Speaker 1: Welcome to brain Stuff production of I Heart Radio. Hey
Speaker 1: brain Stuff, Lauren Bogle bomb here. You can't easily put
Speaker 1: the toothpaste back into the tube. You can't expect molecules
Speaker 1: of steam to spontaneously migrate back together to form a
Speaker 1: panful of water. If you release a bunch of corky
Speaker 1: puppies into a field, it's very unlikely that you're going
Speaker 1: to be able to get all of them back together
Speaker 1: into a crate without doing a ton of adorable fluffy work.
Speaker 1: These are the problems associated with the second law of thermodynamics,
Speaker 1: also known as the law of entropy. Thermodynamics is important
Speaker 1: to various scientific disciplines, from engineering to natural sciences, to chemistry,
Speaker 1: to physics, and even economics. A thermodynamic system is a
Speaker 1: confined space which doesn't let energy in or out of it.
Speaker 1: The first law of thermodynamics has to do with the
Speaker 1: conservation of energy. You know that the energy in a
Speaker 1: closed system remains constant. That is, energy can be neither
Speaker 1: created nor destroyed, that is, unless the system is tampered
Speaker 1: with from the outside. However, the energy in a system
Speaker 1: constantly changes. Forms of fire can turn chemical energy from
Speaker 1: a plant into thermal and electromagnetic energy. Battery turns chemical
Speaker 1: energy into electrical energy. The world turns and energy becomes
Speaker 1: less organized. This is entropy, and it's one of the
Speaker 1: laws that demonstrates how our universe works. So entropy is
Speaker 1: a measure of the disorder in a closed system. According
Speaker 1: to the second law of thermodynamics, entropy in a system
Speaker 1: almost always increases over time. You can do work to
Speaker 1: create order in a system, but even the work that's
Speaker 1: put into reordering increases disorder as a byproduct, usually in
Speaker 1: the form of heat. Because the measure of entropy is
Speaker 1: based on probabilities, it is of course possible for the
Speaker 1: entropy to decrease in the system on occasion, but it's
Speaker 1: statistically very unlikely. It's harder than you think to find
Speaker 1: a system that doesn't let any energy in or out.
Speaker 1: Our universe is as good of an example as we have,
Speaker 1: but after accounting for the fact that it's usually not
Speaker 1: going to be mathematically perfect, entropy does help describe how
Speaker 1: disorder happens in a system as large as the galaxy
Speaker 1: or small as a thermos full of coffee. However, entropy
Speaker 1: doesn't have to do with the type of disorder you
Speaker 1: think of when you lock a bunch of chimpanzees in
Speaker 1: a kitchen, it has more to do with how many
Speaker 1: possible permutations of mess can be made in that kitchen,
Speaker 1: rather than how big of a mess is possible. Of course,
Speaker 1: the entropy depends on a lot of factors, how many
Speaker 1: chimpanzees there are, how much stuff is being stored in
Speaker 1: the kitchen, and how big the kitchen is. So if
Speaker 1: you were to look at two kitchens, one very large
Speaker 1: and stocked to the gills but meticulously clean and organized,
Speaker 1: and another that's smaller, with less stuff in it but
Speaker 1: pretty baseline messy, it's tempting to say that the messier
Speaker 1: room has more entropy, but that's not necessarily the case.
Speaker 1: Entropy concerns itself more with how many different states are
Speaker 1: possible than how disordered it is at the moment. A
Speaker 1: system therefore, has more entropy if there are more molecules
Speaker 1: and atoms in it, and if it's larger, and if
Speaker 1: there are more chimpanzees. Entropy might be the truest scientific
Speaker 1: concept that the fewest people actually understand. Honestly, me sort
Speaker 1: of included. The concept of entropy can be very confusing,
Speaker 1: partly because there are actually different types. The Hungarian mathematician
Speaker 1: John von Neumann lamented the situation by saying, whoever uses
Speaker 1: the term entropy in a discussion always wins, since no
Speaker 1: one knows what entropy really is, so in a debate,
Speaker 1: one always has the advantage. We spoke via email with
Speaker 1: one Marko Popovich, a post auctoral researcher in bio thermodynamics
Speaker 1: in the School of Life Sciences at the Technical University
Speaker 1: of Munich. He said, it's a little hard to define entropy.
Speaker 1: Perhaps it's best defined as a non negative thermodynamic property
Speaker 1: which represents a part of energy of a system that
Speaker 1: cannot be converted into useful work. Thus, any addition of
Speaker 1: energy to a system implies that a part of the
Speaker 1: energy will be transformed into entropy, increasing the disorder in
Speaker 1: the system. Thus, entropy is a measure of disorder of
Speaker 1: a system. But don't feel bad if you're still confused.
Speaker 1: The definition can vary depending on which discipline is wielding
Speaker 1: it at the moment. For example, in the mid nineteenth century,
Speaker 1: a German physicist named Rudolph Classius, one of the founders
Speaker 1: of the concept of thermodynamics, was working on a problem
Speaker 1: concerning efficiency in steam engines, and he invented the concept
Speaker 1: of entropy to help measure useless energy that cannot be
Speaker 1: converted into eve full work. A couple decades later, Ludwig
Speaker 1: Boltzman entropies other founder used the concept to explain the
Speaker 1: behavior of immense numbers of atoms, like even though it's
Speaker 1: impossible to describe the behavior of every single particle in
Speaker 1: a glass of water, it's still possible to predict their
Speaker 1: collective behavior when they're heated using a formula for entropy,
Speaker 1: Popovich said. In the nineteen sixties, the American physicist T. S.
Speaker 1: Jayne's interpreted entropy is information that we miss to specify
Speaker 1: the motion of all particles in a system. For example,
Speaker 1: one mole of gas consists of six times ten to
Speaker 1: the power of twenty three particles. Thus, for us, it
Speaker 1: is impossible to describe the motion of each particle, so
Speaker 1: instead we do the next best thing by defining the
Speaker 1: gas not through the motion of each particle, but through
Speaker 1: the properties of all the particles combined temperature, pressure, total energy.
Speaker 1: The information that we lose when we do this is
Speaker 1: referred to as entropy, and the terrifying and or fascinating
Speaker 1: concept of the heat death of the universe wouldn't be
Speaker 1: possible without entropy, because our universe most likely started out
Speaker 1: as a singularity, as an infinitely small ordered point of
Speaker 1: energy that ballooned out and continues expanding all the time.
Speaker 1: Entropy is constantly growing in our universe because there's more
Speaker 1: space and therefore more potential states of disorder for the
Speaker 1: atoms here to adopt. The scientists have hypothesized that long
Speaker 1: after you and I are gone, the universe will eventually
Speaker 1: reach some point of maximum disorder, at which point everything
Speaker 1: will be the same temperature, with no pockets of order
Speaker 1: like stars and chimpanzees to be found. And if that happens,
Speaker 1: we'll have entropy to thank for it. Today's episode was
Speaker 1: written by Josceline Shields and produced by Tyler Klang. For
Speaker 1: more on this lots of other top x visit how
Speaker 1: stuff works dot com. Brain Stuff is a production of
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