Congratulations to Barry Marshall and Robin Warren, winners of the 2005 Nobel Prize for Medicine for the discovery that stomach ulcers are caused, not by stress as was formerly believed, but by a bacterium Helicobacter pylori. This is a classic Nobel-type discovery beginning with Warren’s acute observation, and continuing with Marshall’s work in culturing and identifying the bacterium.

It’s a striking observation that, thirty years ago, nearly everybody “knew” two things about stress: it was the primary cause of ulcers and it was particularly common among people men in executive jobs. Although widely held, these beliefs had never been properly tested by research and both turned out to be false. Surprising as it may seem, it’s more stressful to be ordered about than to order other people about. More precisely, the prevalence of stress-related diseases increases as you go down hierarchies of authority, status and so on.

The Nobel Prize for Economics[1] must be coming up soon. I have some ideas as to who should win, but as I’m very peripherally involved in the selection process, I’ll keep them to myself.

fn1. Strictly speaking, the Bank of Sweden Prize in Economic Sciences in Memory of Alfred Nobel

The New York Times has an article by Brian Greene, a professor of physics and mathematics at Columbia about Einstein’s famous equation E=mc². In it he says:

The standard illustrations of Einstein’s equation – bombs and power stations – have perpetuated a belief that E = mc² has a special association with nuclear reactions and is thus removed from ordinary activity.

This isn’t true. When you drive your car, E = mc² is at work. As the engine burns gasoline to produce energy in the form of motion, it does so by converting some of the gasoline’s mass into energy, in accord with Einstein’s formula. When you use your MP3 player, E = mc² is at work. As the player drains the battery to produce energy in the form of sound waves, it does so by converting some of the battery’s mass into energy, as dictated by Einstein’s formula. As you read this text, E = mc² is at work. The processes in the eye and brain, underlying perception and thought, rely on chemical reactions that interchange mass and energy, once again in accord with Einstein’s formula.

I only did high school science, but I’m sure I remember learning the exact opposite of this claim, that chemical reactions like combustion leave mass and energy unchanged, only converting some of the chemical energy in the fuel into kinetic energy, and some into heat, with a net increase in entropy. Only nuclear reactions, I was taught, converted mass to energy. Wikipedia seems to back this up, though it isn’t absolutely unambiguous.

Can anyone set me (or, less plausibly, Greene) straight here?

fn1. As an aside, I also remember reading that a more correct version would be E=M. The term in c² just reflects a poor choice of units in the metric system. But maybe that’s wrong too.