*Sorry Tim*... The problem is *not limited to Cryo-EM* .... It affects* all forms of measurements*, including the measurement of *X-ray diffraction patterns*! What is at stake here is that the* Nyquist-Shannon theorem* is fundamentally *flawed *(Shannon 1949). In *X Ray Crystallography* you unfortunately lose the phases collecting such X Ray diffraction patterns, but there is one good thing about that, namely: the *low frequency diffraction peaks* disappear behind the central-beam stop! The discrete, *symmetric-sampling approach* - for the sake of linearity - requires both the *low frequencies* and the* high spatial frequencies* to be apodized to zero long before reaching those limits of the sampling space. (After all, the zero-order frequency of a deterministic *Continuous Fourier Transform*, covers the whole universe in one direction and that is not a measurable perspective on the physical world we live in!).
So sorry Tim, you are not giving a valid argument for *ignoring the Measurement Problem*! But it is great to hear from you again, after so many years! Cheers, Marin On Mon, Oct 6, 2025 at 10:46 AM Tim Gruene <[email protected]> wrote: > I am so happy I do diffraction, not microscopy > Tim > > On Sat, 4 Oct 2025 19:13:10 -0300 > Marin van Heel <[email protected]> wrote: > > > 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 > > > > ######################################################################## > > > > To unsubscribe from the CCP4BB list, click the following link: > > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > > > > This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a > > mailing list hosted by www.jiscmail.ac.uk, terms & conditions are > > available at https://www.jiscmail.ac.uk/policyandsecurity/ > > > > -- > -- > Tim Gruene > Head of the Core Facility Crystal Structure Analysis > Faculty of Chemistry > University of Vienna > > Phone: +43-1-4277-70202 > > https://ccsa.univie.ac.at > > GPG Key ID = A46BEE1A > ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
