I know that if the static port is blocked you can use the alternate static port in the aircraft. However it will react because the cockpit has a slightly lower airpressure on the inside than there is outside. I understand it's there just fine but i'm prepping for my CFI and want to make sure I have it down and I'm not exactly 100% on this question. Is it because of the high speed at which the air is flowing around the cockpit and this causes the pressure on the inside to drop? The Bernoulli Principle?