So you keep stressing that the door opens in - you write that over and over and over - yet you fail to understand why someone would complain that a writer on this subject wouldn’t drop that interesting little factoid in their article???????
No. I fully understand stupidity. It appears to be contagious.
and of course, you were forced to ignore the question about assuming air pressure can push stuff out, because that you couldn’t be the Amusing Mr. Sanctimony Pants