Critical Thinking: The Twin Snowflakes Conundrum

I've always liked "fun facts", and the medium of email makes them easy to pass around.  But just calling something a fact doesn't make it so.  I can enjoy fun facts without necessarily buying into all of them.

Even as a kid, I have had a problem with this old chestnut: "No two snowflakes are alike". Really? How can anyone possibly know that? Having grown up in California where snowflakes are somewhat scarce, I was hardly in a position to dispute this assertion, but it never set well with me. When I finally had a chance to view a real snowflake (my previous experience was limited to cutting out fake snowflakes on folded construction paper), I finally did see the amazing hexagonal crystalline shape. But I also noticed how quickly a snowflake melts.

So, who, I wondered, examined enough snowflakes to make the bold statement that no two are alike? It sounds like lazy science to me. How many snowwflakes have fallen on the Earth since the planet was formed? I would imagine something on the order of quadrillions every single year. Am I supposed to believe there's a less than 1 in a quadrillion chance (that's 1000 trillions, which is a 1000 billions, which is a 1000 million) that two snowflakes, might not match up? Don't forget snow has been falling for billions of years, as well. 

The two twin snowflakes could have occurred several billion years apart, or simultaneously, but thousands of miles apart - or, right next to each other, at the same time. No, I'm not buying this "no matching snowflakes" argument. It's unprovable, and flat out silly.

Another odd one I have heard numerous time is "A duck's quack does not echo."  This one would seem easy to test (hello, Mythbusters?), but on the face of it, it seems specious. Any sound is just a wave form. Any wave form will reverberate off a reflective surface, wouldn't it? 

Sometimes, folks will take advantage of our inherent intellectual laziness to try and shape our thinking, by leading us to conclusions that may not be valid.  Politicians do this all the time.  Here's a true statement:  Mercedes owners are statistically less likely to have missing teeth than other drivers.  May we, then conclude that the Mercedes-Benz automobiles are better for your teeth?  Of course not! The Benz is a higher end model of car, and people with higher incomes tend to be able afford better dental care. 

Here's another trick you want to be wary of: Medical claims based upon incomplete data. "A study shows that 90 percent of cancer patients have absurdium in their system. Beets are high in this substance, so, beets cause cancer." First of all, is the amount of absurdium in cancer patients notably higher than in the general population? Can't tell from this statement. Was it determined that the cancer patients studied ate more beets than the general population?  Are there other likely sources of absurdium? These are the types of questions you should be asking before calling for new legislation, product ban, dietary changes, etc.

Look, it's fun to pick apart assertions of fact, and it's healthy to be skeptical. If the statement really is true, it will survive the application of critical thinking and scientific examination. If not, you've saved yourself from needlessly throwing out potentially delicious beets.  (I hate beets by the way!)