All physical systems can be thought of as registering and processing information, and how one wishes to define computation will determine your view of what computation consists of.

Science consists exactly of those forms of knowledge that can be verified and duplicated by anybody.

In order to figure out how to make atoms compute, you have to learn how to speak their language and to understand how they process information under normal circumstances.

Similarly, another famous little quantum fluctuation that programs you is the exact configuration of your DNA.

By 2020, most home computers will have the computing power of a human brain. That doesn't mean that they are brains, but it means that in terms of raw processing, they can process bits as fast as a brain can. So the question is, how far behind that is the development of a machine that's as smart as we are?

Your attitude, not your aptitude, will determine your altitude.