Uncertainty of Our Existence
Barclays, the UK bank, is to replace the password system on its phone banking service with personal voice recognition. “Unlike a password,” avers Steven Cooper, Barclays’ head of personal banking, “each person’s voice is as unique as a fingerprint.” Yet the reality is we have no idea whether either fingerprints or voices are unique at all.
If you buy a ticket for the lottery, the chances of winning the big prize are about 14m to 1. You might therefore be justified in regarding that as evidence that you are unlikely to win, and not buy a ticket as a result. Yet after the draw is made and Ms X of Glasgow is announced in the newspapers as the winner, the known unlikelihood of winning is obviously not evidence that she did not win. She did win. Unlikely things do happen.
Notorious case of Sally Clark, an English solicitor, for the alleged murder of her two babies illustrates well the problem. The case against her turned on the evidence of an expert witness, Sir Roy Meadow, who argued that it was highly improbable that two of her babies could have been the victim of natural cot deaths. Sally was exonerated by an appeals court after serving three years in prison, but died four years later. Her family said in a statement that she had never recovered from the miscarriage of justice. Expert opinion of Meadow was proved wrong in relying on the statistical improbability. It is like a meteor when it sets going we may, by assessing the available data and past history predict a doomsday scenario. But suppose along the way the larger mass of Jupiter which is at that precise moment throwing up -Aurora flares up on Jupiter is caused by volcanic moon Io*, and its path veers off one millionth of a hair width? Over the wide expanse between the earth and Jupiter the meteor would have strayed so farther off from the earth. In short statistical probabilities are never 100% correct.
The way forward
What do these insights mean in practical terms? People might well argue that even with our limited sampling of human voices, we have good reason to suspect we are very unlikely to come across two different people who have identical voices, even if we could never discount the possibility. Fine. Let us say that.
Human voice patterns or iris recognition need not be assumed to be unique to be useful tools for protecting private access to our bank accounts. In the same way, fingerprints need not be assumed to be unique to be useful in courts.
*Starting in January 2014, a telescope aboard the Japan Aerospace Exploration Agency’s Hisaki satellite focused on Jupiter for two months. At the same time, NASA’s Hubble Space Telescope also focused on Jupiter for an hour each day for two weeks. Both observatories recorded random brightenings of the giant planet’s polar auroras.
These flare-ups occurred on days when the sun’s usual flow of charged particles was relatively weak. So the researchers conclude that they must be the result of the complex interactions between Jupiter and Io, and perhaps the other three Galilean moons of Jupiter — Callisto, Ganymede and Europa. (These four satellites were discovered by Italian astronomer Galileo Galilei in 1610.)
Io, Jupiter’s closest moon, gets “caught in this gravitational tug of war between Jupiter and the two other large moons, Europa and Ganymede,” study co-author Andrew Steffl, from the Southwest Research Institute in Boulder, Colorado, told Space.com. “It gets squished and squashed,” which drives internal heat just like if you bend a paper clip back and forth in your hands.
This process, in turn, drives a series of active volcanoes on Io. And when those volcanoes erupt, they blast large amounts of electrons and electrically charged atoms into space.
Jupiter’s magnetic field catches these charged particles as it sweeps past Io and “forms a donut-shaped region of relatively high-density plasma around Jupiter,” said co-author John Clarke from Boston University. This so-called magnetosphere is so large that it encapsulates all of Jupiter’s 60-plus known moons and extends nearly as far as Saturn.
(ack: The Conversation-Is every human voice and fingerprint really unique?/Aug.11- Hugh McLachlan
Professor of Applied Philosophy, Glasgow Caledonian University