Naked Science Forum
Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: thedoc on 27/11/2012 15:51:19
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In your previous life as Professor of Earth Sciences at Cambridge University, I always think of Earth sciences as being about continents and rocks and big things like volcanoes. How were you using ISIS to answer those sorts of questions?
Asked by Ben Valsler
Visit the webpage for the podcast in which this question is answered. (http://www.thenakedscientists.com/HTML/podcasts/show/20121125/)
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We answered this question on the show...
Martin - Well, the way the Earth works depends upon the properties of materials that make up the Earth. So, much of the inner Earth is made up of different sorts of silicates and then you come up to the crust and you have many more different types of minerals.
The ISIS neutron source is excellent for understanding the properties and structure of these materials. One of the things that you can do with neutrons which is very, very helpful is that you can do experiment where you put the sample under both high pressure and high temperature. And what you can do with neutrons because neutrons tend to need quite large samples, is you have a very large sample, but what you're able to achieve is actually a very good distribution of temperatures and pressures across the samples, so that it isn’t as if the sample is cold at the outside, hot in the middle, and you get a big range. In fact, it’s really quite good.
Dave - So, this is so you can understand how a material works under immense pressures deep inside the Earth which we wouldn’t know about otherwise.
Martin - Yes, that’s right. You couldn’t understand exactly how it compresses, where the atoms move to when it compresses, if some of the processes inside the mineral to cause it to change shape, the bonding changes, you can see all of that.
Ben - So, it gives us a more realistic picture, basically by being able to interact with the physical properties as well as actually just having a look at the structure.
Martin - Yes, that’s right because things like how stiff the material is, it depends upon where the atoms are in relationship to each other. That’s exactly what we’re learning.