Sunday, September 07, 2008

Approximately Irrational Road Repair?

There is some road work being done right near our house. I think it's just some simple repaving. As one drives up to the place where the roadwork will start, there is one of those rectangular signs alerting motorists that there will be road construction for a little while. In particular, the sign says:
Roadwork next 1.41 Miles
This raises a number of questions. First, how many digits are really needed? Would alerting drivers that the construction will last for 1.4 miles be sufficient? How can the additional one hundredth of a mile matter?

But maybe the 1.41 arose because they were trying to approximate the square root of two. Maybe the construction follows the hypotenuse of an isosceles triangle whose legs have a length of one mile. The stretch of road is sufficiently curvey that this doesn't seem to be a possibility. Nevertheless, it's a fun thing to think about.

1 comment:

Andrew Campbell said...

That would have perplexed me, too... although in the struggle between the pedant and the math professor, I see that you took the high road of the math professor. (Sadly, I would still be cursing the unnecessary precision of the sign.)