Ciro Santilli @cirosantilli 37

Often used as a synonym for X-ray crystallography, or to refer more specifically to the diffraction part of the experiment (exluding therefore sample preparation and data processing).

We've come across a few shallow and stylistically similar websites on suspicious ranges with this pattern.

No JS/JAR/SWF comms, but rather a subdomain, and an HTTPS page with .cgi extension that leads to a login page. Some names seen for this subdomain:

The question is, is this part of some legitimate tooling that created such patterns? And if so which? Or are they actual hits with a new comms mechanism not previously seen?

The fact that:suggests to Ciro that they are an actual hit.

In particular, the secure and ssl ones are overused, and together with some heuristics allowed us to find our first two non Reuters ranges! Section "secure subdomain search on 2013 DNS Census"

Some currently known URLsIf we could do a crawl search for secure.*com/cgi-bin/*.cgi that might be a good enough fingerprint, maybe even *.*com/cgi-bin/*.cgi. Edit: it is not perfect, but we kind of did it: Section "secure subdomain search on 2013 DNS Census".

eigenvalue problem of Laplace's equation.

The impact of the work is greater when you examine what one single new technology would do to existing society, as in Primer (2004), rather than "start on a society with severl new technologies", like in Star Wars.

Later on, we've also come across some stylistic hits in IP ranges with apparent slight variations of the CGI comms pattern:Since these are so rare, it is still a bit hard to classify them for sure, but they are of great interest no doubt, as as we start to notice these patterns more tend to come if it is a thing.

TODO confirm, see also: coupled oscillators. And then this idea can be used to define/motivate quantum field theory in terms of quantum harmonic oscillators with second quantization.

web.archive.org/web/20200621205928/https://courses.maths.ox.ac.uk/node/view_material/1720 also mentioned at math.stackexchange.com/questions/579453/real-world-application-of-fourier-series/3729366#3729366 from heat equation solution with Fourier series.

Or is real word data necessary, e.g. with robots?

Fundamental question related to Ciro's 2D reinforcement learning games.

Bibliography:

Cool dude. Uses Stack Exchange: physics.stackexchange.com/users/31790/danielsank

Started at Google Quantum AI in 2014.

Has his LaTeX notes at: github.com/DanielSank/theory. One day he will convert to OurBigBook.com. Interesting to see that he is able to continue his notes despite being at Google.

Existence and uniqueness results are fundamental in mathematics because we often define objects by their properties, and then start calling them "the object", which is fantastically convenient.

But calling something "the object" only makes sense if there exists exactly one, and only one, object that satisfies the properties.

One particular context where these come up very explicitly is in solutions to differential equations, e.g. existence and uniqueness of solutions of partial differential equations.

web.archive.org/web/20120414075927/http://blogs.discovermagazine.com/cosmicvariance/2011/03/30/how-to-get-tenure-at-a-major-research-university/