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Folks, get Siobhan Roberts' book "Genius At Play" to learn more about his life, and about his many other results, in game theory, and his work with Martin Gardner, Elwyn Berlekamp and Richard Guy... Invented notations for polyhedra, worked on octonions and number theory, and even published on free will. As he had to, I must end somewhere, but his work lives on! Farewell!

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John Horton Conway changed the meaning of Life for many of us. He invented surreal numbers, found simple groups - important missing pieces in their classification, wrote a captivating book about quadratic forms, and traded many more cool discoveries for small bits of his hygiene. Thanks to him I'll never forget about the bricks of princeton! I'm sorry that he couldn't live to see the full uncovering of the meaning of the monster group, which will probably take many more decades, if we're lucky.

I don't care about Marxism-Leninism at all, but even if the context tells they mean something about computers I have to look twice if it's about the 'Meta Language' class of typed functional programming languages like Haskell or Ocaml. I like to read about those, and the average quality of posts about Machine Learning is much lower, so I usually don't bother.


Coronacrisis, Iceland's Testing Strategy 

Just wanted to tell @dredmorbius about the following, and the above seems like a nice supplement:

> "Iceland has tested a higher proportion of its citizens for coronavirus than anywhere else in the world. Its found about half of those who tested positive are non-symptomatic"

I have yet to read the linked articles. Thanks for posting, @jeroenpraat, and for boosting, @rysiek

An enjoyable problem (104.B) from the latest Mathematical Gazette: A regular 7-gon is inscribed in the unit circle, with one vertex at (1,0). Find the equations of the two parabolas, symmetric across the x-axis, which pass through the vertices of the heptagon as shown.

I'm quite happy with prometheus + mysqld_exporter and possibly grafana for more convenient graphing. If rrdtool is a tavern, the above stack is a village. If rrdtool is a blacksmith a prometheus stack is a factory. It's multiple generations beyond rrdtool.


If your spacecraft uses fusion or some other nuclear engine, you want as much space as possible between your engine and the crew. Project Orion's designs give a nice idea, and these further have shock absorber thingsies.

The other radiation problem is coming from everywhere, and lots extra from the sun. We don't know about a good way to hold off charged particles, but it's worse with neutrons. Matter shields. Like, lots of water. In all directions around the crew.


Estimating untested infections. Now there's a publication in Nature about an idea I first learned from @ColinTheMathmo.


covid-19, uk, the numbers 

Oh wait, I misread your post. Then 20 is a good guess after all! Ugh.

@ColinTheMathmo @jk

covid-19, uk, the numbers 

Thanks, that sounds more reasonable than the 20 days you had guessed (or set as worst case) when you first published your ansatz. And thanks for that, I find it much convincing than the mere number of positive test results. It's quite difficult to get tested here in Germany, and you have to pay for it (I heard it's 300€ per test), unless you get hospitalized. That's why I don't trust the official figures at all!

@ColinTheMathmo @jk

covid-19, uk, the numbers 

I'd also not worry about cumulative deaths being too high, because you might only want the number of deaths today. Reasoning is this: The number of deaths is a proxy for the number of people infected, it should grow exponentially with the same rate. So it should be dominanted by the more recent future. Maybe we can also say that for any death too long ago we shojld expect there to be more infections to replace it.

@jk @ColinTheMathmo

covid-19, uk, the numbers 

I don't know much about the time from infection to fatality, if anyone has a reference I'd appreciate to hear about it. I think 2% fatalities are a reasonable upper bound. The rest can be inferred from public data, I'd not be too worried that they're off by much. Unless the gov lies a lot about fatalities or positive results, or something really strange is happening with the amount of testing.

@jk @ColinTheMathmo

covid-19, uk, the numbers 

@ColinTheMathmo suggested to estimate the number of infections during exponential growth like so:

num_of_deaths_reported / proportion_of_fatal_cases * daily_infection_growth_rate ^ days_from_infection_to_death

Last time I estimated the growth rate for Germany it was about 1.36. Lower fatality proportion gives higher end result. Time from infection to death is the most significant number.


Thank you, @efz1005!

That's quite a powerful operation, and unlike anything I know from type-safe languages. And I tried to guess what it does %-)


'Chaotic neutral', maybe, but most certainly 'while hallucinating'.


ST:Disco Season 1 

At the time I told everybody who cared to listen to watch The Orville instead. And it really is much closer to TNG in spirit. But now that there is Picard I switched to suggest that instead. It's more wild than TNG, but has preserved a noticeable amount of the original spirit, mostly due to Picard reflecting about what he's doing. I really like the fan moments they've put in, and the characters from the original have developed in a convincing way!


Ansible is... weird? In spite of that it's still much better than anything else I've looked at. By quite a margin. Enjoy!


*Programming in 2D text*

This evening I'm thinking of two ideas I've thought about several times before, but never together.

The first: Arjun Nair's, an esoteric language (art for art's sake) that comes with a cool visualizer. Maybe all languages should.

The second is Dave Ackley's, a tiled processor for very finely grained distributed computation. Programming it is like playing with a cellular automaton.

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