The representation of an integer in base b
has some digits
. For example the
number 42 = 4×101
=2 in base b
It's sometimes convenient to switch to a different base, frequently
=2) or hexadecimal (b
=16). Is there ever a
reason to switch to noninteger b
? What pathologies would
a representation have?
2009-04-20 Monday 14:39:54
A black hole at the end of its Hawking evaporation radiates
with some very large power. But the high-power period
doesn't last very long, since the mass is so small.
Apparently the overall luminosity is small enough
that it'd be hard to see a radiating black hole outside
the solar system.
What limit can you set on the density of
very small black holes
knowing only that, say, there are none in the room right now?
2009-02-04 Wednesday 22:19:29
A metric for cheap eating: calories per dollar?
2009-01-27 Tuesday 11:48:35
Gerrymandered Congressional districts tend to protect extremists
at the expense of moderates. Will the House be more or less
after the turnover in yesterday's elections?
2008-11-05 Wednesday 12:39:29
The Economist claims that some 1200 people have died crossing from
Mexico to the US since 1990, compared to about 300 killed trying to
cross the Berlin Wall during the 28 years it was up. Fatalities per
mile? Fatalities per legal crossing? Estimates of successful
2008-10-11 Saturday 09:54:20
Among the different Nobel prizes, there is a big spread between
when work is done and when it is rewarded. The physics prizes seem
to go to people whose work decades ago has shaped research since,
while the peace prizes seem to go to people who are actively doing
notable things right now. What's the distribution of times
between doing something noteworthy and winning a prize for it? What
about less famous prizes?
2008-10-08 Wednesday 10:54:38
Fresh Air interviewed
Katharine Jefferts Schori
, the primate of the US Episcopal
Church, who has a doctorate in oceanography. Are advanced degrees
in the sciences more common, or less common, in the clergy than in
other nontechnical fields? How does the frequency change across
2008-10-08 Wednesday 10:27:03
If Hawking's connection between black holes and thermodynamics
is right, astrophysical black holes --- for which general
relativity predicts everything bizarre happens well inside the
horizon, and for which there are observational evidence --- are at
the zero-temperature limit. What's the "warmest"
black hole for which there is observational evidence? What's
the transition "temperature" where quantum gravity starts
2008-10-06 Monday 19:45:48
by Consumer Reports
, that breakfast cereals marketed to
children aren't terribly nutritious, has gotten some
evening-news press. The main contribution of the Consumer Reports
release seems to be that they bought a bunch of cereal and read the
nutrition labels. What's new here? Has the composition of
existing products been tweaked? Have some sweeter brands been
introduced to replace healthier ones? How do these sorts of news
blobs correlate with sales, or with marketing spending?
2008-10-06 Monday 12:29:26
If you feed a Markov chain its own output, does its behavior get
more stable or less stable?
2008-09-29 Monday 17:33:56