What goes up

Math is all about patterns. For some reason much of today's news centered around space, gravity, and humanity's inability to control them.

In space since June 8th, the shuttle Atlantis crew of seven has been busy: they installed a new truss segment on the International Space Station with a double-winged solar array, repaired a tear in the shuttle's heat shield, and restarted a critical computer system. But getting back to earth may be the toughest part of all. Even assuming the insulation blanket repair job was a success, bad weather may delay their return, pitting them in a race against time before the shuttle batteries exhaust their hydrogen fuel.

I hope their return to Earth is more successful than the Columbia, South Carolina couple whose rooftop love-making was rudely interrupted by gravity as they plunged stark naked 50 feet to their death. In another bizarre rooftop story, a West Philadelphia man was found dead at 49th and Spruce after an all night party. Across the pond, reports of suicide attempts jumped when artist Antony Gormley placed 31 life-sized replicas of his own naked body on central London rooftops.

Meanwhile, United Airlines passengers couldn't even get up in the air yesterday, as the airline's computers crashed and were unable to calculate weight and balance, an FAA requirement for flight. Pilots who fly small planes will tell you the three most useless things in the world are runway behind you, altitude above you, and fuel still in the truck. At least the United Airlines passengers did not have any of those worries. But passengers on an incoming trans-Atlantic Continental Airlines flight did have to cope with overflowing sewage. Now that’s an immigration problem! Not even the stock market could stay in the air: the Dow lost 146 points yesterday.

But staying on the ground may be no safer. New lava flows on Mt. Kilauea began oozing - that's the technical word the scientists used, they might have borrowed it from the Continental Airlines PR department - after hundreds of small earthquakes last Sunday.

I’m hoping this is one pattern that won’t last and maybe things will stay put a little better than they did yesterday.

The probabilities of shuttle launches

Running the numbers, NASA cleared the Shuttle Atlantis for launch tomorrow, subject to weather and unexpected delays of course. But the same facts told different ways tell different stories. For example, forecasters predict favorable weather with 70% probability, as there is a 30% chance of thunderstorms. These two pieces of information fit together well but paint very different pictures in one’s mind. Seventy percent favorable weather? A sunny day with some puffy clouds. Thirty percent thunderstorms? Quick, get indoors to avoid getting hit by lightning or hail!

Twenty-one years ago, on January 28, 1986, the Shuttle Challenger exploded just seventy-three seconds after takeoff, killing the entire crew. Subsequent analysis showed that when making their launch decision, Morton Thiokol and NASA engineers looked at the right numbers but came up with the wrong story. The engineers correctly chose to analyze a scatter diagram of O-ring failure frequencies by temperature. But their analysis was flawed: They performed a regression test on the data and found no statistical basis for unacceptable O-ring failure rates at 29 degrees Fahrenheit, the expected O-ring temperature at launch. If they instead had looked at the Bayesian probability of O-ring failure below 59 degrees, they would have realized there had been a 100% O-ring failure rate in past flights and thus would have decided not to launch.

Math is more than just the numbers. And a shuttle launch is more than just another flight. A lot is riding on it. I just hope that NASA has both its numbers and its stories right tomorrow.