Wednesday, February 3, 2010

How Science Works


(Picture from here. Original material here.)

The drawing at left is a good visualization of how science works. The original material (second link above) expands that idea and is interactive to show how the different pieces work.

But it brings up something that I think a lot of people don't understand about science. Science is really an extension of critical thinking which also uses a similar approach. Central to science is testing ideas in the real world. This is probably the most important piece of things.

A component of testing is reproducibility. It's not enough that the test works. You have to make it work again. A good example of how this operates is polywater. Polywater was a bit thing in the 1960s: a form of water with an increased boiling point and viscous properties. It's one of the sources for Kurt Vonnegut's Cat's Cradle. Some attempts at reproducing polywater succeeded; some failed. Here lies one of the basic tenets of a scientific paper: the materials and methods section. Not only does a scientist publish the hypothesis, results and conclusion, he must also publish how he did it.

After a while, it was deduced that polywater was a result of contamination. Another round tightly controlled research was unable to reproduce polywater. Subsequent investigation showed the polywater was anything but pure water and the original researcher retracted his conclusion.

The system worked but it worked over about a decade.

The anti-vaccine is another and much more insidious example of popular culture looking at a tiny fraction of science that might connect to previous bias or fear and then holding on to it beyond the point where it is disproved. (See here.)

Critical thinking about the world is, I think, crucial to being a good citizen. That means understanding how critical thinking works and, because it is so important, how science works. Scientific consensus does change-- case in point the role of genes and inheritance. A generation ago, genes were considered the sole source of anything inheritable. Then, a whole lot of junk DNA was found in the genome sequencing project. Then, a lot of that "junk" turned out not to be junk at all. Then, it was discovered that DNA expression in offspring could be modified by a mother's behavior prior to conception.

The Popkes Maxim: If you're looking at something and it looks simple, you've probably not analyzed it sufficiently.

The DNA discoveries did not invalidate previous facts; they shed light and extended previous facts. One of the side effects of this research was to discover yet another way that evolution works. Yet, people who don't understand how this works took much of the research and decided it disproved evolution.

Even the language of the debate shows this lack of understanding. Think how many times the following sentence has been said in the evolution debate:

"Do you believe in evolution?"

As if science is a matter of opinion or faith. It is not. It's like saying, "Do you believe in lightning?" "Do you believe in the ocean?" "Do you believe in lobsters?"

You might say: "Do you believe epigenetic inheritance is significant in the evolution of large scale physiological structures?"

And that question might be answered:

"Yes: the epigenetic evidence can have a significant impact on selection pressure, exposing specific physiological systems to more direct selection pressure. We'll have to see how the data goes."

or

"No: the epigenetic evidence is interesting but not sufficient to have any more specific selection pressure on different physiological systems. We'll have to see how the data goes."

This is not a question of belief but informed opinion based on evidence and facts. People disagree on conclusions all the time.

It's the evidence that will set you free.
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Wall of Idiots
Republicans
Nevada politicians
MMR vaccine study repudiated. Finally.

Links of Interest
Evil fairies battle insects and here
Evil robots
Social robots
Robots and the uncanny valley
The future of humanoid robots
Origin of eucaryotes
Razzle dazzle camouflage
The Hobbit's small brain
Human evolution in the genome
Barefoot running
Development and the Bonobos
Energy teleportation
More on the NASA reboot
V: Jon Stewart on O'Reilly
V: Jon Stewart on Obama
V: Rex the Dog
V: Water rocket awesomeness
V: Seeing radio waves
Composite metal foam
Visual language for designers

DIY
The Carpenter's Tool Chest
Tenon cheating
The arc light. And here.
Thing a day
Musical instrument a day
Quick vacuum pump
Fleece hat
Survival bracelet

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