While driving down the street today with the window down, it hit me that while velocity is relative, pressure is absolute.
My question is, how can something measured as an absolute quantity (pressure) depend on a relative quantity without itself also being relative?
For instance, perhaps I'm standing next to a road and I measure the air pressure as X.
Now, if someone were to drive by me, they would see the air as having some velocity V, so would they measure the same air pressure?
If they did measure the same air pressure, there must be something wrong with the equation relating pressure and velocity, as pressure should decrease with velocity.
If they did not measure the same air pressure, pressure must be relative!
Am I missing something?