This was a very interesting event and one of the best £5-worth's I've had in a long time.

It was held at the Rutherford Appleton Laboratory, at Chilton, Didcot, Oxon. The venue supplied an excellent lunch for £3.50 and coffee, tea and biscuits at the start of the day and during coffee breaks were included in the entrance fee.

The first lecture was on the SOHO project, by Dr Richard Harrison. SOHO is a satellite which observes the sun at various frequencies mainly u/v and X-ray. Its mission started in 1995 and it is still going although it was only supposed to last 2 years. It is sited in a tight orbit around L1 or the first Lagrangian point, which is on a line drawn between the Earth and the Sun at the point where the Earth's and Sun's gravity is equal. The instruments can detect and photograph the corona, coronal emissions, solar flares etc. They also do spectroscopy.

This was an excellent lecture with Powerpoint slides, photographs and animations. The Sun looks like a bowl of spaghetti with tomato sauce when photographed under some wavelengths. It also vibrates and "rings" like a bell. The most interesting statistic for me is that the Earth is only about 100 solar diameters from the Sun, yet this distance is 93 million miles. This brought home to me how huge the Sun is by comparison with the Earth.

After coffee we had the AGM, which was the worst part of the day as everybody seemed to have to thank everybody else at great length, and also to start speeches with "It goes without saying..." or "I'm sure everybody is aware that.." and then go on forever on the subject they'd already said we knew all about. Someone is needed to organise the next conference or there may not be one. Also the Public Liability Insurance is going up. Most of the committee were re-elected.

This over-ran by about 40 min (lasting over an hour) so we only had one more lecture before lunch - by Dr Bob Owens on Kuiper Belt objects. The Kuiper belt is round about the orbits of Neptune and Pluto, and is where most of the short period comets reside. It is more-or-less within the plane of the Solar System. When the period of comets is plotted against their population, there are gaps within the distribution. These gaps are thought to be caused by comets of these periods being ejected from the plane of the Solar System by the gravity of the giant planets. These ejected comets went to form the Oort Cloud, which is well outside the orbits of Neptune/Pluto and is now thought to be a secondary phenomena. The Oort Cloud contains the long-period comets which orbit at random angles not related to the plane of the Solar system.

The star Beta Pictoris appears to have a Kuiper belt type formation around it (ie debris/possible comets within one plane). It is not known if it has an Oort cloud, which would be much harder to detect. An Oort cloud around a star would apparently require giant planets in suitable positions for it to form.

Lunch followed, then there was a short lecture on CCD imaging by Nik Szymanek of Havering AS. This was about how to combine images of the same galaxy taken at different times to get prettier pictures. There seems to be no scientific rationale for this. However it is very striking that pictures of galaxies of the quality which could only be taken by telescopes like Mount Palomar and Mount Wilson in the 1960s, can now be taken with amateur equipment. However for pictures of large objects only film, and large telescopes, will do the job.

The second lecture of the afternoon by Professor Phil Charles of Southampton University, was entitled "Towards the Event Horizon" and went some way over my head. What I did grasp is that Einstein's Theory is known to hold at low to medium gravitational field strength (up to about one millionth of event horizon fields for 10Ms (solar masses) objects) but has not yet been tested at very high fields. Also, we don't yet have accurate equations of state for nuclear matter so the Schwarzchild limit (at which a star on collapsing becomes a black hole rather than a neutron star), which is currently calculated to be about 3.2 Ms, may not be as precise as it appears. It is interesting that most (assumed) black holes are around 10 Ms and most neutron stars a little over 1.4Ms and the error bounds don't overlap 3.2Ms. Mention was made of a space array Xray telescope designed to resolve down to event horizon sizes. The spacecraft would need to fly several kilometers apart to a precision of a few nanometers and pointing to micro-micro radians. When asked how difficult this would be the spacecraft attitude control engineers responded "no problem"!

The last lecture was light relief and a gem. It was called "Sir Isaac Remembers" and was done as a dramatic monologue by Professor Mike Edmund of Cardiff University in costume as Sir Isaac Newton. This was Sir Isaac at the end of his life recounting the events in it. This was very interesting from a social history point of view - for example he could not marry as he would have lost his job as a Fellow of the University of Cambridge, although there was a lady he wished to marry. He also could not be made Master of Trinity as he would have had to swear an oath by the Father the Son and the Holy Ghost and he firmly believed that there was no such thing as the Holy Ghost and was not prepared to perjure himself so he turned down the job.

Also he believed in alchemy and the existence of the Philosophers Stone. He did many experiments, some of them hair-raising as when he blinded himself for 3 days by staring at the Sun, and when he poked a darning needle into his eye to see what he would see and what it felt like. (Don't try this at home!).

He refused to publish some of his works and was annoyed when others discovered the same things and then claimed the credit. Some of his works were considered very obscure, eg "Principia Mathematica" and it seems he delighted in this.

He seems to have simply got tired of mathematics for a while and became Master of the Mint, when he devoted much time and effort to detective work on the track of counterfeiters and coin clippers. One such whom he caught and saw executed, protested his innocence to the last, but then left Sir Isaac his coining equipment!

He was in correspondence with other scientists and mathematicians, and some of his discoveries were made in response to problems posed by others, as when he received a letter asking about the motion of a falling body at 4 pm when he got home from working at the Mint, and stayed up till 4 AM to solve the problem posed.

A final fact about his life is that his father was already dead when he was born, and as a newborn baby he was so small he would fit in a quart pot. The lady sent to fetch medicine for him didn't bother as she thought he would die anyway, but fortunately for us she was mistaken!

That was the end of a superb day. Only Nigel Eke, Stan Waterman and myself attended from LDAS, so I think the rest of you missed a treat, and would be well advised to try to go next year.

- Kathy Hall