May 15, 2007

New Dark Matter evidence

NASA is holding a press conference today in which new evidence for the existence of dark matter will be presented. There will be an audio feed and graphics on the web as soon as the conference starts. A comment at the Angry Physicist’s blog links to the abstract of the upcoming APJ paper which describes this “dark ring”: The mass reconstruction of CL0024+17 obtained in such a way is remarkable. It reveals a ring-like dark matter substructure at r 75"

May 8, 2007

Brighten up your day

It's not a resource per se, but I probably should have mentioned the Astronomy Picture of the Day, run by NASA, which features a different space related picture every day. As you can see, some of these are amazing works of art in their own right, but with the accompanying blurb you can also learn some science while you're at it. The official site doesn't have an RSS feed unfortunately, but Jef Poskanzer has put together an unofficial feed which you can use to get your daily helping easily.

May 4, 2007

Multiverses and Super-Turtles

Last night’s talks were really interesting and it was good to get three different opinions being discussed in a (semi-)public setting. Usually these sort of lectures are one-sided in their opinions, which tends to hide the fact that the hot topics are also the most controversial. So as I mentioned earlier there were three speakers, Bernard Carr, George Ellis and Paul Davies. On the night Chris Isham was not able to attend, so one of the representatives of the Templeton Foundation acted as chairperson.

Bernard introduced the idea of the multiverse, after having plugged the new book and thanked all the contributors. With only thirty minutes allotted to each speaker there wasn’t enough time for a detailed explanation, but he explained some of the different multiverse ideas, in particular using this picture by Max Tegmark to illustrate the hierarchy of multiverse structures. With time running out (and some quite surprising heckling when he asked for some leeway), Bernard had to race through the history of physics on one slide, imploring us to consider it as “an artistic journey”.

May 3, 2007

First paper on the arXiv

[Shameless plug of my own work alert!] So today I finally became a ‘proper’ scientist and saw my name on the listings of the arXiv. Our new paper, Gravitational Wave constraints on DBI inflation, makes life difficult for the usual DBI brane inflation models by specifying some pretty strong limits on their existence, depending on the size of the scalar tensor ratio. In a nutshell, if gravitational waves from the CMB are observed, these models will have a hard time surviving.

May 2, 2007

Universe or Multiverse?

On Thursday evening I am going to the launch of this book, edited by Professor Bernard Carr from QMUL, called “Universe or Multiverse?”. It is a collection of articles about the idea of a multiverse and the prospects (if any) or ever experimentally verifying it. On the night of the launch there are going to be three speakers, Bernard himself, Paul Davies and George Ellis, with Chris Isham chairing. Unfortunately the event is by invitation only and is now fully booked.

April 30, 2007

Questioning the Big Bang

Sean Carroll has a long post at Cosmic Variance, talking about the usual explanations of early universe physics, and why there are some good reasons to question these ideas. All the currently fashionable (and not-so-fashionable) ideas are discussed, with some good explanations for those, like me, who are not up to speed with all the myriad theories. It is a long article, with a long discussion in the comments section as well, but well worth the effort if you want to know about the current trends.

April 26, 2007

Getting to grips with web based research tools

Every day I use web-based tools in my research. Some are specifically designed for scientific research, but some are just general purpose tools. It continually surprises me when other students and more established researchers have not heard of the many different ways the web can help research. This list is not meant to be exhaustive so please let me know if there are any tools you use that deserve a mention.

April 21, 2007

Which one is my second cousin once removed?

If you have ever wondered how your relations are able to rank the extended family as “once removed”, “second cousin” and so on, well here is a handy graph from Wikimedia which should clear things up. It shows an extended family tree back to great great grandparents and down as far as the third cousin twice removed. Might be handy to resolve those arguments about whether Auntie Ethel’s offspring are “once removed” or just “should be removed”.

April 19, 2007

Welcome

Welcome to this new blogging venture, which hopefully will be little better tended than my last effort. There is no over-riding theme for this blog, but I am going to try to explain a little cosmology along the way. As a humble PhD student though this will probably benefit me more than anyone else. The usual rules of decency and courtesy apply to comments which are of course more than welcome.