You know, aside from the obvious.
I’m going to try and avoid politics here, only mentioning some issues as they become relevant points in the discussion. Some topics of scientific research have morphed into ideological lightning rods, but the reasons have nothing to do with the actual science.
In order to explain how science is often misunderstood, I want to use an example situation from a game I think we’re mostly familiar with: Sudoku. For those who may not be familiar, the goal of the game is to place the numbers 1-9 a 9×9 grid in such a way that the numbers do not repeat (i.e., all 9 unique numbers are present) in each row, column, and 3×3 square. For a given setup (you’re given a few initial numbers to get you going, and the quantity and placement of these numbers determines the puzzle’s difficulty level), there is only 1 possible solution. But getting there can be really tricky. Take this puzzle I’ve been working on.
White numbers are the initial set; yellow numbers are ones I’ve placed since starting. Pay particular attention to the empty row of 3 squares in the top-middle 3×3 section. Since all 9 numbers can only be used once in that section, I know only 1,2, and 5 can go there. But in what configuration? From left to right: 5,2,1? 1,5,2? etc?
Here’s a cool trick. Starting at that very middle empty square, examine the entire column. What numbers am I missing? Well, I’m missing a 2…which is also a number I need for that 3-square row. If you check the empty square under the “4” in the middle 3×3 section, you’ll see I can’t put a 2 there because there’s already one in that row (on the left). And I can’t put a 2 in either of the empty squares in the bottom 3×3 section, because that section already has a 2 in it (directly left of the yellow 9). By process of elimination, that leaves only one possible position for the 2 in that middle column: the middle empty square of the top 3×3 section. You should easily be able to find where the 5 goes, and with only one empty square, where the 1 goes. Voila!
Now you ask: what does this have to do with science?
The idiom “we stand on the shoulders of giants” comes to mind. Scientists use what is already known about the world in order to infer new things that are not known. That prior knowledge, in the case of the Sudoku, is encapsulated in the initial (white) numbers. Scientists then employ some sort of model–or representation of how the world works–to infer how something new should behave. Again, with Sudoku, that model is the set of rules that govern how we can place new numbers.
A big point here, which played out in a debate on this blog on evolution awhile back, is that it is very rare for scientists to have direct evidence of a new phenomenon. Take care: “direct evidence” is a murky term that means something different for just about everyone. Scientists would, of course, say they have found direct evidence supporting some new claim. It just may not be the sort of “direct evidence” we, John Q Public, were expecting.
Check the comments on that blog post for where I mention that, in deducing the Standard Model for atomic theory, scientists didn’t pluck out a proton and stick it under a microscope. Quite simply, that’s impossible. Let me illustrate using none other than the Higgs boson!
Because of Einstein’s famous e = mc2 equation, mass and energy are interchangeable, hence the mass of particles are typically measured in electron-volts (eV); in the case of the Higgs, giga-electron-volts (GeV). To greatly simplify things (because I don’t fully understand it myself), particle smashers like the LHC operate by observing the energy of proton collisions in order to determine the types of particles involved. Effectively, the output of smashing protons together is a graph like the one you see above.
When protons are smashed together, the sensors detect new particles from the mini-explosion and can calculate their masses (or energies), which tells scientists what the new particles are. Think of the graph as counts (it’s a histogram): each value on the x-axis represents a possible particle, and the y-axis represents the number of times a particle of that mass (or energy) was observed.
In discovering the Higgs, scientists conducted enough particle collisions to notice the small “hump” in the graph near 125 GeV.
Sound simple? It’s not.
- Prior knowledge. Scientists had to already understand established quantum physics and Einstein theories in order to even know where to look for the Higgs. The LHC, in fact, was built on the premise that it could slam particles together at high enough energies to detect the Higgs if, indeed, theoretical predictions were correct.
- Repetition. There wasn’t a single “ah HA!” experiment. By virtue of the histogram above, particles had to be smashed over and over and over and OVER to generate semi-accurate counts of the particles created from proton collisions. If you only slammed two protons together, the graph above would look like a flat line. You’d need to do it millions of times to get the graph you see.
- Direct evidence? I think not. The ultimate thing to keep in mind: “all” we have to prove that we’ve found the Higgs boson is 1) prior theory predicting its existence, and 2) an energy landscape graph with a high degree of statistical confidence in its findings. We cannot and won’t ever be able to pluck a Higgs boson out of the air, turn it over in our hands, and say “that’s a Higgs.” We can’t isolate one and put it in a test tube.
This whole “direct evidence” thing is, in my opinion, why climate science has become so polarized. Day-to-day temperature, like the types of particles created from colliding protons, is very unpredictable and has a certain amount of randomness to it. One 100+ degree day does not a case for global warming make.
On the other hand, scientists have taken the following approach: if global warming was happening, what would we expect to see? There are quite a few predicted consequences: rise in ocean levels, glacial retreat, ocean acidification, dramatic changes in bird and marine migration patterns, and plenty others. Even when a particular season is unusually hot, this by itself is not grounds for global warming. But when all the other signs point to global warming, the chances that an unusually hot season is due to random chance falls significantly. Just like when you slam enough protons together and see an accumulation of particles at 125 GeV, as you see more and more of them, the probability that you’re seeing random particles drops off quickly.
It’s never 100% certain, but to argue that what we’re seeing in the weather is a 0.001% chance occurrence seems a little absurd.
I suppose the take-home message is this: if you’re wondering how scientists reached the conclusions that they did on some particular topic, before you jump to where they got their funding or what their ulterior motives might be, do a little of your own research. Keep in mind they likely haven’t discovered a crop circle that says “GLOBAL WARMING IS REAL” or a particle with “HIGGS” embossed on it; instead, they discovered something that fits within the partially-completed puzzle of the current state of science, and it was the most plausible explanation for what they were observing.