canon lens guide

Adam Tow of COBA posted a good list of Canon lenses and notes Patrick Murphy’s comprehensive list and database.

for my nikon, i have a 50mm/f1.8, a 17-70/f4.5-5.5 and a sigma 70-300/f4-5.6. since i do a lot of concerts, what i really want is a 20-100/f 1.4. but i can’t imagine such a thing existing (or costing less than my camera). for compairson purposes, note the 28mm/f1.4 is $1700; the 35mm/f2 is only $300.

prius plus plus

while i was out last night, two friends IMd me with news of the CalCars plug-in hybrid initiative and the New York Times coverage.

some folks have hacked a prius by adding more batteries, pushing it well over 100 mpg. (Caveat: burning coal to generate electricity isn’t a net win, coseversation wise. Of course, if you get your power via windmills…)

and lastly, smart start outsmarted some dumb thieves.

mathemical proofs for the 21st century

The Economist examines what it means to prove something, and how formal logic and computers can be used to replace traditional mathemtical proofs.

Formal proof is a notion developed in the early part of the 20th century by logicians such as Bertrand Russell and Gottlob Frege, along with mathematicians such as David Hilbert (who can fairly be described as the father of modern mathematics) and Nicolas Bourbaki, the pseudonym of a group of French mathematicians who sought to place all of mathematics on a rigorous footing. This effort was subtle, but its upshot can be described simply. It is to replace, in proofs, standard mathematical reasoning which, in essence, relies on hand-waving arguments (it should be obvious to everyone that B follows from A) with formal logic.