Book Review: The Labyrinth of Time: Introducing the Universe by Michael Lockwood
This book provides a great overview of the more interesting parts of modern physics, with some emphasis on time and the philosophy of time.
It is less clearly focused on time than the cover suggests. If you want a deep and narrow focus on time, Huw Price’s book Time’s Arrow is more appropriate and provocative.
Labyrinth of Time explains many things better than other physics books do.
For instance, the standard description of the twin paradox suggests that acceleration is responsible for the differences in how each twin ages. Lockwood refutes that with a nifty diagram of a cylindrical space-time where unaccelerated twins age differently on world-lines of different lengths.
The book provides good explanations of why the alleged paradoxes of time travel aren’t sufficient to imply that time travel is impossible.
Lockwood does a relatively good job of arguing in favor of the Everett (many world) interpretation of quantum mechanics, but that section requires enough experience with the subject that many laymen will have trouble following it.
The speculations he reports about how time might mean before the Planck time are really strange.
Archive for August, 2006
Time
Thursday, August 24th, 2006
Tradesports Claim Definition
Wednesday, August 16th, 2006Chris Hibbert writes (in a post that is partly about the mess resulting from Tradesports’ contract on North Korean missile launches):
The fact that pay-outs are limited to the amount spent to purchase claims is integral to the institution of prediction markets. If market operators ever pay off both sides of a claim, that is likely to encourage investors to protest many more close calls.
I disagree. Having pay-outs equal to claim purchases is integral to the normal function of well-written claims, but there’s little reason to stick to that rule with a claim written as poorly as the North Korean missile claim was.
Paying off both sides was the most reasonable suggestion I’ve heard for what Tradesports should have done to limit the damage to their reputation. Experience with similar disputes (such as those on FX) suggests that traders already have sufficient motive to protest questionable decisions that it’s hard to see how disputes produced only by additional incentives could bear much resemblance to reasonable disputes. The increased incentive on Tradesports to word their claims so that fewer people misunderstand how they will be judged is likely to have some desirable effects on how Tradesports explains the meaning of their contracts.
Disputed judgments might be inevitable for exchanges that cover subjects as ambitious as Tradesports does, but there’s nothing inevitable about confusion about whether a contract was about DoD confirmation of where the missiles landed, or whether it was about what the missiles did, with DoD statements merely being used if needed to resolve any uncertainty.
(I didn’t trade any of the North Korean missile contracts).