Jul 16, 2007
Arctic droughts, plastic breakdown, and liquid telescopes
This month’s intute Spotlight from David Bradley is now available online:
Telescopic lunar liquid: A liquid reflector for a vast Newtonian telescope to be based on the surface of the Moon is being developed by scientists in Canada, UK, and US. The new type of telescope could provide the clearest views yet of ancient parts of the Universe.
Arctic drought – Frozen Arctic ponds that have persisted for millennia are drying out during the polar summer, according to evidence from Canadian scientists. Marianne Douglas of the Canadian Circumpolar Institute at the University of Alberta together with John Smol, of Queen’s University, have studied these shallow ponds that dot the Arctic landscape for more than two decades. Changes in such environmental features provide an important indication of how particular regions are being affected by climate change. Douglas and Smol have analysed 24 years of detailed data, including water quality and water levels from about forty Arctic ponds. The data represents the longest record of systematic fresh water monitoring in the high Arctic.
Plastic breakdown – As if to show just how diverse the properties and applications of ionic liquids can be, a new era in recycling of plastics is fast approaching thanks to scientists in Japan. The researchers have developed a process based on ionic liquids that can depolymerise plastic materials back into the component monomers from which they were originally made. The team says the method can then be used to convert waste polymers into new high-quality plastics.
For more site news from Intute Sciences, see Thursday’s Sciencebase.
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July 25th, 2007 at 9:23 pm
Hi David:
I have been in the high Arctic doing fieldwork and have been away from email and phones for almost 3 weeks. In fact, I am now in Resolute Bay with only a slow email connection.
In addition to the 24 years monitoring data, we have detailed paleolimnological data – sediment data tracking changes in the lakes that predate the 24 year monitoring window. So we have paleo data going back several millennia. The ponds did not dry up 6000 years ago – they did not yet exist (the land they are on had not yet uplifted from the sea). This was an area of glaciation and at that time the ponds had not yet formed. So we have our paleo data tracking what happened since the ponds forms, which we dovetail with the 24 years of monitoring data.
More info is at:
http://biology.queensu.ca/~pearl/Threshold.htm
And an earlier study may be of interest at:
http://biology.queensu.ca/~pearl/PNAS2005.htm
Best wishes, John
July 17th, 2007 at 7:37 am
You’re right Paul, it has long been known that a liquid with a curved surface can be used to focus light. The novelty in this work is not in the use of liquids for focusing rather the discovery that an ionic liquid solvent can be coated with a very thin layer of silver. This system would emulate the focusing properties of a liquid mercury reflector but have the advantage of being far less dense and so more transportable to the moon as well as being non-volatile and so not simply boiling away in the near vacuum environment of the moon’s surface.
July 16th, 2007 at 11:55 pm
Regarding the liquid telescope, using liquids to focus happens to me every once in awhile on a small scale. When I take my contacts out and splash water on my face sometimes a bead of water on my eye will momentarily focus or correct my vision. Of course spinning mercury into a parabolic bowl for reflection purposes is more advanced. However, a concept must derive from somewhere, correct? Newton, apple, gravity anyone?
July 16th, 2007 at 4:55 pm
Thanks for the question Scotty. It alludes to an interesting point. I will speak to the team and report back later.
July 16th, 2007 at 2:47 pm
They have only 24 years of data, so they don’t have detailed data from the 1945-1975 global cooling period. Too bad. And these ponds are 6,000 years old, so why did they dry up 6,000 years ago?