Dark energy and the ever-expanding Universe - Professor Carolin Crawford – Wednesday 21st September 2016

Photo by: Morton Hardaker 

Photo by: Morton Hardaker 

This lecture was given by Carolin Crawford, an experienced observational astronomer who also has a significant role in the public communication of science.  

A rapt audience of sixty-five was treated to fast-paced summary of the more recent history of Cosmology. Professor Crawford’s exciting, accessible talk was enjoyed by all. 

The topic focused on key questions. How did the Universe begin? What will happen to it in the future? The talk began with the concept of gravity as the key player in the Universe. It was Newton who was able to demonstrate the physical cause that kept the planets in orbit around the Sun. Newtonian mechanics was phenomenally successful, but was unable to explain everything. One of its failures was in explaining the precession of Mercury. 

The talk jumped to the early 20th century and Einstein. His field equations did away with Newton’s ideas and instead relied on a geometric description of space and time. The mass of bodies in space curved the space-time around it; the bigger the mass the greater the curvature. The theory explained things where Newton’s theory had failed.

A Universe containing other galaxies arrived with the observations of Edwin Hubble. As did the idea of an expanding Universe and, consequentially, the theory of the Big Bang. 

The rate at which this expansion has taken and is taking place was key to the rest of the lecture. The idea of Dark Matter was introduced to explain the motion of galaxies, the large scale structure of the universe and the structure of Cosmic Background Radiation. The concept of Dark Energy was then needed to explain the unexpectedly faster acceleration of the expansion of the Universe.

It was encouraging for the Society that even more younger members are attending our lectures. We seem to be experiencing our own period of expansion.

 

Observatory working party

On Sunday 4th September a few members from the society got together for a working party at the observatory.

The hazel hedge, which had grown mad over the summer and was obstructing views from the 'scope was cut right back with chain saws, hedge trimmers and loppers. The weeds, nettles and overgrown grass was trimmed back. The gutters on the observatory were cleaned out and the algae removed from the dome.

A big thank you to Pat C, Chris T, Mark C, Paul S, Jackie H and Don and Chrissie S for turning out on a Sunday to help and providing tools and to Mark C for the welcomed drinks at the pub afterwards!

An excellent morning / afternoons work.
Sarah

Perseid Meter Watching

Members of Wycombe Astronomical Society have had two lovely evenings of watching the Perseids recently and both with clear skies.

The first event, on Thursday 11th August, was held at Waddesdon Manor. Waddesdon arranged an evening meal and lecture followed by Perseid observing for their paying guests. Sandy delivered another excellent lecture titled “The Restless Universe” which was well received and afterwards they joined members of WAS on the Parterre. Although not perfectly clear it was good enough to enable the guests to see some bright Perseids as well as other objects through the telescopes. About 20 members of WAS assisted and had a very enjoyable evening.

Then on Friday 12th August we had our annual Perseid BBQ. The day had been beautifully sunny and this continued well into the evening.

This year the society borrowed two BBQ’s from members Mark C and Sarah W and these were lighted at 7pm with the view that they would be ready to cook on by 8pm when members would start to arrive. Unfortunately Sarah was a little over zealous with the charcoal and it took a while for them to really get going, helped with some frantic fanning by Sandy. Once ready to cook on though they were far better than the disposable BBQ’s that we have used in the past and some excellent BBQ food was cooked (and cremated).

As in previous years the society also provided the drinks for the evening and these went down well with only a couple of bottles remaining at the end of the evening.  

About 40 members and guests enjoyed the evening and we all saw at least one Perseid! We also saw a nice pass of the ISS low in the southeast. Several members took cameras in the hope of catching a Perseid on “film”.  A couple of telescopes were set up and two Ioptron sky trackers had their first airing too.

All in all, two excellent evenings’, viewing the Perseid meteor shower.

Sarah

 

Astrobiology: Understanding the Origins of Life - Professor Nigel J Mason OBE – Wednesday 20th July

A diverse audience of fifty-four was treated to yet another thoroughly entertaining WAS evening. Professor Mason’s passionate, humorous and interactive talk was enjoyed so much that members wanted to communicate their compliments before the night was out.

The talk focused on key questions. Where and how did life begin on Earth? Is there life elsewhere in the Universe? Are the conditions for sustaining life common throughout the Universe? How is pre-biological material made?

The Professor often encouraged engagement from his audience, occasionally looking to trip them up! 

The make-up of DNA consists of just a few atoms: carbon, hydrogen, oxygen, nitrogen, and phosphorus. Combinations of these atoms form the sugar-phosphate backbone of the DNA -- the sides of the ladder. Other combinations of the atoms form the four bases: thymine (T), adenine (A), cytosine (C), and guanine (G). The question is, how were they made?

Aleksandr Oparin was a Soviet biochemist notable for his untested theories about the origin of life, and for his book The Origin of Life. In the 1950's, biochemists Stanley Miller and Harold Urey tested his theories, conducting an experiment which demonstrated that several organic compounds could be formed spontaneously by simulating the conditions of Earth's early atmosphere. 

The first carbon-containing molecule detected in the interstellar medium was the methylidyne radical (CH) in 1937. Since then an ever increasing number of molecules have been detected. Now there are well over 100 and a fair proportion of these have ten or more atoms. 

How (and where) are smaller molecules then made into larger ones? We don’t know yet. The Prof took us on a tour of the history of Astrobiology and how we might discover whether there really is intelligent life out there.

The earth has not been here long enough for the biochemistry to evolve to the way it is now, which gives rise to the thought that the origins of some of the functional biological molecules may be extra-terrestrial, for example from meteorites or other early collisions.

Professor Mason commented, ‘It was a pleasure to talk to the Wycombe Astronomical Society. I was impressed by the turn out on such a fine evening and by the insightful and interesting questions. It was nice to see some younger members who asked and answered questions so well.’

Chris

“The High Frame Rate Advantage” – Lecture by Pete Lawrence, 16th June 2016

At our recent Practical Sessions we have covered the basics of capturing video images of the Moon, the Sun and Planets and using software to process good quality images. Now it was time for the Masterclass!

Pete Lawrence has been a presenter on the long running BBC Sky at Night television programme since 2005 and is highly regarded in the world of astrophotography. And it’s fitting that Wycombe Astronomical Society can attract such an eminent speaker to help us refine our skills.

Of course one could resort to “lucky imaging” – taking that single shot of Jupiter where the seeing is perfect. But in real life we face that enemy of astro-imaging – our atmosphere and its effects on seeing. To overcome this we need to take hundreds or thousands of images and these days high frame rate video cameras are available which make this relatively easy. Coupled with (usually free) image processing software, planetary imaging is now well within the capability of amateur astronomers and Mr Lawrence gave us valuable detail on how to get the best results.

Collimation, cooling and focus of one’s scope are all critical – so, too, being able to understand the basics of meteorology! We also learned about the pros and cons of mono –v– colour cameras, appropriate focal ratios to employ depending on seeing, the use or otherwise of IR Pass and IR Blocking filters. Finally the ins and outs of frame rates and the number of frames to capture.

And then on to image processing. Mr Lawrence favours Autostakkert!2 for analysing, ranking and stacking just the very best frames, then Registax’s Wavelets for image enhancement. He gave a live demonstration of the use of these tools on a Moon video he’d captured, and showed in detail how to bring the best out of the image. He also emphasised there is still a place for Photoshop in the final stages of image processing.

Judging by the questions which emerged from our Practical Sessions, answers to which Mr Lawrence ably provided during his talk, there is considerable enthusiasm amongst the members of our Society to improve our imaging techniques. So much so that at least one of our members raced straight home to put them into practice!

Sandy