How would science ever progress without anomalies? Theories are useful things, but they are most useful when they’re wrong, when their Newtonian predictions are off, as in the case of the Pioneer space probes, by a hundred-millionths of an inch per second for every second of spaceflight. Robert Lee Hotz has the fascinating story:
Beyond the edge of the solar system, something has gradually dragged two of America’s oldest space probes — Pioneer 10 and Pioneer 11 — a quarter-million miles off course. Astrophysicists have struggled 15 years in vain to identify the infinitesimal force at play. The Pioneer anomaly, as it is called, throws a monkey wrench into celestial mechanics.
Slava Turyshev may have found the answer in NASA’s trash. Reconstructing decades of discarded spacecraft data, the Russian-born astrophysicist and the private space enthusiasts helping him say they believe they are on the verge of solving a mystery of time and gravity that has perplexed a generation of physicists and might have confounded Newton and Einstein.
Bonus fact: Did you know that the moon’s actual orbit is off its calculated course by about six millimeters a year?
This reminds me of one of my favorite philosophy of science papers: “Do the Laws of Physics State the Facts,” by Nancy Cartwright. Her answer, surprisingly, is no:”Not only do the laws of physics have exceptions; unlike biological laws, they are not even true for the most part, or approximately true.”