The red dirt of the Australian Outback is found in the ice of New Zealand glaciers. Enormous dust storms sweep the soil high into the atmosphere, where it plays an important part in our climate. Dust acts as 'seeds' for raindrops, helping the water vapour to form rain by giving the vapour something to condense around. As well, dust enriches the soil, replacing nutrients that have been leached out by weathering. It can travel enormous distances, across oceans. So, we send NZ our dirt, and they send us kiwi fruit - which our dust has helped grow by keeping the soil fertile. Sounds like a fair exchange…

What would you expect to happen under these conditions? Take a log, and carefully weigh it. Now burn it in a special oven, where you can collect all the gases the log emits while burning, and yet still supply plenty of oxygen to keep the fire alight. The log must be reduced completely to ashes. Now, weigh the ashes and the gases. Will the sum of the products of the burnt log weigh more or less than the original log?
Most people believe that the original log will weigh more…and they are wrong. When you burn something, it is oxidised. This means that the chemicals are combined with oxygen during the process. And so, the gases and the ashes have had oxygen added to their composition…and the added oxygen will mean they weight more than the original log.

Eighty percent of all house dust consists of shed skin cells. Yep, no matter how much you might dust and polish, it will be back! So, if it's discarded human tissue, why are so many people allergic to house dust? It's not the actual dust that causes the problem, but its inhabitants: the dust mites. Dust mites live off the skin cells that humans shed on a daily basis, and then scatter their own droppings around. It's these droppings that trigger an allergic reaction in susceptible people (like me). These days, you can purchase products that will help control the numbers of mites around your house. But you won't be able to ever get rid of the dust on a permanent basis…not while you're alive.

Why is anything greasy so dreadful to the touch? (Or at least, that's the excuse my family give when I want them to slather on the sunscreen.) The touch receptors in your skin are most sensitive to any contact - particularly pain. In fact, often a pain message is acted upon before the signal has reached your head to make you say 'ouch'. An example of this is when you accidentally touch a piece of hot metal, say a car door on a summer's day; you will have pulled away from the door before your hand starts to sting. Grease, on the other hand, is made of 'slippery' substances. You touch receptors are fooled by the sensation…they don't have it programmed for a 'pain' or a 'pleasure' response. But, as your instincts are to avoid possible sources of pain, so some people read 'slippery' as unpleasant.