The 2011 Nobel prize in physics has been awarded to S. Perlmutter, A. Riess and B. Schmidt for their path breaking discovery that the rate of expansion of the universe is increasing with time. The trio used Type Ia supernovae (SNe Ia) as standard candles to estimate their luminosity-distances. To appreciate some of the far reaching implications of their work, I have provided an elementary exposition of general theory of relativity, accelerated expansion of the universe, luminosity-distance, SNe Ia and the cosmological constant problem.

Now in its fourth edition, this highly regarded book is ideal for those who wish to solve a variety of practical and recreational problems in astronomy using a scientific calculator or spreadsheet. Updated and extended, this new edition shows you how to use spreadsheets to predict, with greater accuracy, solar and lunar eclipses, the positions of the planets, and the times of sunrise and sunset. Suitable for worldwide use, this handbook covers orbits, transformations and general celestial phenomena, and is essential for anyone wanting to make astronomical calculations for themselves. With clear, easy-to-follow instructions for use with a pocket calculator, shown alongside worked examples, it can be enjoyed by anyone interested in astronomy, and will be a useful tool for software writers and students studying introductory astronomy. High-precision spreadsheet methods for greater accuracy are available at www.cambridge.org/practicalastronomy.

The AAVSO is an international non-profit organization of variable star observers whose mission is:

to observe and analyze variable stars
to collect and archive observations for worldwide access
to forge strong collaborations between amateur and professional astronomers
to promote scientific research and education using variable star data.

This paper presents a hands-on introduction to the medieval astrolabe, based around a working model which can be constructed from photocopies of the supplied figures. As well as describing how to assemble the model, I also provide a brief explanation of how each of its various parts might be used. The printed version of this paper includes only the parts needed to build a single model prepared for use at latitudes around 52{deg}N, but an accompanying electronic file archive includes equivalent images which can be used to build models prepared for use at any other latitude. The vector graphics scripts used to generate the models are also available for download, allowing customised astrolabes to be made.

This is a 4-page reminder of what LaTeX does. It is designed for printing on A4 paper, double-sided, and folding once to A5. (Such an ‘imposed’ version of the document is provided in the distribution, as PDF.)

To our best knowledge, there are no problem books on cosmology yet, that would include its spectacular recent achievements. We believe there is a strong need for such now, when cosmology is swiftly becoming a strict and vast science, and the book would be extremely useful for the youth pouring in this area of research. Indeed, the only way to rise over the popular level in any science is to master its alphabet, that is, to learn to solve problems.
Of course, most of modern textbooks on cosmology include problems. However, a reader, exhausted by high theory, may often be thwarted by the lack of time and strength to solve them. Might it be worth sometimes to change the tactics and just throw those who wish to learn to swim into the water?
The proposed problems constitute our contribution to this cause. There are over 1000 problems, divided into 14 chapters, covering topics from the dynamics of the expanding Universe and CMB to cosmology beyond the Lambda-CDM model and holography. We intend to publish their solutions in later editions. The reader, however, is encouraged to look for answers independently, even though - or especially so because - the problems range from easy to not quite and from elements of scientific folklore already to those with answers not quite settled.

Vereiningung für Jugendarbeit in der Astronomie e.V.

This is a collection of movie clips in which Mathematics appears. I'm collecting DVDs and VHS tapes of such movies. This is a working document to be extended over time. I started this page during spring break 2006. See also the page "Begin of lectures in college teaching" and "End of lectures in college teaching" and "Examples of good talks". To see the movies larger, to see it on the iphone or include it ina presentation, chose the quicktime ipod version, which are files with .m4v extension. (Media RSS link).

The Net Advance of Physics: COSMOLOGY

How do you spark off an interest in maths when the curriculum seems dreary? It's all about mystery, big stories and journeys to infinity and beyond, says Marcus du Sautoy