- Will there be a sound when a tree falls on a river and no one is there to hear it?
- Quantum mechanics say a thing (reality) exists only when we measure it. We are measuring the properties of this universe and hence know that it exists. But we are part of the universe, so it has to exist for our existence in order to measure the properties of the universe to prove its existence.
- What is consciousness? Is bacteria conscious (it can react to different chemicals to promote its growth)?