New views of enzymes
“Enzymes exposed” (SN: 7/17/10, p. 22) was an interesting read, but is there more to the story? When biologists consider the lock-and-key model for enzymes, I wonder if they are stuck in the static stick-and-ball mentality of traditional chemistry. Is biochemistry really static or is it dictated by the vibrational mode of molecules? Maybe enzymes are even more complicated, and their functionality is based on oscillations, resonances and vibrations.
Frederick Thurber, South Dartmouth, Mass.

Too resilient to fail
“Safety in numbers” (SN: 7/17/10, p. 18) suggests to me that Roy Lindelauf’s game theory–based methods for studying terrorist organizational structure could also apply to our financial system: A more resilient financial system might look a lot like his more resilient terrorist cells. Imagine “too big to fail” becoming “too resilient to fail” — a Lehman Bros. or AIG simply splitting into smaller but functional entities instead of collapsing.
Carson Barnes, Loma Mar, Calif.

Time travel confusion, intrigue
I always enjoy your publication even when I haven’t a clue what the writers are talking about! I found the article on time travel conundrums (“Time travel gets more plausible, yet weirder too,” SN: 8/14/10, p. 5) intriguing. Recalling the Back to the Future movies reminds me of another movie: Superman, with Christopher Reeve. In this film, Superman travels back in time by flying against the Earth’s spin, but faster than the speed of light. He succeeds in going back and saving Lois Lane’s life. However, in a similar situation in the comic books, Superman went back in time to stop Abraham Lincoln’s assassination. But no matter how he tried, something always prevented him from saving the president. Superman finally comes to the conclusion that even with his superpowers, it is impossible to change what has already occurred.

Tim Campbell, Cleveland , Ohio