When diet coke cans don’t float better than regular coke cans

This is why you should always test an experiment before you run it…

On recent travels, when I saw that they were serving drinks out of tiny cans, I asked for coke and coke light, because I really like the experiment where you put two coke cans in water and the diet one floats while the regular one sinks.

Soft drinks in cans. Who knew you could do science with them?

And then I had those two new tiny cans sitting in my kitchen. My parents came over and we talked about how I am so happy I got those tiny cans, because it is less equipment to lug around when I travel to workshops or courses. And then my mom says that she has never seen the experiment for real. So of course, I have to show her. And what happens? This!

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Yes, the regular coke might have sunk a little deeper, but this is really not as impressive as the experiment is supposed to be!

Good thing I moved the cans (which a friend’s friend brought to Norway for me, which I then brought from Norway to Iceland and then back to Norway) with me to Germany… As you see: The large cans still show what I wanted them to show!

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So who knows what is going on here? Too much head space in the tiny cans relative to the amount of soft drink they contain? New formula? Anything else?

And the moral of the story: ALWAYS try your experiments when you are using new equipment before you show them to anyone. Who would have thought that this experiment was not fail safe???

One thought on “When diet coke cans don’t float better than regular coke cans

  1. Elin

    seems like the PERFECT exercise for students – here you can easily set up a number of hypothesis and then do measurements to test them! I’m curious…


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