Further to “New theory sees origin of life as inevitable, and Darwinian evolution a special case, physicist Rob Sheldon offers some thoughts on MIT prof Jeremy England’s theory:
This is simply “Maximum Entropy Production Principle” or MEPP theory that was developed in the 80’s and 90’s. It appears–though of course I haven’t got the peer-reviewed paper to check–that this MIT assistant prof needs tenure. Oops, I meant to say that this fellow has made some small incremental improvement on the MEPP model, and the news release is acting as if he has invented the entire discipline from scratch. It is not certain that the American approach to universities produces the best research, but it surely is beyond doubt that it produces the best self-promotion.
So what is MEPP, and why the hoopla about life?
The problem, as physicists will only tell you behind a closed and locked door, is that life violates the 2nd law of thermodynamics. If you throw some water and amino acids and sugar on the stove and simmer it for a few days, you might get great soup, but you surely will not get a single ounce of help writing your next research grant. The reason is that the soup uses all that heat and water and convection to find the highest entropy possible at the given energy. In the reductionist “ideal gas” model, this is a Gaussian distribution of velocities known as a Maxwellian, and it is about as boring as it gets.
But put in one bacterium, and that great soup turns into an acidic, cloudy mess. It no longer is in its maximum entropy state, but highly organized into these little micelles of neutral pH surrounded by low pH excretions and lots of polysaccharide goo. In the reductionist “non-ideal gas” model, this corresponds to non-Gaussian distribution of velocities with a “fat tail” of really energetic fellows who succeed at the expense of lots of lazy atoms populating the lower strata of physics society. One science historian referred to it as “the Matthew principle”, the rich get richer and the poor get poorer.
It so totally violates the 2nd law, how do physicists explain it?
The MEPP principle suggests that energy is flowing through the system–it is hotter on the bottom of the soup pot, and cooler at the top, and steam is constantly coming out from under the lid. So we don’t have to conserve energy, instead, we have to conserve energy flow. MEPP suggests that the soup is trying to keep from boiling over by increasing its ability to transfer heat through the soup. All those bubbling spots are doing a marvellous job carrying heat from the bottom to the top, and in the process, creating a structure in the soup known as convection cells. If the soup is thick, you get a few cells that go from the bottom to the top, if it is thin, you get more cells that only span a portion of the soup. Why? Because the big cells carry heat better, but they are also more organized, so they are entropically expensive and only arrive when the little guys can’t do the job. Then the soup is optimizing the structure of its convection cells to provide the best flow of energy–or in MEPP terminology, it is maximizing the entropy production rate.
Ahhh! says the reductionist physicist, then bacteria are just like convection cells. They arise spontaneously in the soup in order to maximize the entropy production rate. Life is just a law of physics!
Ummm, this is more a case of English homonyms than a case of scientific discovery. And in fact, it isn’t at all obvious that life actually wants maximum entropy production. For example, it may take a week for bacteria to munch through all the sugar in the soup, perhaps months to munch through the oil, but it is a matter of seconds to set fire to the oil and sugar once the water is evaporated. To keep that from happening, the bacteria secrete scum and goo to keep the water from evaporating. So life actually tries to avoid catastrophic entropy production and violates MEPP!
But don’t tell them that until after you get them a dictionary.