Long-time reader Randy Brich reminds us all to head over to Edge.org and read the responses to the 2011 World Question given in the title. It will be worth your time to do so.
Before discussing the responses, here is my own in brief: be less certain. Regular readers will understand immediately what I mean.
This is echoed by Howard “Multiple Intelligences” Gardner who quotes a question Karl Popper would have scientists asks themselves: “How Would You Disprove Your Viewpoint?!” (Too bad Popper never put this to himself about falsifiability.) Gardner says, “a sizeable minority are skeptical about global warming — or more precisely, the human contributions to global change — because efforts to counter climate change would tamper with the ‘free market’.” An excellent point: too many skeptics (mainly non-scientist internet denizens) let the consequences, or rather politics, of global warming influence their estimation of the truth of the theory. The two questions are logically independent: knowledge of one gives no information about the other.
But Gardner forgets that a “sizeable” majority buy every instance of “It’s worse than we thought!” for the exact opposite political, or, better said, theological reasons. The over-certainty in this field is like a raging fever that only a thorough dunking in ice water could cool off.
John Allen Paulos (Innumeracy) gets it right by noting that “most numerical assessments are not point estimates. Rather they are rough distributions”. My own field—whose very purpose is to quantify uncertainty probabilistically—lets us down in this respect thanks to p-values and hypothesis testing, two methods which guarantee over-certainty by reducing all decisions to points.
Reading some of these, it occurs that anthropology is that field of study in which a professor looks to other cultures to confirm political prejudices of his own.
W. Daniel Hills requotes Sherlock Holmes, “Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.” This is true. But left unsaid is that most things are not impossible—which is the strictest possible criterion—they are merely unlikely. Holmes was a better statistician than probabilist.
The “multiverse”, i.e. that (necessary?) concoction of modern physics takes a beating by psychologist Nicholas Humphrey, who has figured that “we” will live forever simply because in some universe in the multiverse one copy of us does so. To those physicists who are reading: see what you have done?
“The world is unpredictable” says computer scientist Rudy Rucker. But this is a technical statement and Rucker treats it as such. His answer is worth quoting at length:
To predict an event is to know a shortcut for foreseeing the outcome in advance. A simple counting argument shows there aren’t enough shortcuts to go around. Therefore most processes aren’t predictable. A deeper argument plays on the fact that, if you could predict your actions, you could deliberately violate your predictions which means the predictions were wrong after all.
We often suppose that unpredictability is caused by random inputs from higher spirits or from low-down quantum foam. But chaos theory and computer science tell us that non-random systems produce surprises on their own. The unexpected tornado, the cartoon safe that lands on Uncle George, the winning pull on a slot machine odd things pop out of a computation. The world can simultaneously be deterministic and unpredictable.
In the physical world, the only way to learn tomorrow’s weather in detail is to wait twenty-four hours and see even if nothing is random at all. The universe is computing tomorrow’s weather as rapidly and as efficiently as possible any smaller model is inaccurate, and the smallest error is amplified into large effects.
What Rucker says is true but incomplete. Take weather forecasts for tomorrow, which most agree are damn useful, meaning that we do a reasonable job saying what the weather will be. But Rucker’s weather is not a meteorologist’s. The real weather tomorrow at, say, noon eastern standard time is the state of every sub-atomic particle from at least the first few meters of the Earth’s crust, extending all the way to the sun. The weather of the meteorologist is a suitable average of these states in space and in time.
Rucker is right in saying that the real weather cannot be predicted, but the meteorologist’s weather can be, at least in some approximate sense. The magic occurs in defining just what “the weather”—or “the climate”—is.
Charles Seife (Proofiness) has some odd, and incorrect, views of randomness. But his heart is in the right place, in that he agrees with our dictum: be less certain.
There are many more, but that’s enough today.