hi all, have been interested/ read about/ delved into cybersecurity for many years now, and its at a whitehot pace as far as news developments. its dizzying, inundating, and impossible to keep up. however this is my small )( contribution (aka “lighting a candle in the darkness”) to collecting/ sorting the copious headlines. the big recent news is the massive OPM hack.[a] there is some reporting on this, but americans seem not to be very aware of it. ofc china is big in cybersec news for all the wrong reasons…[j]
other big news is hillary clintons private emails with classified information found in them.[k] and recently the patriot act expired and was replaced with a new law.[b] what will be the implications of that? somewhat like the expression “do as I say, not as I do”, the NSA may do as it does, not as congress/ the prez/ the LAW says….(the Natl Security State/ Military Industrial Complex/ 4th crosscutting shadow branch of govt is, to put it most politely, kinda “evasive/ twisty/ slippery” that way… which reminds me, did you see the latest news on Guantanamo? oh nevermind! …)
EFF is mounting an NSA lawsuit. did you read about that in the MSM?[c]
:idea: :!: this exercise is partly inspired by looking at a mathematica stackexchange post on collatz and the 1st answer by mgamer which looks at seeds in the form pn where p is prime and n ranges over a few hundred.
that graph did not normalize by seed starting (binary) “width”/ size. started looking at something similar and was interested in replicating it and normalizing by width. then decided to look at mn where m is either composite or prime. since there are fewer primes than composites per random range of integers, this code looks at odd primes and adjacent (also odd) composites. the graph is 1st 50 primes/ composites seed width on x axis, glide length on y axis (div2 compressed). the graphs for prime vs composite m (1st, 2nd below) are distinctly different! amplitudes are larger on the 1st and it has a shorter lower “base” of the higher widths. an immediate hypothesis (from prior experiments) is that maybe this difference is explained by starting seed binary density? but thats also hard to imagine at this point.
have long wondered about prime/ composite effects on the collatz dynamics, have poked at this before, but never found anything notable (previously!). need to find better way(s) to visualize this. this form is somewhat rough, “as discovered”, & surely can be sharpened up somehow. for the low/ leftward starting values (the “hotter/ higher” colors, superimposed/ “painted” last), there is major width variation that makes the graph harder to interpret. a better approach is probably to have all the same width. these graph(s) are also hiding a striking short-interval periodicity in the spikes that could be better hilighted somehow also.
hi all. around here, the philosophy is something like, when in doubt, write a new collatz post. recently ran across a few notable collatz items on reddit and stackexchange and this post is to share those along with other misc new research idea(s).
- cohort/ once collaborator randomra came up with his own codegolf collatz generalization challenge and racked up an impressive 13v.[a1]
- a really significant/ beautiful visualization showed up on math reddit by level1807 using a new command Anglepath in mathematica. it basically creates paths offset by a sequence of angles. the visualization also reveals the recurring fractal aspects of collatz, making it look like a feather, plant, or blood vessels! the post got 214v and 39 comments! level1807 put his code on github. the graph is so striking, cannot avoid incl it here! (this version is by halirutan in next item.)[b1] Continue reading
hi all, there was a recent reddit moderator mutiny where they shut down significant sections of the site, in protest over firing of a popular community relation manager.[a] reddit is currently valued at something like $~¼B dollars! its a complicated situation partly related to CEO Pao being just involved in a high-profie, lost lawsuit with Kleiner Perkins over gender discrimination.[b]
this is an area of big implications for the internet, namely collaborative systems, user generated content, and “collective intelligence”. sometimes the so-called wisdom of crowds can quickly turn into cyber mobs/ vigilantes.
user generated content fuels massive billiondollar corporations like Facebook, and even ultimately Google (which was invented basically to index it!); it also has big connections and crosspollinations to open science such as in “open/ public publishing” etc which is another key topic around here.
hi all. recently Backurs/ Indyk just got a paper accepted into STOC 2015 connecting the Strong Exponential Time Hypothesis (“SETH”) with tight bounds on computing edit distance. the latter has many applications across CS and also plays a big role in bioinformatics and computational biology wrt DNA sequences where it relates to natural alterations, ie more specifically “biologically occurring genetic processes”—eg even occuring in our own bodies… and surely cant get more “applied” than that!
there is some buzz/ excitement on this result as this is regarded as something of a breakthrough. it reminds me of the concept of “the microcosm reflects the macrocosm and vice versa” aka/ in short, “as above, so below”. a polynomial time algorithm speed (“the small”) seems to have major implications for speed of NP complete problems wrt exponential time (“the large”) and vice versa.[a]
:star: :arrow: and moreover/ further, near-dramatic connection/ exhibition/ manifestation/ confirmation of an apparent deep/ recurring principle/ theme/ “design pattern” in CS, interconnection/ interdependency of upper and lower bounds. at times upper and lower bounds seems like the yin and yang of TCS… :idea: :o <3