Try your hand at making your very own Mini Miss party trick!

What to do:

1. Pour some water into the beaker. It doesn't really matter how much, but to start with you should just use a little, then as you get better you can use more. Once you've got the hang of it you could even add a few drops of yellow food colouring to make it look disgusting!
2. Place the postcard (picture side down) on top of the beaker, making sure it completely covers the opening.
3. Put one hand flat on top of the postcard (palm facing down) and push gently. Make sure that you don't push so hard that you bend the postcard.
4. With your other hand grasp the beaker.
5. Now, carefully turn the beaker upside down, gently pushing on the postcard all the time. If water is spilling out, make sure you're not making the postcard bend.
6. With one hand still holding the beaker, slowly remove your hand that is holding the postcard and the postcard shouldn't fall.
7. You may not be able to do this first time, but keep on trying.
8. See how long you can keep the postcard from falling.

Here, there are two things coming into play; air and surface tension.

Firstly, it is air that usually makes liquid fall out of beakers (with help from gravity of course!). Air rushes in, and this pushes the liquid out. Here we are stopping air from getting into the beaker by making a 'water barrier', and this 'water barrier' is all down to the surface tension. Surface tension doesn't mean that water is tense and stressed like a Lab Rat that can't find his shoes. No! Instead it means that the particles that make up water are sticky and they like to hang out together and so they can make a sort of skin, or barrier.

This means that when you turn the beaker and postcard upside down, the water clings onto the postcard and fills in the tiny gaps between it and the beaker. This 'water barrier' blocks air from getting in the beaker, and with no air getting in, no water can be pushed out, so the water and the postcard stay put.