Which air temperature records are valid

Jeff Masters has a detailed analysis of heat records around the world: “Hottest air temperatures reported on Earth.”

Conclusion: Death Valley has the hottest verified records, but much of Africa is not monitored by properly sited instruments.

Mapping can save African forests from logging

Mapping from satellite pictures can warn scientists and governments where illegal logging is taking place in Africa.

Math professor develops better car side-mirror

New mirror above standard mirror

R. Andrew Hicks, a mathematics professor at Drexel University in Philadelphia, has designed a mirror that shows a much wider field of vision and will eliminate the blind spot where side and rear-view mirrors fail to overlap. The mirror covers about 45°, compared to about 16° for the mirrors in use now. See New Side-Mirror.

Train your brain?

This software makes a deliberate attempt to retrain your brain from ADD to more normal functioning, using reminders and practice: Brain Train.

Here’s another company with brain-training exercises.

Data-mining for terrorists doesn’t work

From Ben Goldacre’s Bad Science, 2009: Data-mining for terrorists would be lovely if it worked.

If you have 10 people, and you know that 1 is a suspect, and you assess them all with this test, then you will correctly get your one true positive and – on average – 1 false positive. If you have 100 people, and you know that 1 is a suspect, you will get your one true positive and, on average, 10 false positives. If you’re looking for one suspect among 1000 people, you will get your suspect, and 100 false positives. Once your false positives begin to dwarf your true positives, a positive result from the test becomes pretty unhelpful.

Remember this is a screening tool, for assessing dodgy behaviour, spotting dodgy patterns, in a general population. We are invited to accept that everybody’s data will be surveyed and processed, because MI5 have clever algorithms to identify people who were never previously suspected. There are 60 million people in the UK, with, let’s say, 10,000 true suspects. Using your unrealistically accurate imaginary screening test, you get 6 million false positives. At the same time, of your 10,000 true suspects, you miss 2,000.

This is simply unworkable. But that probably won’t stop governments from spending billions and invading the privacy of all of us trying to do the impossible.

Amazon’s $23-million book

When I see an ordinary book advertised for thousands of dollars, I assume it’s some kind of data error. It never occurred to me that it could be a result of runaway competitive pricing algorithms. But take a look….

NASA’s Grail gravity twins enter moon orbits

Two satellites are going to map the mass profile of the moon.

The first satellite, Grail-A, achieved orbit on Saturday, December 31: “Together, the satellites will make measurements that are expected to give scientists remarkable new insights into the internal structure of the Moon. This new data should clarify ideas about the Moon’s formation and resolve many mysteries, such as why its near and far sides look so different.”

NASA's Grail satellites circling Luna

The second satellite, Grail-B, entered orbit on Sunday, January 1.The two satellites will note tiny differences between the distance between them, caused by variation in gravity as they pass over the surface of the moon. This will enable scientists to calculate variations in the density of the moon’s crust.  This is the first time two satellites have been placed around Luna.

Correlating their distances

You can read more at NASA.

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