Sabine Hossenfelder (theoretical physicist at LMU, Munich: see her
excellent series of videos on YouTube) argues that the measurement problem
in QM is fundamentally different from the one in classical physics. In the
latter it's about errors inherent in the measuring apparatus ("experimental
errors"). In QM there's a fundamental limit on the precision of
measurements (Heisenberg) that is inherent in all quantum systems and no
amount of improvements in the apparatus is going to improve on that. Thus
she concludes "In QM the measurement problem is not about measurement".
-- Ian
On Mon, 6 Oct 2025 at 17:26, Nave, Colin (DLSLtd,RAL,LSCI) <
[email protected]> wrote:
> Dear Marin,
>
> I cheated and asked a LLM view of what you were saying by feeding it the
> email, rather than the series of papers. Is this a fair representation.?
>
> Regards
>
> Colin
>
> *Cryo-Electron Microscopy (Cryo-EM)* is a technique for imaging
> biological molecules at near-atomic resolution. Electron counting cameras
> are advanced detectors that count individual electrons rather than
> measuring their cumulative energy. This leads to more precise imaging.
>
>
>
> *The Measurement Problem in Quantum Mechanics*
>
> The Measurement Problem refers to the puzzle of how and why quantum
> systems appear to "collapse" into a definite state when measured—despite
> being described by probabilistic wavefunctions before measurement. It's a
> central philosophical issue in quantum theory.
>
>
>
> *Claim: Measurement Problem Is Not Unique to Quantum Mechanics*
>
> The statement argues that the measurement problem isn't just a quantum
> issue—it already existed in classical physics. Here's how:
>
> - Classical Newtonian Physics is deterministic: given initial
> conditions, the future is fully predictable.
> - Yet, measurement in practice always involves uncertainty, noise, and
> sampling limitations.
> - This creates a tension: how can we reconcile perfect mathematical
> determinism with imperfect real-world measurements?
>
>
>
> *Shannon’s Sampling Theorem Connection*
>
> Shannon’s sampling theorem (from information theory) states that to
> perfectly reconstruct a signal, you must sample it at twice its highest
> frequency (the Nyquist rate). If you sample incorrectly, you get
> aliasing—distorted or misleading results.
>
> This implies:
>
> - Measurement is inherently tied to sampling rules.
> - If you violate these rules, you misrepresent reality—even in
> classical systems.
>
>
>
> *Cryo-EM’s Unexpected Link*
>
> Electron counting cameras in Cryo-EM are measurement devices. The claim is
> that:
>
> - Their operation exposes fundamental limits of measurement—not just
> technical ones, but philosophical ones.
> - They highlight the need for symmetric sampling—meaning measurements
> must be taken in a way that respects the underlying structure of the system
> (e.g., time symmetry, spatial resolution).
>
>
>
> *Summary Interpretation*
>
> This passage is making a bold philosophical claim:
>
> - The measurement problem is universal—not just quantum.
> - It arises from the gap between mathematical models and physical
> reality.
> - Cryo-EM, through its precision and reliance on electron counting,
> reveals this gap in a tangible way.
> - All measurements—whether in physics, biology, or information
> theory—must obey sampling principles to avoid misrepresenting the system.
>
>
>
>
>
> *From:* CCP4 bulletin board <[email protected]> *On Behalf Of *Marin
> van Heel
> *Sent:* 04 October 2025 23:13
> *To:* [email protected]
> *Subject:* [ccp4bb] Single Electron Counting, The Measurement Problem,
> Symmetric Sampling
>
>
>
> You don't often get email from
> [email protected]. Learn why this is important
> <https://aka.ms/LearnAboutSenderIdentification>
>
>
>
> Dear All,
>
> Electron counting cameras in Cryo-EM have an unexpected direct connection
> to the Measurement Problem in Quantum Mechanics. In fact, the measurement
> problem already existed in Classical Newtonian Physics due to its
> Deterministic Mathematical Axioms and is not specifically tied to Quantum
> Mechanics. The Measurement Problem also existed in Shannon’s sampling
> theorem. All measurements, and not only those in Electron Microscopy must
> adhere to symmetric-sampling rules. Check the link to a series of papers:
>
> https://www.linkedin.com/feed/update/urn:li:activity:7379515419424022528/
>
> Sorry, I know it is tough stuff…
>
> Marin
>
>
>
>
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