Posted by I’m guessing few of you have heard of the physician, Robert Mayer. After all, he lived more than 150 years ago. Yet he is a discoverer of one of Nature’s great laws, the First Law of Thermodynamics (otherwise known as Conservation of Energy). A strange topic for this site? My attention was drawn to it upon reading of the circumstances which prompted his discovery.
In February of 1840, newly graduated he sailed as the doctor aboard the Dutch merchant ship Java enroute to Indonesia. During his enforced leisure aboard ship he studied physiology. Three months after setting off from Rotterdam he was in the Dutch East Indies:
. . . a few days after our arrival at the Batavian roads [off Jakarta, capital of Indonesia] there spread in epidemic fahion an acute . . affection of the lungs. In the copious bloodlettings I performed, the blood let from the vein in the arm had an uncommon redness, so that from the color I could believe I had struck an artery. (from Hans Christian von Baeyer, Maxwell’s Demon, the source for most of the details in this post)
How Mayer got from there to the Conservation of Energy is a bit of a convoluted tale, but here’s the gist. The view at the time was that combustion of food carbon warmed the body which then changed red arterial blood from the heart to venous blood, dark with its remnants of ashes. But less body heat is needed in the tropics so the venous blood should stay brighter red. So far so good.
But Mayer became obsessed with his observation. As a youth he had tried to make a perpetual motion machine and discovered, as so many before him, that you cannot create work from nothing. It has to come from something and he jumped to the idea that motion of the body as well as the heat comes from the combustion of food. He then added his observation (made more famously by Count Rumford) that friction (motion) produces heat to draw the equivalence between heat and work. The body was like a steam engine that produces both heat and work.
Instead of performing experiments to measure the mechanical equivalent of heat Mayer used insight. He knew Lavoisier’s doctrine that matter was neither created nor destroyed, just transformed from one form to another (Conservation of Mass, as we now call it). Mayer was deeply religious and abhored materialism in any form. Wouldn’t it be better if there was something immaterial that was also conserved, that was just converted from heat to work and back again? As von Baeyer observes in his history of the Maxwell’s Demon concept, the Conservation of Energy was Mayer’s weapon against materialism. Whatever its motivation, the paper of the young doctor set out the First Law in close to its modern form: “Forces [energies] are thus indestructible, transformable, imponderable objects.” (cf. von Baeyer readable history).
What started out as an observation made during an epidemic of acute inflammation of the lungs in Indonesia, went on to become a cornerstone of modern science (and ironically, of the materialist viewpoint Mayer so detested). I have no doubt that today we would instead be fixated on whether we were watching the evolution of pandemic influenza from H5N1.
I just found this interesting. There is no lesson or moral I draw from it. Except maybe this. Not everything is about bird flu. Even things that look like bird flu.
October 28, 2006
October 28, 2006
October 28, 2006
October 28, 2006
October 28, 2006
November 7, 2006