BRAINDUMP

Amazing answers to your curious questions

Yes, all of the planets and nearly all asteroids orbit in the same direction – anticlockwise if you were looking down on the Solar System from way above Earth’s north pole – and they all orbit close to the same flat plane as well. This is because they, along with the Sun itself, all formed from the same protoplanetary nebula – a cloud of interstellar gas and dust that began to collapse under its own gravity around 5 billion years ago.

As the nebula became more concentrated, it flattened and began to spin more quickly. The Sun, asteroids and planets then condensed out of different parts of this flattened disc. The few objects that follow backward, or retrograde, orbits – and those whose orbits are sharply tilted to the plane of the Solar System – tend to be the result of close encounters with the disruptive gravity of a giant body like Jupiter.

WHAT’S THE DIFFERENCE BETWEEN POPCORN AND PUFFED RICE?

You can pop corn with any heat source, but to puff rice you also need a pressure chamber. Popcorn is the only grain that can be ‘puffed’ at home because it has the right moisture content – 14 per cent – and a fragile hull. When the temperature of the kernel reaches 100 degrees Celsius, water starts to boil inside the starchy cells of the endosperm, causing them to expand. At 175 degrees Celsius, the superheated starchy material explodes through the hull of the kernel and instantly cools to form a chewy bubble.

Grains of rice don’t contain enough moisture to pop under normal conditions. Instead, the rice must be heated in a pressure chamber at up to 14 kilograms per square centimetre. When the chamber is opened, the sudden change in pressure and volume causes the hot starch cells in the rice to expand rapidly, bursting through and puffing up like popcorn.

WHICH BIRD MIGRATES THE FARTHEST IN WINTER?

The Arctic tern holds the record, making a round trip of 44,000 miles a year. It spends summer in the Arctic and then flies halfway around the world for a second summer in Antarctica. Being seabirds, Arctic terns can feed on fish and krill along the way, but the bar-tailed godwit is a wader and flies an incredible 7,100 miles from Alaska to New Zealand in just nine days without once stopping to eat, drink or rest. The lifetime achievement record, however, must go to the Manx shearwater. This species migrates between Norway and the Falkland Islands each year, and since they can live for up to 50 years, some individuals are estimated to have flown 5 million miles – that’s more than ten round trips to the Moon!