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“Prediction is very difficult, especially if it’s about the future.” -Niels Bohr
What’s going to happen next? It’s perhaps the most important thing to know if we want to be prepared for practically anything in our lives. And without even thinking about it, most of us are actually very good at this in a huge number of aspects of our lives. For example…
Image credit: Crazy Adventures in Parenting.
I was hungry at work today, and I was prepared for it. Somehow, I knew that I was going to need food throughout the course of the day, and so I was prepared for it by bringing food from home. This is an incredibly mundane prediction, but think about it for a moment: how did I know I was going to be hungry?
In my case, it’s because I’ve been in this situation before: thousands upon thousands of times before, in fact. Every day when I wake up, I get hungry after a certain amount of time. Perhaps today would have been different; perhaps it would have been the first time in many years where I simply wasn’t hungry during the day. But I was so certain I would get hungry that I didn’t even stop to consider the possibility that I wouldn’t; I know from my own past experience that I’d get hungry, and therefore I planned accordingly.
Image credit: Johnny Nichols, 2008.
This is a fabulous example of a pre-scientific prediction! I’ve taken information from very, very similar situations that I’ve experienced before, I know — looking back — how those previous situations turned out, and so I can infer how this current situation is likely to turn out. This is something we do all the time in our lives, and something we’ve done frequently throughout history. The phrase Red Sky at Night, Sailor’s Delight didn’t come about because we understood the science behind the next day’s weather and the properties of the atmosphere the night before, it came about because when we observed phenomenon A (the red sky at night), it was very often followed by phenomenon B (good sailing weather the next day).
We use this all the time in our lives: it’s why we have confidence that the next untested apple we eat will be delicious and not poisonous (even though the occasional apple is poisonous), that our house hasn’t burned down when we go to the store (although sometimes houses do burn down when you’re at the store), and that the store you’re going to will have apples to sell you when you go (even though they’re sometimes out of apples).
Image credit: screenshot from weather.com (L) and the Old Farmers' Almanac (R).
Sometimes, this type of pre-scientific prediction is the best we can do. If we can make this into a truly scientific prediction, we stand to do much better, but it’s a much more difficult task. A truly scientific prediction requires the following three things:
- that the scientific theory that governs your phenomenon is completely understood,
- the conditions that will affect the possible outcome(s) are known and understood in their entirety, and
- that you have enough computing power to figure out what the outcome is going to be.
In addition, because measurements are imperfect (and sometimes physical laws aren’t 100% predictive), you are also going to have a quantifiable uncertainty associated with your scientific prediction.
Image credit: NASA / Paul Chodas, Jon Giorgini & Don Yeomans / JPL NEO Program Office.
For some physical systems, the uncertainties can be so small that a prediction will be incredibly powerful; we know that on February 15th, 2013, a 45-meter wide asteroid will miss the Earth by only about 20,000 kilometers. Yet, the law of gravity is so well-known and the asteroid’s properties and trajectory is so well known that we can state with great confidence that there is absolutely a 0% chance that this asteroid will hit the Earth.
In other cases — like meteorology — the uncertainties are very large. It’s why we can’t predict with very much certainty whether Hurricane Sandy will wind up striking New York with strong winds, weak winds, or not at all.
Image credit: NOAA's information about wind speed probabilities as of 10/26/2012.
We can speak intelligently about what the outcome will be in terms of probabilities and uncertainties, but this also requires a few things that are far from given:
- Scientists who can communicate these results clearly and effectively,
- A media / government that can understand that information, make reasonable and effective policies based on that information, and communicate these results to the populace, and
- A populace that’s scientifically literate enough to understand what’s communicated to them and act in accordance with those recommendations.
This ought to be one of the main goals of science, as it’s one of the most important services that science can perform for a society. Sometimes statistically unlikely things happen, sometimes we’re unprepared for a disaster when it does happen, sometimes what seemed like a reasonable policy turns out to be ineffective, and sometimes people simply don’t listen. Unfortunately, when the wrong combinations of those things happen, people wind up dead.
Image credit: collapsed houses in the Village of Onna, Italy, photo by REUTERS/Max Rossi.
In 2009, the L’Aquila earthquake was an unfortunate example of just such a breakdown: scientists correctly assessed the situation, which they then communicated to a civil protection official who issued the following statement:
The scientific community tells us there is no danger, because there is an ongoing discharge of energy. The situation looks favourable.
Which, of course, is not what the scientists said at all. The scientists reached the conclusion that the observed tremors could not help predict whether there would be a major quake, information that they never communicated to the general public.
Image credit: AP Photo / Pier Paolo Cito.
Because of the quake, 309 people were killed. It truly was a scene of horror, with tragic results. Unfortunately, this is what often happens when there’s a natural disaster.
Was it a poor job of science communication? Yes, on the part of the scientists, and in particular on the part of the civil protection official, Bernardo De Bernardinis, who added that citizens should go have a glass of wine. But realistically, recommending evacuation based on what was observed would have been absurd; some natural phenomena are simply presently beyond the reach of science.
In other words, neither the occurrence nor the severity of this disaster could have been predicted. Which is why the following is all the more absurd.
Image credit: CNN.com.
The government official (De Bernardinis) as well as six Italian Seismologists were sentenced for manslaughter in connection with the L’Aquila earthquake. Now, Italian justice may be as phantasmal as an American kangaroo, but this is just absurd. It’s science’s job to use we know to predict — to the best of science’s abilities — what’s going to happen next, along with probabilities and uncertainties. These scientists did their job, and they did their job adequately well, if not spectacularly.
You do the world a disservice when you scapegoat scientists for a disaster they could not predict and an incompetent government official they could not control. We now live in a world where we jail scientists for failing to clean up the government’s miscommunication about a disaster they could not predict, while we simultaneously accuse them of fear-mongering for the impending disasters that good science does predict.
Image credit: National Snow and Ice Data Center.
If you want to know what’s going to happen in the future with any sort of accuracy, you need science. It’s the only thing that’s ever worked, and the more we do it, the better we get at it. This means we need to make the world safe for scientists to do science, we need to treat the science being done with the respect it deserves, and we need to improve and encourage communication between scientists and the public.
Remember, somewhere, right now, a scientist is hard at work trying to understand how some part of this Universe works for the sole purpose of trying to protect you from what are otherwise completely unpredictable natural disasters.
Image credit: http://murninghanpost.com/; a collage of disasters.
I’ll be following very closely the aftermath of the L’Aquila Earthquake and the associated trial, and hoping that the world chooses to value the one defense it has against the wrath of a complex Universe: science.
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