

At 63, Israeli immigrant solves 38-year-old math riddle - edw519
http://www.usatoday.com/tech/science/mathscience/2008-03-20-road-coloring-problem-solved_N.htm

======
mechanical_fish
This guy helps illustrate my theory of why hackers and mathematicians have a
reputation for being young.

First: Because both math and software don't require expensive equipment,
credentials, or direct access to one's mentors (like Ramanujan, you can learn
from books!) you can start your training as a mathematician at a very early
age and be doing professional-grade work before you graduate high school. As I
said the last time this came up, "software is one of the few fields where a
seventeen-year-old can have ten years of pro-level experience".

Second: Mathematicians who want to get jobs in academia have large incentives
to do good work when they're young: Until they make a splash, they're poorly
paid grad students and postdocs. This is also true for other scientists, but
in physics or biology you have to be in grad school before you can even get a
long-term _job_ in the lab where you can _start_ learning to do great
experimental work -- and then you still have to take reams of data, do
multiple postdocs, etc.

By the time they hit age fifty, most talented mathematicians have already
accomplished some math. They have jobs, and possibly tenure. They have
children, they have committee meetings, they have books to write. They have
already proven themselves. Even if they do accomplish some great math papers,
you won't see headlines about "astoundingly old mathematicians". They'll be
billed as "veteran math professors", whom everyone _expects_ to do great work,
since they've been doing great work ever since they were twenty!

But then there's this poor guy, who somehow arrived in his forties and fifties
without tenure or even a job. That was unpleasant for him, of course, but it
gave him a lot of incentive to do some great mathematics in order to get and
keep a new academic job. And, what do you know, he rose to the occasion.
Perhaps if more sixty-year-olds had good reason to do great math, we would see
more of them doing so.

~~~
whacked_new
There was actually formal research done on this topic; IIRC, the results are
generally as you said.

~~~
mechanical_fish
Thanks. I did not know that!

If I were younger and looking for a job in sociology, maybe I would have done
some of that formal research instead of posting half-assed speculation on
news.yc. :)

------
vegashacker
Here's the link to the paper:
<http://arxiv.org/abs/0709.0099?loc=interstitialskip>

It's just 9 pages long, including an intro and bibliography.

------
Raphael
This is a riddle? Just work outward; Each of the destination's adjacent nodes
point to it, and recursion does the rest.

~~~
jcl
Read the Wikipedia description:

<http://en.wikipedia.org/wiki/Road_coloring_problem>

You can't "point" nodes at each other to communicate the directions to the
destination. Instead, you must communicate by coloring each edge with one of k
colors (k is the out-degree of every node). Then, for any chosen destination
node, you give a sequence of colors; the recipient of the directions starts
_in any node_ (even the destination node) and simply follows the sequence of
colors, ending up at the destination. The fact that such a coloring always
exists is somewhat surprising.

