Search found 3054 matches

by orthogon
Tue Jan 29, 2013 6:22 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1145: "Sky Color"
Replies: 211
Views: 71340

Re: 1145: "Sky Color"

Now we're talking about something else: why people tend to misinterpret front-back flips as horizontal flips rather than misinterpreting them as vertical flips. Do they really misinterpret it in their actions ? Or do they do it only in their explanations of the subject, with their actions that invo...
by orthogon
Tue Jan 29, 2013 5:48 pm UTC
Forum: What If?
Topic: What-If 0030: "Interplanetary Cessna"
Replies: 109
Views: 42672

Re: What-If 0030: Interplanetary Cessna

you need to approach Mach 1 just to get off the ground

Does this take into account that Mach 1 on Mars is significantly slower than Mach 1 on Earth?
by orthogon
Tue Jan 29, 2013 11:30 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1166: "Argument"
Replies: 177
Views: 37464

Re: 1166: "Argument"

mishka wrote:We actually live in a perpetual motion machine.

Does anybody else hear this to the tune of the Beatles' Yellow Submarine?
by orthogon
Mon Jan 28, 2013 3:35 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1166: "Argument"
Replies: 177
Views: 37464

Re: 1166: "Argument"

richP wrote:
itaibn wrote:Sadly, it's impossible to generate useful work out of perpetual motion crackpottery.

Sure it's possible, just open an online store selling supplies for homebuilt perpetual motion machines.

Just remember to push back hard when Marketing start wanting to offer complete, pre-built working models.
by orthogon
Mon Jan 28, 2013 3:11 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1166: "Argument"
Replies: 177
Views: 37464

Re: 1166: "Argument"

asdfzxc wrote:... is akin to literally ...

I like the way you found a formulation that lets you use the word "literally" in a figurative sense with impunity.
by orthogon
Mon Jan 28, 2013 2:03 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1166: "Argument"
Replies: 177
Views: 37464

Re: 1166: "Argument"

MeisBarry wrote:I would just like to say that I enjoyed the choice of avatar image for the second poster.

Yes, but (s)he's got the wrong First Law. The First Law of Thermodynamics is you don't talk about thermodynamics.
(Somebody had to say it).
by orthogon
Fri Jan 25, 2013 2:55 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1163: "Debugger"
Replies: 175
Views: 29688

Re: 1163: "Debugger"

This is the reason why Newtonian mechanics is so intuitive to us, even though relativity and quantum effects seem bizarre. I must politely disagree that Newtonian mechanics is as intuitive as all that. Newton's First Law came as quite a surprise to me. Moving things generally slow down and stationa...
by orthogon
Thu Jan 24, 2013 1:56 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1164: "Home Alone"
Replies: 34
Views: 10048

Re: 1164: "Home Alone"

That staircase should have a banister. If they survive, the kids can probably sue him on Health & Safety grounds. Is it like that in the original movie?
by orthogon
Tue Jan 22, 2013 10:04 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1160: "Drop Those Pounds"
Replies: 67
Views: 15000

Re: 1160: "Drop Those Pounds"

According to Merriam-Webster.com, it's pronounced with a hard T (treh - byou - SHET); although since the word is of Anglo-French origin I don't think anybody's going to pin you to a wall if you spell/pronounce it in the French manner — trébuchet (treh - byou - SHAY). If it's Anglo-French, then it w...
by orthogon
Sun Jan 20, 2013 7:06 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0936: "Password Strength"
Replies: 893
Views: 321408

Re: 0936: "Password Strength"

I bank with smile.co.uk who use this kind of setup: They ask for two specified digits from the (4-digit) PIN. These are selected via a dropdown menu in the web page, so most people probably don't type them in using the keyboard. I don't know whether or not that makes it more secure - presumably you ...
by orthogon
Fri Jan 18, 2013 1:59 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1160: "Drop Those Pounds"
Replies: 67
Views: 15000

Re: 1160: "Drop Those Pounds"

I heard "poundal" used for a pound force, too. Since the pound is a unit of force, "poundal" would be entirely redundant. Whoops, a poundal isn't a pound force. It's a derived unit equivalent to the lb.ft.s -2 , in a coherent system where the pound is a unit of mass. A pound for...
by orthogon
Wed Jan 16, 2013 1:34 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1161: "Hand Sanitizer"
Replies: 89
Views: 23587

Re: 1161 Hand Sanitizer

I always assumed (← there might be the mistake) that the 99.99% refers to types of bacteria, while the sneeze droplet's millions of germs would mainly be of the same type? I believe you are correct. So this is either an oversight by Randall. Or the stick man character (I have a hard time telling th...
by orthogon
Tue Jan 15, 2013 6:02 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1155: "Kolmogorov Directions"
Replies: 144
Views: 25839

Re: 1155: "Kolmogorov Directions"

Try telling someone a non Kolmogorov alternative description of a phone number, e.g. 3 2 7 3 2's and a 7 instead of 3 2 7 2 2 2 7 . People always wrote down 3 2 7 3 2 7 and then looked at me waiting for the seventh digit. When I got my mobile (cell) number which was of the form (code) + aabccd I th...
by orthogon
Tue Jan 15, 2013 10:08 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1160: "Drop Those Pounds"
Replies: 67
Views: 15000

Re: 1160: "Drop Those Pounds"

Trebuchets use the dropping of a counterweight which usually weighs hundreds of pounds.  Dropping 30 pounds doesn't seem like it would do much of anything at all; unless you're talking about maybe a working model suitable for destroying model railroads and built on a scale of around 1/48 or so. You...
by orthogon
Mon Jan 14, 2013 11:27 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1159: "Countdown"
Replies: 77
Views: 21640

Re: #1159: Countdown

Reminds me of the time I had a ceiling-projected clock as the only light source in my bedroom, and after lying down and closing my eyes, I awoke to find the room much darker than when I lay down. I had just happened to open my eyes at 1:11am. Being the OCD person I am, I was unable to get back to s...
by orthogon
Thu Jan 10, 2013 1:50 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1158: "Rubber Sheet"
Replies: 50
Views: 13576

Re: 1158: "Rubber Sheet"

Also proportional to the ball weight, for small displacements. I only ask because it looks to me like the force is quadratic in the (small) displacement for the 1D case of pushing on the middle of a rubber band tied on at both ends, if I assume the rubber band starts off unstretched, i.e. the dista...
by orthogon
Wed Jan 09, 2013 6:16 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1158: "Rubber Sheet"
Replies: 50
Views: 13576

Re: 1158: "Rubber Sheet"

BTW, if it is a huge round sheet, with two dimensional symmetry, the displacement is proportional to the logarithm of the sheet diameter S divided by the ball diameter D. log(S/D). If the sheet diameter S is infinite, the logarithm is infinite. That is, put a force on it and it will just keep displ...
by orthogon
Wed Jan 09, 2013 6:04 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1158: "Rubber Sheet"
Replies: 50
Views: 13576

Re: 1158: "Rubber Sheet"

Why is he asking her to imagine a ball on a rubber sheet, when he is at that very moment standing on such a ball on such a sheet? Or are we seeing the image in her mind's eye, and she has inserted beret guy into her mental picture? And then he says "imagining is fun" - is that then his ima...
by orthogon
Wed Jan 09, 2013 2:33 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1158: "Rubber Sheet"
Replies: 50
Views: 13576

Re: 1158: "Rubber Sheet"

Since our problem is cylindrically symmetical, the sheet can be modelled as a simple spring ( F = -kx ). Why? It's not correct. It's stretching the center of the sheet, so it's different. If you stretch in the middle of a spring in a direction perpendicular to the spring, it's not Hook's law. And t...
by orthogon
Mon Jan 07, 2013 2:14 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1155: "Kolmogorov Directions"
Replies: 144
Views: 25839

Re: 1155: "Kolmogorov Directions"

If you had a maze set up in your living room, would your front door and the four walls of the room, plus any other doors, count as part of the maze? I don't know. My wife would never allow it. If you find a cornfield maze, is the gate in the fence surrounding the maze also part of the maze? No, bec...
by orthogon
Sun Jan 06, 2013 7:35 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1155: "Kolmogorov Directions"
Replies: 144
Views: 25839

Re: 1155: "Kolmogorov Directions"

Generally when one speaks of solving a maze, one assumes to stay inside the maze. Unless this is an example of why one of the arguments above is wrong. EDIT: I think I get it? If a maze has contiguous walls and has the entrance and exit on the outer walls, then the only solution is to go around the...
by orthogon
Sat Jan 05, 2013 10:20 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1155: "Kolmogorov Directions"
Replies: 144
Views: 25839

Re: 1155: "Kolmogorov Directions"

This is a Davidyan maze, i.e. the walls are contiguous, but is non-Dudiobugtronian. IMAG0900.jpg Solution: IMAG0902.jpg Left-hand-rule solution. If you insist that you have to come out of the exit, you have to go in and wriggle all around the "output" side of the maze until you get back to...
by orthogon
Sat Jan 05, 2013 11:19 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1155: "Kolmogorov Directions"
Replies: 144
Views: 25839

Re: 1155: "Kolmogorov Directions"

I don't think this, in its entirety, is a maze. You have a structure within a square with two openings, within another square with one opening, within another square with one opening. The actual maze is three levels down, and it does meet the right hand solution. I had believed for decades that you...
by orthogon
Fri Jan 04, 2013 9:39 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1155: "Kolmogorov Directions"
Replies: 144
Views: 25839

Re: 1155: "Kolmogorov Directions"

So what would people think if they heard the initials S.F. or A.L.? Asssuming that you know that it's a geographical location? A.L. doesn't ring any bells as a location. However somebody I know has a mug plugging some presumably long-forgotten corporate initiative known as the "Occupational Ri...
by orthogon
Thu Jan 03, 2013 7:23 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1155: "Kolmogorov Directions"
Replies: 144
Views: 25839

Re: 1155: "Kolmogorov Directions"

Did he optimise the route, then compress the directions? Or did he jointly optimise both? Haha, that's a nice question! Did he optimise the route, then compress the directions? Or did he jointly optimise both? He didn't optimise the route ... he chose the most compressed directions that got the per...
by orthogon
Wed Jan 02, 2013 3:01 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1155: "Kolmogorov Directions"
Replies: 144
Views: 25839

Re: 1155: "Kolmogorov Directions"

... If, for example, I give the cashier $10.03 for a $5.03 order, it's all good. Alternately, if I give the cashier $10.08 for a $5.83 order, it is far more likely to require a "trust me". Woah, until you nerd-sniped me with that example I hadn't thought about how much more interesting th...
by orthogon
Wed Jan 02, 2013 11:02 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1155: "Kolmogorov Directions"
Replies: 144
Views: 25839

Re: 1155: "Kolmogorov Directions"

Davidy wrote:An example of extreme simplicity in directions for solving a very complicated problem is in finding ones way through a maze - simply continue walking, keeping your right hand on a wall and you will eventually reach the exit.

In the UK you have to use your left hand instead :P
by orthogon
Wed Jan 02, 2013 9:24 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1155: "Kolmogorov Directions"
Replies: 144
Views: 25839

Re: 1155: "Kolmogorov Directions"

Did he optimise the route, then compress the directions? Or did he jointly optimise both?
by orthogon
Tue Jan 01, 2013 4:16 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1153: "Proof"
Replies: 64
Views: 18983

Re: 1153: "Proof"

Also - what speising wrote is correct - everything is moving at c all the time. If something is not moving in space at all, it moves through time at c. If it moves a bit, its speed in the direction of time is somewhat lower. That is why moving a considerable fraction of c makes time go slower for y...
by orthogon
Mon Dec 31, 2012 5:53 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1154: Resolution
Replies: 32
Views: 7816

Re: 1154: Resolution

PS Note also the Black Swan and the difficulty in general of estimating the probability of unprecedented events.
by orthogon
Mon Dec 31, 2012 5:34 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1154: Resolution
Replies: 32
Views: 7816

Re: 1154: Resolution

Questions for the stat-literate: How many consecutive failures are necessary to state "There's just no point in trying. Stop." with 95% confidence? I was going to have a go at this but the more I thought about it the harder it got. Considering each resolution as one trial, and presuming t...
by orthogon
Fri Dec 28, 2012 12:35 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1153: "Proof"
Replies: 64
Views: 18983

Re: 1153: "Proof"

squonk wrote:
Brian-M wrote:I'm used to seeing it spelled "Xeno". Seeing it as "Zeno" looks strange to me. But since the ancient Greeks didn't use the Latin alphabet, I suppose either way is equally valid.

I prefer Z-Know.

Eh? "Zedno"? Oh, right.
by orthogon
Wed Dec 26, 2012 10:09 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1152: "Communion"
Replies: 124
Views: 24763

Re: 1152: "Communion"

If the communion wafer transforms into the body of Christ, does it taste a bit like chicken?
by orthogon
Tue Dec 25, 2012 10:23 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1151: "Tests"
Replies: 24
Views: 10144

Re: 1150: "Tests"

She's made another mistake in the procedure: all such tests have to be carried out in low, blue-tinged lighting with funky electronic music playing in the background. http://img822.imageshack.us/img822/4189/athreat.png There The Comic Sans is not a mistake Next time it will be Papyrus Thank you! xk...
by orthogon
Mon Dec 24, 2012 2:14 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1151: "Tests"
Replies: 24
Views: 10144

Re: 1150: "Tests"

She's made another mistake in the procedure: all such tests have to be carried out in low, blue-tinged lighting with funky electronic music playing in the background.
by orthogon
Thu Dec 20, 2012 8:40 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1145: "Sky Color"
Replies: 211
Views: 71340

Re: 1145: "Sky Color"

The whole answer is, to the best of my reckoning, "It radiates, at DC. Constant current in the loop induces a constant magnetic field. That constant magnetic field is the physical embodiment of the non-varying (0 Hz) electromagnetic radiation." A 0Hz EM wave should have an electric field ...
by orthogon
Wed Dec 19, 2012 5:30 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1149: Broomstick
Replies: 114
Views: 25888

Re: 1149: Broomstick

Oh now really... The One Ring, with all its power and ability to twist fate in returning home, didn't know when to duck? It's slipped off of fingers before. Perhaps that would have been a good time to accidentally fall into the Dark Lord's pants. That would only make the cutting-off much more painf...
by orthogon
Wed Dec 19, 2012 2:22 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1149: Broomstick
Replies: 114
Views: 25888

Re: 1149: Broomstick

Yoduh wrote:[...] there could have been many ways for dorothy to get back home, including jumping off a cliff and killing herself to wake herself back up.

I tried that in a dream once (I must have known it was a dream, I guess). I just landed in the sea (which was only about ankle-deep) unscathed.
by orthogon
Wed Dec 19, 2012 1:57 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1148: "Nothing to Offer"
Replies: 93
Views: 24710

Re: 1148: "Nothing to Offer"

On the 18th of April 1930, listeners tuning in to the BBC for the news were informed "There is no news today." and got music to listen to instead. Evidently they hadn't yet mastered the art of filling the time... Maybe they had a big sex abuse story involving a public figure, but dropped ...
by orthogon
Tue Dec 18, 2012 9:47 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1148: "Nothing to Offer"
Replies: 93
Views: 24710

Re: 1148: "Nothing to Offer"

Since we are belaboring the belaboring of the obvious [...] I hope that helps the google-challenged among us understand even more of the joke. Thanks for the explanation, which I enjoyed very much, but this seems to me like a good example of un googleability. What Google search term could be used t...

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