The accidental scientist

  It looked like the whole Northern hemisphere was freezing last week. While my niece was able to walk on the sea for the first time in her life near Helsinki, the thermometer hit -18 degrees in Dallas, last Tuesday. Is that global warming? Well, maybe. It looks like the polar vortex got a bit crazy. In a “ normal ” situation the polar vortex is pretty stable. It is a cold mass of air that spins around the poles in the stratosphere (8 to 50km of altitude). It is contained by the jet stream, a ring of very fast wind that also belongs to the lower stratosphere. All this is inherently stable because the pole area is cold and has a low pressure, and it is surrounded by warmer air at a higher pressure. Climate change causes the poles to warm up a lot faster than the rest. So the jet stream weakens, gets all wavy and can ’ t contain the polar vortex any more. Some bits of it can even separate and wander South as far as Texas. So they get a cold snap, courtesy of global warming. Climat

Question of the week: which country has the biggest banana plantation in Europe? Answer: Iceland. Surprising isn ’ t it. It ’ s done with renewable energy: geothermal heat. They use it to heat huge greenhouses to grow tomatoes, cucumbers and yes, bananas. Iceland hardly imports any of these goods. Hot water is also used to generate 25% of Iceland ’ s electricity. The other 75% come from hydro. A long time ago, Iceland depended on imported coal for power. Not anymore. It got very expensive sometime in the 70 ’ s so they just ditched it. Nowadays all the electricity produced in Iceland comes from renewables. Meanwhile, what is Australia doing in this area? OK, we don ’ t have much hot water coming out of the ground, but we have a lot more sunshine than Iceland. In 2019 the total power used in Australia was around 265 TWh (terawatt hour: 1 terawatt = 1 1 billion kilowatt). Today I wondered how the production of my humble 5kW rooftop solar setup compares to that. It produces about

I like to keep a few coins in a corner of my desk. The reason is my Thursday night meeting with my mates. I have a reputation for having one beer only (typically a Black Fish), paid in coins. I don't use cash a lot these days but every time I handle these coins, I swear I can smell them. Or do I? There is a very old saying: « money doesn't stink ». Apparently, the Roman emperor Vespasian coined it around 70 A.D. He had created a tax on urine. Very successful. Indeed, in those days urine was a rare commodity for material dyeing. His son Titus was not impressed though and he pulled his leg about it. Totally unphased, Vespasian stuck a coin under his son's nose saying « pecunia non olet », money does not stink. What is a smell? We smell something when some volatile chemicals get pumped into our nose. Coins are made of metal, that does not evaporate easily. So Vespasian nailed it, they don't smell. But chemical stuff happens if we rub a coin against our skin. The skin

Space physics is not that hard. If I get it (or at least some of it … ) most of us can. Really? Well, let ’ s have a go. We looked at the Earth geomagnetic field last week. How does it look like from outer space? Like a huge pumpkin. Imagine the Earth is an orange with a magnet (yes, North pole pointing South) in the middle of it. Then put it in the centre of the pumpkin. This gives you a fair idea of what the field lines look like. Or at least what they would look like if we switched off the Sun for a while. The Sun constantly bombards us with high-speed electrons and ions. This is called the solar wind. This can be nasty. Get an overdose of it and your DNA can change. Besides, it could blow away our atmosphere, which is what happened to Mars ages ago. Why? Because Mars does not have a magnetic field. The Earth magnetic field deflects the solar wind. The pumpkin gets a bit distorted in the process but who cares. Most of the wind goes harmlessly past us, some of it gets trapped in bana