Why do magnets stick together?

Each magnet has 2 sides or 2 ends called the south pole and the north pole. This is because if you hang a magnet on a thread, its south pole will be facing to the North. This is because the Earth's core is a large and weak magnet. Your small magnet is attracted to the Earth's core so it points to the North. That's the way the magnet rules in what direction.

Magnets do not always stick together

If you hold two magnets rotating in the wrong direction, they will repel each other; in other words, if you hold two magnets rotating with the South or the North pole together, they will push each other out. Give it a try! You will feel like two magnets wrapped with transparent rubber padding do not let them close together. That invisible layer is called the magnetic field.

The same sign repels : We can use curved arrows (called force lines) to draw the shape of the magnetic field around a magnet.The arrows always start from the north pole of the magnet and point towards the south pole.When the same pole is facing each other, the arrows from the two magnets point in opposite directions and the field lines cannot meet.So the two magnets will repel each other.

Only when you put two magnets near each other and one lump the South pole and the other North pole toward each other, they will attract each other. Now you will see the magnetic field is like a rubber band pulling them together.

The opposite attracts each other : When a north pole points towards a south pole, the arrows point in the same direction, so the force field lines can meet and the two magnets attract each other.

So why do magnets attract or repel each other?

You must have heard of energy. It takes energy to have movement.

A standing motorbike or car will only walk when the engine is started, starting the engine is the way to burn gasoline stored in the vehicle. Gasoline contains energy and this energy is released when gasoline burns. When the energy in gasoline is released, a part will turn into moving energy. Scientists call the energy stored in unburnt gasoline a 'potential energy' and the energy that causes the movement after the gasoline burns is 'kinetic energy'.

When you start running, the energy stored in the food is released and partially transformed into the energy that causes your running motion.

So what about magnets?The magnetic field around the magnet contains the 'potential ', and there is a way to transform that potential, which is how you place the two magnets to turn their heads together which will lead to the way they move.

Rules to remember

Everything in this universe obeys a rule. (Why all follow a rule is another question, which is difficult to explain if we do not have complex mathematical knowledge.)

2 magnets will be pushed in the direction of reducing stored energy.

The rule is this: where there is energy stored in an object (and that object is not tied to or trapped in a fixed place) , that object will be pushed towards where its stored energy is. Consumable. This stored energy will decrease and will be replaced by moving energy.

Therefore, if two lumps of magnet are turned differently to each other (the north pole of one lumps back to the south pole of the other), they will come closer together and reduce the energy stored in the magnetic field. They will be attracted to each other, also known as attraction.

If two magnets spin the South pole together or the North pole together, the stored energy will decrease as they move further apart.

So this rule says that two lumps of magnet will be pushed in the direction of reducing stored energy.

This rule also says that when the object is pulled towards the Earth and falls, it is not due to magnetism, but because of gravity. The Earth is also surrounded by a gravitational field containing stored energy.

Unlike magnetism, gravity never pushes because gravity is only one way. Gravity has no North Pole or South Pole at all.

Can you take energy stored in magnetic forever?

Is not.

Once the two magnets are stuck together, you need to return a portion of the 'potential' to the field by pulling the two magnets apart. You cannot take energy without returning anything.

The energy required to pull two magnets apart is your energy, and you get the energy through food. The fruits and vegetables you eat get your energy from other plants and animals, or from the Sun. All energy must come from somewhere.

• How have magnets changed the world?
• What "magic" made the pieces of plastic in this picture stick together?