- Editorial Comments
- Beginners Cosmology
- A Walk Through the Universe
- In the Sky
- Observatory News
- Astronomy Day Memories
Prince George Astronomical Society Executive 1993 :
Bob Nelson 562-2131 President: 563-6928
Alan Pretty Vice President: 562-3562
Brian Potts 565-3625 Secretary: 562-8113
David Sundberg Treasurer : 562-5774/6655
Jim Livingstone Mem. at Large 964-0155
Rod Marynovich Mem. at Large 562-0952
PeGASus Project Directors
Ted Biech 562-2131 Director: 564-2838
Orla Aaquist 562-2131 Programs 964-9626 Coordinator
Bob Nelson 562-2131 Observatory 563-6928 Director
Is Wednesday evening the best time to hold our monthly meetings? The question arose at the Editor’s Office when in walked a beautiful woman with long flowing red hair. “I want a job at the Editor’s Office “, she said. The expression on her face told me she was serious. I knew that look from somewhere. But where? I thought long and hard. Then it came to me. The women was my wife, Shannon.
Now Shannon assembles the newsletter. She designed the current format, corrects all of my spelling and grammar error, and she thought up the word PeGASus as the name for the newsletter.
Shannon suggested that Friday is better if we are to have youth participation because Friday is not a school night. At Astronomy Day, a few participants indicated that it would be easier for them to attend meetings on Friday evenings because it is difficult to get away from home on a school night (even for adults).
So, I would like to ask for your input. Come to the next meeting to voice your opinion or give me a call at the Editor’s Office (964-9626).
By the way, as you read this issue of the newsletter, you may notice that Shannon is not here to correct spelling and grammar errors. Hurry back, Shannon!
PeGASus needs your input! Please feel free to write letters, articles, book reviews or whatever and submit them to the editor for publishing in our newsletter. Send them to the address on the inside front cover.
Beginners Cosmology: by Ted Biech
Cosmology is the study of the large-scale structure and evolution of the universe. Cosmogony is the study of the origin of celestial structures such as stars, clusters, galaxies and clusters of galaxies. There have been many attempts to create a comprehensive theory which encompasses cosmology and cosmogony. The current theory of favour is the so-called “Big Bang” Theory. The Big Bang Theory has been able to broadly outline the evolution of the universe, but many vexing problems remain with this theory i.e. the structure, origin, and sizes of the galaxies. The Big Bang Theory should not be thought of as the final theory of the universe but rather as another approximation to the observations which we make of the universe.
A good understanding of cosmology is rooted in a clear understanding of the basic principles which are ASSUMED at the beginning of any theory. The first key principle is the COPERNICAN COSMOLOGICAL PRINCIPLE. This principle states that we do not observe the universe from a privileged viewpoint i.e. the earth does not occupy a special place in the universe. This principle is named after Nicolas Copernicus who, in 1543, proposed that the earth might not be at the centre of the universe, a heretical view-point for that time. By viewing deep-space photos of galaxies and counting their spatial distribution in different directions, we see that on the largest distance scales, the Copernican Cosmological Principle is approximately valid.
An attempt to extend the Copernican cosmological principle to hold for time, i.e. that the universe appears to be unchanging, called the Perfect Cosmological Principle, has been shown by observation not to hold. The Prefect Cosmological Principle was the basis of the “Steady State” class of cosmological theories. These theories were proposed by H. Bondi, T.Gold, and F Hoyle in 1948. For about 17 years, this theory was a competing theory against the Big Bang Theory. In fact, the term “Big Bang” was invented to denigrate this competitor to the Steady State Theory. To be continued .
A Walk Through the Universe: by Orla Aaquist
First Step: Imagining the Earth: The universe as we have come to know it in the last hundred years is a big place. We are told that it is hard to imagine how large, and if we try to imagine the immensity of it then we will feel very small, insignificant, and humble. Well perhaps this is true.
It is true that the universe is immense in comparison with our everyday experience. Everyday experience involves looking at the fine print on the national referendums, wandering around the house picking up after the kids, working in the yard, walking to the corner store, or driving to the mall. On rare occasions we may venture out on our treacherous B.C. highways and travel south to Vancouver. So our everyday experiences range from dust to the distance to Vancouver.
The range of distances involved in our everyday experience start at a fraction of a millimetre (perhaps one-tenth of a millimetre) to 1000 kilometres. There are 10,000,000,000 (10 billion) one-tenth millimetres in 1000 kilometres. That is, if you lined up 10 billion dust particles, each one-tenth of a millimetre in diameter, then they would reach from here to Vancouver. This is the range or our everyday experience. Our brain can comprehend 10 billion. But can we comprehend 10 billion 10 billions?
In order to get an appreciation for the size of the universe, a good approach is to try to scale it down to something that we can comprehend: like a comparison between a grain of dust 0.1 mm across to the distance to Vancouver. You could, for example, imagine that you are the size of a grain of dust and ask yourself how large the earth would be on that scale. If you are 6 feet tall (1.8 metres) and you wish to scale yourself down to a grain of dust, then the size of the earth can be found by simple ratios if we know the actual diameter of the earth in metres, which we do. It is about 12,756,000 metres. So, scaling that down to our new dust sized beings, the earth is about 710000 mm in diameter. This is about 7 kilometres.
Hence, we arrive at the following point of view: we are but particles of dust moving about the surface of a giant ball which is 7 kilometres in diameter. Seven kilometres? That’s about the diameter of the bowl in which Prince George sits. Take a look at a speck of dust in your house and imagine it to be you. Then try to imagine your tiny dust-body attempting to walk from downtown Prince George to the growing UNBC campus on Cranbrook Hill. If you managed to walk that distance you would have walked about one third the distance around the 7 kilometre diameter world — as you know the world is not flat. There are, in fact, just over three diameters in one circumference.
Looks pretty far to walk when you are the size of a grain of dust. Just what kind of progress could you make in a day. Lets say that you can walk your own body length every second. So in 10 seconds you can walk 1 millimetre; in 100 seconds you can walk 1 centimetre. You can walk one whole metre in about three hours allowing for a 15 minute break. So in one whole 9 hour day of walking you can cover three metres. It would take you a few days just to get out of your full scale house.
As you can see, the world is a big place compared to the size of your body. But what about the rest of the universe?
The earth’s nearest neighbour is the moon. The moon is actually 384,404 kilometres away from the earth; that’s just over 30 earth diameter. So, if you are a speck of dust and the earth is a 7 km ball resting in the P.G. bowel the moon is a 2 kilometre diameter ball near Williams Lake, south of Prince George, about 200 kilometres away. Can you imagine being the size of a speck of dust living on a 7 km ball and being asked to travel to a moon which is 200 kilometres away? Humans have done just that. But the moon is just our nearest neighbour. What about the rest to the solar system?
We have taken the first step. In order to explore the rest of the solar system, we have to take another step. To be continued in a later issue .
Casino: by Bob Nelson
This was our fourth casino event and was held over two days (instead of three) for the first time (it included a week-end evening). We raised $2517 on the Thursday and $1000 on the Friday for a total of $3517 (this was up from $2800 earned last time). All told, the executive is quite pleased with this amount. Thanks go out to Ted Biech, Gerhard Bierman, Jon and Peter Bowen, Don Goldie, Rod and Steve Marynovich, Alan Pretty and Larry Steel (your reporter also served).
Quite accidentally, I learned that, contrary to the rule a few years back, we are not restricted to one casino event a year. All we have to do is submit the report and request a new date (there is a waiting time of from four to six months). We could therefore have up to three events a year, earning somewhere in the neighbourhood of a cool $7,000 – 10,000. Judging from the opinions of those who staffed this event, we are not close to volunteer burnout yet; however, we shall have to be careful on this score. As our club gets bigger, though, we will be able to share the load more (even this time, there were some members who did not have to be called upon).
A worrisome trend in the classroom addition is the tendency to go over budget as there are things we did not think of and higher costs than expected. The nice things about more casino events is that now there can be no doubt that we will be able to pay for the new building and whatever new equipment we need.
Meetings: by Orla Aaquist
The next meeting of the PGAS will be on Wednesday May 26 at 7:30 P.M. at the College of New Caledonia in room 2-223. At this meeting, the time of the summer meetings will be discussed (as suggested by the Editor). Bob Nelson will describe the most recent progress at the PGAO, and Orla Aaquist will summarize the events of the May 21 partial eclipse of the Sun. Also, some new hardware made available through the PeGASus project may be on display. The feature presentation for the evening is entitled, ‘Three Times in the Moon’s Shadow, Making Your Own Good Luck’. In this talk, Alan Whitman (PGAS member) will look back at three total solar eclipses and forward to the eclipses scheduled in the next decade.
At the last meeting on April 28, we saw several new faces. The PGAS executive and regular membership would like to take this opportunity to welcome you and invite you to attend the upcoming meeting. Bob gave an update on the latest developments at the observatory and classroom addition. Volunteers for the casino event were asked for. Orla summarized the current PeGASus Project activities and the scheduled events for the Astronomy Day (night) activities at the Fraser-Fort George Regional Museum. After tea and coffee, Bob Nelson illustrated the simulation software ‘Dance of the Planets’.
In the Sky: by Orla Aaquist
On morning of June 4 there will be a Lunar eclipse. Prince George residence will be able to catch the initial stages of this event as the moon enters the penumbra (the outer part of the Earth’s shadow). Shortly afterwards the moon sets.
Most of June is a good time to view Mercury in the early evening sky. It appears farthest from the Sun on June 17 (greatest elongation) and will shine with a magnitude of 0.6.
Venus shines bright at -4.5 magnitude in the predawn sky. It will continue to dominate the sky for the remainder of the spring and most of the summer. Venus reaches greatest elongation on June 10.
Mars is quite dim in the western twilight after sunset and is easily overlooked. It sets about four hour after the Sun. You will have to stay up past midnight if you want to have a look at the ringed planet, Saturn. By morning, it is visible in the southeast.
Jupiter shines at magnitude -2.1 among the relatively fainter stars of Virgo. Jupiter will be visible all summer. On June 27 the giant planet is at quadrature (it lies 90 degrees east of the Sun). Near the time of quadrature, you can see Jupiter’s phase more easily than at any other position in its orbit. Even though Jupiter appears 99 percent lit, the eastern limb supposedly does look less defined than the western limb. Watch for eclipses of the Galilean satellites in June because the eclipses occur farther from the planets disk than at any other time. In particular, on the night of June 8, Ganymede vanishes behind Jupiter’s western limb at 16:57 PDT and reappears from behind the eastern limb at 19:51 PDT. Unfortunately, the Sun is still up at this time. However, at 21:57 Ganymede will disappear again while well away from Jupiter’s disk. It then magically reappears again 39 minutes past midnight. Can you explain why Ganymede can be eclipsed twice in such short succession?
If you have any questions about the night sky, I will be happy to look into my crystal ball. Give me a call (562-2131 local 307).
Observatory News: by Bob Nelson
Well, a lot has happened. Jim Livingstone has come up with a nice set of plans for the classroom addition in consultation with John Morgan, (a professional engineer at CNC who can approve our drawings). Thanks Jim and John. Brute Drilling and Contracting excavated on May 11, the forms for the footings were completed on May 14, and at time of writing, the footings were supposed to have been poured on May 17. By the time you read this, the foundations should have been added as well and perhaps the brickwork started. As Ted Biech and I are committed to working full time on this thing, we should be able to get the basic shell up by the end of the month.
Also on May 17, the insulation and drywall in the warm room should have been installed and the CNC electrical class should have completed the wiring in the original building (no more extension cords!).
The donations have started to come in. I’m pleased to announce that the Pas Lumber Company has generously donated 105 pieces of 2″x10″x10′ lumber and Northwood has generously donated 50 sheets of 5/8″ T&G plywood for the floors. Donations greatly reduce costs and make all this possible.
On another front, I attended a meeting of the West Lake Community Association where the item of interest was the possibility of natural gas coming to the area. Although it’s not certain to proceed, the majority of the 50 or so people were in favour and it appears probable that natural gas will be provided next summer. (In case you’re not aware, heating costs with natural gas are about 1/3 of those with propane.) Although I did not speak at the meeting, I did talk with several people at the break. Interest is high in our project and a note will appear in their next newsletter. I believe we can count on the support of the people in the area (which is important for our security and other things). We need good neighbours!
Astronomy Day Memories: by Orla Aaquist
On May 1, the Prince George Astronomical Society (PGAS) and the Fraser-Fort George Regional Museum hosted an evening of star gazing in celebration of the 20th anniversary of Astronomy Day. Although there were very few stars at which to gaze (it rained), the evening was a tremendous success. It was an educational experience for all who attend, and the few who remained until 10:45 even got a glimpse of the moon and Jupiter through Bob Nelson’s 33 cm Dobsonian.
I was pleasantly surprised by the influx of people. Because of the heavy cloud cover and rain, I had anticipated a turnout of only a handful of people. However, Cindy Rebman (the museum’s program coordinator) estimated that about 90 people passed through the museum. This shows that there is a considerable public interest in astronomy in Prince George.
Thanks to all members who came down to help make the evening a great success, especially Bob Nelson who brought his big eye, Ted Biech who brought his computer and simulation programs, and Alan Whitman who brought his video of the 1991 solar eclipse. I also got a glimpse of Jon Bowen actively sidestepping through the crowds. I had anticipated performing last minute organizational activities after the museum doors opened, however I was swept away into the conference room at 8:15 to give my presentation and I did not emerge before 10:30. This left many of the members to their own devices. Thanks for surviving the evening on your own.
Next year we hope to be better organized. Astronomy day will be held on April 16 (1994). The moon will be 6 days old, so craters will be easily seen. Of the planets, only Venus and Jupiter will be visible. Venus will be close to the horizon just after sunset and very small at 11 seconds of arc. Venus will set just as Jupiter rises at about 9:30 p.m. Perhaps we could have a day long display at the museum, with solar viewing during the day and ending with a star party in the evening. By next year, the PGAS will have more show and tell items from the PeGASus Project and hopeful a larger membership.
Published monthly by the Prince George Astronomical Society.
Prince George Astronomical Society inquiries and PeGASus correspondence may be mailed to: PGAS c/o 1393 Garvin Street Prince George, B.C. V2M 3Z1