The short answer
One dot is a position record. A distribution is a statement about many such records. An experiment can make the connection visible without making those two kinds of information identical.
Selected records and original analysis
Three records from the same invented run
The event list is supplied, not observed.
| Record | What it retains | What it discards |
|---|---|---|
| Arrival list | Position-bin order | No fine position within each bin was supplied |
| Histogram | Counts [1, 4, 4, 1] | Arrival order |
| Relative frequencies | [0.1, 0.4, 0.4, 0.1] | Total sample size unless retained separately |
Chronology
A timeline of the turning points
Selected record
The 1989 paper reports single-electron buildup.
Original learning example
New stipulated inputs and an independently checked reference answer.
What the selected paper actually reports
The original abstract describes an electron microscope with a biprism and a position-sensitive counting system. It reports a movie of an interference pattern building from incoming single electrons.
The institutional account places the demonstration within Tonomuraโs coherent-electron-instrument programme. It emphasises buildup without other electrons present.
The movie was not watched for this study. The invented table below illustrates accumulation and information loss; it is not a quantum-mechanical prediction. How does a list of individual positions differ from its accumulated pattern?
Original task: a sequence and its histogram
Invent four equal-width detector bins, numbered 1โ4, and ten detections in this order: 1, 2, 2, 2, 2, 3, 3, 3, 3, 4. Form the count in each bin and the relative frequencies. Repeat the calculation after reversing the arrival order. Which records change?
A second invented run contains 100 events with counts 10, 40, 40, 10. Compare its relative frequencies with the first run. Do not treat either set as historical measurements or as evidence that every finite run must have those frequencies.
Sources for this section: [1]
Reference answer: the reduction discards order
The ten-event histogram is [1, 4, 4, 1], with relative frequencies [0.1, 0.4, 0.4, 0.1]. Reversing the arrival list changes the first and last recorded events but leaves all four counts and frequencies unchanged. The histogram cannot recover that order.
The 100-event run has the same relative frequencies. It contains more events, but this stipulated match does not estimate an uncertainty or establish that the two underlying sources are identical. A single detection in bin 2 is consistent with many possible later histograms; it is not itself a fringe pattern.
Sources for this section: [1]
An accumulated pattern does not supply every answer
The record preserves where detections occurred. It does not, by itself, label a path through the apparatus for each electron. Nor can a histogram alone show whether arrivals were equally spaced in time. Those questions require different observations or assumptions.
An acquisition sequence, its total count and its spatial distribution are complementary records. Preserving the first as well as the last lets a researcher investigate changing conditions rather than assuming that a final image tells the whole history.
Sources for this section: [1]
Continue the chronology
Related history guides
Biography context
Explore Japan through connected lives
Connected biographies
Researcher and context
Quick answers
Common questions
- Is the 100-event table an actual experiment?
- No. It is an invented comparison with exact supplied counts.
- Can one detection identify the distribution?
- No. Many different distributions can produce an event in that bin.
Primary and institutional sources
How this history was checked
The cited selections support the historical explanation. The new examples state their own assumptions and do not reconstruct an uninspected experiment. This article was reviewed on 31 October 2026.