It may feel like the world’s not moving, but once a year, the Earth orbits the sun, and every 24 days the moon orbits the Earth. What’s more, every 24 hours, the Earth makes a full rotation on its axis. This makes it look as though the sun is moving, but it’s actually us!
Waves are caused mainly by wind and the gravitational pull of the moon affects them too. Waves show us that the surface of the ocean is always moving. When the moon’s gravity pulls, it moves the ocean water, making the sea fuller on the gravitational side and causing waves to move higher up on the beach. This is called high tide. Of course, that means another beach somewhere else is getting emptier. This is called low tide. There are two high tides and two low tides every day. Other factors that cause waves are earthquakes. When there’s an earthquake, the waves formed can be big and dangerous, and are called tsunamis (say: tsoo-nah-mees).
Have you ever tried to figure out how fridge magnets stay stuck to the fridge door? A magnet has two ends called poles – a north pole (or north-seeking pole) and a south pole (or southseeking pole). The north pole attracts the south pole of another magnet, while the north pole of one magnet moves away from the north pole of another.
Did you know? If you cut a magnet in half, you get two new, smaller magnets – each with its own north and south pole.