SCIENCE:

ASTRONOMY


Our April meeting was held as usual at the Driftwood Spars Hotel St Agnes, the meeting was well attended.
The talk which included a number of short videos was on 'Black Holes', one of the strangest objects in our universe. We saw how building on the work of Newton Einstein's 1915 theory of general relativity led to a understanding of gravity in terms of the bending of 4 dimensional spacetime. Using Einstein's result physicists during the early 20th century were able to predict the possibility of black holes, neutron stars and white dwarf stars and the conditions needed for their formation. We looked at how astronomers have been able to detect black holes including recent experiments to measure gravitational waves caused by two black holes coalescing. The talk was followed by an interesting question and answer session.
Our next meeting will be a week later than usual on Monday the 20th May, 2pm at the Driftwood Spars.
The subject of the talk will be 'The Moon and where it came from'. After reminding ourselves about the formation of the solar system we will look at the various ideas put forward for the formation of the Moon, including the modern theory based on analysis of lunar material. We will then remind ourselves of the remarkable events of nearly 50 years ago, the first Moon landing.
The May meeting will be the last of this session, the Astronomy Group will resume after the summer break in October.


Bob Williams 01326 219334


 

SCIENCE MEETING.


Please note that the time and day of the meetings for 2018 has been changed to 10:30 on the second Thursday of month at the Victoria Inn, Threemilestone Coffee is available from 10.00 am.

The Vic are offering us a special morning snack deal. A croissant + coffee for £4:00 or bacon bap + coffee for £5:00. Also if you are planning to have lunch and/or attending the quiz later, then reserve a table in advance on 01872 278313 and mention that you are with the science or quiz group. 

 


In April Arthur Willis gave an interesting talk on ‘Radioactive Waste Management Decommissioning and Disposal in the UK’,an area in which he was involved with for most of his career in the nuclear industry.  

Click here for the slides of the presentation.  
Waste management and decommissioning nuclear reactors are key challenges for nuclear power if it is to continue to be deployed in the UK. Radioactive waste can be in solid, liquid and gaseous form and is mainly produced by nuclear power stations, reprocessing of spent fuel, weapons manufacture and nuclear plant decommissioning. For the first 60 years of the nuclear industry waste management was neglected. However, the establishment of the Nuclear Decommissioning Authority(NDA) in 2004 resulted in substantial progress with improved standards for a safe and efficient clean up of our nuclear legacy involving a detailed inventory of all sources and quantities of radioactive waste. Current stocks and an estimate of future waste until 2125 would fill a volume roughly the size of Wembley stadium.  About 90% of this is either very low level or low level solid waste and goes for shallow burial. Around 10% is intermediate level waste such as ion-exchange sludges, which get packaged into cement- based material and stored in stainless steel drums. Currently these wastes are being stored a each site of origin, although eventually they will go to a deep geological repository. High level waste represents only 0.03% and is mainly fuel reprocessing liquid waste containing highly radioactive fission products. This is converted into a stable solid form and then encapsulated in glass in stainless steel canisters. As these generate heat they require cooling and long term deep ground storage.  
The NDA also oversees the decommissioning of our redundant nuclear power plants and develops waste disposal routes, These take place over 3 phases which in total add up to 100 years. Dismantling the reactor core(phase 3) does not take place until after 70 years for safety reasons, by allowing for radioactive decay.  
Although we need to safely store small amounts of highly radioactive waste for a very long time, nuclear power still needs to be an integral part of our energy programme if we are going to phase out our dependence on fossil fuels. This is a small price to pay in order to avoid a likely climate a catastrophe from the rising levels of carbon dioxide.  
Slides from the talk are available on the website.  


On 9th May a well attended meeting heard an excellent and riveting talk by Steve Tarrant, Assistant Mine Manager, about the exciting new developments planned for South Crofty mine that will re-establish the fortunes of Cornish tin as a major world producer. Tin has been mined at South Crofty for over 400 years until the crash in the world tin price in 1985 that lead to closure of tin mines in Cornwall, South Crofty being the last one in 1998.
What has changed now is that tin has become the number one metal impacted by new technology since the use of lead-free solder. This has resulted in a large demand for tin from industries based on electronics, including battery technology, solar panels and power storage units, which now use 48% of the global production. As demand is outstripping supply, the price of tin has rocketed making this the main driver for re-opening South Crofty by Strongbow Exploration, a Canadian company who have purchased a mineral licence valid until 2071.
The South Crofty mine is particularly attractive as it has high grade tin(1.8%). Its total historic tin yield was 450,000 tonnes. A preliminary economic assessment estimates that 1.6 million tonnes could now be extracted with a mine working life of 8 years. With further potential from associated mines, the amount of tin produced could rise three fold with a mine working life of 20 years.
Most of the tin is in the lower mine, which extends below 450 metres. It is planned to utilise much of the existing infrastructure and shafts. The major challenges that have to be overcome are to produce a dewatering system using high-head multi-stage submersible pumps as the existing water level is at 50 metres. A water treatment plant is also required which involves a 6-stage process to remove toxic levels of metals and arsenic as a sludge, so that ‘clean water’ can be discharged into the Red river.
There is a strong community and government support to see South Crofty producing tin again with the creation of 275 jobs. Could now be a good time to buy shares in Cornish tin?  For a more detailed information on this project visit www.strongbowexploration.com/projects/uk/south-crofty/ .

On 13th June Dr Paul Lucas will talk on “How our Bodies deal with Toxins and Drugs”
We are exposed to a variety of toxins from other species e.g. plants and microorganisms, and other environmental sources. Our own metabolism also produces a number of substances which, if allowed to accumulate, would be toxic. We've evolved an array of defence systems to deal with these by minimising their absorption into the body and/or hastening their removal from it. Very vulnerable tissues, particularly the brain, have additional protective mechanisms. These systems which include a wide range of enzymes and membrane carrier proteins, have proved to be sufficiently flexible to provide some protection from drugs and other synthetic chemicals to which we may be exposed even though many of these are novel compounds that have not previously occurred in nature. These protective mechanisms show considerable variation between individuals. Individual enzymes or carriers may be under or over expressed or present in a less or more active forms resulting in very different sensitivities to alcohol and other drugs as well as diseases including jaundice and endocrine problems. They may also contribute to neuro-degenerative conditions such as Parkinson's and Alzheimer's diseases.

Roy Fisher  01872 270528      raf59@talktalk.net


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For all activities, please check our Google Calendar to confirm dates, times and locations

Pat Harrod & Wendy MorrisGroups coordinator