Wednesday, May 12, 2010

Speed kills

In his book How Math Can Save Your Life (Wiley, 2010) James D. Stein asks whether it makes sense to cut a few minutes off your trip by driving faster. The short answer is no. He looks first at kinetic energy, which increases as the square of the velocity. A car traveling at 70 mph has 36% more kinetic energy than one traveling at 60 mph (702/602) and a car traveling at 75 mph has 56% more kinetic energy than one traveling at 60 mph. You can do a lot more damage to yourself and your car in an accident at higher speeds.

Stein also cites the work of MIT physicist Max Tegmark who did some expected-value calculations based on data compiled in the early years of this century. Fasten your seatbelts! “Each hour of driving on an interstate freeway decreases life expectancy by 19 minutes. . . . Each hour of driving in local city traffic decreases life expectancy by 8 minutes. . . . Each hour spent riding a motorcycle decreases life expectancy by 5 hours.” (p. 82)

According to some hypotheses, at least, last Thursday’s tape indicates that high frequency trading may be even more dangerous than racing a motorcycle on a freeway when an “accident” happens. Speed kills—and traffic seizes up.

1 comment:

1. Brenda,

Yes, it's funny how some people I know that drive at 100 mph at the highway (ok, actually at 160 kph on the autopista) tell me that trading is dangerous: you could lose... your money! When I try to explain to them that risk is always relative to reward I always get something in the line of how they won't allow the government telling them how to drive.

As for motorcycles, you have to account for the increased light-years increase in fun! ;) (I guess I'm not that rational anyway).