Air Mail: Circulating Forever

 

            Today's Snack: Air-popped popcorn, from the microwave.

 

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Supplies:

 

Scratch paper and pencil

Empty liter bottle

Empty 8-ounce cup

Water

 

 

            Air - it gets around. Literally!

 

            And there's sure a lot of it. How many molecules of air are there in the world?

 

            Well, don't take the time to count each one (!) because it's something like this:

 

10⁴⁴

 

            That's a 10 with 44 zeroes after it. Take a piece of scratch paper, write a 10 over at the left, and then write 44 zeroes. It's a lot, isn't it? It's an enormous number.

 

With every breath you take, you take in air. Of course, it's going to be a LOT less than all the air in the world. But wait 'til you see how much it really is.

 

With each breath, you take in about one-thirtieth of a liter of air. To estimate how much that is, fill up the empty liter bottle with 8-ounce glasses of water, until it's full. How many 8-ounce glasses did it take? How much was left? You can add up how many ounces went in to filling the liter bottle, and then divide it by 30 to come up with the amount of air that you take in with each breath.

 

            Doesn't look like a whole lot of air, does it?

 

            But get this: there are so many molecules of air in that one-thirtieth of a liter, there would be too many to count. Literally countless! And guess what? They've been around for a long, long time. And they spread fast.

 

            Take a deep breath. Hold it. Exhale.

 

            Now take a guess:

 

What is the probability that you just breathed in a molecule of air that was also inhaled once by Julius Caesar, more than 2,000 years ago, in Rome, Italy?

 

            It's a 99 percent chance!

 

            That shows you how many molecules there must be in one lung-full of air, and how much those molecules get around.

 

            Kind of gives new meaning to the old adage "clear the air." There's an awful darn lot of it to clear!

 

Isn't that fascinating about the Julius Caesar connection? Kind of . . . TAKES YOUR BREATH AWAY, doesn't it?

 

            This exercise also gives you a glimpse into why we are working so hard to stop air pollution. Like air itself, pollution spreads fast . . . and lasts a looooooong time.