well, it’s not just the door opening and closing. it’s the air flow moving and stopping. Something is going through the doorway and then something isn’t going through the doorway. The doorway is a participant in a system
something has to pass through a doorway or it’s not a doorway. That’s its function. Light can pass through it. Air. People.
i was obsessed with this for a while a few months ago
A doorway I consider similar to a vestibule – a mixing area where different airs (indoor and outdoor for example) mix together.
Or an airlock in space where the ship air and the outerspace mix together momentarily as doors open and close, pressures equalize.