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True! In the summer, the steel of the bridge heats up and it grows slightly. Engineers call this effect “thermal expansion”, and they have to take it into account when designing large structures. On a hot day, the Sydney Harbour Bridge can get 18 centimetres taller! So engineers attached it to the ground with hinges that allow the arch to rise and fall.

False! Sunlight is more than just the light we can see. Infrared (IR) is invisible light that feels warm on our skin. Meanwhile invisible ultraviolet (UV) doesn’t feel like anything, but it damages your cells and causes sunburn. UV can travel through clouds that might block IR and visible light. This is why it’s always a good idea to slap on some sunscreen.

Air is the most important ingredient (by volume) in ice cream! As the fat, milk and sugar is frozen, the mixture has air added to it, trapping it in little bubbles all throughout. These air bubbles make up 30-50% of the ice cream’s volume. If you’ve ever accidentally melted a whole container of ice-cream, you would have noticed it shrink – that’s because some of the air escaped!

The most common waves are caused by wind – think of a choppy ocean on a breezy beach day. The gravitational pull of the Moon (and the Sun) causes high tide and low tide. Tides move a lot of water, and that movement can cause waves big and small, the biggest Moon waves are called tidal bores and happen in bays and rivers. Meanwhile, Tsunamis are huge waves caused by underwater landslides or earthquakes.

True! But this is just a coincidence, and it’s only true for people in the Southern Hemisphere. The Earth is closer to the Sun in January, and further away in July. Which means in the Northern Hemisphere, summer happens when the Earth is furthest from the Sun. In any case the distance only changes by about 3% over the entire year.