I Heisenberg Microscope: Exploring Single Photon Diffraction

Axel Togawa
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diffraction pattern generated in the thought experiment of Heisenberg
In the thought experiment proposed by Heisenberg, a single photon is scattered by the electron that we want to observe, and entering the microscope lens (the photon), it will create a diffraction pattern that gives the uncertainty on the position according to the law of optics. I wanted to ask how the single photon could create a diffraction figure?
 
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Axel Togawa said:
I wanted to ask how the single photon could create a diffraction figure?
It can't, not if you're considering a single photon.

Threads like this are the reason Physics Forums generally encourages people to include the sources that they've using. Without knowing that, we have no way of knowing whether you've misunderstood the explanation or the explanation was bad. So if you could tell us more about your starting point, you'll get more and more helpful answers.
 
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Yeah, sorry you are right. Anyway i found it on these sites:

http://www.bio-physics.at/wiki/index.php?title=Heisenberg's_Microscope
https://chem.libretexts.org/Bookshe...eory/Electrons_in_Atoms/Uncertainty_Principle
https://en.wikipedia.org/wiki/Uncertainty_principle#Heisenberg's_microscope

maybe i misunderstood the explanations, but i wanted to ask because in my physics lecture the use of only photon was specified to influence as little as possible the electron
 
A single photon will not create a diffraction pattern. Your links don't say that either.

A succession of many single photons can create a diffraction pattern.
 
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Ok thank you fro the answer
 
You can well argue with a single photon. It's only the meaning of the diffraction pattern which changes in a "revolutionary way". The diffraction pattern is of course a "wave phenomenon", i.e., it occurs when using classical em. waves or many single photons.

The important "revolutionary" change between classical electromagnetism and quantum electrodynamics is the meaning of this diffraction pattern when considering the case of a single photon: According to the Born rule of quantum theory the diffraction pattern depicts the probability of the single photon to hit the screen at a given place. The uncertainty of the position of the electron using a single photon is due to the randomness of the position where this photon is detected, i.e., you cannot trace back in a one-to-one connection the position of the electron which scattered the photon from the place where the photon was detected.
 
I read Hanbury Brown and Twiss's experiment is using one beam but split into two to test their correlation. It said the traditional correlation test were using two beams........ This confused me, sorry. All the correlation tests I learnt such as Stern-Gerlash are using one beam? (Sorry if I am wrong) I was also told traditional interferometers are concerning about amplitude but Hanbury Brown and Twiss were concerning about intensity? Isn't the square of amplitude is the intensity? Please...
I am not sure if this belongs in the biology section, but it appears more of a quantum physics question. Mike Wiest, Associate Professor of Neuroscience at Wellesley College in the US. In 2024 he published the results of an experiment on anaesthesia which purported to point to a role of quantum processes in consciousness; here is a popular exposition: https://neurosciencenews.com/quantum-process-consciousness-27624/ As my expertise in neuroscience doesn't reach up to an ant's ear...
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
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