Dear students, Nazywam si� Boud Roukema, jestem kosmologiem, zacz� jak adiunkt w Centrum Astronomii.

This semester, I'm giving a "monograph course" on "the Shape of the Universe", or more precisely, on observational ways of trying to measure the shape of the Universe, aimed at the level of 4th year students, but 3rd years or other students are also welcome. You'll find more information on this at:

http://www.astro.uni.torun.pl/sympa/shape-univ/index.html

Sorry for the confusion about the starting date! Because of this, the next session will have a subject which is essentially the same as the first, unless you all think it is too easy and you already know it! So here are the details:

---------------------------------------------------------------------- Time/Date: 14:00-16:00 Friday 1 March 2002 Place: Radio Observatory main lecture room, Piwnice

Goal of first lecture: * Basic concepts of curvature, topology, extra dimension as a psychological tool to help imagine curved and/or multiply connected spaces, comoving coordinates, with the aim of making sure the 4th year students (or others relatively new to cosmology) understand these. ----------------------------------------------------------------------

Two students who were there, Pawel and Andrzej, said that it was very easy, so if they can explain everything to you, we could maybe move immediately on to observational techniques. But this depends on you.

Apparently there was another course on something about business and computing in the other building this afternoon.

Well, the best way to learn computing if you want to be able to find a job in it and/or want to create your own software company is in the free software movement, e.g. GNU/Linux and the GNU Public Licence (GPL):

http://www.gnu.org/home.pl.html http://groups.google.com/groups?group=pl.comp.os.linux

If you write software for a company which is *not* protected under the GPL, and if the company fires you and you want the freedom to use this software in another company, you will not be allowed to! Not only will you have lost your job, but all your intellectual effort will be wasted. :-(

And starting your own company would be much easier with free software, since you would only have to add one small new idea to the huge amount of existing free software. You would not have the cost of buying proprietary software or using an unstable, inefficient operating system full of bugs.

So free software is better, z moim skromnem zdaniem...

In astronomy, most of the software we use and write is more or less free software, but its commercial value is about... zero z�oty. However, if you help work on cosmology GPL software, it would be a good learning exercise.

And I think that one of the best ways for you to learn about observational measurements of the shape of the Universe is to work with software that is related to observational work on the shape of the Universe. I would be happy to support students interested in doing this, and hope that both the face-to-face lectures and the shape-univ mailing list (and archive) can be used to think about this.

Anyway, the content of the course is more or less:

---------------------------------------------------------------------- = Quantitative =

- curvature measurements, e.g. http://de.arXiv.org/abs/astro-ph/0201092

- topology measurements, e.g. http://de.arXiv.org/abs/astro-ph/0010185

[This is the ref I promised during today's lecture. For a *lot* more detail on topology (but slightly out-of-date regarding observational research and with a few small, minor errors) is LaLu95:

http://de.arXiv.org/abs/gr-qc/9605010

]

Please look for good introductions to these on the web (w po polsku lub w po angielsku), i prosz� wysylacie any links that you think are good to the shape-univ mailing list. That way, everybody else can just click and read.

= Qualitative =

- curvature Here's one which seems nice, but is essentially without algebra:

http://www.astro.princeton.edu/~clark/ToC.html

It's said to be at high school level, but it's important to develop intuition. Understanding is not just abstract symbols on paper, it's also intuitive understanding.

But please provide a better link if you can!

- topology - intuition

Here's a good exercise for developing topology intuition:

http://humber.northnet.org/weeks/TorusGames/

Don't be embarrassed to play the games - it's part of learning. ----------------------------------------------------------------------

To subscribe to the list, send an email to

sympa@astro.uni.torun.pl

and put

subscribe shape-univ

in the Subject: or main body. To send an email to the list, just send it to shape-univ@astro.uni.torun.pl .

Hope to see you next Friday, Pozdrawiam Boud