# Mathematics

It's been a decades-long experiment to throw darts at a dartboard and see if it outperforms the picks of experts. Darts win and lose at the same rate as the average of experts.

Some people clearly make money in financial markets but the old saying among brokers = 'we make money selling stocks, not buying them' - still applies.

Yet someone must know what they are doing. And backtesting is a good way to seem empirical. Example: Your financial advisor calls you up to suggest a new

investment scheme. Drawing on 20 years of data, he has set his

computer to work on this question: If you had invested according to

this scheme in the past, which portfolio would have been the best?

His model assembles thousands of such simulated portfolios and

Mathematicians are not created equally. Some people are just better at it, just like Usain Bolt runs faster than, well, everyone.

But a new psychology paper says that some people may be at greater risk to *fear *math, not only because of negative experiences but also because of genetic risks related to both general anxiety and math skills.

But I have never understood why anyone buys a medium pizza, much less a small. If you understand what a circle is, and you understand what a dollar is, it makes no sense.

First, the dollar. The economics should be obvious; like buying any food in bulk, you can see there are fixed costs. A small pizza or a large has someone making it, it has an oven in a shop. Those costs are fixed regardless of which pizza you get. The actual ingredient differences between a small and a large are not a big cost.

They just can't be sure, because it is too big for a human to replicate.The resulting proof generated is an enormous 13 gigabytes, 30 percent larger than downloading all of the content on Wikipedia.

There is a reason some schools on the coast of California only have a 25 percent vaccination rate. Not 25 percent exemption, 25 percent vaccination. In California overall, exemptions rates rose by 25 percent just between 2008 and 2010 and that trend has been mirrored in states like Washington and Oregon.

The recent rash in anti-vaccination hysteria can be mathematically modeled, say scholars from the University of Guelph and the University of Waterloo.

Stock price movements are predictable during short windows, according to a paper written by academics in the Tippie College of Business at the University of Iowa.

They write that price movements can be predicted with a better than 50-50 accuracy for anywhere up to one minute after the stock leaves the confines of its bid-ask spread. Probabilities continue to be significant until about five minutes after it leaves the spread. By 30 minutes, the predictability window has closed.

*An infinite number of mathematicians walk into a bar. The first mathematician orders a beer. The second orders two beers. The next orders four. Followed by the next who orders eight. The bartender interrupts them: "ok guys, cut the crap: you owe me one beer".*

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A recently posted Numberphile video is heading towards 2 million hits on YouTube. That is an impressive score for a video focusing on a math subject. The two physicists in the video try to convince the viewer that all positive integers add up to -1/12. Yes, you read that correctly: these damn physicists dare to argue that 1 + 2 + 3 + 4 + ... = -1/12.

The difference between 1 and 2 and 101 and 102 is the same, yet children perceive 1 and 2 as being much farther apart, because two is twice as much as one.

It takes years of education to recognize that the numbers in both sets are only one integer apart on a number line. But a new paper shows that different is not necessarily weaker and educated adults retain traces of their childhood number sense — and that innate ability is more powerful than recognized.