The accidental scientist

      I recently read an article saying that the Gulf Stream was slowing down. This would be bad news for France and the UK, I thought. This part of the world still enjoys mild winters. For example Edinburgh is at the same latitude as Moscow and doesn’t get nearly as cold. What powers the Gulf Stream? In short, it’s three giant pumps. The Gulf Stream is part of a global system called the Thermohaline Circulation. In Greek, this means temperature (thermo) and salinity (haline). Cold water is heavier than warm water so it sinks. Salty water is heavier than fresh water so it sinks. The three giant pumps are the three deep water formation places shown on the map. There, water sinks because it is cold and because when sea ice forms, some salt is left behind so the water gets saltier. All this cold salty water sinks fast. It is replaced by warm(er) surface water and it feeds the deep cold water currents. The trouble is that global warming slows this down in two ways: 1- The p

  Many of us remember the 2004 tsunami. It was the deadliest in history, killing 230,000 people. My mate David was in Kuala Lumpur, Malaysia, at the time and he told me KL was not affected. However we both went to Penang soon after and found out that 50 people had died there on a single beach. A tsunami happens when a very large volume of water is suddenly displaced. This can happen at the boundary between two tectonic plates when one plate suddenly slips under, or over the other. In the 2004 tsunami case, the epicentre was somewhere near the Northern tip Sumatra, on the West side. This creates a circular wave in the water, a bit like when you throw a stone in a pond. Only much bigger and faster. The odd thing is that in open water, the wave is hardly noticeable with a height of less than 1 m. But it moves at a frightening speed, like 500 to 1000 km/h, and hardly loses any energy. That’s why the 2004 beast killed people all the way to the East coast of Africa. When it

  Last week I heard on the ABC that the Macquarie Island research station (Macca) may be moved to higher grounds because of the risk of tsunami. Back in 2000 Macca was my home away from home! I even remember a minor earthquake there and then. The station is built on an isthmus between a ca p e called North Head and the rest of the island which consists mainly of a plateau at about 200m of altitude. When the westerlies blow about 70 knots, it is not uncommon to see a big wave cross the isthmus. This annoys the elephant seals a bit, but a tsunami… I can’t remember this being mentioned during the 9 months training or the year I spent there. A tsunami is a different kind of wave. It happens when a very large volume of water suddenly moves up from the bottom of the sea or lake. This kind of movement may be caused by an earthquake, a sub-sea landslide, a volcanic eruption or a meteorite impact. Located 1600km South-East of Hobart, Macca sits on the boundary between the Pacific

  Homeopathic globules   Homeopathy is often described as pseudoscience. It was conceived in 1796 by the German physician Samuel Hahnemann . It is based on the assumption that a substance that causes a symptom can be used to cure it when used at a very low concentration. So homeopathic remedies consist of substances very diluted in water. So diluted that the probability to find a single molecule of the original substance in the final product is almost 0. It is said that the water keeps the memory of the substance and that this memory has the desired curative effect. The patient may drink some of this water, or alternatively swallow some tiny globules that have similar properties. What a lot of rubbish, I thought… Until that day many years ago when I managed to catch chicken pox at the age of 40+. I went to see a doctor who diagnosed me and promptly sent me into confinement for 2 weeks. Chicken pox is caused by a virus, extremely contagious and there is no known remedy fo

  After a short break courtesy of La Nina, it looks like climate change is getting crazy again. We haven’t been too affected so far in the Northern Rivers this year but between floods in Germany, huge bushfires from California to Siberia, and recently sand storms in China, we are well into it. It’s only in the last few years that climate change has been in the media, but its main cause, i.e. the greenhouse effect, has been known for a long time. Until recently we thought an Irish scientist named John Tyndall had nailed it. But according to a newly digitised copy of the American Journal of Science and Arts, a lady named Eunice Foote beat him by a few years. Armed with two glass cylinders and four mercury thermometers, Eunice engaged in a series of experiments. With air in one cylinder, she filled the other one with various gases and compared the temperature rises of the cylinders when exposed to sunlight. And guess what, she found that CO 2 had the cake. It got u