Psychopaths know the technical difference between right and wrong - which is one of the reasons their insanity pleas in criminal cases so rarely succeed; they just fail to act on that knowledge.

Everybody loves to spend money at least some of the time - because everybody loves the stuff you can buy with it. The key to the pleasure level of any transaction is the balance between the pain of the payment and the reward of the purchased object.

What makes spinal-cord injuries as devastating as they are is that everything about them plays out in absolutes: they are instantaneous, utterly disabling and horribly permanent.

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

There's no one place a virus goes to die - but that doesn't make its demise any less a public health victory. Throughout human history, viral diseases have had their way with us, and for just as long, we have hunted them down and done our best to wipe them out.

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.

Spare a thought for the poor introverts among us. In a world of party animals and glad-handers, they're the ones who stand by the punch bowl. In a world of mixers and pub crawls, they prefer to stay home with a book. Everywhere around them, cell phones ring and e-mails chime and they just want a little quiet.