This is a short post to announce that I have added a further page to the “talks” section of this blog. This is a sermon that I gave two weeks ago at Lady Margaret Hall college, Oxford, at the kind invitation of the chaplain Dr Doig. The sermon is an approximately twenty minute talk which looks at cosmology, and briefly discusses the structure of scientific explanation in general, with a view to showing that these things point towards further layers of meaning in the world, without being able to provide them. It can be found here.
I included in the sermon a brief reaction to something that I know bothers many people, and I decided to display that part here as a “thought for the day” for anyone who does not want to read the sermon. The thought is about whether we matter to God.
This week we had another lecture in the area of the physics of the vacuum (see Whoops! A Universe). It was the 11th Dennis Sciama Memorial Lecture, given by Professor Philip Candelas of the Mathematical Institute, University of Oxford. Here are the title and abstract:
Simple Calabi-Yau Manifolds and the Landscape of String Vacua
Abstract: It is widely known that there are a great many vacua of string theory. A small subset of these lead to four-dimensional worlds that are somewhat like the world that we observe. The great majority lead to worlds very different from our own. A vacuum is determined by a Calabi-Yau manifold together with certain extra structure. I will discuss the landscape of Calabi-Yau manifolds and a programme to find realistic string vacua based on simple cases.
You don’t need to understand the technical terms in order to follow the point I wish to make. All I want to emphasize here is that this lecture illustrates very well how completely wrong it is to describe the state of the universe in the absence of matter as somehow simple and not in need of explanation. Some of the best mathematical brains on the planet are puzzling over the nature of vacuum, and it is far from obvious or easy. And yet we continue to see utterly misleading headlines like the following (selected randomly from the web):
Before I embark on this blog post, a few words for regular readers. I have to apologise for the blog falling dormant for a month. This was because I have been working intensely on a book (a physics textbook), and also because I have been mulling over what to write. Also, I put up quite a lot of content just before the dormant period so I hope there was enough to be going on with (see under resources/talks). Finally, regarding comments: thanks for all constructive comments. They are all much appreciated and encouraging. However it is hard to keep up with moderating them because I have had over 7000 comments in total, almost all of them spam. I hope some day to get some help with the filtering process, but until I do that the situation will continue to be slow.
The post you are reading now was prompted in part by a recent talk at the physics department here in Oxford. The talk was the 2015 Wetton Lecture, delivered by Professor Carlo Frenk, Director, Institute for Computational Cosmology, University of Durham, and it had the title
“Everything from nothing, or how our universe was made”
Held by an image of our outer space:
Spots, dots, and whirls of white and red,
Time-tunneling in silent grace,
Parsecs where only thought can tread.
Blue blazes of the younger fire,
Red smudges of the ancient mist,
Vast mergers of the flowing gyre
Down ages of the world persist.
These distant forms of space and truth
Work back upon the thoughts we frame;
Prayer puzzles through a shaping sieve:
Dead words or else a larger name.
Still, quietly ask the teeming sky:
Draws over there that which can love?
Lights there a dance which can rejoice?
Rests there a hold of things above?