Ciro Santilli @cirosantilli 37

Start by looking at: Maxwell-Boltzmann vs Bose-Einstein vs Fermi-Dirac statistics.

TODO what's the largest molecule done on a classical computer?

This is a family of computers. It was a big success. It appears that this was a big unification project of previous architectures. And it also gave software portability guarantees with future systems, since writing software was starting to become as expensive as the hardware itself.

Media:

This metric is so dumb! It only helps maintain existing closed journals closed! Why not just do a PageRank on the articles themselve instead? Like the h-index does for authors? That would make so much more sense!

Good film, it feels quite realistic.

It is a shame that they tried to include some particularly interesting stories but didn't have the time to develop them, e.g. Feynman explaining to the high school interns what they were actually doing. These are referred to only in passing, and likely won't mean anything to someone who hasn't read the book.

The film settings are particularly good, and give what feels like an authentic view of the times. Particularly memorable are the Indian caves shown the film. TODO name? Possibly Puye Cliff Dwellings. Puye apparently appears prominently up on another film about Los Alamos: The Atomic city (1952). It is relatively close to Los Alamos, about 30 km away.

The title is presumably a reference to infinities in quantum field theory? Or just to the infinity of love etc.? But anyways, the infinities in quantum field theory theory come to mind if you are into this kind of stuff and is sad because that work started after the war.

It is quite amazing to read through books such as The Supermen: The Story of Seymour Cray by Charles J. Murray (1997), as it makes you notice that earlier CPUs (all before the 70's) were not made with integrated circuits, but rather smaller pieces glued up on PCBs! E.g. the arithmetic logic unit was actually a discrete component at one point.

The reason for this can also be understood quite clearly by reading books such as Robert Noyce: The Man Behind the Microchip by Leslie Berlin (2006). The first integrated circuits were just too small for this. It was initially unimaginable that a CPU would fit in a single chip! Even just having a very small number of components on a chip was already revolutionary and enough to kick-start the industry. Just imagine how much money any level of integration saved in those early days for production, e.g. as opposed to manually soldering point-to-point constructions. Also the reliability, size an weight gains were amazing. In particular for military and spacial applications originally.

The different only shows up for field, not with particles. For fields, there are two types of changes that we can make that can keep the Lagrangian unchanged as mentioned at Physics from Symmetry by Jakob Schwichtenberg (2015) chapter "4.5.2 Noether's Theorem for Field Theories - Spacetime":

From defining properties of elementary particles:

From the spacetime theory alone, we can derive the Lagrangian for the free theories for each spin:Then the internal symmetries are what add the interaction part of the Lagrangian, which then completes the Standard Model Lagrangian.

You modify the DNA of a cell and stick a fluorescent protein right before or after another protein. Then when it gets translated, the GFP is stuck to the protein of interest, which hopefully hasn't lost its function as a result, then you can just see the protein of interest.

The summary from www.geeksforgeeks.org/tree-traversals-inorder-preorder-and-postorder/ is a winner:

In principle one could talk about tree traversal of unordered trees as a number of possible traversals without a fixed order. But we won't consider that under this section, only deterministic ordered tree traversals.

Course plan:

If you shine microwave radiation on a Josephson junction, it produces a fixed average voltage that depends only on the frequency of the microwave. TODO how is that done more precisely? How to you produce and inject microwaves into the thing?

It acts therefore as a perfect frequency to voltage converter.

The Wiki page gives the formula: en.wikipedia.org/wiki/Josephson_effect#The_inverse_AC_Josephson_effect You get several sinusoidal harmonics, so the output is not a perfect sine. But the infinite sum of the harmonics has a fixed average voltage value.

And en.wikipedia.org/wiki/Josephson_voltage_standard#Josephson_effect mentions that the effect is independent of the junction material, physical dimension or temperature.

All of the above, compounded with the fact that we are able to generate microwaves with extremely precise frequency with an atomic clock, makes this phenomenon perfect as a Volt standard, the Josephson voltage standard.

TODO understand how/why it works better.

1926 translation A. D. Cowper: www.maths.usyd.edu.au/u/UG/SM/MATH3075/r/Einstein_1905.pdf

He was a leading figure at the MIT Radiation Laboratory, and later he was head at the Columbia University laboratory that carried out the crucial Lamb-Retherford experiment and the anomalous magnetic dipole moment of the electron published at The Magnetic Moment of the Electron by Kusch and Foley (1948) using related techniques.