Air Pressure: Egg into a Flask

This is another classic! 

In preparation for this demonstration, you'll need to hard boil some eggs.  When cool, peel them. 

You'll need a flask or bottle (Snapple bottles are a good size) with an opening that's smaller than the egg (the egg should be able to sit on top of the opening.  You may wish to grease the opening a little to help the process, but it usually isn't necessary.

To perform the demonstration:
Light a small piece of paper on fire with a match or lighter.  Drop the paper into the flask/bottle.  Quickly place the egg on the opening.  Watch.

The fire will extinguish when all the oxygen has been consumed.  And the egg will slowly work its way into the bottle/flask.

Since the oxygen has been consumed, there is less air in the flask, so the air pressure outside of the flask pushes the egg in. 

(At this point, you're probably looking for an additional picture.  My camera went on hiatus, so there is no picture, but I can tell you that my egg was too large for the bottle I had on hand, so even if I had a picture, it wouldn't look terribly different from the one above.)

There are ways to use air pressure to get the egg out, but I can never get them to work.  Instead, I break up the egg with a knife and dump it out.  Not as dramatic, but it works!  If you're interested in trying it for yourself, do a Google search and you'll find numerous sites with directions.

You'll probably want to try this demonstration once before performing, to check that your bottle/flask opening and egg are a good size match.  (See above).  Of course, eggs are all slightly different sizes, so there's no guarantee that you won't get the egg stuck in the neck of the flask, but it should give you a good idea!