In the mid-19th century, a German physicist named Rudolph Clausius, one of the founders of the concept of thermodynamics, was working on a problem concerning efficiency in steam engines and invented the concept of entropy to help measure useless energy that cannot be converted into useful work. Thus, entropy is a measure of disorder of a system."īut don't feel bad if you're confused: the definition can vary depending on which discipline is wielding it at the moment: Thus, any addition of energy to a system implies that a part of the energy will be transformed into entropy, increasing the disorder in the system. "Perhaps it is best defined as a non-negative thermodynamic property, which represents a part of energy of a system that cannot be converted into useful work. "It is a little hard to define entropy," says Popovic. The Hungarian mathematician John von Neumann lamented the situation thusly: "Whoever uses the term 'entropy' in a discussion always wins since no one knows what entropy really is, so in a debate one always has the advantage." The concept of entropy can be very confusing - partly because there are actually different types. And if there are more chimps.Įntropy might be the truest scientific concept that the fewest people actually understand. Entropy concerns itself more with how many different states are possible than how disordered it is at the moment a system, therefore, has more entropy if there are more molecules and atoms in it, and if it's larger. So, if you were to look at two kitchens - one very large and stocked to the gills but meticulously clean, and another that's smaller with less stuff in it, but pretty trashed out by chimps already - it's tempting to say the messier room has more entropy, but that's not necessarily the case. Of course, the entropy depends on a lot of factors: how many chimpanzees there are, how much stuff is being stored in the kitchen and how big the kitchen is. It has more to do with how many possible permutations of mess can be made in that kitchen rather than how big a mess is possible. However, entropy doesn't have to do with the type of disorder you think of when you lock a bunch of chimpanzees in a kitchen.
#Symbol for entropy full
It's harder than you'd think to find a system that doesn't let energy out or in - our universe is as good an example of one as we have - but entropy describes how disorder happens in a system as large as the universe or as small as a thermos full of coffee. Because the measure of entropy is based on probabilities, it is, of course, possible for the entropy to decrease in a system on occasion, but that's statistically very unlikely. According to the second law, entropy in a system almost always increases over time - you can do work to create order in a system, but even the work that's put into reordering increases disorder as a byproduct - usually in the form of heat. "It is one of the most important laws in nature."Įntropy is a measure of the disorder in a closed system. "The second law of thermodynamics is called the entropy law," Marko Popovic, a postdoctoral researcher in Biothermodynamics in the School of Life Sciences at the Technical University of Munich, told us in an email. The world turns and energy becomes less organized. A battery turns chemical energy into electrical energy. However, the energy constantly changes forms - a fire can turn chemical energy from a plant into thermal and electromagnetic energy. The first law of thermodynamics has to do with the conservation of energy - you probably remember hearing before that the energy in a closed system remains constant ("energy can neither be created nor destroyed"), unless it's tampered with from the outside.