Showing posts with label pictures. Show all posts
Showing posts with label pictures. Show all posts
05 May 2010
27 November 2007
Collections of images of mathematicians
The Sarong Theorem Archive, which claims to be "the only public repository of sarong-wearing mathematics images". If I had a sarong, and a digital camera with batteries in it, I'd be here. The people at the Secret Blogging Seminar have lamented the fact that this collection is not growing quickly. Incidentally, it seems to me that the best theorems for picture-taking are ones that have nice pictures associated with them, so I nominate Eric Paniagua proving the Pythagorean Theorem as the best of the lot.
Female mathematicians with teal hair. I'm not here because, well, my hair isn't teal. I don't know any of these people, although I went to college with a female mathematician named Teal.
On a more serious note, there are various pages which list a large number of mathematicians and have links to pictures of them; this is useful for putting a face to a name, although it would be more useful in the reverse direction of putting a name to a face. This is true in general; wouldn't it be nice to have something like identifont for faces? (Identifont asks a series of questions to help you identify an unknown font. After nineteen questions, it identified the font of this blog as Trebuchet, which is correct. I'm curious how exactly identifont works -- in particular, if I answer some questions wrong, can I still get the correct font? This is a question about error-correcting codes in disguise.) This isn't just for mathematicians, but for any population. There's a significant difference, though; usually when you're trying to identify a font, you have a sample of it in front of you, whereas if you have a picture of someone in front of you that would be good enough for such a method to be fruitful, you probably also know someone who knows their name. So a tree-like facial identifier patterned on Identifont would be more of a curiosity.
Female mathematicians with teal hair. I'm not here because, well, my hair isn't teal. I don't know any of these people, although I went to college with a female mathematician named Teal.
On a more serious note, there are various pages which list a large number of mathematicians and have links to pictures of them; this is useful for putting a face to a name, although it would be more useful in the reverse direction of putting a name to a face. This is true in general; wouldn't it be nice to have something like identifont for faces? (Identifont asks a series of questions to help you identify an unknown font. After nineteen questions, it identified the font of this blog as Trebuchet, which is correct. I'm curious how exactly identifont works -- in particular, if I answer some questions wrong, can I still get the correct font? This is a question about error-correcting codes in disguise.) This isn't just for mathematicians, but for any population. There's a significant difference, though; usually when you're trying to identify a font, you have a sample of it in front of you, whereas if you have a picture of someone in front of you that would be good enough for such a method to be fruitful, you probably also know someone who knows their name. So a tree-like facial identifier patterned on Identifont would be more of a curiosity.
26 September 2007
Fun with images! (Mostly about math tattoos.)
Stokes' theorem graffiti. In a bathroom. Only in Camberville. (I would have said "only in Cambridge", but this particular graffito is actually in Somerville. Diesel Cafe, to be precise; there was a summer where I spent a lot of time there doing math, so I'm not surprised.)
and a tattoo of the Y combinator, which is part of this collection of images of science tattoos. Other mathematically inspired tattoos in that collection are:
I can think of others. An ex-girlfriend had an infinity symbol tattooed on her (although I believe that was more of a literary thing than a scientific one). A friend of mine has
¬ (p ∧ ¬ p))
tattooed on his leg. A friend of a friend in college had the Taylor series for sine on her arm. It's written out, as
except with exactly enough terms to go once around her arm; it's not in the more compact form
.
I don't have any tattoos; I can't think of anything I'd want permanently inked on me. But if I were to get a tattoo, the equation
would be up there. (I had it written on my wall in college.) I've heard it called the "computer scientist's identity"; it's an analytic version of the fact that every positive integer has a unique binary expansion. The left-hand side expands to
(1+z1)(1+z2)(1+z4)(1+z8)...
and you can imagine expanding that out; then you get something like
1 + z1 + z2 + z2+1 + z4 + z4+1 + z4+2 + z4+2+1 + ...
where each sum of distinct powers of two appears as an exponent exactly once. The right-hand side is the geometric series
1/(1-z) = 1 + z + z2 + z3 + ...
and in order for these two expressions to be equal, the coefficient of zn in each of them has to be equal. All the coefficients on the right-hand side are 1; thus the coefficients on the left-hand side must be too. That means each nonnegative integer appears exactly once as an exponent, i. e. as a sum of distinct powers of two. The fact that one can disguise this combinatorial fact as a fact about functions from C to C -- and then apply the methods of complex analysis, although they're not incredibly useful in this particular case -- is a fascinating example of the interplay between the discrete and the continuous.
and a tattoo of the Y combinator, which is part of this collection of images of science tattoos. Other mathematically inspired tattoos in that collection are:
there exists a unique beth (marred only by the fact that it's not true;- something with a pentagon titled golden ratio tat, a logarithmic spiral, and the Greek letter φ (why is the golden ratio so popular for tattoos?);
- a Mobius strip
- 25
I can think of others. An ex-girlfriend had an infinity symbol tattooed on her (although I believe that was more of a literary thing than a scientific one). A friend of mine has
¬ (p ∧ ¬ p))
tattooed on his leg. A friend of a friend in college had the Taylor series for sine on her arm. It's written out, as
except with exactly enough terms to go once around her arm; it's not in the more compact form
.I don't have any tattoos; I can't think of anything I'd want permanently inked on me. But if I were to get a tattoo, the equation
would be up there. (I had it written on my wall in college.) I've heard it called the "computer scientist's identity"; it's an analytic version of the fact that every positive integer has a unique binary expansion. The left-hand side expands to
(1+z1)(1+z2)(1+z4)(1+z8)...
and you can imagine expanding that out; then you get something like
1 + z1 + z2 + z2+1 + z4 + z4+1 + z4+2 + z4+2+1 + ...
where each sum of distinct powers of two appears as an exponent exactly once. The right-hand side is the geometric series
1/(1-z) = 1 + z + z2 + z3 + ...
and in order for these two expressions to be equal, the coefficient of zn in each of them has to be equal. All the coefficients on the right-hand side are 1; thus the coefficients on the left-hand side must be too. That means each nonnegative integer appears exactly once as an exponent, i. e. as a sum of distinct powers of two. The fact that one can disguise this combinatorial fact as a fact about functions from C to C -- and then apply the methods of complex analysis, although they're not incredibly useful in this particular case -- is a fascinating example of the interplay between the discrete and the continuous.
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