MIT Technology Review reports on a study out of the Federal University of ABC in Brazil in which researchers say they have been able to reverse the arrow of time. No, this isn’t a “Back to the Future” scenario. It has to do with the laws of thermodynamics and entropy.
Entropy, in a basic sense, is the movement of a system toward equilibrium. If you place a cold object in a hot environment, the heat energy moves from the environment to the object, resulting in a warming of the cold object and a cooling of the hot environment until they are both at equal temperatures (equilibrium). At the macroscopic level, the process moves in only one direction, toward increasing entropy. The arrow of time points toward entropy.
But what if you could reverse the arrow of time so that entropy could decrease rather than increase? Heat could flow from cold objects to hot ones, making the cold object colder and the hot object hotter. The Brazilian researchers have devised such a system at the quantum level (go to the article to learn the details of how this happens).
If this basic research in quantum physics can eventually be translated for practical use in our macroscopic world (admittedly at big “if”, but that work is being done in the field of quantum computing) it could lead to profound advances in medical device technology.