This is how your coffee cools down the longer it’s left out - the heat from the coffee flows into the room. He recognized that heat from a body at a high temperature would flow to one at a lower temperature. Clausius was oblivious to Carnot’s work but hit on the same ideas.Ĭlausius studied the conversion of heat into work. I say attributed because it was a young French engineer, Sadi Carnot (1796–1832), who first hit on the idea of thermodynamic efficiency however, the idea was so foreign to people at the time that it had little impact. The identification of entropy is attributed to Rudolf Clausius (1822–1888), a German mathematician and physicist. Let’s take a look at what entropy is, why it occurs, and whether or not we can prevent it.
Zoom out a lot further, and we see the entire universe marching towards a collapse. Zoom out a little, and businesses are failing, crimes and revolutions are occurring, and relationships are ending. Cells within your body are dying and degrading, an employee or coworker is making a mistake, the floor is getting dusty, and the heat from your coffee is spreading out. Thy hand, great Anarch! lets the curtain fall Īnd universal darkness buries all.” - Alexander Pope, The DunciadĪs you read this article, entropy is all around you. Lo! thy dread empire, Chaos! is restored Nor human spark is left, nor glimpse divine! “Nor public flame, nor private, dares to shine The Greek root of the word translates to “a turning towards transformation” - with that transformation being chaos. In short, we can define entropy as a measure of the disorder of the universe, on both a macro and a microscopic level. The more disordered something is, the more entropic we consider it. Energy disperses, and systems dissolve into chaos. Left unchecked disorder increases over time. In fact, you can think of it as nature’s tax. More specifically, the second law of thermodynamics states that “as one goes forward in time, the net entropy (degree of disorder) of any isolated or closed system will always increase (or at least stay the same).” Įntropy is simply a measure of disorder and affects all aspects of our daily lives. So, while this is still a highly speculative and unsettled chapter of cosmology, it is true that phase transitions provide the greates hope in explaining this otherwise mysterious number.Entropy, a measure of disorder, explains why life seems to get more, not less, complicated as time goes on.Īll things trend toward disorder. While no one can compute with any reliability the entropy per baryon which derives from these processes, they are generally thought to be inescapable, and much more effective than shock waves in producing entropy. So this beckons the question: what determined this initial value? Until 1980, the basic answer that could be given was shock waves, which are the most powerful generators of entropy known on cosmological scale.īut since perhaps the late seventies-early eighties, the à la mode answer is that this is a consequence of the fact that very large number of both baryons and antibaryons are produced in the early phases of the Big-Bang, to annihilate later into many photons (among other particles) leaving behind a small left-over which constitutes the present population of baryons in the Universe. In other words: something, very early in the history of the Universe determines the total entropy content of the Universe, and GR's only task is that of keeping this value a constant. It is very easy to understand why: there are basically no irreversible processes in the Universe, so that the entropy per unit mass must be conserved.īasically, this means that General Relativity has nothing meaningful to say about entropy: GR-models of the whole Universe could have been built with twice as much, or half as much entropy density than observed, and the models would have been perfectly legitimate. In Friedmann-Robertson-Walker models of the Universe, it can easily be shown that the total entropy density (in comoving coordinates) in photons is conserved. What evolution there is, is all due to non-reversible processes in baryonic matter, but it amounts to very little compared to that in photons. Since the photons of the CMBR do not at present interact with anything, the entropy of the Universe is very close to being a constant. The first reference by Qmechanic gives you the precise value.
The current entropy in the Universe is all stored in photons.
0 kommentar(er)
