTC
Forum: What If?
Topic: What-If 0068: "Little Planet"
Replies: 70
Views: 14895

Re: What-If 0068: "Little Planet"

The average velocity of air is 500 m/s.(http://www.dummies.com/how-to/content/u ... ir-mo.html). You would need to cool it down to a few degrees Kelvin to keep it on the asteroid.
by DaveMcW
Mon Mar 04, 2013 5:45 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1181: "PGP"
Replies: 52
Views: 22317

Re: 1181: "PGP"

Hypothetical situation: suppose you're Nigerian and a formerly high-placed government official, and you actually do have a bunch of money stashed away somewhere that you can't get out of the country by yourself. How would you go about extending an offer of partnership to someone who might be able t...
by DaveMcW
Tue Jan 15, 2013 3:10 am UTC
Forum: Individual XKCD Comic Threads
Topic: 0936: "Password Strength"
Replies: 893
Views: 276050

Re: 0936: "Password Strength"

Fortunately, modern hashes use much more than 32 bits.

MD5 has 128 bits, which is fine for password hashing even though recent cracks have made it unsuitable for verifying large files.
SHA1 has 160 bits.
SHA512 has, you guessed it, 512 bits.
by DaveMcW
Fri Jan 11, 2013 6:15 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1159: "Countdown"
Replies: 77
Views: 18742

Re: #1159: Countdown

For all we know, the odds are in our favor.


If you estimate the odds using Benford's law, we are still doomed.
by DaveMcW
Mon Dec 31, 2012 5:43 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1154: Resolution
Replies: 32
Views: 6889

Re: 1154: Resolution

modulating wrote:Isn't the halting problem undecidable?

Only for computers capable of infinite loops. People tend to stop looping after a hundred years or so.
by DaveMcW
Wed Nov 28, 2012 5:22 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1140: "Calendar of Meaningful Dates"
Replies: 152
Views: 21797

Re: 1140: "Calendar of Meaningful Dates"

In months other than September, the 11th is mentioned substantially less often than any other date. It's been that way since long before 9/11 and I have no idea why.

Maybe 11 is the most likely number to be misread by text recognition software.
by DaveMcW
Mon Nov 05, 2012 7:53 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1130: "Poll Watching"
Replies: 87
Views: 14737

Re: 1130: "Poll Watching"

Randall is one of Nate's biggest fans.
by DaveMcW
Wed Oct 24, 2012 5:35 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1125: "Objects In Mirror"
Replies: 70
Views: 23226

Re: 1125: "Objects In Mirror"

That warning doesn't really work on a normal convex mirror. It's not the redshifted objects you need to watch out for, it's the blueshifted ones.

But if Mr. Hubble has a custom mirror that corrects for redshift/blueshift, that is pretty awesome. :D
by DaveMcW
Tue Oct 09, 2012 4:28 pm UTC
Forum: What If?
Topic: What-If 0015: "Mariana Trench Explosion"
Replies: 55
Views: 15914

Re: What-if 0015: Mariana Trench Explosion

Next week: "What if we tried to launch a spaceship using carbonated beverages?" Randall explained how to calculate that in What-if 0007 . Fuel-to-ship ratio = e^(v escape /v exhaust ) Assuming 100m/s exhaust velocity for the beverage, and 1 ton for the spaceship, we get e^(13/0.1) = 2.8 x...
by DaveMcW
Wed Sep 19, 2012 7:14 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1110:"Click and Drag"
Replies: 595
Views: 653756

Re: 1110:"Click and Drag"

Firefox cheat code. (Thanks SheepEffect)

Spoiler:
To enter the code console, type [Crtl] [Shift] K

Paste the following in:

Code: Select all

document.getElementById('comic').style.overflow='';

Type [Crtl] [Shift] K again to close the console.

Use [Ctrl] + and [Ctrl] - to zoom.
by DaveMcW
Wed Aug 29, 2012 3:37 pm UTC
Forum: What If?
Topic: What-if 0008: "Everybody Jump"
Replies: 155
Views: 44339

Re: What-if 0008: Everybody Jump

1. how tall would the tower of people be? Each floor needs enough room for the person and enough for them to jump, maybe ignore thickness of the floors for simplicity given our fictional material that somehow supports all this weight. 2. Would the combined jump force crush the entire tower into the...
by DaveMcW
Fri Jul 20, 2012 8:56 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1084: "Server Problem"
Replies: 123
Views: 47004

Re: 1084: "Server Problem"

It combines three system files that should not be modified:
/usr/share
/root/sbin
ls

... with three apps that are not suitable for managing a server:
/Adobe
/android_vm
.jar

... plus one file that indicates the author is a total newbie:
/doc/example
by DaveMcW
Thu Jun 21, 2012 6:33 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1071: "Exoplanets"
Replies: 176
Views: 42435

Re: 1071: "Exoplanets"

El Cucui wrote:Given this scale, is the larger circle that could circumscribe all those planets the size of our sun?

Extrapolating from 31 pixels for Jupiter, the scale is 4600 km per pixel. That makes the large circle 6.9 million km in diameter. The sun's diameter is less than 1.4 million km.
by DaveMcW
Wed May 09, 2012 5:35 am UTC
Forum: Logic Puzzles
Topic: The perfect Chess AI engine
Replies: 89
Views: 39766

Re: The perfect Chess AI engine

Chess is a draw. A perfect AI engine will easily see and avoid any loss, and so will its opponent. Thus, draw. Exhaustively proving the above statement is outside the reach of physical computers, but here is how I convince myself. 1. One extra move is worth about 1/3 of a pawn according to opening t...
by DaveMcW
Thu Aug 26, 2010 9:59 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0784: "Falling Asleep"
Replies: 96
Views: 26602

Re: Falling Asleep discussion (784)

Kisama wrote:The algorithm is
Spoiler:
google
?


A common misconception. Randall hijacked the campaign with some success.
by DaveMcW
Thu Feb 11, 2010 11:10 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 34141

Re: "Tensile vs. Shear Strength" Discussion

there's air resistance. Bottom line, its not all going to flash into heat all at once. A nuke releases its total energy in a handful of microseconds and in a volume not much larger than the bomb itself. The cable will have a volume of, ooh lets say, 1e4 cubic metres? And it might take 10 minutes (s...
by DaveMcW
Mon Jan 18, 2010 6:00 am UTC
Forum: Individual XKCD Comic Threads
Topic: 0690: "Semicontrolled Demolition"
Replies: 158
Views: 29838

Re: "Semicontrolled Demolition" Discussion

Reminds me of the overton window politics.
by DaveMcW
Fri Dec 25, 2009 9:59 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0680: "December 25th"
Replies: 148
Views: 21125

Re: "December 25th" Discussion

And I thought it was bad being born on Thanksgiving... Hey thats my birthday too! (well my birthday every once in a while). Do you realise how many times a pie of some sort has been my present?!? ... actually now that I'm thinking about it I'm pretty sure I'm ok with that.. Mine too. And I have sev...
by DaveMcW
Fri Dec 18, 2009 11:59 am UTC
Forum: Individual XKCD Comic Threads
Topic: 0677: "Asshole"
Replies: 84
Views: 19286

Re: "Asshole" Discussion

Image
An asshole, am I?
Perhaps you'd like to see how assssss-holish I can be!

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