Gravity and magnetism are ‘forces’: movements which make an object move, stop, change direction or change shape. In their play, children can exert forces themselves and they can be affected by external forces such as gravity, too. See ‘motion and forces’ in March’s edition for more on forces relating to motion (pushes and pulls).
in the moment
Gravity is the force that pulls objects towards one another; on Earth, it pulls everything towards the ground and is the reason we don’t float away and why objects fall to the ground when dropped. There are a few ways to demonstrate this invisible force to children – like magnetism, if can feel a bit magical because it can’t easily be seen.
- Drape a piece of fabric over the top of an empty trough or bowl, keeping it taut. Carefully place a few very light objects around the edge of it, so that they stay in place – leaves, marbles, snail shells will work. Then place a heavier object – a ball or stone – into the middle of the fabric. The fabric will pull or sink under the weight of the ball (the Earth) and the lighter objects (the people) will all move towards it.
- When playing on the swing, ask children if they can feel the pressure on their chest and back as they swing back and forth. The greater the speed, the greater the G-force; when we run, or speed along on a bicycle, we can feel the extra pressure the air is placing on our bodies. Gravity also makes the swing come back down from its highest point – it is being pulled ‘back to Earth’.
quick wins – forces and gravity
Sir Isaac Newton’s first law of motion explains that an object at rest remains at rest unless it is acted upon by an external force.
Explore the garden with a group of four or five children and identify objects that are not moving, for example, a ball, water in a puddle or trees and clouds.
- What will happen if we touch one of the still objects on the ground? What will happen if they aren’t touched? If a child touches a heavy object, very gently, will anything happen? What about if they really push or pull it with all their might?
- Find a heavy object that you, as an adult, can move relatively easily, such as a wooden plank or a crate of Bottle Babies*. Demonstrate your strength by lifting and moving it. Do children think they will be able to move this object on their own? If not, how many children will it take?
- Using a range of balls, test the idea that more force (power) will make an object move further or faster. On a hard, level surface, start with gentle pushes and work up towards forceful kicks and record how far each ball will go. If you have a sandpit or grass, repeat this experiment on those surfaces; what effect does the kind of surface have on how far the balls go and how hard they have to be pushed?
- What other forces are acting on objects in the environment? Look at the clouds and the trees nearby – what is making them move? If you have a globe, show it to children and speculate about what force is stopping scientists and animals in Antarctica from falling off the Earth into space. It is, of course, gravity.
continuous provision
Plenty of your everyday resources will work well for exploring gravity, but you may need to borrow or invest in a few others to explore magnetism – see Enhancement. It’s often about understanding the science and technology and applying it to everyday play in an accessible way, rather than introducing resources.- Art supplies, for creating models and drawings, including drip pictures demonstrating gravity (why does paint drip down?) and flick pictures showing forces (paper is the ‘force’ preventing the paint from just continuing to move through the air).
- Magnets – e.g. the fishing game with a magnet on a fishing rod; telescopic magnet wands; directional com passes; magnet construction toys and building blocks; and U-shaped magnets. Use the magnets to test for magnetic and non-magnetic objects around the garden and indoors (e.g. paperclips, coins, plastic toys, pieces of wood, fabric, cutlery, door handles).
- Wheeled items are crucial for exploring force and power – but think beyond just bikes and trikes. What else has wheels or castors? Chairs, tuff-trays, small-world cars, shelves or cupboards, trolleys…
- Balls, feathers, leaves, stones and bubble mix for testing gravity and wind; small-world toys, floaty scarves, plastic bags and string to make parachutes.
- Play equipment such as swings or rope swings, slides and see-saws (DIY is fine!) to feel the effect of gravity (G-force) on the body.
- Magnets are often small; close supervision is essential when using them.
Enhancement
A ‘grab and go’ box of resources with:
- Bicycle or balloon pump, to feel the force of air coming out of the end; discuss how much more efficient a pump is than blowing an object up ourselves.
- Moon phases calendar and planisphere (which shows the planets on any given day); a globe.
- Night sky apps such as Pocket Universe and SkyView; illustrated books; lunar phases poster.
- A piece of lodestone, which is a naturally magnetic stone, or the ‘magnetic chess’ game, which is made from shiny, polished lodestones.
- Iron filings (above) – we recommend you seal them into a clear plastic bag that children cannot open, or source a child-safe disk of iron filings. Iron filings clearly demonstrate the effect of a magnet’s attracting and repelling forces.
planning ahead
As we move into the shorter days of autumn, full-day settings may get to observe solar and lunar events in the dusk – alternatively, send details home with children to explore with their parents or carers. The next event is a ‘supermoon perigee’, which is when the full moon appears larger and brighter because its orbit is as close as it gets to the Earth (the gravitational pull of the moon is stronger during a supermoon, which also leads to higher and lower tides). The next supermoon is on 18 September, and there is another on 17 October. These provide a chance to examinethe moon’s surface through binoculars.
exploring magnetism
Hide magnetic objects in the garden and send children out with a U-shaped or telescopic magnet wand to find them. If you can source a piece of lodestone, place it with other rocks for children to find (the other rocks will not be magnetic).- Play with compasses; they always point north, even in the southern hemisphere. Some compasses are more accurate than others – small ‘pound shop’ ones will not be as well made as a ‘real’ one but are good value, fun resources and great to encourage the use of geographical words such as ‘north, east, south and west’. Purchase or borrow a hiker’s compass to compare accuracy, and look at the compass on a phone or tablet too – although these work with GPS rather than magnetism.
- If you can afford to, purchase a magnetic panel or noticeboard (about £10-£20 from DIY stores) to install outdoors. Children will enjoy testing out what will stick to it, and older children can use pennies or other magnetic objects to create pictures – check out artist Paul Cocksedge’s outdoor sculpture called ‘Drop’ for inspiration (see picture above).
Glossary: Magnetic, attract, repel, lodestone, Push, pull, fall, Gravity, forces, supermoon, lunar, solar
