Hi Bruce -

This is actually something that is debated in theoretical physics. Look up "Copenhagen interpretation".

Quantum mechanics (and its successors, quantum field theory, etc) shocked us by revealing that reality at the particle level only manifests when there is an observer. Until then, the particle is a "possibility" and is not real. It is the observation that makes it real.

As shocking and counter-intuitive as that is, it has been proven six ways to Sunday over the past 100 years.

But now if you scale that up from a single particle to a tree (or to Schrodinger's cat), things are different because one cannot know the complete wave function of a tree or a cat. But quantum's rules still apply. How this adds up is that one can know the range of states (trees), but not the exact tree that one will see if one looks.

Physicists are unsure what this means for "forests" that we have not walked through yet. Do they have trees before we look?

We have learned that nature is not the way we expect. Our common sense is governed by what we observe. Before quantum mechanics was discovered, no one imagined that nature would turn out to be so different.

It turns out that conscious observation generates reality. Before observation, there is no reality. That's what the data tells us, hard as it is to believe.