The first working one in 1947 by John Bardeen and walter Brattain in Bell Labs Murray Hill.
People had already patented a lot of stuff before without being able to make them work. Nonsense.
As the name suggests, this is not very sturdy, and was quickly replaced by bipolar junction transistor.
  • 1: Jim Prideaux captured. Some ex-colleague invites Smiley to dinner and keeps asking how incompetent people like Alleline climbed to the top of the Circus. Smiley recalled to service to meet Ricki Tarr.
  • 2: Ricki Tarr tells his story to Smiley. Peter Guillam starts stealing material from the Circus, find missing page on the communication officer list. Smiley sets up his investigation operation.
  • 3: Smiley meets Connie who tells that she was fired for suspecting Poliakov. Flashbacks show the ousting of Control and Smiley.
  • 4: Guillam steals more material from the circus. While doing that, he is called by the top officers to inquire about Ricki Tarr being in England, which they suspect because they discovered that his family has come.
  • 5: Jim Prideaux tells his story to Smiley, who cannot easily access the Circus reports about it. When he is returned to England, there was basically no debriefing, and Esterhase already knew about the Tinker Tailor codenames, presumably through Merlin.
  • 6: Smiley hears the story of yet another ousted man, who heard the Russians knew in advance about Jim Prideaux' coming. Toby Esterhase dismissed him for alcoholism.
Grand Unified Theory by Ciro Santilli 37 Updated 2025-07-16
Appears to be an unsolved physics problem. TODO why? Don't they all fit into the Standard Model already? So why is strong force less unified with electroweak, than electromagnetic + weak is unified in electroweak?
Nobel disease by Ciro Santilli 37 Updated 2025-09-11
The Eighth Day of Creation has a related quote:
In a conversation a few weeks earlier at the faculty club of the Massachusetts Institute of Technology, a couple of biologists had speculated whether Pauling, whose recent popular book on the benefits to health and sanity of massive doses of vitamin C was stacked in display near the entrance of the M.I.T. bookstore, was showing signs of what one of the men called "old scientist's disease" - which they defined as what happens to great men when they grow beyond the psychological reach of the salutary system by which scientists blow the whistle on one another's mistakes.
Video 1.
The Nobel Prize Winners With Crazy Theories by Qxir
. Source.
Google Maps by Ciro Santilli 37 Updated 2025-07-16
Owned/developed by Google as of 2020.
Early on jumpstarted from several acquisitions, notably Keyhole Inc. and Where 2 Technologies.
Mt. Gox by Ciro Santilli 37 Updated 2025-07-16
The first Bitcoin exchange. Coded as a hack, and they didn't manage to fix the hacks as the site evolved in a major way, which led to massive hacks.
Their creation is clearly visible on the archive history of bitcoin.org: web.archive.org/web/20100701000000*/bitcoin.org which started having massively more archives since Mt. Gox opened.
Video 1.
One Mistake Brought Down This FBI Most Wanted Hacker by Crumb (2023)
. Source. Good overview of Mt. Gox.
One parameter subgroup by Ciro Santilli 37 Updated 2025-07-16
The one parameter subgroup of a Lie group for a given element of its Lie algebra is a subgroup of given by:
Intuitively, is a direction, and is how far we move along a given direction. This intuition is especially vivid in for example in the case of the Lie algebra of , the rotation group.
One parameter subgroups can be seen as the continuous analogue to the cycle of an element of a group.
ThinkPad by Ciro Santilli 37 Updated 2025-07-16
This is Ciro Santilli's favorite laptop brand. He's been on it since the early 2010's after he saw his then-girlfriend-later-wife using it.
Ciro doesn't know how to explain it, but ThinkPads just feel... right. The screen, the keyboard, the lid, the touchpad are all exactly what Ciro likes.
The only problem with ThinkPad is that it is owned by Lenovo which is a Chinese company, and that makes Ciro feel bad. But he likes it too much to quit... what to do?
Ciro is also reassured to see that in every enterprise he's been so far as of 2020, ThinkPads are very dominant. And the same when you see internal videos from other big tech enterprises, all those nerds are running... Ubuntu on ThinkPads! And the ISS.
Those nerds like their ThinkPads so much, that Ciro has seen some acquaintances with crazy old ThinkPad machines, missing keyboard buttons or the like. They just like their machines that much.
ThinkPads are are also designed for repairability, and it is easy to buy replacement parts, and there are OEM part replacement video tutorials: www.youtube.com/watch?v=vseFzFFz8lY No visible planned obsolescence here! With the caveat that the official online part stores can be shit as mentioned at Section "Lenovo".
The only thing Ciro never understood is the trackpoint: superuser.com/questions/225059/how-to-get-used-of-trackpoint-on-a-thinkpad Why would you use that with such an amazing touchpad? And vimium.
Markua by Ciro Santilli 37 Updated 2025-07-16
In leanpub you write your book in a markdown variant they call Markua, marketed as "markdown for books".
TODO is there a reference implementation that runs locally for HTML output? Or the only reference implementation is closed under leanpub?
Lagrangian density by Ciro Santilli 37 Updated 2025-07-16
When we particles particles, the action is obtained by integrating the Lagrangian over time:
In the case of field however, we can expand the Lagrangian out further, to also integrate over the space coordinates and their derivatives.
Since we are now working with something that gets integrated over space to obtain the total action, much like density would be integrated over space to obtain a total mass, the name "Lagrangian density" is fitting.
E.g. for a 2-dimensional field :
Of course, if we were to write it like that all the time we would go mad, so we can just write a much more condensed vectorized version using the gradient with :
And in the context of special relativity, people condense that even further by adding to the spacetime Four-vector as well, so you don't even need to write that separate pesky .
The main point of talking about the Lagrangian density instead of a Lagrangian for fields is likely that it treats space and time in a more uniform way, which is a basic requirement of special relativity: we have to be able to mix them up somehow to do Lorentz transformations. Notably, this is a key ingredient in a/the formulation of quantum field theory.

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