Welcome to the site that tries to make sense of chance, risk, luck, uncertainty and probability. Mathematics won't tell us what to do, but we think that understanding the numbers can help us deal with our own uncertainty and allow us to look critically at stories in the media.
It’s all very well telling someone their life expectancy but this does not communicate the variability around that central value. But the life tables published by the Office for National Statistics (ONS) have a convenient column labeled $d_x$ - this is the probability density for survival, expressed as the expected number of deaths at each age out of 10,000 births, assuming the current mortality rates continue.
Sadly another passenger plane crashed yesterday - the third in 8 days, the Air Algerie flight on July 24th, the TransAsia flight in Taiwan on July 23rd, and Malaysian Airlines in Ukraine on July 17th. Does this mean that flying is becoming more dangerous and we should keep off planes? The following analysis may appear cold-hearted, but is not intended to diminish the impact of this tragic loss on the people and families involved.
Since the start of our relationship my partner and I disagreed about the best way to travel the approximately hour long journey between our homes on either side of the peak district. She preferred the well lit M60 and M62 route, feeling that it is considerably safer. I preferred the Woodhead pass, the quicker route which winds its way over the hills, and was after all suggested by Google Maps.
Dominic Lawson's article in the Sunday Times today[paywall] quotes me as having the rather cynical heuristic: "the very fact that a piece of health research appears in the papers indicates that it is nonsense." I stand by this, but after a bit more consideration I would like to suggest a slightly more refined version for dealing with science stories in the news, particularly medical ones.
Yesterday the Daily Mail trumpeted “For every hour of screen time, the risk of family life being disrupted and children having poorer emotional wellbeing may be doubled”, while the Daily Telegraph said that "for every hour each day a child spent in front of a screen, the chance of becoming depressed, anxious or being bullied rose by up to 100 per cent”.