Arguments about the safety of high-energy experiments
sometimes cite the rate of high-energy few-particle collisions
when cosmic rays hit the moon.
What's the production rate for making
transuranic elements from this process?
What fraction of the universe's element 118
was made in earthbound accelerators?
2009-06-11 Thursday 15:34:41
Venoms have evolved independently in several different
vertebrate lineages: in snakes and lizards, and in
the platypus, and in one other mammal.
What are the transitional stages for venom to appear?
How would the appearance go in, say, a population of people?
2009-04-01 Wednesday 17:41:46
To an outside observer,
an object dropped onto a black hole never actually
crosses the horizon; it approaches the horizon
asymptotically and light from it becomes more and more redshifted.
Suppose I drop a room-temperature blackbody in a hole.
How long does it take before the redshifted temperature
is colder than the Hawking temperature of the horizon?
2009-02-27 Friday 23:24:26
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
Suppose I replace an incandescent light bulb with a more expensive,
more energy-efficient, longer-lived light — a CFL, an LED,
whatever — based on the expectation that it'll cost less over
its life. How old does my incandescent bulb have to be before I
actually save anything?
2008-10-28 Tuesday 21:42:08
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
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
The Economist claimed that an oil price spike on September 22 (or
thereabouts) was a quirk of timing, due to some minor supply quirk
that happened to happen in the last couple days to fill contracts
for delivery October 1. When I hear about "the oil price"
on the news, what am I hearing? Is there information in the spread
between short- and long-term prices that isn't reflected in
either market alone?
2008-10-03 Friday 00:57:19