I'm Speechless

Primitive Technology

This guy's videos are quite mesmerizing, and his descriptions are quite interesting to read.

Making Charcoal

Building a tiled roof hut

Sling

When U.S. air force discovered the flaw of averages

https://www.thestar.com/news/insight/2016/01/16/when-us-air-force-discovered-the-flaw-of-averages.html

He decided to find out. Using the size data he had gathered from 4,063 pilots, Daniels calculated the average of the 10 physical dimensions believed to be most relevant for design, including height, chest circumference and sleeve length. These formed the dimensions of the “average pilot,” which Daniels generously defined as someone whose measurements were within the middle 30 per cent of the range of values for each dimension. So, for example, even though the precise average height from the data was five foot nine, he defined the height of the “average pilot” as ranging from five-seven to five-11. Next, Daniels compared each individual pilot, one by one, to the average pilot. 

Before he crunched his numbers, the consensus among his fellow air force researchers was that the vast majority of pilots would be within the average range on most dimensions. After all, these pilots had already been pre-selected because they appeared to be average sized. (If you were, say, six foot seven, you would never have been recruited in the first place.) The scientists also expected that a sizable number of pilots would be within the average range on all 10 dimensions. But even Daniels was stunned when he tabulated the actual number.

Zero.

Man Bullies Robot

https://youtu.be/rVlhMGQgDkY?t=85

The Secret Wizard of the Far Right

http://www.gq.com/story/rex-elsass-secret-wizard-of-the-far-right

While you've likely never heard of him, chances are good you know his clients. Name a conservative firebrand and Elsass has likely been on his or her payroll. Ted Cruz, Rand Paul, Michele Bachmann, Newt Gingrich—he's worked with all of them, as well as a slew of Republican agitators who aren't yet household names but are doing everything in their power to change that. Elsass now counts more than 60 members of Congress on his client roster, many of whom belong to the rebellious Freedom Caucus that last fall hounded the Speaker of the House, John Boehner, into early retirement. This year, while most eyes are fixed on the presidential race, he's quietly obsessing over the Republicans' control of Congress, guiding the fortunes of 15 first-time candidates whom he hopes will join his small army already wreaking havoc in Washington.

Not surprisingly, Elsass's electoral success has made for a lucrative business, as the fleet of late-model Mercedes sitting outside his firm's headquarters attests. During the 2014 elections, the Strategy Group grossed more than $150 million—a figure that would be stunning even if the firm was located in the Beltway and not out among the mega-churches and big-box stores of exurban Columbus.

Kids, forget console gaming—play the FBI’s browser-based game instead

http://arstechnica.com/tech-policy/2016/02/kids-forget-console-gaming-play-the-fbis-browser-based-game-instead/

It basically looks like a prequel to the world's first-ever video game. The player uses the left- and right-arrow computer keys to move a running goat to avoid blocks. The blocks apparently represent violent extremists. Hit the block, and the goat explodes.

Nerdwriter1

https://www.youtube.com/user/Nerdwriter1/videos?sort=p&view=0&flow=grid

I've been watching these videos for a while now.  They're interesting discussions of a variety of topics.

How Donald Trump Answers A Question

The Death of Socrates: How To Read A Painting

Seinfeld: What "Nothing" Really Means

Why did crime plummet in the US?

http://www.vox.com/cards/crime-rate-drop/crime-rate

I thought this was a very good compilation of the various proposed reasons for the huge drop in crime in the 90s, and some debate for and against each.

Listen to Wikipedia

http://listen.hatnote.com/

Listen to the sound of Wikipedia's recent changes feed. Bells indicate additions and string plucks indicate subtractions. Pitch changes according to the size of the edit; the larger the edit, the deeper the note. Green circles show edits from unregistered contributors, and purple circles mark edits performed by automated bots. You may see announcements for new users as they join the site, punctuated by a string swell.

Powerball Odds

So there is a lot of Powerball talk, and I am again intrigued by the possibility of a positive expected value for a lottery.  If you remember I wrote a post about Megamillions a few years ago, when the jackpot grew to $640 million.  The result, after taking into account both taxes and multiple winners, was that it still wasn't worth playing.  I decided to quickly do the same thing for this latest Powerball jackpot.

In a separate post, I made a model to predict the ticket sales based on jackpot amount.  This was quite a bit of work, so I'm not doing that here.  I'm just going to use the data for the latest drawing (Jan 9th, 2016) to see if that one drawing had a positive expected value in retrospect.

To begin, the expected value of the non jackpot prizes is $0.32, or about $0.28 if you include tax on the $50,000 and $1,000,000 prizes.  Note here, I'm ignoring the "Power Play" thing, which increases the payout for the nonjackpot prizes, but costs an extra $1.

Now we need to look at the jackpot.  The estimated upfront payout was $587,662,740.  After taxes that's $340,844,389.  The odds for Powerball recently got way harder, which is why this jackpot is so large.  This drawing had 440,321,172 tickets sold.  Doing the Poisson distribution we see the probability of various numbers of winners based on the odds and tickets sold:

0	22.1594%
1	33.3922%
2	25.1595%
3	12.6377%
4	4.7610%
5	1.4349%
6	0.3604%
7	0.0776%
8	0.0146%
9	0.0024%
10	0.0004%
11	0.0001%
12	0.0000%
13	0.0000%
14	0.0000%
15	0.0000%

The odds for no winners (which is what happened) was 22%.  This is due to the much lower odds of a jackpot in general.

Adding up the adjusted jackpot shares gives a total of $176,335,787.  This could be thought of as the true jackpot value after adjusting for taxes and the possibility of splitting the jackpot.  Multiplying by the odds of winning gives an expected value for the jackpot of $0.6035.  Adding the nonjackpot expected value gives a total Powerball expected value of $0.88.  The ticket costs $2, so it's not even half the value.

Some thoughts:  The odds were just increased in Oct 2015, and this is the first huge jackpot after that change.  More will follow, so it is possible that the expected value will improve as people get over the hype of a billion dollar jackpot.  However, it is worth noting that even if the jackpot doubled, and ticket sales remained constant the expected value would still be below the ticket price.


I haven't gone into details for the math here.  The calculations and commentaries are the same as the Megamillions post.  So please see that for more discussion.