Zoom out a lot further, and we see the entire universe marching towards a collapse. The identification of entropy is attributed to Rudolf Clausius — , a German mathematician and physicist. I say attributed because it was a young French engineer, Sadi Carnot — , 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.
Clausius studied the conversion of heat into work. He recognized that heat from a body at a high temperature would flow to one at a lower temperature.
This happens naturally. But if you want to heat cold water to make the coffee, you need to do work — you need a power source to heat the water. Clausius also observed that heat-powered devices worked in an unexpected manner: Only a percentage of the energy was converted into actual work. Nature was exerting a tax. Perplexed, scientists asked, where did the rest of the heat go and why?
Clausius solved the riddle by observing a steam engine and calculating that energy spread out and left the system. In the second place, with each non-reversible change is associated an uncompensated transformation…. The second fundamental theorem [the second law of thermodynamics], in the form which I have given to it, asserts that all transformations occurring in nature may take place in a certain direction, which I have assumed as positive, by themselves, that is, without compensation… [T]he entire condition of the universe must always continue to change in that first direction, and the universe must consequently approach incessantly a limiting condition.
The entropy of the universe tends to a maximum. Entropy is one of the few concepts that provide evidence for the existence of time. It is the non-reversible process wherein entropy increases. Let us draw an arrow arbitrarily. If as we follow the arrow[,] we find more and more of the random element in the state of the world, then the arrow is pointing towards the future; if the random element decreases[,] the arrow points towards the past.
That is the only distinction known to physics. The Arrow of Time dictates that as each moment passes, things change, and once these changes have happened, they are never undone. Permanent change is a fundamental part of what it means to be human.
We all age as the years pass by — people are born, they live, and they die. See, in the life of the universe, just as in our lives, everything is irreversibly changing. In his play Arcadia , Tom Stoppard uses a novel metaphor for the non-reversible nature of entropy:. When you stir your rice pudding, Septimus, the spoonful of jam spreads itself round making red trails like the picture of a meteor in my astronomical atlas.
But if you stir backwards, the jam will not come together again. Indeed, the pudding does not notice and continues to turn pink just as before. Do you think this is odd? The longer one exists, the more it grinds out restrictions that slow its own functions. It reaches entropy in a state of total narcissism. Only the people sufficiently far out in the field get anything done, and every time they do, they are breaking half a dozen rules in the process.
One way to understand this is with an analogy to entropy. Just as energy tends towards a less useful, more disordered state, so do businesses and organizations in general. We come back two months later to find that five of them have quit, five are sleeping with each other, and the other ten have no idea how to solve the litany of problems that have arisen.
The employees are certainly not much closer to the goal laid out for them. The whole enterprise just sort of falls apart. It reminds one distinctly of entropy: For every useful arrangement of affairs towards a common business goal, there are many orders of magnitude more arrangements that will get us nowhere.
For progress to be made, everything needs to be arranged and managed in a certain way; we have to input a lot of energy to keep things in an ordered state.
In practice, both models seem to be useful at different times. Any startup entrepreneur who has stayed long enough to see a company thrive in unexpected ways knows this. The amount of diligent management needed will vary. Entropy occurs in every aspect of a business.
Employees may forget training, lose enthusiasm, cut corners, and ignore rules. Equipment may break down, become inefficient, or be subject to improper use. Products may become outdated or be in less demand. Even the best of intentions cannot prevent an entropic slide towards chaos. Successful businesses invest time and money to minimize entropy.
For example, they provide regular staff training, good reporting of any issues, inspections, detailed files, and monitoring reports of successes and failures. Anything less will mean almost inevitable problems and loss of potential revenue. Without the necessary effort, a business will reach the point of maximum entropy: bankruptcy.
Fortunately, unlike thermodynamic systems, a business can reverse the impact of entropy. A balance must be struck between creativity and control, though. The absolute entropy of any substance can be calculated using equation 1 in the following way. Imagine cooling the substance to absolute zero and forming a perfect crystal no holes, all the atoms in their exact place in the crystal lattice.
Since there is no disorder in this state, the entropy can be defined as zero. Now start introducing small amounts of heat and measuring the temperature change. Even though equation 1 only works when the temperature is constant, it is approximately correct when the temperature change is small.
It is conceivable that the process would reverse so that the ink molecules would reconstitute and form once again into a black blob, but probability working in conjunction with the arrow of time predicts otherwise.
Energy can change from one form to another, but it can be neither created nor destroyed. The pressure of a gas, for example, can decrease, but simultaneously its temperature will decrease while its caloric energy content remains constant. This makes possible the seeming paradox of refrigeration. There are several versions, the most basic statement being that the entropy of all perfect crystalline solids is zero at absolute zero temperature.
Thus entropy can be viewed as a measure of energy dispersal as a function of temperature. In chemistry, the kind of energy that entropy measures are both the motional energy of molecules moving around and vibrating and phase-change energy enthalpy of fusion or vaporization. Put another way, entropy measures how much energy is spread out in a process over time or how spread-out the initial energy of a system becomes at constant temperature.
It is mathematically simple to compute exactly how much energy is dispersed in a phase change or temperature change. Most often computations of entropy are actually computations of an entropy change, the measurement of a change in the amount of energy dispersal in a system or surroundings before and after a process. Standard entropies of formation are given in molar quantities this way because they assume you are creating one mole of the substance. W can be counted using the equation:.
Basically, the Boltzmann formula shows the relationship between entropy and the number of ways the atoms or molecules of a thermodynamic system can be arranged. Consequently, the entropy change between two thermodynamic equilibrium states of a system is often measured experimentally. The task involves devising a reversible path between the initial and final states for which the heat flow can be measured somehow.
In the real world, there is no perfectly reversible path, so experimenters go for something that is as reversible as possible. It can also be difficult to measure the amount of heat flow, so it is sometimes done indirectly. An example might be measuring the isothermal quasistatic expansion of a gas stoked by a heat bath. The measured amount of work could be how hard the gas pushes on a piston, determined perhaps by incrementally removing small weights on the piston.
This would be equal to the amount of heat added. The three laws of thermodynamics were formulated at different times by different theoreticians, but are now considered a single framework for understanding entropy, particularly as it relates to the one-way nature of time. A video sequence can be run in reverse, giving us an idea of how things look where the laws of thermodynamics do not apply.
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