Introduction to Astonomy
by Alan Ledbury |
Alan introduces himself and goes straight into a look at a particular telescope and explains how particular types are required for different observation tasks There are illustrations by projector with slides.
He goes on to demonstrate the working technology that enables the viewer to identify particular objects and then be able to move the lens as the object moves through the sky ie to follow or track the object.
He also goes through a particular brand of telescope and shows its ability and gives an indication of cost.
A large telescope he tells us can be made on a DIY basis and built to be dismantled.
Other facts the astronomer needs to know are that you will always get better viewing when the air is dry. It can be a lengthy job to get one’s telescope set up. The Walsall club he is in has telescopes of its own. There are such things as remote telescopes by which the image in view can be put onto the internet for viewing. In making your own telescope you can build a scale model and then scale it up.
There are hundreds of large telescopes worldwide used by eg universities. The university will buy one second hand for a particular project, complete the project in say twelve months and then quite often be able to resell it to realise the same cost as that paid for it. We are shown a picture of the largest telescope in the world which has a lens 34 feet wide.
Alan explains about the Pole Star. He shows us a picture of a very precise section of sky viewed through his telescope in Walsall. He then shows us precisely the same image using the same telescope in North Wales to illustrate how much more detail comes into the image in a clear atmosphere away from an urban area.
There is now technology by which a view can be seen several times over with each image being digitally put on top of the previous one/s so that by the end of this compounding a very good sharp image will result.
He shows us work done by the telescope at Barr Beacon explaining that the strength of the resolution is such that when looking at a plane near Birmingham Airport you can more or less see the faces of the crew inside the cockpit.
Alan then shows us the relative sizes of the spheres in respect of the earth, the other planets, (each one is getting bigger up to Jupiter) and the sun (far bigger again). The circumference of the largest star viewable by Man is such that it would take a car driven at 70mph 6000 years to drive round that circumference.
He shows us flares exploding and burning off the sun. One of these hit Canada causing a very serious problem taking out the whole of the electricity grid for some time. Do not worry about the sun burning itself out since it is considered to have about 60 million years left to burn and shine.
At that “intergalactic speed” of 70mph it would take you 6 months to travel to the moon, 150 years to the sun, 1500 years to get to Saturn, 5000 to Neptune and 300,000 million years to the nearest star in the galaxy.
Alan demonstrates how an eclipse of the sun and moon actually work. He has also brought with him a sample of a meteorite.
He then concludes with his ten favourite facts and figures. On is that people often find these eclipses to be a quasi religious experience; they become speechless with wonder, extremely animated and totally in awe.
The talk concludes and we are extremely grateful. We go on to talk a bit about UFOs, questions are put and Alan’s session comes to an end. We thank Alan in the usual way.
David McLean
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