Scarily, football helmets, which do a fine job of protecting against scalp laceration and skull fracture, do little to prevent concussions and may even exacerbate them, since even as the brain is rattling around inside the skull, the head is rattling around inside the helmet.

Sadoway does more than entertain; he gives you a glimpse into the future of energy.

Credit or debit cards, for starters, are nothing short of shoppers' Novocain. Even in the age of digital purchases and virtual money, we still attach a special value to dirty paper with pictures of presidents on it. Handing some of that to a cashier simply hurts more than handing over a little sliver of plastic.

Identical twins are ideal lab specimens for studying the difference between learned and inherited traits since they come from the womb preloaded with matching genetic operating systems. Any meaningful differences in their behaviors or personalities are thus likely to have been acquired, not innate.

When we're awake, cortisol can fragment memories - one reason eyewitness crime scene accounts are so unreliable. But at night that very fragmentation allows creative recombinations of ideas.

It's a deep and all but certain truth about narcissistic personalities that to meet them is to love them, but to know them well is to find them unbearable. Confidence quickly curdles into arrogance; smarts turn to smugness, charm turns to smarm.

If we were a culture of high-risk alcoholics, and suddenly we had Jack Daniels piped into our houses, we would be feeding that fire. Social networking, and the internet as a whole, seems to have simply landed in an extremely fertile place in an extremely fertile time in history, when we all have these narcissistic tendencies anyway - you can go further back into the self-esteem movement, and Dr. Spock, and the 'everybody gets a ribbon at the track meet' sort of thing, which preceded the internet - and then you drop the internet into the middle of this, and we've all gone haywire.