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| Little Auk |
On Saturday I set off on a mission to fill a gaping hole in my UK bird list by means of a Little Auk which had recently taken up residence at Weymouth Harbour. I would not call it a rare bird as such, many hundreds pass down the east coast during late autumn on migration, but views are normally distant and you can spend the whole day sea watching without seeing one only to find a report of a hundred flying by the spot you were starting at a few days later. These sea watching views are normally distant and brief and somewhat physically challenging! What is rare is to have one stay in a pleasant location allowing decent views. This exact opportunity presented itself when last week a bird took a liking to Weymouth harbour and its multitude of moored boats.
The little Auk as its name suggests is our smallest and most northern Auk, no bigger than a Starling. It is black and white with a very small stubby bill. In flight its small wings are flapped rapidly in a distinctive whirling fashion. They breed in large noisy colonies on islands in the high Artic and winter out to sea in the North Atlantic.
I set off from home after a pleasant early morning dog walking in the surrounding countryside and arrived at the harbour just after midday. The bird had been seen at various locations in the long narrow harbour from a bridge down to the lifeboat spanning perhaps 500m. The many boats of all shapes and sizes moored along the various platoons provided almost endless nooks and crannies for the Auk to disappear in. The Auk was also highly mobile when feeding, appearing very briefly on the surface to catch its breath before disappearing again under the water. They are sublime swimmers and will quite often surface a long way from where they dived. I read that they mainly eat crustaceans, especially copepods, and an adult bird needs on average to eat 60,000 individuals per day. This certainly explained why it was spending so long under water!
What with spending most of its time underwater and the many hiding places afforded by the boats, it could be incredible elusive at times. When I arrived there was no sign for the first 45 minutes but it then appeared from nowhere right in front of me before immediately diving and disappearing again. Without being observed again on the surface, it would soon be found in a different location several hundred meters from where it dived. Now, rather intriguingly, two boatsman swore blind to me that they had seen two off the end of their boat when they were down in the harbour. While this would explain why it would suddenly be relocated hundreds of meters from its last position, it would surely be very surprising indeed if an experienced birder hadn’t seen them both together at the same time and, perhaps, even got a photograph of them side by side. The only possible confusion I can think of is that one of the birds the boaters saw was a Little Grebe as there was at least one in the harbour but I don’t see how you would easily confuse one with a Little Auk. While I am dubious about two birds being present, birding has taught me you can’t go far wrong if you expect the unexpected!
After giving all present a right old run around for a couple of hours, the bird finally settled comparatively close to the harbour wall allowing everyone to get the pictures they so craved. Resting on the water, it was almost Penguin like, an impression confirmed by my wife when she looked at my pictures later.
OK so off we go again on a physics related subject and one that I feel quite passionate about. My mission here is to convince you that not all nuclear is bad and, in fact, that one particular type potential offers the route to endless clean carbon neutral energy. It’s really no surprise that the word nuclear has such terrible connotations, c.f. horrific weapons of mass destruction, Chernobyl etc. When my old company developed the first body scanners in collaboration with Nottingham university in the seventies it was quickly decided to drop the word nuclear from nuclear magnetic resonance imaging for that very reason.
There are currently two basic methods for generating electricity. You can use the power of sunlight to create an electrical current in a semiconductor, so called solar power, or you can either burn a fuel or use the power of the wind to turn a turbine. In the case of burning a fuel, you normally use the heat generated to turn water into steam which is then used to rotate the turbine. This heat can be generated by fossil fuels or nuclear reactions. Now here is the important part about nuclear energy, there are two types of nuclear reaction that produce energy, fusion and fission.
All current nuclear reactors use fission. In this process a heavy unstable element, such as Uranium or Plutonium decays into a lighter element with the reduction in mass converted into energy via Einstein’s famous equation. It is this energy that is used to heat the water and turn it into steam. There are two massive problems with this. Firstly, the lighter elements produced tend to themselves be radioactive with half-life’s stretching into hundreds of thousands of years giving you the problem of where the heck to store it and the dire consequences if any of it escapes. Secondly, apart from their radioactivity, these heavy metals by themselves are extremely chemically toxic.
The other nuclear reaction process is called fusion where very light elements, normally Hydrogen or its isotopes are fused together to make a heavier element, e.g. Helium, again with the release of energy. If we could use this energy to generate electrical power there would be two massive advantages over current fission reactors. Firstly the fuel, i.e hydrogen, is not toxic. Secondly, any radioactive by products have very short half-life’s meaning that the radioactivity disappears rapidly leaving no nasty waste products to store and haunt future generations.
Why then, I hear you ask, do we not make fusion rather than fission reactors. The answer is that making a viable fusion reactor is very hard and is technology that we have not yet mastered. Fusion is the process that powers the sun and hence makes life on earth possible. The sun fuses about 600 million tons of hydrogen every second, yielding 596 million tons of helium. The remaining four million tons of hydrogen are converted to energy, which makes the sun shine and gives us life. To fuse two hydrogen atoms together to make helium you must first overcome the enormous electromagnetic repulsion between them. The sun achieves this by means of its enormous gravity which forces the hydrogen nuclei together at high temperatures.
So in order to make a fusion reactor we have to create a sun on earth. The lower densities we can generate without the benefit of the suns enormous gravity equates to requiring a temperature of around 100 million degrees, this is about 20,000 times hotter than the surface of the sun! Amongst the many problems researchers are grappling with is how to confine, i.e hold, something at this temperature. There is no material substance that can do this so you have to use incredible strong magnets to hold the hot gas with magnetic fields. Confining the hot gas (actual plasma) for long enough and getting it to a high enough temperature to get more energy out than you put in, a basic requirement for power generation, is hence incredibly challenging. A prototype reactor has been operating for many years at Culham and my passion for fusion has at least been partially driven by my association with Culham, initially as a consultant and then as a board member, over a number of years working with the incredibly talented and passionate people there. The government has recently announced funding for a new reactor called STEP, a prototype fusion energy plant and a massive step toward commercial fusion power. Culham will build STEP at another as yet to be decided site in the UK. You can read more about this here
Great photos Jim!
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