Search found 198 matches

by HenryS
Tue Apr 19, 2011 3:15 pm UTC
Forum: XKCD Meetups
Topic: Melbourne meet-up?
Replies: 449
Views: 102575

Re: Melbourne meet-up?

I might make it.
by HenryS
Sun Apr 17, 2011 10:52 am UTC
Forum: XKCD Meetups
Topic: Melbourne meet-up?
Replies: 449
Views: 102575

Re: Melbourne meet-up?

I was suggesting that fertilizer might make trousers reproduce.
by HenryS
Sun Apr 17, 2011 5:20 am UTC
Forum: XKCD Meetups
Topic: Melbourne meet-up?
Replies: 449
Views: 102575

Re: Melbourne meet-up?

Have your trousers sprouted?
by HenryS
Sat Apr 16, 2011 9:04 am UTC
Forum: XKCD Meetups
Topic: Melbourne meet-up?
Replies: 449
Views: 102575

Re: Melbourne meet-up?

Yeah, that game is looking at bit like EVE Online: I want to hear about or watch really good players, but I'm not sure I'd want to play it myself...

That photo really makes it look like my head is 4 times bigger than Jess'.
by HenryS
Sat Apr 16, 2011 7:45 am UTC
Forum: XKCD Meetups
Topic: Melbourne meet-up?
Replies: 449
Views: 102575

Re: Melbourne meet-up?

http://www.segerman.org/random/xkcd_meetup_16_4_2011.jpg End of the day myspace photo! ToeOfDoom, Gelsamel, dragon, theduffman dinosplosion, fantasyprone, __jess, HenryS (I didn't remember everyone's name, someone tell me how to fill in the blanks.) (Edit: Thanks!)
by HenryS
Fri Apr 08, 2011 1:06 pm UTC
Forum: XKCD Meetups
Topic: Melbourne meet-up?
Replies: 449
Views: 102575

Re: Melbourne meet-up?

Randomly checked the meetup forum for the first time ever, and there's one happening a block away from me next week. Bizarre.

Carlton gardens is pretty big. Which bit?
by HenryS
Wed Sep 22, 2010 2:30 pm UTC
Forum: Mathematics
Topic: Which is it? (straight line or circle through a portal?)
Replies: 33
Views: 4876

Re: Which is it? (straight line or circle through a portal?)

I happen to know someone who works at Valve, and pointed out that Portal is really about applying a physics engine to Euclidean orbifolds. I think there is a trend towards more complicated and interesting topology and geometry in computer games (Portal, Fez, and upcoming Miegakure to list a few exam...
by HenryS
Thu May 06, 2010 2:18 pm UTC
Forum: Mathematics
Topic: Fitting circles into a circle
Replies: 6
Views: 1745

Re: Fitting circles into a circle

The first example to think about is two circles of half radius of the original. Their total area is exactly half of the original circle, and they only just fit, so 50% is an upper bound on what could be possible.
by HenryS
Wed May 05, 2010 8:51 pm UTC
Forum: Mathematics
Topic: Fitting circles into a circle
Replies: 6
Views: 1745

Fitting circles into a circle

I don't think this has been asked before... Suppose you have an open circular disk D in the Euclidean plane. Suppose I give you a finite collection \{D_1, D_2, \ldots, D_n\} of open circular disks whose total area is at most half the area of D . Can you always arrange these disks to fit inside of D ...
by HenryS
Thu Nov 05, 2009 5:18 pm UTC
Forum: Mathematics
Topic: Can anyone maximize this expression?
Replies: 11
Views: 1539

Re: Can anyone maximize this expression?

Write some code and generate some data?

Presumably you can get numerical answers up to the biggest size of any real life game very easily.
by HenryS
Sat Oct 17, 2009 5:04 am UTC
Forum: Mathematics
Topic: Definition of dy and dx?
Replies: 16
Views: 1845

Re: Definition of dy and dx?

In the context of a calculus class I think differentials are a terrible idea. Everything you can do with them you can do with linear approximation, and much less confusingly. In the class I'm teaching right now, we did exactly that.
by HenryS
Mon Oct 12, 2009 3:13 am UTC
Forum: Mathematics
Topic: Becoming a Mathematician?
Replies: 17
Views: 4635

Re: Becoming a Mathematician?

Be aware that grad school is a pyramid scheme. 1 tenured professor teaches 10+ PhD students in their career, and after they retire maybe gets replaced by a single professor (or not). It isn't quite as bad as this, there are lots of undergraduate institutions without graduate programs that need prof...
by HenryS
Mon Oct 05, 2009 8:43 pm UTC
Forum: Mathematics
Topic: Inverse functions and derivatives
Replies: 3
Views: 2046

Re: Inverse functions and derivatives

I think you're supposed to use the result that (f -1 )'(x) = (f'(x)) -1 . (The inverse function graph is a reflection of the original function graph along the line y=x, so you can tell what happens to the reflected tangent line as well: the slope of the new tangent is the inverse of the slope of the...
by HenryS
Sun Sep 06, 2009 9:12 pm UTC
Forum: Mathematics
Topic: Why Do Mathematicians Play Go?
Replies: 23
Views: 2401

Re: Why Do Mathematicians Play Go?

According to the Wikipedia link, Many Faces of Go is the best computer program, and according to the M.F. Go website , at its strongest level it's 2 Kyu on a 19x19 board, or 3 Dan on a 9x9 board. That means on a 19x19 board it's equivalent to a top-tier amateur player, and on a 9x9 it's as good as ...
by HenryS
Mon Jul 20, 2009 3:23 am UTC
Forum: Mathematics
Topic: What should I put on my "Calc Clock"?
Replies: 12
Views: 2007

Re: What should I put on my "Calc Clock"?

I think it would be good to have some number (not necessarily 12) of important constants arranged around the circle at the correct positions mod 12. So pi would appear a little below the right hand middle point of the circle, and 163 would appear in the 7 o clock position.
by HenryS
Thu Jul 02, 2009 4:58 am UTC
Forum: Mathematics
Topic: chaos grapher
Replies: 9
Views: 1730

Re: chaos grapher

Python Imaging Library might be useful for producing pictures.
by HenryS
Sat Apr 11, 2009 6:08 am UTC
Forum: News & Articles
Topic: Students Fear Math
Replies: 42
Views: 4625

Re: Students Fear Math

I've read in a few places opinions from mathematicians along the lines of the big problem with math(s) education being the focus on calculus as the core goal of the high school curriculum. This is a problem because calculus really isn't that useful for most people, unless they go on to study the sci...
by HenryS
Mon Apr 06, 2009 6:55 am UTC
Forum: Mathematics
Topic: Spheres and cubes in high dimensions
Replies: 7
Views: 1006

Re: Spheres and cubes in high dimensions

According to http://en.wikipedia.org/wiki/N-sphere , if V_n is the volume of an n -ball of radius R then \frac{V_n}{R^n} \rightarrow 0 as n\rightarrow \infty . The largest that any ball that fits inside a cube of side length 2 can be is the ball of radius 1, and so its volume goes to 0, whereas the...
by HenryS
Sat Apr 04, 2009 9:53 pm UTC
Forum: Logic Puzzles
Topic: The Devil's Quarter Game
Replies: 87
Views: 39449

Re: The Devil's Quarter Game

Ok then, again with quarters of radius 1: Devil plays first at (-n,0) (n is some big number) Player plays at (0.5,0) (which is not mirror-able and blocks the center position so:) Devil plays at (n,0) Player plays at (-1.5,0) (not mirror-able, cent...
by HenryS
Sat Apr 04, 2009 5:45 pm UTC
Forum: Logic Puzzles
Topic: The Devil's Quarter Game
Replies: 87
Views: 39449

Re: The Devil's Quarter Game

Right, that's exactly the problem with the example I gave: since the quarters are radius 1, there is no room to put one in the center. If the game is played "on a grid", by which I assume you mean that there are a finite number of non-overlapping spots on which a quarter can be played...
by HenryS
Sat Apr 04, 2009 3:48 pm UTC
Forum: Logic Puzzles
Topic: The Devil's Quarter Game
Replies: 87
Views: 39449

Re: The Devil's Quarter Game

What happens if the following are the first two moves (played with circles of radius 1):
Spoiler:
Devil: (-1,0)
Player: (1,0)

Then neither the players move nor the Devil's starting move is mirrorable.
by HenryS
Sun Mar 22, 2009 8:32 pm UTC
Forum: Logic Puzzles
Topic: Image cypher
Replies: 11
Views: 2446

Re: Image cypher

Here's an entirely different image cypher (I was playing this kind of game on a different forum some time ago).
by HenryS
Sun Mar 22, 2009 8:30 pm UTC
Forum: Logic Puzzles
Topic: Image cypher
Replies: 11
Views: 2446

Re: Image cypher

Actaeus wrote:HenryS:
Spoiler:
The solution is 31337357... it's l33t
Spoiler:
Sorry, I must be missing how you get that from the number? It isn't base 8...
by HenryS
Sun Mar 22, 2009 6:25 pm UTC
Forum: Logic Puzzles
Topic: Image cypher
Replies: 11
Views: 2446

Re: Image cypher

Spoiler:
Tried a few things with that number, nothing jumps out... it factors as 3 x 13 x 37357, doesn't look like it's telling us a way to rearrange the pixels into some other rectangle. In hexadecimal it is 163B1B, might encode a colour but I don't see how that would be useful.
by HenryS
Sun Mar 15, 2009 6:34 am UTC
Forum: Mathematics
Topic: Fair multiple choice test
Replies: 11
Views: 1825

Re: Fair multiple choice test

I taught multivariable calculus last semester using an online multiple choice system for homework. It did have some advantages over open response (and of course the disadvantages people have already mentioned). For one, students get immediate feedback on if their answer is correct, and have the oppo...
by HenryS
Tue Mar 03, 2009 5:06 pm UTC
Forum: Mathematics
Topic: Math and instant messaging
Replies: 2
Views: 1114

Re: Math and instant messaging

There is also the facebook latex app: http://apps.facebook.com/mathematics/, although that works in messages and wall posts rather than IM.
by HenryS
Mon Feb 23, 2009 4:23 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0547: "Simple"
Replies: 121
Views: 22966

Re: "Simple" Discussion

Re: math professors explaining things in simple English: There certainly is a tension between making a proof or explanation short versus making it more understandable, but it isn't as simple as gaining one loses the other. Precision of language is very important in mathematics, it isn't good enough ...
by HenryS
Fri Feb 13, 2009 4:18 pm UTC
Forum: Mathematics
Topic: best excuse for being fat!
Replies: 17
Views: 2638

Re: best excuse for being fat!

You mean surface area to volume ratio. And the insulation probably doesn't hurt either :)
by HenryS
Tue Feb 10, 2009 5:23 am UTC
Forum: Mathematics
Topic: What is the smallest positive integer with no google hits?
Replies: 34
Views: 4745

Re: What is the smallest positive integer with no google hits?

Right, if we are going to allow non standard representations to count, then we should just go all out and note that "the smallest positive integer with no google hits" currently returns 2 hits, and therefore does not exist...
by HenryS
Mon Feb 09, 2009 7:26 am UTC
Forum: Mathematics
Topic: What is the smallest positive integer with no google hits?
Replies: 34
Views: 4745

Re: What is the smallest positive integer with no google hits?

I know neither the answer nor an efficient way to find it. Someone just asked me what I would guess (my initial guess was something around 100000, way too low). I suspect it might be relatively quick for someone internal to Google to find out.
by HenryS
Sat Feb 07, 2009 10:53 pm UTC
Forum: Mathematics
Topic: What is the smallest positive integer with no google hits?
Replies: 34
Views: 4745

Re: What is the smallest positive integer with no google hits?

I wasn't sure about the forum placement, but then I read somewhere else about someone estimating the answer using a smattering of probability theory. http://godplaysdice.blogspot.com/2008/09/first-number-not-in-google.html thinks that the answer has to be in the high eight digits.
by HenryS
Sat Feb 07, 2009 8:44 pm UTC
Forum: Mathematics
Topic: What is the smallest positive integer with no google hits?
Replies: 34
Views: 4745

What is the smallest positive integer with no google hits?

So, what would you guess is the smallest positive integer with no google hits?
by HenryS
Fri Feb 06, 2009 10:13 pm UTC
Forum: Mathematics
Topic: Line Integral of a Space-Filling Curve
Replies: 6
Views: 943

Re: Line Integral of a Space-Filling Curve

Although, if the function is holomorphic, then the integral is 0 no matter the sequence of approximations.
by HenryS
Fri Feb 06, 2009 9:10 pm UTC
Forum: Mathematics
Topic: Line Integral of a Space-Filling Curve
Replies: 6
Views: 943

Re: Line Integral of a Space-Filling Curve

Well, I was thinking along the lines of contour integrals of holomorphic or meromorphic functions, when you should get a sensible answer of integrating around the Koch snowflake, as long as there aren't any poles too near the curve. I see what you mean though: even in this case the limit only exists...
by HenryS
Fri Feb 06, 2009 7:29 pm UTC
Forum: Mathematics
Topic: Line Integral of a Space-Filling Curve
Replies: 6
Views: 943

Re: Line Integral of a Space-Filling Curve

You could try evaluating the integral along the curves approaching the space filling curve, for many of the constructions the curve is piecewise, so these will be possible to integrate. Then see if the limit exists. I would imagine that you'd get something sensible for integrating around the Koch cu...
by HenryS
Mon Jan 12, 2009 12:41 am UTC
Forum: Mathematics
Topic: Where to publish
Replies: 10
Views: 1421

Re: Where to publish

It is on arXiv?
by HenryS
Thu Nov 27, 2008 8:11 pm UTC
Forum: Logic Puzzles
Topic: Portal Paradox
Replies: 137
Views: 33601

Re: Portal Paradox

Basically, if I can send information from one end of the barn to the other quickly enough (ie faster than light), then there are two distinct versions of reality, one in which the barn can be closed, trapping the pole and its bearer inside (the version from the barn person (...master?)), and the ot...
by HenryS
Tue Nov 18, 2008 5:05 am UTC
Forum: Mathematics
Topic: Trouble using Beamer
Replies: 3
Views: 1594

Re: Trouble using Beamer

I've used pdf figures and pdflatex to compile beamer code, has worked well.
by HenryS
Mon Nov 17, 2008 7:11 am UTC
Forum: Individual XKCD Comic Threads
Topic: 0505: "A Bunch of Rocks"
Replies: 406
Views: 114931

Re: "A Bunch of Rocks" Discussion

The Swiss patent office reference implies that desert guy is Einstein.
by HenryS
Sat Nov 15, 2008 9:20 am UTC
Forum: Logic Puzzles
Topic: Portal Paradox
Replies: 137
Views: 33601

Re: Portal Paradox

Portals do violate one concept in relativity automatically-information can't be transferred faster than c. I don't think there's a problem here, you get the same effect with wormholes, which afaik are possible in relativity. All you have there is the wrong concept of distance. Space-time with a por...

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