Kyoto medal Updated +Created
Microwave source Updated +Created
Microwave only found applications into the 1940s and 1950s, much later than radio, because good enough sources were harder to develop.
One notable development was the cavity magnetron in 1940, which was the basis for the original radar systems of World War II.
Military-industrial complex Updated +Created
This is notably what the United States emerged to be after World War II. But it was likely what Nazi Germany also was, and many other superpowers.
Ciro Santilli feels that much more relevant would be to also include academia as in "military-industrial-academic" complex, the Wikipedia page actually mentions precedents to this idea.
The addition of congress/politicians is also relevant.
But hey, the name wouldn't sound so slick with three parts.
It is basically in this context that American science and technology flourished after World War II, including notably the development of quantum electrodynamics, Richard Feynman being a prototypical example, having previously worked on the Manhattan Project.
Europe Updated +Created
For the most part, a great pseudo-country to live in with lots of cultural diversity, art and safety.
However, Europe is in economic decline after all its Jewish and German geniuses fled in/after World War II and due to having more than one natural language is bad for the world.
Web portal Updated +Created
CIA 2010 covert communication websites / Wayback Machine crawl date search Updated +Created
Many hits appear to happen on the same days, and per-day data does exist: archive.org/details/widecrawl but apparently cannot be publicly downloaded unfortunately. But maybe there's another way? TODO select candidates.
Computer science course of the University of Oxford variant Updated +Created
Euclidean algorithm Updated +Created
Greatest common divisor Updated +Created
The "greatest common divisor" of two integers and , denoted is the largest natural number that divides both of the integers.
For example, is 4, because:
  • 4 divides both 8 and 12
  • and this is not the case for any number larger than 4. E.g.:
    • 5 divides neither one
    • 6 divides 12
    • 7 divides neither
    • 8 divides only 8
    and so on.
Ciro Santilli's undergrad studies at the University of São Paulo Updated +Created
The University of São Paulo had been elected the best South American university in the Times Ranking 2013 (archive) in all subjects.
Ciro finished the course with honors of "The Best Student in Automation and Control of the year 2013".
Ciro didn´t learn basically any control engineering however unfortunately. He did only the 3 base years of the electrical engineering course, and the rest got lost on stupid politics of having to go back to do 6 months from France to validate his Brazilian degree, see also: Section "Don't force international exchange students to come back early".
Mineral Updated +Created
Minkowski inner product matrix Updated +Created
Since that is a symmetric bilinear form, the associated matrix is a symmetric matrix.
By default, we will use the time negative representation unless stated otherwise:
but another equivalent one is to use a time positive representation:
The matrix is typically denoted by the Greek letter eta.
Minkowski space Updated +Created
with a weird dot product-like operation called the Minkowski inner product.
Because the Minkowski inner product product is not positive definite, the norm induced by an inner product is a norm, and the space is not a metric space strictly speaking.
The name given to this type of space is a pseudometric space.
Mitochondria have DNA because they need to be controlled individually Updated +Created
Basically, energy supply has to be modulated rather quickly, because we spend a lot sometimes, and very little other times.
Even not turning it off quickly enough is a problem, as it starts to generate free radicals which fuck you up.
If control came from the nucleus, it has no way to address different mitochondria. But it might be that only one of the mitochondria needs the change. If the nucleus tells all mitochondria to stop producing when only one is full, the others are going to say: "nope, I'm not full, continue producing!" and the one that need to stop will have its signal overridden by the others.
Parallel light Updated +Created
Often just called collimated light due to the collimator being the main procedure to obtain it.
However, you move very far away from the source, e.g. the Sun, you also get essentially parallel light.
MNIST database Updated +Created
70,000 28x28 grayscale (1 byte per pixel) images of hand-written digits 0-9, i.e. 10 categories. 60k are considered training data, 10k are considered for test data.
Playing with it is the de-facto computer vision hello world.
It was on this dataset that Yann LeCun made great progress with the LeNet model. Running LeNet on MNIST has to be the most classic computer vision thing ever. See e.g. activatedgeek/LeNet-5 for a minimal and modern PyTorch educational implementation.
But it is important to note that as of the 2010's, the benchmark had become too easy for many applications. It is perhaps fair to say that the next big dataset revolution of the same importance was with ImageNet.
The dataset could be downloaded from yann.lecun.com/exdb/mnist/ but as of March 2025 it was down and seems to have broken from time to time randomly, so Wayback Machine to the rescue:
wget \
 https://web.archive.org/web/20120828222752/http://yann.lecun.com/exdb/mnist/train-images-idx3-ubyte.gz \
 https://web.archive.org/web/20120828182504/http://yann.lecun.com/exdb/mnist/train-labels-idx1-ubyte.gz \
 https://web.archive.org/web/20240323235739/http://yann.lecun.com/exdb/mnist/t10k-images-idx3-ubyte.gz \
 https://web.archive.org/web/20240328174015/http://yann.lecun.com/exdb/mnist/t10k-labels-idx1-ubyte.gz
but doing so is kind of pointless as both files use some crazy single-file custom binary format to store all images and labels. OMG!
Monstrous moonshine Updated +Created
Moving magnet and conductor problem Updated +Created
This is a well known though experiment, which Richard Feynman used to emphasize
In the above experiment:
  • from the wire frame, the charge feels electromagnetic force, because it is moving and there is a magnetic field
  • from the single charge frame, there is still magnetic field (positive charges are moving), but the body itself is not moving, so there is no force!
The solution to this problem is length contraction: the positive charges are length contracted and the moving electrons aren't, and therefore they are denser and therefore there is an effective charge from that frame.
The Godfather Part III (1990) Updated +Created
This film is an abomination and disgrace to the bilogy.
Transmon Updated +Created
Used e.g. in the Sycamore processor.
The most basic type of transmon is in Ciro's ASCII art circuit diagram notation, an LC circuit e.g. as mentioned at youtu.be/cb_f9KpYipk?t=180 from Video "The transmon qubit by Leo Di Carlo (2018)":
+----------+
| Island 1 |
+----------+
   |   |
   X   C
   |   |
+----------+
| Island 2 |
+----------+
youtu.be/eZJjQGu85Ps?t=2443 from Video "Superconducting Qubits I Part 1 by Zlatko Minev (2020)" describes a (possibly simplified) physical model of it, as two superconducting metal islands linked up by a Josephson junction marked as X in the diagram as per-Ciro's ASCII art circuit diagram notation:
+-------+       +-------+
|       |       |       |
| Q_1() |---X---| Q_2() |
|       |       |       |
+-------+       +-------+
The circuit is then analogous to a LC circuit, with the islands being the capacitor. The Josephson junction functions as a non-linear inductor.
Others define it with a SQUID device instead: youtu.be/cb_f9KpYipk?t=328 from Video "The transmon qubit by Leo Di Carlo (2018)". He mentions that this allows tuning the inductive element without creating a new device.
Video 2.
Calibration of Transmon Superconducting Qubits by Stefan Titus (2021)
Source. Possibly this Keysight which would make sense.

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