Wave equation solver Updated 2025-07-16
This section talks about solvers/simulators dedicated solving the wave equation. Of course, any serious solver will likely be able to solve a wider range of PDE, so this section contains mostly fun toys. For more serious stuff see: Section "PDE solver".
JavaScript toy solvers:
Wave function collapse Updated 2025-07-16
Similar to quantum jump in the Bohr model, but for the Schrödinger equation.
The idea the the wave function of a small observed system collapses "obviously" cannot be the full physical truth, only a very useful approximation of reality.
Because then are are hard pressed to determine the boundary between what collapses and what doesn't, and there isn't such a boundary, as everything is interacting, including the observer.
The many-worlds interpretation is an elegant explanation for this. Though it does feel a bit sad and superfluous.
Wayback Machine rate limit Updated 2025-07-16
archive.org/details/toomanyrequests_20191110 says 15 archives / minute, but apparently aslo 15 retrievals per minutes on Wikipedia, after which 5 min blacklist. After that, you start getting some 429s, and after that, server refuses to connect at al.
CDX: no limits apparently, they might just throttle you? Made 10k requets on bash loop and was going fine. But not that if you get blacklisted by create/fetch requests blacklist, server fails to connect here as well.
Superfluid helium-3 Updated 2025-07-16
Surprisingly, it can also become a superfluid even though each atom is a fermion! This is because of Cooper pair formation, just like in superconductors, but the transition happens at lower temperatures than superfluid helium-4, which is a boson.
aps.org/publications/apsnews/202110/history.cfm: October 1972: Publication of Discovery of Superfluid Helium-3 contains comments on the seminal paper and a graph which we must steal.
Good points:
Fock space Updated 2025-07-16
Yup, this one Focks you up.
John Archibald Wheeler Updated 2025-07-16
Richard Feynman's mentor at Princeton University, and notable contributor to his development of quantum electrodynamics.
Worked with Niels Bohr at one point.
Web of Stories interview (1996): www.youtube.com/playlist?list=PLVV0r6CmEsFzVlqiUh95Q881umWUPjQbB. He's a bit slow, you wonder if he's going to continute or not! One wonders if it is because of age, or he's always been like that.
John von Neumann Updated 2025-07-16
This is the one Ciro Santilli envies the most, because he has such a great overlap with Ciro's interests, e.g.:
Video 1.
John von Neuman - a documentary by the Mathematical Association of America (1966)
Source. Some good testimonies. Some boring.
This is what happens when you apply a step voltage to a series RC circuit: TODO graph.
In this chapter Richard Feynman talks about his experiences in Brazil.
"O Americano, Outra Vez!" means "The American, once again!" in Portuguese, which is what one of the samba school boss exclaimed when Feynman was not playing well his instrument, the frigideira, during a rehearsal.
Feynman really enjoyed Brazil's (and notably Rio's) stereotypical "take it easy and enjoy life" attitude.
Sycamore processor Updated 2025-07-16
This is a good read: quantumai.google/hardware/datasheet/weber.pdf May 14, 2021. Their topology is so weird, not just a rectangle, one wonders why! You get different error rates in different qubits, it's mad.
Figure 1.
Google Sycamore Weber quantum computer connectivity graph
. Weber is a specific processor of the Sycamore family. From this we see it clearly that qubits are connected to at most 4 other qubits, and that the full topology is not just a simple rectangle.
Theodicy Updated 2025-07-16

There are unlisted articles, also show them or only show them.