Reasoning laboratory · Preview
The same average can hide different arrangements.
Seeing half the points inside on average does not tell you whether they were placed independently. Keep the point count and region fixed, and compare points placed one by one with points locked to a single shared position.
Keep the mean. Change the dependence.
Static worked exampleUnderdetermined: the selected measurements have identical predictions. These choices cannot distinguish the two candidates.
| Observable | Independent | Locked | Kept? |
|---|---|---|---|
| Probability that one specified point is inside | 0.5 | 0.5 | No |
| Mean number of points inside | 2 | 2 | Yes |
| Probability that all points are inside | 0.0625 | 0.5 | No |
| Variance of the number inside | 1 | 4 | No |
Independent positions
Each labeled point is placed uniformly and independently. Several, all or none may land inside.
Perfectly locked positions
All labeled points share one uniformly placed, coincident position. Only all-in or all-out is possible. This is not a finite-size rigid cluster straddling a boundary.
Inspect the full count distributions
Each bar uses the same probability scale, zero to one. The numbers are model probabilities, not a sampled histogram.
| K | Independent | Locked |
|---|---|---|
| 0 | ||
| 1 | ||
| 2 | ||
| 3 | ||
| 4 |
Connect the joint event to the entropy argument
The all-inside constraint has probability W = fn for independent points, but W = f for perfectly locked points. Applying Boltzmann’s logarithm gives ΔS/kB = ln W, with the same reference volume and point count.
Independent: -2.7725887. Locked: -0.69314718.
This is the log weight of a constraint, not the Shannon entropy of the count distribution. Agreeing with a volume law does not uniquely prove independence or establish the light-quantum hypothesis.
Test a count record against both models
Record how often K = 0, 1, …, 4 points were inside across independent repeat placements at the displayed settings. Enter one frequency for each K, including zeros. Consecutive frames of one correlated trajectory are not independent trials.
No file is uploaded and nothing is stored automatically. Analyzing asserts exact counting, known n and f, and identical independently repeated trials. Counting errors, finite cluster geometry and partially correlated models are not included.
Or replace the settings and record with an explicitly constructed example:
The link shares settings and selected measurements only. Your count record and explanation stay out of it. Copy them separately before leaving this tab.
Four points placed in half a box end up with two inside on average, whether each is placed on its own or all four are locked together. The average cannot tell the two apart; how often all four land inside, one time in 16 against one time in 2, can.
The light-quanta paper's §5 asks how likely it is that n points moving independently in a volume v0 are all found, at a chosen moment, in a part v of it. For independent points the answer is (v/v0)n, and through Boltzmann's principle the logarithm of that probability gives the entropy change (R/N) n ln(v/v0), with the number of points as the coefficient. §6 then reads radiation's entropy in the same form and concludes that, where Wien's law holds, radiation behaves as if it consisted of independent quanta. The workbench tests the premise that makes the exponent n rather than 1. It keeps four points and a region of half the volume, f = 1/2, and compares two ideal candidates: points placed one by one, and all four locked to one shared position. Both give a mean of 2 points inside, and both give each point a one-half chance of being inside, so neither measurement distinguishes them. The chance that all four are inside does: 1/16 = 0.0625 for independent points and 1/2 for locked ones, which is fn against f. So does the variance of the number inside, 1 against 4. A count record can be entered as how often 0, 1, 2, 3 or 4 points were inside. A single placement with 1, 2 or 3 inside is impossible for the locked candidate, and the workbench reports its likelihood as zero, not as a small number. With one point, or a region of none or all of the volume, the candidates agree on everything and no measurement separates them.
Put four points into a box one at a time, each with a one-half chance of landing in the left half. The chance that a particular point is inside is 1/2. The chance that all four are inside is 1/2 × 1/2 × 1/2 × 1/2 = 1/16, because the chances of independent events multiply. Counting every arrangement gives the whole distribution: 0, 1, 2, 3 or 4 points inside happen in 1, 4, 6, 4 and 1 of the 16 equally likely arrangements, so with chances 0.0625, 0.25, 0.375, 0.25 and 0.0625. The mean is (0 × 1 + 1 × 4 + 2 × 6 + 3 × 4 + 4 × 1)/16 = 32/16 = 2. The variance, the average squared distance from that mean, is (4 × 1 + 1 × 4 + 0 × 6 + 1 × 4 + 4 × 1)/16 = 16/16 = 1. Now lock the four points together, so that one placement decides all of them. Half the time all four are inside and half the time none are: the chances are 1/2 for 0 and 1/2 for 4, and zero for 1, 2 or 3. The mean is (0 + 4)/2 = 2, the same as before, and each point is still inside half the time. But the chance that all four are inside is 1/2, not 1/16, and the variance is ((0 − 2)² + (4 − 2)²)/2 = 4, not 1. In general, with n points and a fraction f of the volume, the all-inside chance is fn for independent points and f for a locked group. §5 takes the logarithm: ln fn = n ln f, while ln f = 1 × ln f. Multiplied by R/N, that logarithm is the entropy change, so the number of independent placements becomes the coefficient in front of ln(v/v0). Four labels locked into one unit give a coefficient of 1, not 4. The two constructed records show how counts decide. The record 1, 4, 6, 4, 1, sixteen placements in exactly the independent proportions, contains counts of 1, 2 and 3, which the locked candidate cannot produce, so its likelihood under locking is zero. The record 8, 0, 0, 0, 8, all or nothing every time, is possible under both. Each all-or-none outcome has chance 1/16 for independent points and 1/2 for locked ones, a factor of 8, so sixteen of them are 816 ≈ 2.8 × 1014 times more likely under locking, and the workbench prints the logarithm of the ratio, ln(Lindependent/Llocked) = −33.27. It reports no prior, posterior or cutoff. Both records were constructed to illustrate the comparison and neither is a measurement. Last, the degenerate cases: with n = 1, fn is just f, and with f = 0 or 1 both candidates are certain, so every measurement agrees.
The §5 argument is Boltzmann's principle, S = (R/N) ln W, applied to n independently moving points, and the paper's title calls the resulting view of light a heuristic one. The Brownian paper's §2 relies on the same independence: the configuration integral of n suspended particles grows as Vn, which gives their osmotic pressure RTν/N. Neither paper considers a partly correlated alternative. The quanta are independent only where Wien's law holds: in 1909 Einstein showed that the energy fluctuations of radiation obeying Planck's law have a term like that of independent particles and a term like that of waves, and Bose's derivation of Planck's law in 1924 counted quanta in a way that does not treat them as independent. The two candidates here are ideal extremes built for the comparison, not historical models.
Which premise earns the exponent?
These are two explicit ideal candidates, not every possible form of correlation. The comparison calculates predictions and can analyze a count record you enter. It does not produce historical observations or claim a reviewed edition.
The light-quanta paper’s §5 counts independently placed points. The chance that every one lies in a fraction f of the original volume is fn. One perfectly locked group has only one placement to make, so its corresponding probability is f. The logarithm turns this difference into an entropy coefficient.
In the Brownian configuration argument, independently placed units likewise determine the power of available volume. Constituents locked into one ideal point-like unit do not acquire independent placements merely because you can count several labels.
Try keeping only the mean, then add the all-inside probability or the variance. Finally set n to one, or choose the empty or whole region: a useful measurement can cease to distinguish the candidates in a degenerate case.
Rejecting perfect locking does not establish every independence assumption. Finite-size clusters, partial correlations, measurement errors and time dependence need other models. Real measurements must specify those conditions and their uncertainty.
Inspect the numerical owners
The same binomial and locked-probability functions serve this comparison and LQ-05. The workbench projects their results; its controls do not implement a second probability law.
Configuration-count source · Prediction and likelihood source