# Is air subject to inertia?

Dear Cecil:

Why is it that when traveling in a car with the air conditioning on, with the vent blowing directly on you, the "breeze" goes off you for a few seconds when you turn the corner? Is air subject to inertia?

Cecil replies:

Get hep, T. — of course it is. We can demonstrate this by means of the following experiment. Take a balloon filled with helium along next time you’re out for a drive and put it on the passenger’s side. Now SWERVE LEFT TO AVOID THAT OLD LADY, YOU IDIOT! Sorry, just trying to make a point. Normally when you turn sharply left, everything in the car is thrown to the right. When we swerved left just now, however, the helium balloon was thrown to the left, the opposite of what you’d expect.

How can this be? Credit the inertia of the air. When you swerved left, the air, like everything else in the car, wanted to keep going straight, so it got crammed into the right (passenger) side. The heavy air forced the light helium balloon out of the way, and the only place for said balloon to go was left. Interesting, no? Believe me, the kids will love it.

Send questions to Cecil via cecil@straightdope.com.