I started my PhD in September, and as I finished at work last week for Christmas I found myself contemplating at my desk what I had achieved in that time. And of course, where the time had gone! It feels like (and is!) a long time since I made a blog post, so as I now have some free time, I thought I’d let you know what the starting few months of my PhD was like: what triumphs and traumas have occurred, and how I’m getting into the swing of being a fully fledged research student.
To do this, I thought a ‘day in the life’-esque post would be fun, but then I realised that most of my day consists of tinkering with excel spreadsheets and drinking tea with the ‘occasional’ trip to the lab, so perhaps that wouldn’t be overly exciting. (For evidence of excessive tea-breaks, see below – a text stream from my office mate)
But apart from that, what do I do with my time that warrants 8am-7pm days? Well, geochronology takes a lot of time, so it can feel like an eternity of preparation before you can even think about getting near a mass spectrometer, never mind getting an age!
This preparation includes crushing, sieving, XRF-ing whole rocks, mineral separation, in my case – this means hand picking fresh minerals by hand with a pair of tweezers. An extremely laborious and potentially soul-destroying process if you sneeze and the wrong moment.
XRF, that’s X-Ray Fluorescence Spectrometry, preparation is quite fun, though. It involves melting your rock into what is essentially lava (I know, very cool!), and then squashing it into a glass disk in order to analyse major element oxides such as SiO2, MgO and Al2O3. below is a picture of one of my sample glowing white-hot in a platinum crucible just before I squash it into a disc.
Then of course, you have to undergo chemical separation and purification of the elements you want to analyse, to reduce mass interferences when inside the mass spectrometer. This means column chemistry, which takes a long time, but I find really interesting. For a fun, and unnervingly accurate poem about the woes of column chemistry: http://blog.eag.eu.com/isobloke/a-geochemistry-ditty/
Then, if the Geochemistry Gods have smiled on you, It’s time to load them into a mass spectrometer and cross everything in hope that the samples run well, and the standards give the right value. Would you like to see a mass spectrum from the TIMS machine that my samples are analysed in? Of course you would! (who wouldn’t?)
Unf. Just look at those peak-flats. Ahem, sorry.
All this work for just one single isotope ratio. Why do I do it?
Maybe I’m crazy but I love it. Even though I’ve had a few disasters (some of my samples seem to defy the laws of physics and fractionate heavy isotopes before lighter ones…), but at the end of it, I know something about these rocks that no-one else does. I know when and (hopefully!) how they were formed. It’s a learning curve, and I’m already becoming competent in the lab to know when things are going wrong and what to do about it. And surely that’s one of the reasons for a PhD, To become a competent researcher?
So I might not have any new ages after 3 months of work, but it doesn’t matter overly. The process is as important as the results at this stage.