Generator

Each stage takes 25.0 per cent of what is left

One function in the thermal library, called 29 times across 5 essays. Below: what it draws at its defaults, what it draws at every branch an essay asks for, whether the site's own gate puts a claim to it, and everywhere it is called.

At its defaults it draws each stage takes 25.0 per cent of what is left. Entropy against temperature for a spin-½ paramagnet at 0.25 T and 1 T, with the cooling cycle drawn between them: a vertical drop is isothermal magnetisation, a horizontal move is adiabatic demagnetisation. Starting from 1 K the treads are at 1.000 K, 0.250 K, 0.062 K, 0.016 K, 3.91 mK. Each is 0.2500 of the one before — a ratio read back off the drawn treads rather than written into them, and equal to the field ratio 0.25/1 because this refrigerant's entropy depends on the field and the temperature only through their quotient. The steps therefore shrink in proportion to what is left, and no finite number of them arrives.

entropy-staircase is one function in lib/figures/thermal.js — cycles, distributions and the statistics underneath them. Everything below came out of it during this build, at parameters taken from the essays rather than invented for this page. A figure here is the figure a reader meets in an essay, and if the generator changes, this page changes with it.

At its defaults

Drawn even though every essay passes options, because a default nothing exercises is a trap for the next essay to call this with none — which has happened here twice.

Each stage takes 25.0 per cent of what is left. Entropy against temperature for a spin-½ paramagnet at 0.25 T and 1 T, with the cooling cycle drawn between them: a vertical drop is isothermal magnetisation, a horizontal move is adiabatic demagnetisation. Starting from 1 K the treads are at 1.000 K, 0.250 K, 0.062 K, 0.016 K, 3.91 mK. Each is 0.2500 of the one before — a ratio read back off the drawn treads rather than written into them, and equal to the field ratio 0.25/1 because this refrigerant's entropy depends on the field and the temperature only through their quotient. The steps therefore shrink in proportion to what is left, and no finite number of them arrives.

Entropy against temperature for a spin-½ paramagnet at 0.25 T and 1 T, with the cooling cycle drawn between them: a vertical drop is isothermal magnetisation, a horizontal move is adiabatic demagnetisation. Starting from 1 K the treads are at 1.000 K, 0.250 K, 0.062 K, 0.016 K, 3.91 mK. Each is 0.2500 of the one before — a ratio read back off the drawn treads rather than written into them, and equal to the field ratio 0.25/1 because this refrigerant's entropy depends on the field and the temperature only through their quotient. The steps therefore shrink in proportion to what is left, and no finite number of them arrives.

The entropy each degree of freedom has not yet given up

The options are the ones A law about spectra, not about heat passes. A branch drawn at its own defaults instead would be a picture no essay asked for and no assertion has been run against.

The entropy each degree of freedom has not yet given up. The entropy carried by each kind of degree of freedom, drawn against the temperature at which it orders and hands that entropy over. Lattice vibrations freeze out around room temperature; electron spins in a paramagnetic salt order in the millikelvin range, which is what makes adiabatic demagnetisation work; and nuclear spins hold R ln(2I+1) — 11.5 joules per kelvin per mole for copper — down to some tens of nanokelvin, where their own dipolar interactions finally sort them out. A copper sample at a microkelvin therefore has a large entropy and violates nothing: its nuclear spin system has not reached its ground state, and the third law is a statement about ground states rather than about thermometers.

The entropy carried by each kind of degree of freedom, drawn against the temperature at which it orders and hands that entropy over. Lattice vibrations freeze out around room temperature; electron spins in a paramagnetic salt order in the millikelvin range, which is what makes adiabatic demagnetisation work; and nuclear spins hold R ln(2I+1) — 11.5 joules per kelvin per mole for copper — down to some tens of nanokelvin, where their own dipolar interactions finally sort them out. A copper sample at a microkelvin therefore has a large entropy and violates nothing: its nuclear spin system has not reached its ground state, and the third law is a statement about ground states rather than about thermometers.

What is left at zero is a logarithm of a count

The options are the ones A law about spectra, not about heat passes. A branch drawn at its own defaults instead would be a picture no essay asked for and no assertion has been run against.

What is left at zero is a logarithm of a count. The entropy remaining at absolute zero for 5 kinds of ground state, computed as R ln g from the number of equivalent arrangements and set beside the calorimetric value where one exists. The third law in its statistical form says the entropy of a system in its ground state is k ln g, and it is zero only when the ground state is unique. Every measured residual entropy in the table is a count of orientations that the crystal never had time to sort out. Where the freezing-in is complete the count reproduces the calorimetry to a few per cent; where it is partial — carbon monoxide, whose molecules manage some ordering on the way down — the count is an upper bound the measurement falls below. So the law is a statement about the degeneracy of a spectrum, and a substance that appears to violate it is a substance whose ground state was not reached.

The entropy remaining at absolute zero for 5 kinds of ground state, computed as R ln g from the number of equivalent arrangements and set beside the calorimetric value where one exists. The third law in its statistical form says the entropy of a system in its ground state is k ln g, and it is zero only when the ground state is unique. Every measured residual entropy in the table is a count of orientations that the crystal never had time to sort out. Where the freezing-in is complete the count reproduces the calorimetry to a few per cent; where it is partial — carbon monoxide, whose molecules manage some ordering on the way down — the count is an upper bound the measurement falls below. So the law is a statement about the degeneracy of a spectrum, and a substance that appears to violate it is a substance whose ground state was not reached.

What is left at zero is a logarithm of a count

The options are the ones A law about spectra, not about heat passes. A branch drawn at its own defaults instead would be a picture no essay asked for and no assertion has been run against.

What is left at zero is a logarithm of a count. The entropy remaining at absolute zero for 4 kinds of ground state, computed as R ln g from the number of equivalent arrangements and set beside the calorimetric value where one exists. The third law in its statistical form says the entropy of a system in its ground state is k ln g, and it is zero only when the ground state is unique. Every measured residual entropy in the table is a count of orientations that the crystal never had time to sort out. Where the freezing-in is complete the count reproduces the calorimetry to a few per cent; where it is partial — carbon monoxide, whose molecules manage some ordering on the way down — the count is an upper bound the measurement falls below. So the law is a statement about the degeneracy of a spectrum, and a substance that appears to violate it is a substance whose ground state was not reached.

The entropy remaining at absolute zero for 4 kinds of ground state, computed as R ln g from the number of equivalent arrangements and set beside the calorimetric value where one exists. The third law in its statistical form says the entropy of a system in its ground state is k ln g, and it is zero only when the ground state is unique. Every measured residual entropy in the table is a count of orientations that the crystal never had time to sort out. Where the freezing-in is complete the count reproduces the calorimetry to a few per cent; where it is partial — carbon monoxide, whose molecules manage some ordering on the way down — the count is an upper bound the measurement falls below. So the law is a statement about the degeneracy of a spectrum, and a substance that appears to violate it is a substance whose ground state was not reached.

The entropy each degree of freedom has not yet given up

The options are the ones A law about spectra, not about heat passes. A branch drawn at its own defaults instead would be a picture no essay asked for and no assertion has been run against.

The entropy each degree of freedom has not yet given up. The entropy carried by each kind of degree of freedom, drawn against the temperature at which it orders and hands that entropy over. Lattice vibrations freeze out around room temperature; electron spins in a paramagnetic salt order in the millikelvin range, which is what makes adiabatic demagnetisation work; and nuclear spins hold R ln(2I+1) — 11.5 joules per kelvin per mole for copper — down to some tens of nanokelvin, where their own dipolar interactions finally sort them out. A copper sample at a microkelvin therefore has a large entropy and violates nothing: its nuclear spin system has not reached its ground state, and the third law is a statement about ground states rather than about thermometers.

The entropy carried by each kind of degree of freedom, drawn against the temperature at which it orders and hands that entropy over. Lattice vibrations freeze out around room temperature; electron spins in a paramagnetic salt order in the millikelvin range, which is what makes adiabatic demagnetisation work; and nuclear spins hold R ln(2I+1) — 11.5 joules per kelvin per mole for copper — down to some tens of nanokelvin, where their own dipolar interactions finally sort them out. A copper sample at a microkelvin therefore has a large entropy and violates nothing: its nuclear spin system has not reached its ground state, and the third law is a statement about ground states rather than about thermometers.

The entropy each degree of freedom has not yet given up

The options are the ones A law about spectra, not about heat passes. A branch drawn at its own defaults instead would be a picture no essay asked for and no assertion has been run against.

The entropy each degree of freedom has not yet given up. The entropy carried by each kind of degree of freedom, drawn against the temperature at which it orders and hands that entropy over. Lattice vibrations freeze out around room temperature; electron spins in a paramagnetic salt order in the millikelvin range, which is what makes adiabatic demagnetisation work; and nuclear spins hold R ln(2I+1) — 11.5 joules per kelvin per mole for copper — down to some tens of nanokelvin, where their own dipolar interactions finally sort them out. A copper sample at a microkelvin therefore has a large entropy and violates nothing: its nuclear spin system has not reached its ground state, and the third law is a statement about ground states rather than about thermometers.

The entropy carried by each kind of degree of freedom, drawn against the temperature at which it orders and hands that entropy over. Lattice vibrations freeze out around room temperature; electron spins in a paramagnetic salt order in the millikelvin range, which is what makes adiabatic demagnetisation work; and nuclear spins hold R ln(2I+1) — 11.5 joules per kelvin per mole for copper — down to some tens of nanokelvin, where their own dipolar interactions finally sort them out. A copper sample at a microkelvin therefore has a large entropy and violates nothing: its nuclear spin system has not reached its ground state, and the third law is a statement about ground states rather than about thermometers.

What checks it

physicscheck asserts something about entropy-staircase that could fail — it draws it and measures the result against a value reached some other way.

Across the library: 100 interrogated, 2 exercised only, 1 untouched, of 103. Read out of the gate's source by the gate's own two patterns — and the gate's last claim fails the build if that read disagrees with what it was handed while running.

Where it is called

Changing this generator changes every figure on this list. That is what makes the list worth publishing rather than keeping in a check script.

Thermodynamics

A law about spectra, not about heat

The third law is usually met as a statement about cooling. Its statistical form is a statement about a spectrum: the entropy of a system in its ground state is k ln g, and it vanishes only when the ground state is unique. Every apparent exception is a degeneracy or a system that never reached its ground state — and copper nuclei carry eleven joules per kelvin per mole down to a hundred nanokelvin without violating anything.

Thermodynamics

Hotter than any temperature there is

A system whose energy has a ceiling can be pushed past the point where adding energy adds entropy. Its temperature is then negative — and negative temperatures are not cold. They sit above every positive temperature on the only scale that decides which way heat flows, and a working laser is at one.

Thermodynamics

The count that decides which entropy is right

There are two ways to count the states of an isolated system: the states at its energy, which is Boltzmann's entropy, and the states at or below it, which is Gibbs's. For large systems in ordinary conditions they agree to the last measurable digit. For a system whose energy has a ceiling, past the halfway point, one gives negative temperatures and the other forbids them. Definitions cannot settle which is right, but a temperature is for something — saying which way heat will flow — and putting two such systems in contact lets the count of states answer.

Thermodynamics

The entropy that depends on how fast it was cooled

Ice's residual entropy is a count, and it comes out the same whoever measures it. A glass's does not. A glass keeps whatever entropy it happened to have when its own relaxation time crossed the experiment's, so cooling ten times more slowly leaves less behind — and extrapolating the equilibrium liquid below that point takes its entropy under the crystal's at a finite temperature, which cannot happen and does not, for a reason that is still argued about.

Thermodynamics

The staircase that never reaches the floor

Absolute zero is unreachable, and the reason is not that the apparatus is not good enough. Every stage of cooling removes a fixed fraction of what is left rather than a fixed amount, so the steps shrink in proportion to the distance remaining — and the fixed fraction cannot be made one, because the entropy curves at two field strengths are required to meet where the axis is.

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