August 24th, 2006


Today ...

Arrived at client site: five minutes past noon.

Exchange information store mounted successfully: half past midnight.

Sorry if anyone was expecting to see me at the BSFA meeting.

Backup now.

More about Octocon...

For my own reference, really.

BMI 127 depart LHR 13:30 arrive DUB 14:50 Fri Oct 13th.
That won't involve too much rushing at either end.

BMI 130 depart DUB 17:35 arrive LHR 18:55 Mon Oct 16th.
That'll allow reasonable amounts of time for getting confused at the Porterhouse at Monday lunchtime.
BMI 132 depart DUB 19:55 arrive LHR 21:15 Mon Oct 16th.
That'll allow a bit more, but I won't be home until nearly midnight.

Each of these itineraries are £63.55.

Travel to and from Heathrow will be about £15-£20, and travel from the airport via Dublin to the hotel and back will be some similar-sized handful of Euros. Neither are complicated enough to need planning in advance.

Convention membership €25, which is about £17.

Hotel, three nights at €99 is €297, which is about £200.

So that's just over 300 quid, plus whatever I eat and drink. And, as I discovered in 2004, Forbidden Planet is round the corner from the pub in Dublin.

It's all looking a bit believable. I might even throw in a few days with my brother in Kilkenny too.

Top tip for today

When you plug the USB cable into your PDA and nothing happens, before you reboot everything and then phone Douglas for help, try checking that the other end of the cable is actually plugged into your laptop.

Octocon, yet again.


I seem to have booked a convention membership and a hotel room.

I've texted my brother in Kilkenny, and I'll book flights when I know if he's around for a few days before or after the con.

Question for proper astronomers

The new definition of "planet" is as follows:
    A "planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
Both the BBC and CNN say that Pluto was disqualified because it crosses Neptune's orbit -- and therefore that Pluto hasn't "cleared the neighbourhood around its orbit".

Surely (leaving aside questions of eccentricity) Neptune crosses Pluto's orbit and therefore hasn't cleared it's neighbourhood? Why isn't Neptune disqualified as a planet?

I suspect that Pluto has been disqualified as a planet because of its relationship with Charon, and not because of its relationship to Neptune. I've said as much in a thread here, and I've suggested that the BBC and CNN, staffed by journalists instead of astronomers, may have misreported the facts.

I'm not an astronomer, I'm a mathematician. There are some proper astronomers on my friends list. Is anyone able to offer some clarification?

Mercury most eccentric

As a side note, now that we've booted Pluto out, Mercury is the planet with the most eccentric orbit. I've just made a one-line change in the "examples" section of the wikipedia page for "orbital eccentricity", and in the usual way someone will come along afterwards and word it a little more elegantly than I've been able to.