A lack of offensive forum posts, a renewed blue sky, a pleasant evening and some pleasing news has for the moment cheered me up Michele. Also the fact that I only have TWO DAYS until my holiday is lifting my spirits.

The good news today was that I've been invited to work at a University in Tokyo for a week and Kyoto for a week at the end of February on a really interesting project, which is clearly good for several reasons. Not least of these reasons is that I've been wanting to see Japan for a long time and it will be interesting to see how it compares to my vision, influenced largely by Haruki Murakami novels (which I highly recommend) and Japanese movies. I'm hoping that it doesn't parallel too many details of Audition, a great film, I think often misunderstood as simply a nasty movie but I think it's a beautifully paced and written story of loneliness and cruelty (doesn't sound fun I know but I think it's worth a watch if you have a strong stomach).

Anyway, I look forward to some really interesting work and a truckload of great fresh fish (Slow motion - Pole).

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My music listening has recently been revolutionised once again by a program on a site called pandora.com. It's a personalised radio player. You put in the name of an artist or track that you like, it then plays you something with a similar feel by analysing the rhythm, tempo, ambiance etc. of your choice. The next track is again in a similar vein but at any point you can vote for or against a track and it will bias the choices in the directions you decide.

So far, having started with Plaid, I've been listening to a whole world of electronica that I've never heard before. I really advise giving it a spin. If you register (for free, but you don't have to in order to use it), it will save
the stations that it's made for you from your initial choices and likes/dislikes of a particular playlist so you immediately have many personalised stations which are likely to play music that you haven't heard but fits in very well with your tastes.

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Be warned, I have plans of talking physics again soon. Lots of interesting stuff to discuss but will have to wait momentarily. For now, just a couple of bits of news:

The first is actually a couple of weeks old now but I think worth mentioning. Various theories of cosmology predict that at different regions of space where different phases (phases of quantum fields, not liquid/gas etc.) meet there will be defects at the boundaries between the phases.

Think of a large group of people in a room. Everyone is looking at the floor to start with. Placed around the room on the walls are a large number of interesting pictures. People start randomly to look up. One person sees a picture he likes and gets the people around him to look at the picture as well. As more people around him look at it, so the people around them look at it as well. Now there's a small subgroup of all the people all looking in the same direction, influenced by that first random glance. The group of people looking in the same direction is increasing in size as more people are influenced to look in that direction.

However, somewhere else in the room there was another person who looked up initially and saw a different picture in a different direction. They also have a group being influenced by that first glance, which increasing in size. In fact, there are several of these sources of influence (people who influence an ever increasing group around them to look in a particular direction). However, as the size of the groups increase, two of them will meet at a line of people. One side of the line will be looking one way, the other side will be looking another. This is the defect caused by different regions of the universe choosing a different phase (read direction). The people at these defects will have a lot of energy as they argue with the ones directly next to them about which way to face (The analogy is a little weak here but it's roughly right!). I don't know if that makes any sense at all to anyone but me!

Clearly because of the gradient across the boundary, the energy of such a configuration will be huge and, consequently, so will the gravitational field of such an object. The possible defects are given by the internal symmetry group, broken by the choice of phase, and the number of dimensions of space-time. One possibility in a 4d universe is that there could be 'cosmic strings' out there stretching across vast swathes of the universe. This isn't some cosmic fantasy but is truly predicted by many theorists. It would really be like a massive piece of extremely long string stretching across the sky.

The signal for such an object should be pretty easy to spot by the way that its gravity warps the light coming from objects behind it as it reaches us. Great excitement a while ago when it was believed that a cosmic string was found
from this image though unfortunately it has now been shown not to be a real string.


(Sorry if you've seen this on every physics related blog on the web!)

It's still an interesting example of gravitational lensing, one of the predictions made by Einstein on GR. The search continues. Incidentally, cosmic superstrings are also predicted in string theory (produced during the inflationary era) and the debate (I believe) continues as to whether you would be able to tell a cosmic string from
a cosmic superstring (Polchinski vs. Tong I think).

(My apologies if anyone who understands it knows it already and anyone who doesn't, doesn't have the faintest idea at what I'm blathering on about!)

Anyway, the second more positive piece of astronomical news is that an Earth-like planet has been found circling a star in our galaxy. It's too far from its parent sun and therefore too cold to harbour life, but of the 160 or so extrasolar planets now found, this is the closest we've got to something like the Earth. These 160 have all been found in the last couple of years and as our techniques for finding them improves, it seems pretty likely that before long we will find a planet pretty similar to our own. A really exciting prospect, especially as with all its efforts SETI has turned up zilch so far.

In summary:
1) We thought we'd spotted the signatures of a vast piece of string stretching light-years across the universe. We hadn't but we had taken a nice snap of an interesting phenomenon.
2) We've seen (again, the signatures of) an Earth-like extrasolar planet. At the current rate of discovery, my view is that the likelihood of finding one emitting an intelligent signal is not vanishingly small.

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Last of all for now. Fireworks have been banned in Beijing for the last 14 years or so. Tomorrow is New Year's eve and fireworks are back. People have a lot of catching up to do. This should be big!