I went back to the Point, and as I was going up the escalator I could see George RR Martin at a table below, with a long queue of people waiting for him to sign things for them. I heard that people started queuing at 2pm for the signing at 4pm.
I was going for more astronomy, at the talk about I-LOFAR.
The I-LOFAR radio telescope does not look like a telescope. It looks like a series of black slabs in a field, some of them with poles in the middle.
The presentation began with some slides of radio telescopes that look like the traditional idea of a radio telescope - the Jodrell Bank model. The biggest free-standing radio telescope dish like this was at Green Park in the US, and was 300m across - and then it collapsed. The Chinese have a dish that is built into the ground, which is 500m across - of course, it can only point straight up. When I went to the Astronomer Royal's talk at Hay Festival he also showed a slide of this telescope.
But this is about as big as it's possible to go with a single telescope. Fortunately for astronomers there is a thing called interferometry - a way of joining several telescopes together to make one huge one. The LOFAR project is the size of Europe. They have fields full of these black slabs, which collect the radio waves, as far south as the north of Italy, across to Poland, dotted across Europe - and at Birr Castle, County Offaly. From Birr to the Polish site is 2,000km.
The third Earl of Rosse, who built the Leviathan telescope at Birr, was the first astronomer to discover the spiral arms of galaxies - the shape that is now familiar to everyone who has seen pictures of other galaxies.
The only problem with the LOFAR array is that it picks up radio waves which include local radio stations and taxi firms and mobile phones, so the arrays can only be built in areas which are reasonably remote from these things, and where the local authorities are not going to build radio masts - or wind farms. The rotation of the blades also interferes with the work of the arrays. Even so, there is a big chunk of frequencies that cannot be studied by the arrays.
One of the PhD students giving the talk had worked on wiring the on-site processor, along with other students and 40,000m of cable. This does the initial processing of the vast amount of data collected, which is then sent to the Netherlands for further study. She was excited to be a part of such a Europe-wide project, at the cutting edge of science, and she didn't have to leave Ireland to do it. It also means that Irish astronomers can access the information from all the other sites across Europe.
They study a variety of things, including the Epoch of Re-ionisation, which is the moment after the Big Bang. They also do all sky surveys, look at cosmic magnetism, solar science and space weather - this last is commercially important, for all sorts of satellites, as they can predict solar flares that might knock out electrical circuits.
At the end of the talk it was revealed that the two PhD students who gave such a brilliant presentation were last minute replacements for the original speaker who couldn't come, and they only had about 2 hours to put their slides together!
On the way out, I saw one of the Con's featured artists, Afua Richardson, chatting in the Art Show. She's a comic book artist who has worked on Black Panther, among other things. The Con organisers wanted to make artists a big feature this year, and I think they succeeded in that.
Back at the Convention Centre I had a pint of Foxe's Rock Red Ale for E6.50 in Martin's Bar (named in honour of Martin Hoare, a fan who died recently, but had been very much involved in organising Con bars over the years).
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