Many of you have written in to ask our experts some of life’s most baffling questions. What’s inside a black hole? Where does dust come from? How fast can a dolphin swim? How do they get chocolate on Maltesers without leaving a little flat bit? There are many questions about the world that perplex human beings, but thankfully some help is at hand from How It Works magazine and the Science Museum
Every issue a panel of experts from the Science Museum will be applying their expert knowledge to our readers’ questions and you can get involved by either mailing us your question at firstname.lastname@example.org or by leaving a message on the forum. We can’t guarantee an immediate answer, but we promise that the best questions will find their way into the pages of How it Works. In the meantime enjoy these questions and answers from issue three on sale now.
Where do birds’ feathers get their colours from?
Dennis Collins, email
The majority of the colours found in birds’ feathers come from pigments obtained from the food they eat. These pigments are responsible for which colours of the visible light spectrum are absorbed or reflected. There are different groups of pigments associated with certain colours. The nano structure of the feathers can also produce an optical illusion.
How are mushroom clouds formed?
Alec Rose, email
Any large explosion can create a mushroom cloud. They’re formed when low-density gases of great heat near the Earth’s surface collide. This ball of gas shoots upwards to form a column. It then cools and spreads further afield forming the top part of the mushroom, and is fuelled by the stem constantly sucking up debris and fire in its centre from the explosion.
How do boomerangs work?
Adam Joseph, email
The two arms of the boomerang are a lot like the wings of an aeroplane in that the faster they move through the air the more lift they generate. Unlike aeroplane wings they spin as they move through the air and this combination of spin and forward movement means that some parts of the boomerang are moving quicker than others. Because the boomerang is spinning the aerodynamic lift occurs at different rates on different parts of the boomerang, as the wings of the boomerang are thrown at an angle the net lift is towards the centre of the circle that the boomerang moves on. A spinning boomerang is very similar to a spinning gyroscope and the gyroscopic effect makes the boomerang circle around at just the right rate.