The world’s largest working watermill is the Laxey Wheel, also called the Lady Isabella. It can be found on the Isle of Man. A small island which lies in the middle of the Irish Sea between Britain and Ireland. As one can see from the photograph, the wheel is huge and towers over the nearby [more...]
If you want to float a thing that weighs one kilogram in water, how much water do you need? First, of course, the thing must float in water: a piece of wood, a can of peanuts or glass of instant coffee, any closed container weighing one kilogram (2.2 lb) that is larger than one liter [more...]
To understand why water is wet, we first need to know what “wet” means. Obviously, for something to be wet it must be a liquid so that you can feel it as you run your hands through it. Carbon dioxide isn’t wet. Gravel isn’t wet. But for something to be wet, it must also stick [more...]
It was noticed in 2006 that professional drivers were five times as likely to catch Legionnaire’s disease as anyone else, and the UK’s Health Protection Agency set out to find out why. They surveyed the habits of survivors of the disease, and of a control group without the disease. It turned out that those who [more...]
Few people know how much the water from their cold tap costs, and even fewer realise how much the water from their hot tap costs. The cost of cold water in the UK is around a quarter of a penny per liter, so that's our starting point. How much more does it cost to heat [more...]
The expression meander is used to describe something that winds around without crossing itself, be it it a creek or river, or a repeating decoration in art or architecture, or also the description of such a line in mathematics. The word dates back to classical Greece, the name then and now for a river in [more...]
If you worry about radon radiation, radio waves emitted by cellphones, potential risks of cancer from the fumes of hot cooking oil, and many other things, you may cringe at reading about dihydrogen monoxide (DHMO). You can at least be reassured that dihydrogen monoxide in pure form is not carcinogenic, but you will not be [more...]
In the United Kingdom, oxidane kills over five hundred people each year; in the United States it's more than five thousand per year. The substance is so deadly because it can harm people in a variety of different ways. If liquid oxidane gets into the lungs it blocks the entry of oxygen into the blood, [more...]
The Aral Sea should be the largest body of water in Uzbekistan, shared with Kazakhstan, but since the 1960s it has shrunk to 10-20% of its original volume, entirely due to human intervention by draining off water from the Amu Darya (the Oxus river in classical times) to irrigate cotton fields in Uzbekistan. A good [more...]
The euphemism for going to the toilet used to be “spending a penny”. This probably referred to the price paid to visit a public toilet cubicle back then. But how much do we pay for the water that we flush down the loo? People pay different amounts for their water, but I’ve arbitrarily used the [more...]
Water is necessary for life; we can’t live more than a couple of days without it. And yet, too much of it can kill us. If we drink very large amounts of water too rapidly, our kidneys cannot dispose of it fast enough. The water enters our cells and makes them swell. Inside the brain, [more...]
There are two standard ways to decide on which side to mount the hot tap. I suggest you enquire locally as to which is in use in your area. The first approach is to always put the cold tap (cold faucet) on the right and the hot tap on the left. The reasoning behind this [more...]