Archive for Bad Honnef

The Inflationary Bubble

Posted in The Universe and Stuff with tags , , , , on July 9, 2013 by telescoper

The Summer School I’m attending on Inflation and the CMB got under way yesterday morning with a couple of lectures (90 minutes each) by Andrei Linde, one of the pioneers of the theory of cosmic inflation. I enjoyed the first part of the session, but then he went off into the technical details of a specific model for which there seemed previous little in the way of physical motivation or testable consequences. There’s an occupational hazard for people working on inflation which is that they become so absorbed by their calculations that they forget that they’re supposed to be doing science. It sometimes appears that this field has reached a critical density of activity which means that it’s in danger of forming a closed universe completely incapable of communicating with the world outside and perhaps of collapsing in on itself.

The other thing I didn’t like was the evangelism about the multiverse, which is widespread amongst theorists these days. I’ve stated my position about this before so I won’t repeat my objections here. I will, however, lodge an objection to the way Prof. Linde answered a question about whether the multiverse theory was a testable of various fine-tuning problems in cosmology by saying

Ihe multiverse is the only known explanation so in a sense it has already been tested.

I don’t mind particularly if theories are not testable with current technology. New ideas often have to wait a very long time before equipment and techniques are developed to test them, but Linde’s response is rather symptomatic of a frame of mind that does not consider testability important at all. The worst offenders in this regard are certain string theorists who seem to thing string theory is so compelling in its own right that it just has to be the one true description of how the Universe works, even if the framework it provides is unable to make any predictions at all.

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Germany Calling…

Posted in Biographical, Books, Talks and Reviews, The Universe and Stuff with tags , , , , on July 7, 2013 by telescoper

Just a quick post to break radio silence and announce my arrival in the picturesque town of Bad Honnef, spa town in Germany near Bonn in the Rhein-Sieg district of North Rhine-Westphalia. We’re right on the banks of the Rhine actually, and there are some fine views of castles and hills to be had all round.

To get here I took my life in my hands and flew with a German budget airline called Germanwings from Heathrow to nearby Bonn-Cologne airport. I mean it’s near to Bad Honnef, not to Heathrow. Apart from the fact that I had to queue for an hour at check-in because the staff apparently didn’t know how to operate the computer system, and the flight was delayed leaving because it was delayed on the way in, it wasn’t actually too bad; we arrived only about 25 minutes late and I was able to have a few beers and some food when I arrived at my destination.

The reason for this expedition is that I’m giving two lectures at the Deutschen Physikalischen Gesellschaft (henceforth DPG) Summer School on Inflation and the CMB. The list of other speakers is very impressive so I assume that some form of administrative error is responsible for my invitation, and especially for the fact that I’ve got to give two lectures while everyone else is just giving one…

Anyway, it’s lovely weather here – although a little on the toasty side for my cold English blood – and I hope to get the chance to take a few pictures as well as some updates from the meeting. I also hope to find out why this place is called Bad Honnef. I know I’ve only been here a few hours, but it seems to me that, as Honnefs go, it’s really not bad at all…