Colour your own flowers

Find out how to make your own garishly coloured flowers, and how it relates to the way plants lift water to their leaves.

What is going on?

Land plants have a problem, the water, minerals and other nutrients they need are in the ground but they are needed in their leaves which need to have access to the sun, so they have to be up in the air. This means the plants need a mechanism for transporting water with dissolved nutrients up their stems to the leaves.

They do this using a tissue called xylem, which is made of thousands of tiny tubes, which run from the roots each to a different part of the plant.

Normally the roots sort out what the plant wants and allows that into the xylem. Bit if you cut the stem, you loose the filtering of the roots and the xlem will suck up whatever they are sitting in. This means that you can keep a cut flower hydrated and fairly healthy for a couple of weeks if you put the right nutrients into the water.

It also means that if you put something coloured into the water it will be sucked up all the way into the leaves and the petals.

Resource: thenakedscientists.com See for Full details

Fruit Fireballs

You may think that oranges seem are a fairly boring sort of fruit. Discover their more exciting side in this simple experiment.

What you need

What to Do

If you bend a piece of orange peel you often get a spray of orange oily stuff coming out. The idea is to direct this spray upwards into the side of a candle flame.

Be careful, this can be more effective than you expect. Make sure that your hands and anything else easily damaged by flame is below the candle flame!

Resource: thenakedscientists.com See for Full details

Dropping Eggs

How to stop an egg from breaking when dropped without any padding, and what it has to do with a womb.

What is going on?

If you drop an egg on the floor its speed changes from about 3m/s to stopped in a very short period of time, this means that is accelerates (decelerates) very rapidly. A large acceleration requires a large force and because this force is concentrated in one place the eggshell isn't strong enough to support this force and it breaks.

Resource: thenakedscientists.com See for Full details

Confusing colours

Confuse your eyes with this colourful experiment, and find out how it relates to seeing in the dark

What is going on?

Your eye is constantly doing what is know in the world of photography as white balancing. You see the world in a variety of different coloured lights, a sunny day, a cloudy day and sunset all have very different colours of light so the light bouncing off an object will vary from minute to minute. However you are really interested in what the object is not the exact colour of the light boucing off it, so your eyes compensate. Over a wide range of colours of illumination you will see a white  piece of paper as white, you can see how much the colour actually changes by taking photographs with a digital camera with a fixed white balance setting.

This white balancing means that if you look at the world through a yellow piece of plastic your eye will try too see a white piece of paper as still white by becoming much more sensitive to blue light. Then when you remove the piece of plastic your eyes take a while to adjust and the world looks blue.

Resource: thenakedscientists.com See for Full details

Recycling Paper

Take some of those old bits of paper and recycle them to make some new paper. It is far more fun than buying recycled paper in a shop.

What you need

Resource: thenakedscientists.com See for Full details

Weighing Buoyancy

Does a glass get heavier if you put your finger in the water? Find out in this experiment.

Resource: thenakedscientists.com See for Full details

Bendy and Brittle Bones

Bone is an incredible material - as for its weight, it can be stronger than steel. Find out why it is so strong with this kitchen science.

What is going on?

Bone is a composite structure made up of two main components: A mineral called hydroxy-apatite and a protein called collagen. Hydroxy-apatite is a hard brittle material, and collagen is a stringy rubbery polymer - it is the stuff which the end of your nose is made of.

Sharks and babies have their bones made entirely of collagen, which is flexible, and tough (it can absorb a lot of energy in an impact) but they're not rigid enough to support large forces. This is where the Hydroxy apatite comes in, as this makes the bones stiff.

When you leave the bone in vinegar, the hydroxy-apatite dissolves away, leaving the collagen. Now the bone that is far too flexible to be useful. Similarly, when you heat  bones in the fire, you turn most of the collagen protein into charcoal. This leaves the hard, but brittle hydroxy apatite, with very little holding it together, so the bones are very weak and brittle.

Resource: thenakedscientists.com See for Full details

Build your own helicopter

Build your own helicopter using just a piece of card, some tape, and a few pencils.

Resource: thenakedscientists.com See for Full details