Friday, July 30, 2010

Magic In The Morning, Or More 30 Second Science

Want to wow your children, with science, before breakfast (or anytime of day)? All you need is an empty, plastic bottle, with a cap, and some hot tap water.

  • Fill the bottle with hot water, as hot as you can handle, but not hot enough to melt it.

  • Dump the hot water out of the bottle.

  • Put the cap on, as quickly as possible

  • Place the bottle in the middle of the table, and watch it magically crush itself.


It really never gets old.

There is a science lesson here too, of course. As the hot air trapped inside the bottle cools, the pressure inside decreases, allowing the force of the air pressure outside the bottle, to push in the sides (or something like that, it's really hard to find a clear explanation of this experiment).

But, one way or another, it's cool to watch, and when you open the bottle, it pops right back to its normal shape.

It's great to be a homeschooler.

6 comments:

Wonder Mom said...

You know, I'm certain your kiddos find you to be the coolest mom ever...

Raising a Happy Child said...

This is pretty cool - have to try it out :)

Phyllis said...

I have done this with a metal can. I put some water in a metal can and heated it on the stove and then put the cap on. As it cooled it collapsed in on itself. It is pretty dramatic because the metal creaks and groans when it collapses. Your experiment is a much easier way to do it, however! I had thought the explaination was that when you put hot water in, it was so hot that some of the water molecules were in the gas phase and that when the water vapor cools it collapses the can or bottle because no air could rush in and fill the void left behind by the condensing vapor. The condensing vapor was taking up less volume. We did the experiment to show the difference between the phases of matter in terms of the volume they occupy. I am sure there are lots of different ways to explain it though, and perhaps mine is not the best. :)

An Almost Unschooling Mom said...

Phyllis - Your explanation is the one my oldest guessed at before we looked it up. I was really amazed at how hard it was to find a clear explanation online.

Christy said...

I can't wait to try it. Cool!

Ticia said...

Oh that would be fun to amaze my kids with.