Science quickies

#### Activities

How high is that building?
Lenses under water
Telling eggs apart
A trip around the moon
Universal solvents 1
Universal solvents 2
A puzzling puzzle
Other pages on this site

## Details

Universal solvent
Why is a universal solvent impossible?
Universal solvent revisited
Having shown that a universal solvent is impossible, how could you keep some in a glass bottle?
The height of a building
Your problem: to come up with a creative way of using a barometer to measure the height of a building. It is a mercury-filled Fortin barometer, 800 millimetres high, weighing just under 10 kg. Be imaginative!
Which egg is which?
You have two eggs in your refrigerator. One of them has been hard-boiled, while the other egg is raw. How can you tell which egg is which?
Underwater spectacle
Suppose you have a magnifying glass, and you want to look at a fish. Would it help to put the magnifying glass under water, close to the fish?
Once around the moon
Your lunar exploration vehicle has fuel tanks which will carry it one third of the way around the moon, and it can carry twelve spare fuel containers, enough to take it another third of the way around the moon. This means that a full fuel load will let you travel one third of the way around the moon and back, or two thirds of the way around the moon before you run out of fuel.

You can top up the fuel tanks at any time: what is the smallest number of fuel containers (starting with the tank empty) that you will need to travel once around the moon?

And when you have solved that, can you come up with an answer for a situation where twelve fuel containers only carry you a quarter of the way around the moon?

Can you make this?
When I saw this one, about twenty years ago, it was described to me as a test for budding architects in Russia. They were shown this shape, given a pair of scissors and a filing card, and told to make it. They had the advantage of seeing the real thing, but this is a good test of your ability to think in three dimensions.

You do not need glue, tape,staples, or any other attaching things.