Thursday at WorldCon - Fanzines and Pulsars

My original plan, since I was actually staying at Trinity College, was to wander over to the Old Library after breakfast to have a look at the Book of Kells before it got too busy, and then go up to the Convention Centre to check in at the Con.
I had a wander around the grounds - it really is a green oasis in the middle of the city.

Then I turned the corner to the entrance to the Book of Kells Exhibition, which opened at 9.30am.
It was 9am, and there was already a queue.

So I went straight up to the Convention Centre instead. My Leap card worked perfectly on the Luas, which took me from Abbey Street to Spencer Dock.
It's a wonderfully futuristic building.

The check in process was easy - I liked the little stiff fans the volunteers at the counters were waving, with the word "NEXT" on them. I was also impressed to see that they had stickers you could add to your name badge with your preferred pronouns. I picked up "SHE".
The organisers had put some thought into making the Con welcoming and inclusive. There were also signs up in all the toilets, which basically said "If you see someone who you think is in the 'wrong' toilet, leave them alone and let them pee in peace." I saw one person taking a photo of the sign, and I wish I had now, to get the exact wording, because it was excellent.

The way to remember which floor you were on was - if you can see the river, you're on Liffey, and if you can see the mountains in the distance you're on Wicklow. The Dealers' Room was on the ground floor and there was a food area and the entrances to the Auditorium above.

I headed to my first panel, Fanzines Now!
This was a discussion that ranged from some of the earliest fanzines right up to websites and blogs like File 770. Joe Siclari, on the panel, is involved in saving some of those historic fanzines for posterity, and could be seen throughout the Con on a table to one side of the Dealers Room with some of the old fanzines they were digitising.
Recommendations from the panel included e.fanzines.com, bananawings and The Incomparable podcast. The chap I was sitting next to in the audience gave me a mini folded zine called 'zine + origami - because you can't fold PDFs'.
I sneaked out when the questions from the floor started with "This is more of a comment than a question..."
Also, I wanted to get to The Point in plenty of time, and I wasn't sure how far away it was or how often the Luas ran. Part of the programming for the Con had overflowed into the Odeon complex at The Point, with the children's programming in the hotel next door to it (so I didn't see many children over the weekend). The Art Show was also at The Point.

One of the Guests of Honour this year was Professor Jocelyn Bell, who discovered pulsars, and I really wanted to get to her talk. She played us the sound of real pulsars, which are picked up by radio telescopes. A pulsar is a very dense star which is spinning incredibly fast, and as it spins it sends out a beam, rather like a lighthouse, which can be detected here on earth - if the pulsar is facing towards us. There must be many more out there we don't know about because their beams go in different directions. The first sound she played us came from a star that was spinning at 11 times per second, had a mass of 10 to the 27 tonnes, and was 10km across. That's incredibly dense, and this is the end stage of the life of a big star which has collapsed down after a supernova.
She also explained why there is so much pink on pictures of nebulae and gas clouds and so on - that's hydrogen, which is the most abundant element in the universe.
A supernova was observed from earth in 1954AD, by Chinese astronomers. This was the Crab Nebula, which is brighter than it would normally be expected to be because there is a pulsar in there. The beam of the pulsar keeps the gas cloud energised.
She went through some of the reasons why it was a bad idea to get too close to a pulsar, including the tidal disruption of bodies that would tear a person's body apart. The gravitational forces bend light, and make clocks run twice as slow as normal. Then there's the magnetic field of 10 to the 8 Tesla (for comparison a fridge magnet is one hundredth of a Tesla).
About 3,000 pulsars are known and of these only 20 are visible to the human eye. About 100 are detected by X-rays, and 200 by gamma rays.
Some pulsars even have planets.
The regular spinning means that pulsars are very accurate clocks, and they can also be used for space navigation, because each one spins at a slightly different rate.