2014 December 10

originally posted on facebook

“If Obama had written”moveForward(“three steps”);“, the program would have failed, offering only a cryptic error message and exposing the president to the near-perpetual state of frustration most software developers live in.”

https://qz.com/308904/heres-the-first-line-of-code-ever-written-by-a-us-president/

2014 December 02

originally posted on facebook

It seems clear in retrospect, but apparently the limiting factor that determines the size of the outer solar system is tidal effects due to the Milky Way. It turns out we can calculate the upper limit of the size of the solar system (that is, the distance to the L1 point of the sun and the Milky Way) knowing only the mass of the sun and the galactic year:

\text{distance} = \sqrt[3]{\frac {G M T^2} {12\pi^2}} \approx 260\,000 \text{ AU}.

Wikipedia

An interesting article on the oldest known star:

Wikipedia

2014 November 13

originally posted on facebook

“Mr. Obama announced that the United States would emit 26 percent to 28 percent less carbon in 2025 than it did in 2005. […] China’s pledge to reach peak carbon emissions by 2030, if not sooner, is even more remarkable.”

NYT

This is great as a stepping stone towards future agreements for real reductions, as it shows that actual international agreement among major players is possible, but the limits placed on China are far from enough, as this graph shows:

NYT

In any case it is clear that China’s larger motive is the need to reduce coal burning due to the severe health impacts, and any reductions in CO2 emissions are largely a nice side effect.

2014 October 07

originally posted on facebook

The Nobel Prize in medicine was awarded yesterday to those who discovered, in 2005, the existence of “grid cells” in the brain. These cells help animals keep track of their position in space… using a regular hexagonal grid.

NYT

Wikipedia

2014 September 23

originally posted on facebook

So I’ve learned that rogue planets have actually been discovered (2 to 7 of them, the first confirmed in 2013). All of them are very large (sub-brown dwarfs) and young, and so warm enough to be seen directly (usually in infrared); discovering an earth-sized rogue planet would be far harder. Estimates of the number of rogue planets in the galaxy vary from 2 to 100000 per star.

Wikipedia

2014 September 21

originally posted on facebook

NYT

The Atlantic

2014 September 06

originally posted on facebook

The Minamata Convention, if it takes effect (which it looks like it will), would (among other provisions) ban all mining of mercury almost world-wide around 2020. So I guess mercury recycling is going to become a thing? “3. Each Party shall not allow primary mercury mining that was not being conducted within its territory at the date of entry into force of the Convention for it. 4. Each Party shall only allow primary mercury mining that was being conducted within its territory at the date of entry into force of the Convention for it for a period of up to fifteen years after that date.”

Incidentally, one of the provisions of the convention can be fulfilled by “Setting national objectives aiming at dental caries prevention and health promotion, thereby minimizing the need for dental restoration”.

Wikipedia

2014 August 10

originally posted on facebook

Japan’s anti-nuclear hysteria seems a lot less hysterical now that I’ve read a bit about Japan’s rather spotty nuclear safety record and history of government cover-ups. Global accidents in the last two decades include two lethal accidents in Japan, one uncontrolled criticality in Japan, and four comparatively minor radioactive materials leaks in other countries.

Wikipedia

Not included on that list is a steam explosion at a Japanese nuclear plant killing 5 in 2004, and a variety of lesser events.

Wikipedia

Fortunately the anti-nuclear movement in Japan has led to a very strong push for renewables there, including solar and wind. Unfortunately this movement has spread somewhat to Germany and Switzerland, which have been replacing nuclear with fossil fuels.

The US, incidentally, has had (at least?) 9 fatalities at nuclear reactors; 3 in a steam explosion (1961), 1 radiation exposure (1964), 4 electrocutions (1971, 1980, 1987, 1988), and 1 falling object (2013).

Wikipedia

In 1945, Albert Stevens had terminal cancer and was injected with a lethal dose of plutonium as part of a government experiment. He ended up living 20 more years, thus being exposed to the highest radiation dose of any person, without ever learning that he had been injected with plutonium or that the cancer was a misdiagnosed ulcer.

“None of the people at UCSF or those who treated Stevens ever explained to Stevens that he did not have cancer, nor did they disclose to him that he was a part of an experiment; his wife and daughter”figured they were using him for a guinea pig," but that the experimental treatment had worked."

Wikipedia

2014 July 28

originally posted on facebook

Apparently there is no road link between North and South America. The first time anyone drove between the two continents was in 1987, taking more than two years at the rate of 1 mile per week. It had previously been done in 1973 by bicycle.

Wikipedia

Around 1690-1700, Scotland invested a fifth of the wealth of the whole country into colonizing that location in Panama, the disastrous results thereof leading to the political union with England in 1707.

Wikipedia

2014 June 23

originally posted on facebook

In comparison to other sources of energy, nuclear power may as well be magic, and it baffles me that many environmentalists continue to oppose it. Here is an open letter from four leading climate scientists calling on environmental groups to adopt pro-nuclear policies:

NYT

And, here is an ill-reasoned rebuttal that could be summarized “Fukushima was bad” by four Japanese researchers working on climate change policy:

http://www.cneas.tohoku.ac.jp/labs/china/asuka/_src/2014/nuclear_power-climate_change_enver2.pdf

2014 May 25

originally posted on facebook

“NextGen Climate will spend about $100 million this year to influence several Senate and governor’s races in which climate change could play a major role.”

NYT

A detailed and informative article: “What is remarkable is that Munich Re first warned about global warming way back in 1973, when it noticed that flood damage was increasing. It was the first big company to do so”

https://www.theglobeandmail.com/report-on-business/rob-magazine/an-industry-that-has-woken-up-to-climate-change-no-deniers-at-global-resinsurance-giant/article15635331/?page=all

2014 May 17

originally posted on facebook

Apparently North Korea has its own OS.

Wikipedia

Also, for only $68 you can purchase an SD card with 32 GB of storage, a wireless connection, and runs a webserver on linux. (And is full of security holes.) Next thing I bet they’ll make an SD card with built-in camera.

http://haxit.blogspot.com/2013/08/hacking-transcend-wifi-sd-cards.html

If a CPU cycle is one second, then accessing L1 cache is 3 seconds and accessing the disk takes 1 to 12 months.

https://blog.codinghorror.com/the-infinite-space-between-words/

2014 May 09

originally posted on facebook

I wasn’t expecting Flight of the Bumblebee performed on the organ to mean the feet… (see inset). Also, the oldest documented permanent organ installation was in 1361, with three manuals and a pedalboard, and it “had twenty bellows operated by ten men, and the wind pressure was so high that the player had to use the full strength of his arm to hold down a key.”.

Wikipedia

2014 March 30

originally posted on facebook

http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.html

2014 March 28

originally posted on facebook

“Russian Elections: An Oxymoron of Democracy”

https://www.ucis.pitt.edu/nceeer/2008_822-11_Ordeshook.pdf

The pdf link below has been doing the rounds, and Figure 1 gives a very nice visualization that makes fraud apparent at a glance. However the methodology is not as novel nor sophisticated as the shiny figures suggest, and I would recommend instead the link above to Ordeshook’s more insightful and more snarky article.

PNAS

Or, there’s this:

Wikipedia

2014 March 21

originally posted on facebook

After having heard the news that some hundreds of migrant construction workers are believed to have died in Qatar in preparations for the 2022 world cup, I learned that the consultants hired by FIFA to analyze the bids ranked Qatar last out of those countries bidding for 2022. (They also ranked Russia, the 2018 host, last out of the 2018 bidders.) One concern is that Qatar plans to build an airport, 4 cities, and 9 stadiums (using cooling technology that does not exist yet) by 2022 to meet minimum requirements for hosting. Below are two tables from the consultants’ report.

Some of the individuals who voted for Qatar allegedly walked away with over a million dollars in bribes.

2014 February 27

originally posted on facebook

“A space in the indiscrete topology is like an enormous room. Everyone is lumped together, and nobody is housed off. In fact, the indiscrete topology is the most un-housed-off topology there is.” -Mathematics Made Difficult

2014 February 24

originally posted on facebook

“parent Jennifer Reynolds said she sees the computers as […] part of a move to have students ‘indoctrinated of the concepts of global warming, evolution, defaming the Founders.’”

https://tucson.com/news/local/education/arizona-senate-panel-votes-to-dump-common-core/article_512d157d-054f-5bc0-8a29-2076f69cc35a.html

State senator Al Melvin “said the program uses ‘fuzzy math,’ substituting letters for numbers in some examples.”

“you can’t spell ‘crazy’ without ‘R-AZ’”

http://www.goodmath.org/blog/?p=2882

2014 February 13

originally posted on facebook

Mathematics made difficult: A handbook for the perplexed

http://i7-dungeon.sourceforge.net/math_hard.pdf

“Are any two numbers comparable? Objection. The kinds of comparison - the absolute, comparative, and superlative - are called degrees. Hence the question refers to the numbers of degrees used in recording temperatures. But if the temperature exceeds a certain level, mathematics is impossible, since mathematicians require pencils and paper and these would ignite. Hence only small numbers are comparable to other numbers. Reply. A mathematician can deal with arbitrarily large temperatures under the most comfortable working conditions, simply by inventing new scales for a measurement of temperature. This is done by means of a ‘scaling factor’ which converts one degree into as many degrees as one likes in the new scale.”

This is also the only math textbook I’ve seen that references Borges. And that teaches how to count and add having presumed proficiency in category theory.

“Simplicity is relative. To the great majority of mankind it is a simple fact that, for instance, 17 x 17 = 289, and a complicated one that in a principal ideal ring a finite subset of a set E suffices to generate the ideal generated by E. For the reader and a select few, the reverse is the case. One needs to be reminded of this fact especially as it applies to mathematics. Thus, the title of this book might equally well have been Mathematics Made Simple; whereas most books with that title might equally well have been called Mathematics Made Complicated.”

2014 January 26

originally posted on facebook

Wikipedia

2014 January 13

originally posted on facebook

“In 1952, the logician Leon Henkin flipped Gödel’s idea around and asked about a sentence in the language of arithmetic that says: ‘This sentence is provable.’ He asked: is this provable or not? The answer is much less obvious than for Gödel’s sentence.”

https://johncarlosbaez.wordpress.com/2013/12/26/logic-probability-and-reflection/

“Suppose that you and all your future selves believe their later self’s promise to finish your paper. Then you just refer the paper to your future self, who refers it to their future self, and so on indefinitely. All of you believe the paper will eventually get done, but there is no finite time at which the paper gets written. We call this the Procrastination Paradox.” In the example they consider, each future self believes that the paper will get written some nonstandard (i.e. infinite) integer number of iterations in the future.

https://intelligence.org/files/ProcrastinationParadox.pdf

“Viktor Klee, in a parody of the usual optimistic prophecies people like to make, wrote that: ‘…progress on this question, which has been painfully slow in the past, may be even more painfully slow in the future.’”

https://johncarlosbaez.wordpress.com/2013/12/08/lebesgues-universal-covering-problem/

Wikipedia

2014 January 12

originally posted on facebook

Here’s a generalization of a puzzle about logic gates I posted in July, which (if you are one of the roughly two people who solved it) neatly explains how the puzzle works. (The original source I saw for this puzzle claimed further that any boolean function could be computed by a logic circuit using only two not gates, which I now think is unlikely to be true as this article demonstrates a solution requiring O(log(n)) not gates for a function with n inputs, and I think one might easily show that the solution in the article is optimal.)

https://rjlipton.wordpress.com/2014/01/12/details-left-to-the-reader/

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