Suppose that 'Unsolved Mysteries' called you with news of a long-lost identical twin. Would that suddenly make you less of a person, less of an individual? It is hard to see how. So, why would a clone be different? Your clone would be raised in a different era by different people - like the lost identical twin, only younger than you.

Suppose that every prospective parent in the world stopped having children naturally, and instead produced clones of themselves. What would the world be like in another 20 or 30 years? The answer is: much like today. Cloning would only copy the genetic aspects of people who are already here.

One of the ugly secrets of the renewable-energy industry is that its products make no economic sense unless they are highly subsidized.

The first thing that is not obvious to people is global warming is a less-than-1% effect. It's like being shortchanged at the bank by a penny every dollar. Over a long period of time with lots of transactions, that piles up.

Economists want their discipline to be a science, and they have nailed down a few precepts, but many of their debates are still clouded by ideology.

It's very hard for individual inventors to get paid. For the same reason that private equity is valuable - broadly, that's a good thing - in the case of patents, many that own them aren't in a good position to take the next step.

If you had a really good - battery, it wouldn't matter that the sun goes down at night and the wind stops blowing sometimes. But at the moment, battery technology is nowhere near good enough to use at utility scale.