Spit, sawdust & science
PubhD Leicester reaches its fourth event, this time at Duffy’s Irish Pub. The format is the same as always – 10 minute talk followed by a Q and A session. For this the speakers are rewarded with drink.
First up is Steve who is researching detector physics at the Space research Centre. But how does his new detector differ from current technology?
A normal camera, such as the one in our smart phone, uses a Charge Collective Device (CCD) It’s made up of pixels, each one a semi-conductor that detects light. Each pixel can detect a photon and builds up an image.
Instead, Steve’s detector uses Micro-Channel Plates. This is made up of millions of thin glass tubes. When a photo hits one of these tubes it produces an electron. As this electron bounces down the tube, it’s amplified. In fact one electron can be amplified to as much as one million electrons.
At the end of the tubes is a readout board. On the board are 4 connectors that collect the charge. The different ratios from the connectors show where the electrons hit e.g distance along x-axis = (A+B)/(A+B+C+D), distance along the y-axis = (A+C)/(A+B+C+D)
The image is then converted into digital and finally fed through a digital signal processor.
While a normal CCD works in the visible spectrum, Steve’s MCP can capture images from the ultraviolet spectrum. For this reason it’s being sent to Jupiter in 2022 in order to photograph the aurora. It’s far more suited to this task than a solid state CCD as it isn’t damaged by the very particles that actually create the aurora.
Key learning: The auroras on Jupiter are at the north and south poles just like on Earth
Middle man Kieran is a geologist. He is looking at sediment physical properties and is preparing to go on a summer expedition to Dogger Bank (west or southwest 5-7, occasionally 8)
One way to examine sediment is to drill a borehole and take out a core. These are 6 inches in diameter and can tell you about the properties of the sediment such as how dense it is and its acoustic properties. However, as you depressurise the core, you lose some of its properties.
These boreholes vary in depth but can cost as much as $40M per kilometre. Hence there are other ways to investigate the sediment. You can look at the gamma radiation coming from the rock; clay is radioactive while sand isn’t. You can also fire acoustic energy into the rock and then detect the reflections using 48 sensors behind your ship. However, the resolution of this method is poor.
With so much seabed in the north sea and so few boreholes; how do you bridge the resolution gap? Can we come up with better statistical technique to draw better contours between similar areas?
Kieran is hoping that his new modelling method will be able to answer these questions. There are plans to build a wind farm on Dogger Bank and the engineers involved will need to know the physical properties of the sediment there before they begin construction.
Dogger Bank will be a good test for this new model. It was formed from a glacier and so has a highly complex geology including mud-stone and shale.
Key learning: Modern scientific expeditions come with a gym, cinema and souvenir shop on-board ship
Finally there is Geoff who is looking at the history of science. Primarily, what did it mean to be a scientist in the 19th century?
In the 19th century everything is in flux – in 1800 there are 1,000 periodicals, by the end of the century there are 10,000. The most famous of these is Nature which was founded in 1869. This was also the century where geology and astronomy were formalised.
But what did it mean to be a professional scientist? How did it differ from today? Did they have an equivalent to today’s citizen scientists? In fact it was in the 19th century that there was the development of the amateur into the professional.
Science Gossip was another periodical that started in the 19th century and lasted for around 40 years. It was written by amateur naturalists and was designed to be read by the lay-person.
Geoff’s research is looking at the illustrations in Science Gossip. He’s looking at whether each page contains any illustrations and if they do, what the illustrations are of. This should show whether any particular branch of science requires illustrations more than any other.
At the time, most articles weren’t vetted. In fact it, in the 1830s and 1840s we don’t even know who contributed these articles. It was only as the century went on that authorship became more popular. So there is an interesting question about whether an illustration gives an author more acceptance.
Key learning: You can help Geoff with his research (and become a citizen scientist yourself) by visiting www.sciencegossip.org