Diluting your alcohol

Real nerds know that global warming is for sissies, the real ultimate, unavoidable death to all things in the universe is the ever increasing entropy. Real nerds might also know that when you combine water and alcohol they seem to mix in an exothermic reaction, and the overall volume of the solution is less than the combined volumes of the water and the alcohol because of hydrogen bonding. However according to this reasearch, they never truly mix: "Nobody has ever tasted a microscopically perfect mix of alcohol and water," says ALS scientist Jinghua Guo, one of the leaders of this research. We found that the mixing of alcohol and water on the microscopic level is incomplete no matter how long you wait."
So what does this mean for entropy. Well when mixing two perfect pure liquids, you would expect entropy to increase substantially as the mollecules randomly distribute in the solution. However because water and alcohol don't mix, alcohol mollecules create ordered cages of water, thus decreasing the entropy... "The rings formed when alcohol and water are mixed are stable structures because the hydrogen bonds are saturated," says Guo. "One would expect to see even further reductions in the entropy of the system if there were more methanol and water molecules forming highly ordered structures."
So there you go, save the world one drink at a time.

Physicists are crazy

Over the holidays I was reading about entropy and what it means to quantum mechanics. Apparently all the formulas of quantum mechanics are time-symmetric, meaning they have no time-directionality. The question was, how do we get a time arrow and things like directionality of entropy if these principles are not present in the underlying quantum physical laws. In other words, in quatum mechanics you can find the equations that govern a glass reassembling itself from fragments on the ground, and filling itself with the water spilled on the carpet and jump back on the counter next to you playing wii tennis. Entropy on the surface seems a very anthropic principle, since we are needed to judge what is disordered and what the direction of time is. Of course there are good explanations involving phase space that kind of explain entropy but it still seems odd that quantum mechanics is symmetric. On this topic, I also recently stumbled across some great lectures by non other than Hans Bethe entitled quantum physics made relatively simple, and a personal entropy calculator, perhaps armed with these you can make sense of this connundrum. It's never too late, even the reverse-sprinkler problem of Feynman was recently elucidated.... "We discuss the reverse sprinkler problem: How does a sprinkler turn when submerged and made to suck in water? We propose a solution that requires only a knowledge of mechanics and fluid dynamics at the introductory university level. We argue that as the flow of water starts, the sprinkler briefly experiences a torque that would make it turn toward the incoming water, while as the flow of water ceases it briefly experiences a torque in the opposite direction. No torque is expected when water is flowing steadily into it unless dissipative effects, such as viscosity, are considered. Dissipative effects result in a small torque that would cause the sprinkler arm to accelerate toward the steadily incoming water. Our conclusions are discussed in light of an analysis of forces, conservation of angular momentum, and the experimental results reported by others. We review the conflicting published treatments of this problem, some of which have been incorrect and many of which have introduced complications that obscure the basic physics involved."