Journal of the Northern Sydney Astronomical Society Inc. Volume 22 Number 2 July 2011

President’s Message In this issue he year for NSAS is already halfway to be interesting in the future. The next Page 1: President’s message Tthrough, and it’s been eventful so program will be in August. Page 2: Calendar/Communications far. Some of you who do not attend ISS and Endeavour meetings may have missed the 2nd edition The guest speaker program this year Page 3: A Quadruple Conjunction of Reflections this year, as it was not has continued to run strongly and, at the Page 4: Parkes Field Trip published for the simple reason that moment, NSAS has guest speakers from Page 5: Lindfield School Event there were so few contributions from the the professional astrophysics community Page 6: Paul’s Corner membership that it would have not been booked for the rest of the year, with a Page 7: Supermassive Black Hole worthwhile. I’d like to remind everyone number of candidates selected for 2012. Page 8: Book Review in the Society that Reflections is a journal Our speakers so far have come from Editorial for the members, but also of the members. CSIRO, Macquarie, Sydney, and NSW the Central West Astronomical Society There’s no point in rehashing information Universities and they have talked to us on (see the more detailed article inside). Our that is available in the newspapers or the a wide range of subjects that form their intentions are to run another field trip, Web in Reflections, as these are available areas of expertise. possibly to Coonabarabran and the AAO, to most of our members. later in the year. Don’t forget that the Geoff Welch Prize for As you know, we recently made a move in We have also tried to start our arrangement best article submitted to Reflections is short our meeting place from the Fr. Mac Pavilion with WSAAG at Linden Observatory this listed by the Committee in September, and to Regis Hall at St. Ignatius, which is big year, but they are equally frustrated with the winner is chosen by the membership at step up in our facilities and ability to host the observing conditions. the September General Meeting so, if you a large group. It’s probably just as well, as haven’t contributed this year, it’s already the membership of the Society has slowly We’ve recently lost our Secretary, Anna too late! grown over this year towards the level that Koeneman, who has resigned due to a the Committee would like to see. In fact, we broken (writing) wrist, after 3 years of On to other, happier, matters. The Society have gained 12 new members, at the loss support in this important area of Society has had a busy and fruitful year so far, both of 3 members at the last renewal. So please documentation. She has left her position in attracting new members and in running introduce yourselves to our enthusiastic with the often chaotic paperwork now its various internal programs and outreach. new members at the next opportunity. very neat and tidy. The Committee wishes The Theory Group has continued to attract to thank her for her loyal support. We new attendees and the last meeting had On the outreach side NSAS has been will attempt to get by for the rest of the about 20 persons attending. somehow busy. After a quiet start to the Society’s year within the Committee but The New Astronomers Group (NAG) has year, we ran a primary school star program I’d like everyone to start thinking about the been moving slowly through the art of at Lindfield Public School in May, followed makeup of the Committee next year prior observing over the year, and a number by the Parramatta Park star party and the to the elections in October. of new and existing members who have Seaforth Public School event in June. Due to my likely return to university not been active in observing have been The major outreach event for NSAS this next year, I will be stepping down as attending. The sad state of observing year will be the star party we will run as a President to offer myself in a slightly less during the last year due to the La Nina part of the Lane Cove Council Cameraygal active position, so I’ll be looking for a weather pattern has continued to dog our Festival on September 3. This is a major replacement. scheduled observing program, but we’ve event comparable to our parties for managed to continue the NAG on other Willoughby Council and it will require I wish everyone a pleasant winter of subjects. Hopefully we are finally seeing broad support from the membership, so astronomical interests, and the return of better skies, and this winter expect to be asked for help. hope to see more of you may allow us to run a more frequent at the various meetings observing program. As you may remember, a survey of the and observing sessions. membership at the last membership renewal Also starting up this year has been Bob indicated a strong desire for field trips this Best Regards, Roeth’s “Fifth Tuesday” Mathematics and year and we made our first trip in late June Astronomy programs. These have been to Parkes, where a 30-strong group of well-attended by both the mathematically members and wives toured the Dish, and inclined and the rest of us and they promise attended a joint observing session with Bob Fuller Calendar General Meetings: July 19th Guest Speaker: Baerbel Koribalski (CSIRO); the Wallaby project August 16th Guest Speaker: Daniel Yardley (Sydney Uni); gravitational wave detection September 20th Guest Speaker: David Free (Macquarie Uni); subject TBA

Theory Group Meetings: July 12th - August 9th - September 13th

NAG Meetings: July 26th - August 23th - September 27th

Observing Nights: Consult NSAS’ web site at http://nsas.org.au/observing/

Deadline: Please send your contributions to the October issue of Reflections in time to reach the editorbefore September 15th to [email protected]

ISS and Space Shuttle Sighting n May 21ST 2011, the Space Shuttle The whole of this pass starts at 5.45pm It is due to continue towards the ESE and OEndeavour had already joined and and it is due to rise over 10 degrees in will enter the Earths Shadow when it is was linked to the International Space the NNW in the constellation of Gemini only 18 degrees high at 5.50 pm, just after Station. near the main stars Pollux and Castor at just reaching Scorpio 5.47pm Both are passing over Sydney and more By this time the sky should be relatively closely over Gosford and dark but since the ISS and the Shuttle the HKG village hwere I are now joined together the vision of reside at a very high angle, the two should be very bright in the up to 66 degrees high as it reflected evening sunlight as seen at closes on the star Spica that altitude of well over 380 km. in Virgo, on Saturn, the Southern Cross and the Report of this sighting: prominent 2 pointers. On time and on course and quite brilliant. In fact there is quite a I have never seen the ISS quite so bunch of craft all together bright as it soared overhead. Seemed to in this pass as they are have quite a few points of light. Since followed by the Soviet it looked more like a Sydney bus with Soyuz TMA 20 and the all its lights on, I rechecked my notes Soyuz TMA 21, these are and timings and its trajectory, just in transport modules that case I was watching a rather low flying transport goods to the ISS Jumbo jet, albeit very silent with no and are kept nearby for disposal of waste Endeavour and the ISS as seen from Soyouz sign of any navigation lights red or green when the ISS is filled. TMA 20 supply ship. Credit NASA No it was the ISS and the space shuttle Its interesting to also note that the sewage absolutely on the predicted course and from the ISS is also disposed this way Progressing it reaches higher and higher in on time! and who knows, the next time you see a the northerly sky, past Leo and on to Virgo ‘Falling Star’ and make a wish , well it passing to our right of Saturn by 5.49pm. This sighting was one of the best I have could just be one of these craft burning up Remember it is quite fast as it is traveling witnessed and it excelled in the fact the that waste in our atmosphere. at over 17,000 km per hour but is over 380 NNW to ESE direction was in fact the exact We do not want to pollute space, just km distant so it is quite a steady track. Total length of the HKG valley and it cleared all Earth’s atmosphere. But no problem, in the visual transit will take up to 5 minutes. the trees except for the initial 2 minutes. reentry the craft do burn up with the heat This spectacle was well worth the time generated in the fiery descent By the time it gets near the small taken to enjoy the view of this special constellation of the Southern Cross it will event. There is also a 3rd extra craft in this bunch, be at its maximum height of 66 degrees Continued on page 8 called the ATV Johannes Kepler 2. At this and be positioned on our left of the Cross stage I am not too sure of its function with and the two Pointers. the others. *

Shop 3075, Westfield Shopping Ctr Shop 416 Macquarie Shopping Ctr Shop 111, Level 1 Cnr Florence and Hunter Streets 197-223 Herring Road Warringah Mall Hornsby NSW 2077 North Ryde NSW 2113 Brookvale NSW 2100 Phone: (02) 9257 0092 Phone: (02) 9257 0078 Phone: (02) 9257 0075 A Quadruple Conjunction riday May 13th, 08:00 pm Saturday May 14th, 05:15am Done, now let’s see what we can see FI’ve missed the news on ABC1 but Here goes the alarm clock, a quick look through the scope. Jacqueline, my wife, watched them. through the windows, perfect, the sky is She asks me: “Do you know about the clear and the stars are twinkling but it’s Obviously, the field of view is too small to planets tonight, on the news they spoke pretty cold. show more than one planet at a time. about something happening tonight.” Let’s get dressed and out to the balcony. Venus: it’s noticeably gibbous, very bright, - Really? No I don’t see what they were almost blinding and, as always, completely talking about. Ohhhh yesss… here they are! featureless. - Nobody talked about it at your club? It Absolutely stunning, Venus, Jupiter and Mercury: not much to see, appears like a seems to be something big and people Mercury in a neat rectangular triangle with minuscule quarter moon are already preparing themselves for it Mars a bit lower. Mars: I did not expect much and yes there all over the place. To the naked eye, Venus, Jupiter and not much to see with a small aperture - Well, no, nobody’s mentioned anything Mercury look pretty much as bright but scope, just a tiny brownish disc. but let me see…” Mars is just a faint reddish dot. Jupiter: at last something worth looking at, Binoculars show the triangle in the same 2 dark bands are clearly visible and its four Ok, let’s see what the 2011 Astronomy field of view and you can see the discs of main moons are neatly aligned, Callisto book says. But where is it? Venus and Jupiter. Ganymede and Io on one side and Europa Ah here it is. on the other. S o o o … M a y … 06:15am The Sun is not far from planets… rising, the stars are disappearing here we and Mars is fading. It’s time to are: pack up the gear and to get back - Mercury: inside to a warm cup of coffee. the month o p e n s Well, I’m no longer used to getting w i t h up that early but I’m glad I did not Mercury miss this show. just below Jean-Luc Gaubicher V e n u s with the c l o s e duo of Mars and J u p i t e r f u r t h e r below. - Venus: Stellarium Screenshot of the Venus and Conjunction J u p i t e r are 0.6° apart on the 12th, a magnificent sight! Now let’s take some pictures. I’ll take a few bursts of 10 shots and I’ll Okay, so there really seems to be something stack the best ones with RegiStax. interesting happening tonight or rather tomorrow morning. So, let’s fire up the computer and see what’s going on with Stellarium… Oh yes! That’s look impressive and, for once, the action takes place in the East. We shall be able to see it from the balcony. A quick look outside, clear skies and the forecast for tomorrow morning is good. - Camera… checked - Tripod… checked - Binoculars… checked -Scope… checked, the small 4” Skywatcher will do - Alarm clock… checked Time to go to bed... Parkes Field Trip fter months of planning, 29 NSAS Saturday night was a special observing Amembers and wives traveled to Parkes night jointly held between CWAS and in the Central West of NSW for the first NSAS at their Cookamidgera site about NSAS Field Trip in a number of years. 20km South of Parkes. 18 NSAS observers made their way by The main attraction for the trip was a tour convoy to this very dark site, where the of the CSIRO Parkes Radio telescope, or only light pollution was a small glow from “The Dish” as it is popularly known. Parkes to the North. As it was well dark On the occasion of a visit to the Dish in when we arrived, most of us had a shock February while on an Aboriginal astronomy field project, I was “hamburger” it is often described as and introduced to Dr. John Sarkissian, many other galaxies were visible in the the Operations Scientist for the larger scopes. facility. John kindly gave me a personal tour of the telescope, As the evening wore on, the temperature which is something not available to dropped, and so did the dew and many of the public, and I had a chance to talk us were busy swapping eyepieces from to some of the radio astronomers pocket to scope and warming secondary while at work. The idea for a NSAS mirrors dewing up from radiation. field trip was hatched and, as John is also the current President of the Central West Astronomical Society, we discussed some joint activities at the same time. Eventually, we came up with the dark end of June, Saturday the 25th, for the event.

About 10 PM, the dew suddenly stopped as the temperature dropped to around zero and some scopes actually started to ice up on the metal tubes! By when we stepped out of our vehicles, 10 or 11 most of us were frozen and called looked up and saw the Magellanic it a night, dreaming of our warm beds back Clouds even before our eyes had in the Parkview Motel in Parkes. dark-adapted! Everyone traveled independently to Parkes The sky was spectacular, with the Milky The next morning everyone got together in on Friday and most got together for dinner Way visible from horizon to horizon and, the motel parking lot to discuss the events in Parkes that night. for those interested, the Emu clearly visible of the weekend and organize for the trip in the dark lanes. back to Sydney. Our large group split into two and Having been each had a one- made aware of the hour detailed temperature by tour of the the Friday night telescope, which low, everyone had was working at dressed warmly the time as it is but when the for 85% of the CWAS observers 24/7 workweek. i n t r o d u c e d Joris, a German themselves their radio astronomer, “freezer suits” (full gave all of us a brief on his current pulsar length insulated suits as used in project, while John gave us an insight into cold stores) were the envy of us all. The trip generated a lot of enthusiasm the history and operational aspects of the Scopes were rapidly set up and everyone amongst the participants, so the Committee facility. set about looking at whatever interesting will discuss another trip later in the year, Those in the half not on the tour took objects we could find in a sky so full of possibly to Coonabarabran and the AAO. advantage of the first-rate café at the stars it was difficult to orient oneself. Bob Fuller Visitors Centre for their lunch. After the Galaxies were the flavour of the night, tour, a number of us watched the excellent with everyone having a chance to see Photo credits: Alex Abbey (CWAS), Robyn films at the Centre. them. Centaurus A looked just like the Fuller, Peter & Yuki Nosworthy (NSAS) Lindfield School Event n May 14th, the society participated The students began arriving for the Saturn was the only bright planet visible on Oin an outreach event at Lindfield sleepover at about 6pm and we began the night and this naturally proved popular Public School. setting up our scopes in the playground with everyone. Omega Centauri, the Jewel We had been contacted by a teacher from the at about 6.30pm while the students and Box and a few other bright clusters were school, Nicky Jones, who said that her 5th a few parents watched. In addition to the only other objects bright enough to grade class was scheduled to study space myself, we had four members supporting observe in the conditions. and astronomy during the term. She was the event: Peter Korber, Gary hoping to hire a telescope or have someone Maas, Graham Nicholson and come to the school to show the students Josephine Lindquist. Between s o m e us we had o b j e c t s four scopes with a in a range telescope of types and during a sizes. sleepover at the The students school. b e g a n lining up at We agreed each of the to support scopes and (2) the event, took turns at the and a eyepieces. I was We finished at about 8pm after a short but c o u p l e glad I had brought my exciting session. of weeks (1) stepladder as most of the The students then presented us with gifts before, I went to the school to meet Ms. students needed it to reach the eyepiece of and some huge ‘Thank You’ cards that they Jones and to assess the site. The proposed my scope. had hand-made in a space theme. observing site was a balcony adjoining the For logistical reasons the date of the event Thanks to the students, parents and Nicky 5th grade classroom. However this offered coincided with a gibbous Moon. This, Jones for making it an enjoyable night for a limited view of the sky, particularly to and the school’s location on the Pacific those of us who attended. the north and east. It would also require Highway, made for a very bright sky. We Peter Nosworthy carrying our scopes up the stairs as therefore had to concentrate on just a few there was no lift. After discussing these bright targets beginning with the Moon problems with Ms. Jones, we agreed to use itself. the playground area instead. The rugged mountains and craters along the The weather on the day looked a little lunar terminator were dubious but, as evening approached, the an impressive sight and sky looked better and by sunset there were brought many exclamations only a few clouds about so we decided to of awe from the students go ahead. as they took turns at the eyepiece. Some even said that they could see an alien on the Lunar surface!

At one point, pizzas arrived causing great excitement and a temporary pause in observing. (4) And not just the kids were excited!

Photos by the author: (3) (1) Gary and Peter (2) Nicky Jones - Teacher (3) Graham and Josephine (4) Cards presented to us by the students Paul’s Corner n the 7th July, the Moon will be Turn left and you will find M8 and M20 was the very reason I took the image as Owaxing and in Virgo in the NW sky angled away from each other. You are now part of a sequence of several to look for high above Leo and closely joined by in the middle of a mass of goodies awaiting the dot that moved along over a period of Saturn. your inspection. several days, rather along the lines of Clye Constellations on view in the North will be At the centre of all those is Pluto that has Tombah searching for Pluto in 1930. Leo, Hydra, Corvus, Coma Berenices will returned but it is still very distant at over After that, it was relatively easy to trace gain altitude during the night and would be 31.055 AU and at 13th mag could be lost the progress of Vesta with binoculars over a good subject for inspection from the star in the crowd. It maybe found by looking the weeks. Not bad for a block of rock only Denebola eastwards for the many Galaxies for M15, which is close by, but do not 458 km radius. therein, do not overlook the Leo triplet get confused by another good globular This month Vesta is in Capricorn at its first. cluster, M22 that can, on a favorable night, eastern end (lowest) very near the star HIP be a good sight even in my small 4.5” 106143 at 5.5 mag, see if you can find it Much higher up we will come to Beta Newtonian scope. It is very close to the again. Librae (β Lib, β Librae), which is the Ecliptic line. brightest star in Libra. Watch the Milky Way if the sky is dark It has the traditional name Zubeneschamali As a matter of interest, Gordon Stott, enough and see the Big Emu. meaning the northern claw. Now try saying one our founder members, told me when It was named by the Aborigines and it is that quickly with a mouth full of sausage I showed him one of the photos I had placed below the Southern Cross, extending sizzle! previously taken, that the star Sag 28 down as far as the top of Scorpio. Better still also find Alpha Librae (α Lib, α right on the Ecliptic line was occulted by Librae), which is the second brightest star Saturn, now many New Moons ago, and Look at the picture taken by me at my in Libra despite its Bayer designation favorite dark Sky site. as alpha. It has the traditional name Can you see an emu trotting Zubenelgenubi. The name, from up the slope? I can almost see Arabic (al-zuban al-janūbiyy), some wings as well, a product means “southern claw” and was of my imagination? or a fault coined before Libra was recognized in the film? I need to go back as distinct from Scorpius when Libra and check that out. If you was added as the 12th constellation. go to Linden please double check and let me know. Below Beta Libra you will come across M5 described as the best Sorry for the blobby stars , globular cluster in the Northern It was a fairly small sized skies. Have a look to see if you would fisheye lens I used, with a agree. M5 was used as a prominent fixed f8 lens that I was kindly marker when some NSAS members lent by an NSAS member went looking for Pluto, the then 9th to do a special project some planet, some years ago from our site years ago when chasing at the NTGC. Comet Hyakutake. Pluto was then claimed to be at its The head is the coal sack just closest approach to earth for the next below the Southern Cross, 315 years in its oval shaped orbit not to be confused with the before exiting off stage to go way False Cross above. beyond Neptune’s orbit. This stands out very clearly in a dark sky and it’s quite Now, lets move to the East to see eerie to be watched by this what is rising looming up in the night sky. he explained that, as the story goes, it had No wonder that the aborigines gave it a I see the centre of our Milky Way rising been used to measure the thickness of name. with the tail of Scorpio, followed by several rings of Saturn as it passed in front Paul Shallow Sagittarius and then Capricorn. of that star. M7, Ptolemy’s Cluster, is prominent I was also quite astonished that he was and best seen with binoculars just below able to name a star so quickly just on a Shaula, the stinger of Scorpio. photograph! To the left (North) you may sight M6, the In my image I also had Uranus, Neptune Butterfly Cluster. and Vesta, the third largest asteroid , which

FOR SALE. • Celestron “NextImage” CCD camera. New, never been used. Connects direct to USB port. Ideal for Solar System images: $100 • Maksutov-Cassegrain telescope, 90mm, F=500mm, 1.25” eyepiece connection, erecting prism, wedge and screw tripod connections, carry bag included: $200 ono Contact Ray Harraway (02) 9712 7779 Surprise: Dwarf Galaxy Harbours Supermassive Black Hole he surprising discovery of a black hole. This greatly strengthens the While central black holes of roughly the Tsupermassive black hole in a small case for the black holes developing first, same mass as the one in Henize 2-10 have nearby galaxy has given astronomers a before the galaxy’s bulge is formed,” been found in other galaxies, those galaxies tantalizing look at how black holes and Reines said. all have much more regular shapes. Henize galaxies may have grown in the early Reines, along with Gregory Sivakoff 2-10 differs not only in its irregular shape history of the Universe. and Kelsey Johnson of the University of and small size but also in its furious star Virginia and the National Radio Astronomy formation, concentrated in numerous, very Finding a black hole a million times more Observatory (NRAO), and Crystal Brogan dense “super star clusters.” massive than the Sun in a star-forming of the NRAO, observed Henize 2-10 with “This galaxy probably resembles those in dwarf galaxy is a strong indication that the National Science Foundation’s Very the very young Universe, when galaxies supermassive black holes formed before Large Array radio telescope and with the were just starting to form and were the build-up of galaxies, the astronomers Hubble Space Telescope. They found colliding frequently. All its properties, said. including the supermassive black hole, are giving us important new The galaxy, called Henize clues about how these black holes 2-10, 30 million light- and galaxies formed at that time,” years from Earth, has Johnson said. been studied for years, and is forming stars very The National Radio Astronomy rapidly. Irregularly shaped Observatory is a facility of the and about 3,000 light- National Science Foundation, years across (compared to operated under cooperative 100,000 for our own Milky agreement by Associated Way), it resembles what Universities, Inc. scientists think were some of the first galaxies to form . in the early Universe. Credit: Reines, et al., David “This galaxy gives us Nidever, NRAO/AUI/NSF, NASA important clues about a very early phase of galaxy The dwarf galaxy Henize 2-10, seen in visible light by the Hubble evolution that has not been observed Space Telescope. The central, light-pink region shows an area of radio before,” said Amy Reines, a Ph.D. emission, seen with the Very Large Array. This area indicates the candidate at the University of Virginia. presence of a supermassive black hole drawing in material from its Supermassive black holes lie at the cores surroundings. This also is indicated by strong X-ray emission from this region of all “full-sized” galaxies. In the nearby detected by the Chandra X-Ray Observatory Universe, there is a direct relationship -- a constant ratio -- between the masses of the black holes and that of the central a region near the centre of the galaxy “bulges” of the galaxies, leading them to that strongly emits radio waves with conclude that the black holes and bulges characteristics of those emitted by super- affected each other’s growth. fast “jets” of material spewed outward from areas close to a black hole. Two years ago, an international team of astronomers found that black holes They then searched images from the in young galaxies in the early Universe Chandra X-Ray Observatory that showed were more massive than this ratio would this same, radio-bright region to be indicate. This, they said, was strong strongly emitting energetic X-rays. This evidence that black holes developed before combination, they said, indicates an active, their surrounding galaxies. black-hole-powered, galactic nucleus. “Now, we have found a dwarf galaxy with “Not many dwarf galaxies are known to no bulge at all, yet it has a supermassive have massive black holes,” Sivakoff said.

The Binocular and Telescope Shop 84 Wentworth Park Road Glebe NSW 2037 Phone: (02) 9518 7255 www.bintelshop.com.au ISS and Space Shuttle Sighting Continued from page 2 The launched date has been set for july 8th planned likelihood of arriving in our local When you read these lines, Endeavour will and this ultimate mission is planned to last skies will be advised, prior to the event, for be back home and there will only be one 12 days. your benefit and enjoyment. more STS trip to the ISS. That event is Once the date and time of its arrival at Paul Shallow planned for the space shuttle Atlantis. the ISS are determined, more news of its

* Ed: The Johannes Kepler ATV, or Automated Transfer Vehicle 002, was an unmanned cargo resupply launched by the . The spacecraft was launched on 17 February 2011 on a mission to supply the International Space Station (ISS) with 7,000 kg of propellant, air and dry cargo. Johannes Kepler had a total mass of over 20,000 kg and is the heaviest payload ever launched by the ESA. A Reentry Breakup Recorder was placed aboard before the ATV’s separation on 20 June 2011. It deorbited on the following day with its remains impacting the Pacific Ocean. The Calendar - Book Review his book, by David Ewing Duncan 829: they thought the Earth was round and much later in during the 11th century in Tcaught my eye and I borrowed it from they could measure its diameter; algebra China and 13th century in Europe. the NSAS Library after a general meeting. was invented. Cesium clocks now rule our time and, being I have read it twice, so decided to do a 1079: Omar Khayyam, who was a Persian a nanosecond out every now and again, review for members who may like to have mathematician and astronomer, worked Earth is not regular enough to keep up with a look at it. out a solar calendar. cesium time. 1126: Earth rotates but its orbit varies. This book describes “ The 5000-year 1582: Pope Gregory issued a papal bull Bell towers struck on the hour; struggle to align the clock and the implementing his calendar, which was I hope this works. Heavens” widely accepted by 1752. Till then ‘Time Lydia Bell belonged to God’ and it was sacrilege to Do you know what a ‘femtosecond’ is? Not meddle with it. very long! But we can measure that now.

Time may mean “Wet” and “Dry” Time may mean “Harvesting Time” when Editorial the cuckoo sings, “Low sex drive” when “Wine tastes best and goats are fattest.” es, it’s unfortunate but we missed Yone issue of Reflections due to a lack Man needs to know when taxes are due, of contribution. or the appropriate time to make a sacrifice But, as you can see, this installment is a to appease an angry god. bumper one, so much so that this editorial Mayans, Egyptians, Chinese and Cro- had to be relegated to the last page and Magnons, all needed to know just when reduced to its bare essentials. important (to them) events needed to happen. So they made their calendars. What I like about this issue, and what I This book tells many fascinating stories would like to see more in the future, is that of the struggles and the countless attempts most of the articles are what you can call that have been made. personal essays, which, as pointed out by our President in his message, is what it’s Caesar, Greek philosophers, Persians, all about. Indians, Druids, Arabs, Turks and indeed all men, had their concepts of how to Well, I hope you enjoyed reading this measure all these variables to suit their installment as much as I enjoyed putting important needs. Trading grew and times and dates for it up together. Paper was first made in Baghdad in 794 deliveries became essential. Cheerio, CE; calendars could then be printed. 1924: Greece adopts the Gregorian calendar Jean-Luc Gaubicher Muslims needed to pray 5 times a day, so but China waits until 1949 to do so. they needed time to be measured. Their month began 2 days after the new Clocks: early in history were water clocks moon. and sundials; mechanical clocks came

Reflections is published quarterly by the Northern Sydney Astronomical Society Inc PO Box 56 Lane Cove 1595 Tel: 0423 971 374 E-mail: [email protected] Web site: www.nsas.org.au