Queensland floods: How can water be so destructive?
d ~ 33'446'400 km: day 13
We have all seen the floods that have ripped apart Queensland Australia, and in a time that would normally mark the end of rainy season in Sri Lanka have also seen abnormal cloud outbursts driving nearly 325,000 people from their homes, according to last reports. Clearly water is an essential part in keeping us nourished in our day-to-day lives but its disastrous nature can also make us feel powerless.
In a sense, flood water is like a leaking battery. Energy from the sun lifts water up (by evaporation) and gives it a huge amount of gravitational potential energy, charging the battery. When you look at a river, you're looking directly at energy on the move. On the plus side, we can use some of that energy to generate electricity to run ram pumps, one of my favourite inventions. On the negative side, the huge amount of available energy means a lot of stuff that's been broken and moved can be left behind. This is what enables water to carve river beds out of solid rock, to devastate any human habitation that gets in the way of a tsunami and to pick up things like cars and boulders and carry them off. Something gets in the way of an aqueous river of energy, and pays the price.
Love-hate relationship with water
Humanity really does have a love-hate relationship with the power of water, and the people of Queensland Australia are currently wading through the second half of that association. The problem with water is that it's really heavy and flows fairly easily. But the best thing about water is also that it's really heavy and flows fairly easily. The ocean of air that we live in also flows easily, but it's less dense than we are (so a fixed volume of air is much lighter than the same volume of human) and that makes all the difference. When we push on the air, there isn't much resistance. But when we push on water, it really pushes back.
Helen Czerski is co-presenter of 23 degrees