[freedumb2003]

The Earth is silent. Sound is our brain's interpretation of vibrating air. Sound is a function of humans and not a function of trees.

I don't think you understand the question. You POSTULATE the falling tree vibrates the air. You are PROBABLY right. But you have no way of KNOWING, since no observation takes place.

It keeps sophomores up at night, like the universal existence of the term that sounds like "jinantonix" keeps sophomore lingists up late at night.

[Techster]

Just like dihydrogenmonoxide will keep the chemist up all night.

[zeugma]

But you have no way of KNOWING, since no observation takes place.

Ya, I believe the folks exploring quantum mechanics might well say that without observation, the forest disappears.