Science Weekly 3/22/20

Thoughts by Richard Bleil

Not long ago, a friend on my social media page made a comment to the effect of, “I read it in Science Weekly.” I replied, “Oh, I used to love reading that magazine!” She replied yet again saying she made up the name. And we laughed…

Science Weekly was a little news magazine that you could read when I was in middle school. Think mid ‘70’s. Obviously written for kids, it was a review of science news of the day and interesting articles of applied science. One issue, for example, had a “cover story” that asked the question, “can you drink from a 30-inch straw?” Before reading the article, a friend of mine asked me if it was possible (yes, I was always the geeky science kid), and being arrogant and overly confident (at least in the sciences), immediately shot back “well, of course, why couldn’t you?”

Well, you couldn’t drink from a 30 in straw because of why straws work in the first place. See, when you use a straw, you create a vacuum in the empty space between your mouth and the liquid, but the liquid does not go up the straw because “nature abhors a vacuum”, but rather, because air pressing down on the liquid around the straw is pushing the liquid up. When there is no vacuum, the pressure pushing on the liquid inside the straw is equal to the pressure outside of the straw, so it’s a draw. These equal pressures is why the liquid remains at equal levels inside and outside of the straw rather than having a continuous fountain effect. But, once a vacuum is created, air exerts a finite amount of pressure. Even in a perfect vacuum, here on earth, the air can only push the liquid up about 30 inches (and you’ll never create a perfect vacuum). So, it actually is impossible to drink from a thirty-inch straw.

This is what science does. It seeks cause and effect. “Nature abhors a vacuum” was how ancient scientists explained the movement of matter into vacuum before they understood air pressure. Of course vacuums pick up dirt; the dirt is trying to fill the vacuum because nature abhors a vacuum. Well, no, it’s not that nebulous of an explanation. A scientist will observe some kind of action, like the action of a straw, and ask, “what is the cause?” Once we understand the cause, we can extrapolate that information to make predictions, or even turn it into a tool to work for us like the vacuum cleaner using air pressure to do our cleaning for us.

As the viral isolation continues, and parents find themselves trying to home-school their children, I can’t help but ask myself a question that has nagged me for as long as I can recall; why don’t people like science more than they do? I’ve always been fascinated about the underlying causes of why things are the way they are, and why things work the way they do. My fascination does seem to go much deeper than most people, and I get that; I’ll take everything down to the thermodynamical underpinnings of everything that is and happens such and the enthalpy and entropy of vacuums. Okay, I get that that’s not everybody’s cup of tea, but as my few followers (thank you) read this, I can’t help but wonder how many of them have ever really pondered why it is that liquids go up a straw, or posed the hypothetical question of a thirty inch straw.

I used to do a demonstration show for second and third graders many years ago. I enjoyed a simple demonstration to get maybe half a dozen students from the audience to participate as the last thing we would do. I had a large beaker filled with a little bit of solvent (I used acetone, the active ingredient in many nail polish removers), and brought out a huge box of Styrofoam (the non-biodegradable packing peanuts) and let the kids take handfuls and dump it into the solvent. The Styrofoam would melt immediately on contact with lots of fizzing, and in the end, the entire box of Styrofoam would disappear into the little bit of solvent. The fizzing was not because of a chemical reaction, but rather because of the release of the air pockets that gives it such a great cushioning property (the reason they are used in the first place). Once that air is gone, the huge volume of Styrofoam would occupy very little space, creating a gooey messy slime. We would discuss volume and air in the demonstration. What the kids could NOT see is what happened when the solvent would eventually evaporate (simply because it took too long), and this slimy goo turns into a solid plastic puck like material. This, to me, is science.

If you are teaching your kids science at home, this is my recommendation; do fun activities. There are many out there that can be done safely with household products, but science shouldn’t be a chore. Yes, we can talk about volume occupied by air in Styrofoam, or for more advanced kids even density as the same mass occupies a smaller volume and therefore is more dense, but it’s also just fun to see the Styrofoam dissolve. Asking the simple question of how so much Styrofoam can fit into such a small volume is the first step of the scientific method, getting students to ask why and conjecture as to possible reasons, and a great introduction to Science. Weekly.

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