SARS-CoV-2 Nsp3 Updated 2025-07-16
SARS-CoV-2 Nsp5 Updated 2025-07-16
SARS-CoV-2 Nsp12 Updated 2025-07-16
Nick Leeson Updated 2025-07-16
Good documentary about it: Nick Leeson and the Fall of the House of Barings by Adam Curtis (1996).
One is reminded of Annie Dookhan.
Raspberry Pi Pico H Updated 2025-07-26
Has Serial wire debug debug pre-soldered. Why would you ever get one without unless you are a clueless newbie like Ciro Santilli?!?!
It is however possible to solder it yourself on Raspberry Pi Pico W.
Raspberry Pi Pico W Updated 2025-07-27
Microwave Updated 2025-07-16
Microwave production and detection is incredibly important in many modern applications:
- telecommunications, e.g. being used in
- Wi-Fi
- satellite communicationsyoutu.be/EYovBJR6l5U?list=PL-_93BVApb58SXL-BCv4rVHL-8GuC2WGb&t=27 from CuriousMarc comments on some piece of Apollo equipment they were restoring/reversing:Ah, Ciro Santilli really wishes he knew what that meant more precisely. Sounds so cool!
These are the boxes that brought you voice, data and live TV from the moon, and should be early masterpieces of microwave electronics, the blackest of black arts in analog electronics.
- 4G and other cellular network standards
- radar. As an example, 1965 Nobel Prize in Physics laureate Julian Schwinger did some notable work in the area in World War II, while most other physicists went to the Manhattan Project instead.This is well highlighted in QED and the men who made itby Silvan Schweber (1994). Designing the cavity wasn't easy. One of the key initial experiments of quantum electrodynamics, the Lamb-Retherford experiment from 1947, fundamental for modern physics, was a direct consequence of post-radar research by physicists who started to apply wartime developments to their scientific search.Wikipedia also mentions en.wikipedia.org/w/index.php?title=Microwave&oldid=1093188913#Radar_2:
The first modern silicon and germanium diodes were developed as microwave detectors in the 1930s, and the principles of semiconductor physics learned during their development led to semiconductor electronics after the war.
- microwave is the natural frequency of several important Atomic, Molecular and Optical Physics phenomena, and has been used extensively in quantum computing applications, including completely different types of quantum computer type:Likely part of the appeal of microwaves is that they are non-ionizing, so you don't destroy stuff. But at the same time, they are much more compatible with atomic scale energies than radio waves, which have way way too little energy.
- trapped ion quantum computer; Video "Trapping Ions for Quantum Computing by Diana Craik (2019)"
- superconducting quantum computer; e.g. this Junior Microwave Design Engineer job accouncement from Alice&Bob: archive.ph/wip/4wGPJ
Quantum field theory lecture by Tobias Osborne (2017) Lecture 1 Updated 2025-07-16
Bibliography review:
- Quantum Field Theory lecture notes by David Tong (2007) is the course basis
- quantum field theory in a nutshell by Anthony Zee (2010) is a good quick and dirty book to start
Course outline given:
- classical field theory
- quantum scalar field. Covers bosons, and is simpler to get intuition about.
- quantum Dirac field. Covers fermions
- interacting fields
- perturbation theory
- renormalization
Non-relativistic QFT is a limit of relativistic QFT, and can be used to describe for example condensed matter physics systems at very low temperature. But it is still very hard to make accurate measurements even in those experiments.
Mentions that "QFT is hard" because (a finite list follows???):But I guess that if you fully understand what that means precisely, QTF won't be too hard for you!
There are no nontrivial finite-dimensional unitary representations of the Poincaré group.
Notably, this is stark contrast with rotation symmetry groups (SO(3)) which appears in space rotations present in non-relativistic quantum mechanics.
www.youtube.com/watch?v=T58H6ofIOpE&t=5097 describes the relativistic particle in a box thought experiment with shrinking walls
Quantum field theory lecture by Tobias Osborne (2017) Lecture 2 Updated 2025-07-16
- the advantage of using Lagrangian mechanics instead of directly trying to work out the equations of motion is that it is easier to guess the Lagrangian correctly, while still imposing some fundamental constraints
- youtu.be/bTcFOE5vpOA?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=3375
- Lagrangian mechanics is better for path integral formulation. But the mathematics of that is fuzzy, so not going in that path.
- Hamiltonian mechanics is better for non-path integral formulation
- youtu.be/bTcFOE5vpOA?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=3449 Hamiltonian formalism requires finding conjugate pairs, and doing a
Quantum field theory lecture by Tobias Osborne (2017) Lecture 3 Updated 2025-07-16
- symmetry in classical field theory
- from Lagrangian density we can algorithmically get equations of motion, but the Lagrangian density is a more compact way of representing the equations of motion
- definition of symmetry in context: keeps Lagrangian unchanged up to a total derivative
- Noether's theorem
- youtu.be/cj-QpsZsDDY?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=3062 Lagrangian and conservation example under translations
- youtu.be/cj-QpsZsDDY?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=3394 same but for Poincaré transformations But now things are harder, because it is harder to describe general infinitesimal Poincare transforms than it was to describe the translations. Using constraints/definition of Lorentz transforms, also constricts the allowed infinitesimal symmetries to 6 independent parameters
- youtu.be/cj-QpsZsDDY?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=4525 brings out Poisson brackets, and concludes that each conserved current maps to a generator of the Lie algebra
Quantum field theory lecture by Tobias Osborne (2017) Lecture 4 Updated 2025-07-16
- quantization. Uses a more or less standard way to guess the quantized system from the classical one using Hamiltonian mechanics.
- youtu.be/fnMcaq6QqTY?t=1179 remembers how to solve the non-field quantum harmonic oscillator
- youtu.be/fnMcaq6QqTY?t=2008 puts hats on everything to make the field version of things. With the Klein-Gordon equation Hamiltonian, everything is analogous to the harmonic oscilator
Quantum field theory lecture by Tobias Osborne (2017) Lecture 5 Updated 2025-07-16
- something about finding a unitary representation of the poincare group
Quantum field theory lecture by Tobias Osborne (2017) Lecture 8 Updated 2025-07-16
Quantum field theory lecture by Tobias Osborne (2017) Lecture 9 Updated 2025-07-16
Quantum field theory lecture by Tobias Osborne (2017) Lecture 14 Updated 2025-07-16
Quantum field theory lecture by Tobias Osborne (2017) Lecture 15 Updated 2025-07-16
Quantinuum hardware Updated 2025-07-16
Cambridge Quantum Computing Updated 2025-07-16
Honeywell Quantum Solutions Updated 2025-07-16
There are unlisted articles, also show them or only show them.