April 8, 2022

Dear Nikola,

Thank you for your telephone call, and thank you especially for your invitation to write to you. In all these many years, I have found out that the attempt to explain to someone like yourself how I feel and think, is the most productive intellectual exercise accessible to me.

For many years now, I have been wrestling with Kierkegaards dictum "subjektiviteten er sandheden" (subjectivity is the truth) with which he countered the presumptions of "objective" historical accounts of the life of Jesus, (Ernest Renan, David Friedrich Strauß) 

In the past few days, in the course of falling asleep or waking up bent over the computer keyboard, with my eyes already or still closed, I perceive visual images so vivid, that I sometime touch my lids to confirm that they are closed. Perhaps it's the onset of some as yet unnamed mental illness or the brain's entanglement in a longstanding "viral" disorder.

The word "entanglement" summarizes my present involvement with and understanding of quantum mechanics; and quantum mechanics has turned out to be the instrument which facilitates my understanding not of outward galaxies, black holes, singularities or subatomic particles, but the inward entanglement of my thoughts.

The words of language and the equations of mathematics, the "Symbolic Functions" celebrated so awkwardly by Ernst Cassirer, present themselves to me as the keys to the encrypted reality, - no, not the reality outside of me, but the reality within me.  My keys to language seem to function reasonably well, but that's probably because I use them so selectively.  If I tried to learn to understand Hebrew or Arabic, Chinese or Sanskrit, I would most likely be as frustrated by them as if they were Hilbert spaces.

Without doubt it is a facet of senility, that the concepts of mathematics, the point, line, plane, solid, length and duration, seem to me to be reflections in my mind of a transcendental reality otherwise inaccessible to me. The same is true of both "classical" and contemporary relativistic and quantum physics.  

I have tried to understand an essay about the derivation of the Planck constant. https://edisciplinas.usp.br/pluginfile.php/48089/course/section/16461/qsp_chapter10-plank.pdf If I understand correctly Planck's quantization of black body radiation is not an observable phenomenon but a mathematical inference. I interpret Planck's hypostasis of black body radiation as quantal rather than continuous to be a reflection of my experience of perception of the limitations of continuity. That would not be an acceptable answer on any physics exam.

I very much hope that you are well, and that you stay well.

EJM