Coke Floats, part 2

Okay, so waaaaay back a long time ago I wrote this post about the floating properties of Diet Coke and Coca-Cola. The gist is that Diet Coke is supposed to float in water, and regular Coke is supposed to sink, but I got some different results.

After that, I did some back and forth with another site (Science and Food-ucation) about why I got weird results. Eventually I rebooted the site and lost the comments, so half of the conversation was gone. It's been a pretty popular entry, though, and for some reason I would get the least literate of comments on just the one post. I couldn't really figure out why.

This evening, though, it all came together. A man whom we shall call Jared* wrote to me to say that he has performed the experiment many times and that the results are consistently in the "Coke sinks, diet coke floats" realm, which is not entirely what I recorded.

He suggested that perhaps I had an air bubble under my can, and that was causing the floating. He went on to tell me that whenever he teaches this for his science class…

…And that's when I realized. Of course! This is a relatively standard experiment in a science class. It has cola, which kids relate to, and is inexpensive to acquire the materials. Also, once you're done, you can drink the subjects of the experiment, which is not nearly as common as aspiring mad scientists might hope.

So what happens is that these kids get a science lesson about Diet Coke floating, and perhaps a bit of homework to find out more. They run to The google and type Diet coke floats and come back with the 5th result from the top saying "However, it should be pointed out that, despite the introductory picture for this quick note, Coke does not sink while Diet Coke floats." The kids are all like "Whaaaaa?" and rush to tell me that I suck.**

So, mystery one is cleared up.

Mystery two is pretty close to being solved by the likelihood of an air bubble trapped under the can, so I ran to the kitchen and grabbed a couple of cans of Coke, a big transparent container, and a video camera. The result is:

And yes, I know the video kind of sucks, but I am not afraid to suck, so there.

*- For that is his name.

**- Incidentally, that should be a lesson for you kids. It won't be, but it should. All it took was a reasonably well thought out discussion to get me to re-examine the experiment. Those of you who suggested that I was a big liar, well, I pretty much ignored you.