The Joy of Astronomy

Mare Imbrium

The Joy of Astronomy

I first started observational astronomy in my thirties. That was when I constructed an 8 inch reflector using a car axle for the alt-azimuth motion and housing that in a solid wood tripod. I followed instructions from a ‘how to’ book and was amazed that, after some fine tuning, I saw pin-point sharp images of stars and could see distant galaxies. I used the scope for a number of years but finally sold it and that was the end of my telescopic observations (I occasionally used binoculars, which by the way is the best way of getting to know the constellations).

Fast forward forty four years. Last December I bought a used 5 inch reflector – the model often advertised as a ‘beginner’s scope.’ I started using it in my bedroom looking through window glass. All the advice suggest this is a bad idea for obvious reasons. However, I found it was a good way of getting to know the scope and how to use the equatorial mount. There seemed very little distortion that you would expect looking through glass and hardly any you could notice when observing the moon.

The next stage I attempted was astro-photography. I’d seen stunning images taken with smartphones on Facebook. You hold the phone camera up to the eyepiece and, hey presto, you have your photo! Well, it’s not quite that simple in practice. For a first attempt I struggled for over half an hour lining up the camera lens with the eyepiece. Eventually I got my first image of a daytime moon that I was pleased with.

The next stage was to buy an adaptor so you could attach the phone to the eyepiece. This was an improvement on the hand-held method but it was still fiddly aligning the camera lens to get all of the image centred. However, I persevered and took the scope outside to photograph the moon.

So, four months have been a steep learning curve – and it continues. This last week I downloaded a free image-editing programme which enables you to enhance your photos. In the days when digital cameras first came on the scene ‘improving’ images in this way was seen as cheating! Nowadays, it’s an accepted part of the whole digital process. So far, I’ve used it judiciously; mainly to sharpen an image as in these two photos. I added the star for artistic effect, but I’d have to look again at the programme to see how I did that.

If you can alter the shutter speed of your camera you can take longer exposures of stars, planets, nebulae and galaxies. Maybe that’s my next step but my phone is an old one so may not be up to it.

How to begin to describe the fascination of astronomy? As I said to a friend today, I’ve always had one foot in the Arts and one in the Sciences. I had a brass microscope when I was 12 and before that spent hours and hours constructing Meccano models and balsa wood planes. Amateur Astronomy is a hands-on hobby. Moreover, it combines aesthetics, science, poetry and art. (I’ve painted a few pictures inspired by astronomy and written a few poems.) You could throw in ‘philosophy’ and ‘religion’ into the mix too. Blaise Pascal found the immensity of space frightening. Most people find it awe-inspiring but also impossible to grasp what 100,000 light years, for example, actually is. The ‘God by Design’ argument in philosophy is best exemplified by viewing the night sky on a clear night. For me it’s enough to feel a sense of the numinous as I manoeuvre my scope onto a galaxy 2,000 light-years distant. It’s no wonder ancient cultures populated the night sky with gods and legends.

[Perhaps I could write a Part Two about the symbolism of the moon and how different cultures have viewed our nearest galactic neighbour.]

Astronomy: Mother of all Sciences?

Insight Lander on Mars – it will drill down into Mars’ crust to analyse the rock

Is the ‘Scientific Method’ Different in Astronomy?

The scientific method is common to all the sciences; however, in astronomy the ‘objects of study’ are often millions of light years distant!

The scientific method, per se, can be illustrated by considering how Galileo used his telescope in 1610. When he aimed it at Jupiter he saw four points of light, rather like stars, strung out in a line from the planet’s disc. Subsequent views showed the star-points in many different positions. Galileo then made a hypothesis to explain the data; he wrote that the objects were orbiting Jupiter and were in fact, moons. He calculated their orbits and predicted their motions.

Although astronomers cannot usually experiment on tangible substances in the laboratory (unlike chemists and biologists) they can, nevertheless, use instruments such as telescopes to make many thousands of observations and make hypotheses to explain the observations. The hypotheses can then be tested by predicting an event, for example, and confirming it. A large part of the method involves rejection or refinement of hypotheses once they have been found in error.

Astronomers nowadays use other types of telescope such as radio, infra red, X-ray – these advances have established that the universe is expanding and that what we can see visually with a telescope is only a fraction of the electromagnetic spectrum.

Spacecraft have landed on bodies such as our Moon. Instruments on board have been able to do experiments similar to those done by a chemist in a lab. Astronauts have also brought back rock samples from our Moon. Our knowledge of the origins of the solar system has thus increased by these more lab-based analyses. Probes have landed on Mars and other planets and sent back interesting data. For example, a small moon of Jupiter called, Enceladus, was found to have geysers containing sodium. Titan, a large moon of Saturn, has lakes and rivers of methane and ethane. These solar bodies are far from inactive and may even harbour primitive life.

Another huge area that has contributed to astronomical knowledge has been mathematics and its use in theoretical cosmology. Stretching from the Ancient Greek’s measurements of the Earth to Einstein’s Theory of Relativity and beyond – we can see how logic, calculation and measurement are embedded in the scientific method. Hipparcus (170-120 BCE ) even measured the length of the year with great accuracy – 365.2467 days, whereas the modern figure is 365.2422 days. A foundation for modern astronomy was laid with feats of calculation such as this.

We only have to think of the Four Forces in the Universe to sense how much science and theoretical cosmology have developed in the last hundred years. The Four Forces in nature are:

  1. Gravity
  2. Electromagnetism
  3. Strong Nuclear Force – (holds the atomic nucleus together)
  4. Weak Nuclear Force – (radioactive decay)

In this respect – the use of mathematics and making theoretical models– astronomy is no different to the other sciences. And, of course, chemistry, physics, and even biology, play their parts in astronomy. Perhaps that suggests astronomy is the ‘mother’ of all the sciences.