Too small to see
To understand some of the wonders of the quantum world and to think about important things that we sometimes ignore.
by Gordon Lamont
Suitable for Key Stage 3
Aims
To understand some of the wonders of the quantum world and to think about important things that we sometimes ignore.
Preparation and materials
- A thick glove.
- A tennis ball or similar sized ball.
- A ping-pong ball.
- A jar of salt or sand.
Assembly
- Ask for a show of hands for the following questions:
Who has heard of the phrase ‘Quantum Mechanics’?
Who has heard of the Large Hadron Collider?
Who has heard of the phrase ‘the speed of light’?
If appropriate, ask for explanations of these terms from those who’ve put up their hands and/or give your own brief responses. - Quantum Mechanics is a term used to describe the behaviour of very small particles at the atomic level – the bits inside atoms, if you like!
The Large Hadron Collider is a device for doing experiments on these sub-atomic particles, recently opened in Switzerland . . . and France! It spans the border.
The speed of light is the fastest speed that it is possible to travel (roughly 300,000 kilometres per second).
A simple explanation of why it is not possible to travel faster than this:
According to Einstein and others, and now demonstrated by experiment, as you move faster through space, time slows down for you. Light travels very fast but cannot go faster than 300,000 kilometres per second because, at that speed, time slows to a stop, and if there’s no time, you can’t move! - The subatomic particles are the building blocks of everything that there is – you me, planets, sounds, iPods . . . everything. Yet these smallest particles are in fact too small to see.
Why is this?
Could we see them if we built better and better microscopes? Could we see them with ultra mega, mega pixel digital cameras? No. You will never see the smallest particles. - Explain that the smallest particles are smaller than the wavelength of light. Demonstrate this by asking for a volunteer.
He/she comes to the front, puts the glove on and closes his/her eyes, holding out the gloved hand.
Reveal the tennis ball to the assembly and place it on the volunteer’s gloved hand. Ask the volunteer to tell you when he/she detects something and then to feel it through the glove and tell you what it is.
Do the same with the ping-pong ball.
Finally, reveal your jar of salt or sand and take out just one grain or a very few grains. Drop this onto the gloved hand. There will be no response.
Thank your volunteer and ask him/her to sit down. - Make the point that you had one large particle (a gloved hand) which acted as a detector, just as light detects what it falls on, revealing it to our eyes. You had other particles of different sizes. The one that was too small couldn’t be detected, and so it is in Quantum Mechanics: we cannot see the smallest particles because light is, if you like, too big!
- Explain that the Large Hadron Collider doesn’t show scientists the smallest particles but shows them the effects they have on the particles around them. So these fundamental building blocks of everything are literally too small to see, yet they are perhaps the most important things in the universe because without them there would be no universe!
Time for reflection
The universe is a very strange place, full of surprises and mysteries. Even the greatest thinkers of the past would be amazed at what we are discovering about the world within the atom.
Just as the subatomic particles are too small to see, yet too important to ignore, are there small things in our lives that we need to give more time to? Should we make more time for certain people or put more effort into some activities or relationships?
Music
One of the older ‘electronic’ pieces of music, such as ‘Oxygen’ by Jean-Michel Jarre, to be played as students enter and leave.
