A Large Sunspot Group
Drawn by Geoffrey Johnestone
This large sunspot group (active area) was drawn on 1998 February 14th at 11.30 UT, using an 80mm refractor. The image was recorded by projection onto a white card. The large spot was measured at 354 millionths of the Solar surface, a naked eye spot is at least 400 millionths.
Watching the sky both at night and during the day can be fascinating hobby, you never know when you will see something which you have never seen before. This happened to me recently during a photography shoot in Portugal. We had just arrived at our hotel in Evora and after a rest and unpacking we all went upstairs to the roof top bar for a well earned drink.
Strolling out onto the hotel balcony with a glass of beer in hand, a truly magnificent sunset was in progress. I was amazed at the brightness of the rays from the setting sun crossing the clear sky above us. From its position behind the clouds on the horizon, five or six strong rays shone from between gaps in the silver and gold lined clouds. These fanned out and after passing overhead, continued onwards towards the opposite horizon where they met in a pink and purple haze. I have never seen such strong rays from the setting sun before radiating out from the 180∞ point opposite the sun (this is called the anti-solar point). The whole effect was magical, changing every few seconds as we watched.
Of cause every one asks, "Did you get a photograph?" No I didn't, I didn't even try to rush back to my room to grab the 35mm because if I had, I might have missed it. Some effects just don't last long enough to take in photography. So instead of missing the superb effect running for the camera, I watched it and I will remember it long after the prints would have faded.
A short time ago, around the beginning of December last year, I observed Venus, very bright just after sunset near a three day old crescent moon. A lovely sight. Venus was behind a slender tree about 100 feet away shining through the leaf-less branches. I then remembered a piece I had wrote a while ago in MIRA whether the skywatchers of old knew that the planets were different from the stars, (see MIRA 35, Stars of Old - Stars of New). By carefully placing the planet close to a branch and moving the head slowly to the side it was possible to make the planet dim out! It did not suddenly wink out, but faded. This is something else I have never witnessed before. At the time Venus was a thin crescent about 36" arcseconds across, so had a considerable size, astronomical speaking, making this a possibility.
Let me know if you have any unusual sightings to report and lets print them here in MIRA.
The follow article; The Tired Light Theory, is by Dennis Spratley, one of the two speakers who came to the Society in 1998 January to give the talk on Was there a Big Bang?. If you were at this meeting you will remember the discussion (and argument) it provoked from members and the lively debate after about modern cosmology. Dennis tells me Peter Wise and he, enjoyed the evening and the talking through of their ideas and both ". . felt delighted to be able to make our views known", and that the members of our Society ". . have scientific tolerance." to new ideas.
I feel proud to belong to such a group as ours which can and does talk about such ideas, for how can we be sure that the ideas we hold dear on how the universe works are really correct and not just the result of poor observation or undiscovered facts which in a few years will be changed?
From talking to Dennis it appears that other Astronomical Societies frown on any such debate which may challenge the accepted views of cosmology. Luckily we do!
All we can hope is that we are getting some of the facts right about how the universe started! But anyone who reads the history of astronomy will know how things can change in a few years with new information flowing in in ever greater quantities than before.
So read this article which was first published in the Leicester Astronomical Society Newsletter of Winter 1997 and if you don't agree or have any comment please write and say so. I will print any thoughts you have in the next MIRA.
Ivor Clarke, Ed.
The Tired Light Theory . . .
Can it Now be Laid to Rest?
By Dennis W. Spratley
THE COSMOLOGICAL TIRED LIGHT THEORY
If the interpretation of the cosmological red-shift as being caused by the general expansion of the Universe is rejected and other explanations sought then invariably the so-called 'Tired-Light Theory' (TLT) is offered as a viable option. The term 'tired-light' is used to indicate that the light quanta (particles that constitute light, also called photons) have lost some energy in traversing the long path from the cosmological object that emitted them to the astronomer's instruments, there being no relative motion along the line of sight joining the cosmological source and the instrument. In fact it is often asserted that the TLT should be regarded as a new law of physics, and that it is valid across any distance, even in the laboratory, but over a few metres its effect is so tiny as to be undetectable, at least at present.
This means that the famous Hubble Law that relates the cosmological red-shift to distance is simply left as such; it is not to be interpreted as indicating a recession of the cosmological object emitting the photons; there is no expansion of the Universe.
The attraction of the TLT is two-fold. Firstly, for those for whom the whole concept of an expanding Universe is an anathema it offers a way out. Secondly, a less severe usage is to consider that the cosmological red-shift is a combination of tired-light and the expansion of the Universe. By means of this concept, the "true" Hubble Constant, not the value currently obtained by astronomers, could be comfortably lower at about, say, 50 km per sec per Mpc. However, recent estimates of the Hubble Constant seem to be gradually creeping down to this figure so perhaps the TLT can, for the astronomers at least, be returned to the shelf.
Nevertheless, the question arises as to whether the TLT can be taken seriously at all. Certainly not in the form given in popular astronomical expositions. There it cannot be called a scientific theory. Consider first the observation on which it is based and the chain of argument leading to it.
That light from a distant cosmological source is red-shifted and that the relative displacement of the spectral lines is proportional to the distance of the source from the observer; Hubble's Law.
(a) On its arrival in the astronomer's instrument the photon has a wavelength greater than that which it possessed when emitted at the source.
(b) By Planck's Law, which states that the energy of a photon is inversely proportional to its wavelength, a loss of energy and increase in wavelength of a photon occur together. The fraction of energy lost is, in fact, directly proportional to the relative displacements of the spectral lines, i.e. the relative change in the photon wavelength.
(c) The fraction of energy lost over a cosmological distance is proportional to the distance travelled by the photon from source to instrument.
(d) In general, light becomes 'tired', in the sense of losing energy in travelling any distance, even in the laboratory, and the 'degree of fatigue', which is the fraction of energy lost, is independent of the wavelength and proportional to the distance travelled. The chain of argument is simply: a → b → c → d.
Now the TLT, at least in its usual naive form, takes as its basic postulate statement (d), the last link in the argument given above. In fact, (d) is to be regarded as a new law of physics which purports to 'explain' the cosmological red-shift. The chain of argument is now: d → c → b → a.
It should be clear from the above that the usual form of the TLT fails to meet any criteria as to what constitutes a scientific theory. The cosmological observation leading to Hubble's Law followed by some elementary physics leads to the idea that over any distance light 'tires'; that is, loses energy. But commencing with this idea and reversing the argument leads to Hubble's Law, which is not surprising: however, nothing new has emerged. The 'theory' as advanced lacks any predictive power: it does not suggest a further experimental test of a hitherto unexpected phenomenon. The statement: red-shift → tired-light → red-shift is without doubt tautological.
What is required is a theory which at least gives the means by which the photons allegedly dissipate energy as they travel through space. The effect simply cannot be caused by their interaction with an intergalactic medium: a sort of scattering.
Although the discussion has centred around light, the red-shift applies to the whole electro-magnetic spectrum from the longest radio waves to the hardest gamma radiation and it would be a very strange medium indeed to produce this effect because in the red-shift the relative change in wavelength is independent of the wavelength. So what carries off the energy from the photon and where does this energy go? In the case of an accelerated electron, it loses energy by radiating photons. So a legitimate question that must be posed is to ask what is the particle that carried off the energy from a 'tired' photon - another photon or a particle unknown to physics?
There's the rub. There is nothing known to physics that could account for 'tired-light', and tinkering with the physical laws of the properties of light such as assigning a non-zero rest mass for the photon (as has been suggested albeit for completely different reasons in the case of the neutrino) or postulating that the speed of light is not a universal constant but varies with the age of the Universe meets with a cool reception from both the theoretical quantum physicist and the general relativist. This is a very understandable reaction.
One advocate of the TLT was William Duncan MacMillan of the University of Chicago. At the time that the Steady-State Theory was causing much acrimonious debate in 1958, the American physicist Richard Schlegel pointed out an earlier theory put forward by his former colleague MacMillan as early as 1918. MacMillan wanted a static, indefinitely old, recycling universe. Tired-light 'explained' the red-shift and was part of the process of the recycling of energy. No mechanism seems to have been suggested: his ideas were speculative.
Unlike MacMillan, who did not find the concept of an expanding Universe acceptable, others who followed him saw in the TLT the means to explain the truly huge value of ~500km per sec per Mpc for the Hubble Constant, this being the estimate obtained in the late forties. The Steady State Theory had also been put forward as a cosmology that could accommodate such a value for the Hubble Constant, and that is why Schlegel drew attention to MacMillan's ideas.
At the present time, the value for the Hubble Constant that is being suggested is that which the cosmologists would like ~55km per sec per Mpc. This would imply that the TLT is no longer required but things do have a nasty habit of going wrong and it could be that new revised estimates of both the Hubble Constant and stellar ages would again result in an embarrassing situation of a Universe younger than the objects within it. Then one could expect the TLT to be taken down, given a dusting, and aired once more.
The problem of a firm theoretical foundation for the TLT would then once more have to be sought - or would it? Can, in fact, the whole concept of 'tired-light' be laid to rest? It would appear so, and the following is submitted as the reason.
Regardless of the absence of any known physics for 'tired-light', it is possible to take as a postulate (d) as given above, making it a new law of physics, albeit provisionally as always, and use it not just to 'prove' the red-shift but to take another route into a different aspect of physics and, most importantly, to be in a position to make a falsifiable prediction. That is, we seek, through (d), a further consequence that is our prediction which can be made the subject of observations or tests which, if resulting in failure, means that (d) is false. This does not mean, however, that if the tests or observations do not result in failure that (d) is necessarily true! Such a prediction can indeed be made.
The mature of this prediction does not concern the red-shift but the black-body spectrum, or Planckian spectrum, as it now seems to be called in many texts. The mathematical description of black-body radiation is given by Planck's Radiation Law which expresses the distribution of energy throughout the frequencies of the radiation emitted by a perfect black-body radiator. As a graph, the shape of the curve of this distribution is very characteristic. A different curve exists for each thermal equilibrium temperature of the radiating body. In practice, in nature, bodies such as stars are only approximate black-body radiators as are galaxies.
Suppose, however, that a distant cosmological source was indeed a perfect black-body radiator and that the radiation was reaching the Earth and was intense enough to be detected by astronomers. Given the temperature of the source the Planckian spectrum of the radiation at the onset of its journey is clearly defined. If the postulate (d) of the TLT is now introduced it may be used to modify Planck's Radiation Law to determine how the spectrum would appear to astronomers on or near the Earth. It can be shown that for any distant source of a given temperature the effect would be that the characteristic Planckian spectrum would be seriously distorted to the extent that the source would not be regarded on Earth as a distant black-body emitter. The result of this is a strong prediction; postulate (d) of the TLT asserts that no cosmological source can appear to have a Planckian spectrum: or put another way, there are no observable cosmological black-body radiators. This is a prediction that, if found to be the case (that is, if a search for black-body radiators proves fruitless) does not in itself verify the TLT postulate (d)! This is because if indeed there are no cosmological black-body radiators then, since all sources could have unknown emission spectra, if the content of the radiation was modified on its Earthbound journey the arrival spectra would tell the astronomer nothing. However, the opposite is the case: postulate (d) can be shown to be falsified.
When various forms of the TLT were first proposed, such a prediction as that given above would have been received with little enthusiasm because the astronomers of the time would have considered it extremely unlikely that the Universe could contain anything that radiated as a perfect black-body.
In contrast, today, our Universe is indeed known from observations to be filled with a cold background radiation with an incredibly accurate black-body spectrum of a temperature of 2.736 ± 0.017K. This is the now well known Cosmic Microwave Background (CMB) radiation. It is also extremely isotropic; technically it may be regarded as an infinite number of very distant sources distributed over the sky. Now, in the extreme form of the TLT the picture of the Universe is that of a static one; no expansion, with the red-shift determined by postulate (d).
According to the TLT the CMB radiation should not have a pure Planckian spectrum. Because, suppose that at some time in the distant past, space in the static Universe of the TLT has been filled with a black-body radiation, then after a cosmic time obtained from, say, the estimated ages of galaxies and galactic clusters the spectrum of this background radiation would be distinctly non-Planckian. But the CMB radiation exists with a very accurate Planckian spectrum and this near purity shows the prediction obtained from postulate (d) to be false.
The question may be raised as to whether postulate (d) is 'completely' false; that is, is it possible to modify the TLT in some way to avoid the difficulty? It is always possible to salvage a theory by grafting on, post facto, further postulates, and indulging in the abandonment of scientific methodology. Modern cosmologists are quite happy to do so but they would draw the line at coming to the assistance of the TLT!
So to save the TLT it is now necessary to assert an additional postulate that says not only do the photons become 'tired' on their journey across the cosmos but that also a subtle selection process must be at work causing some to give up completely. They have to vanish. It is not known if anyone has investigated this idea to put it on a firm theoretical basis: that is doubtful. In any case, it is poor scientific methodology.
Two untestable 'laws' of physics have been introduced; postulate (d) and a further postulate designed to circumvent the undesirable consequences of (d).
A possible way is as follows. If the red-shift is interpreted as being caused by the expansion of the Universe which is, of course, our standard accepted view, then the effect of this expansion on the CMB radiation is such as to preserve the Planckian spectrum's characteristic shape. The radiation is cooled by the expansion, i.e. its temperature falls. However, the change from one temperature to another merely changes one Planckian distribution curve for another. This preservation occurs because the expansion reduces the number density (number per unit volume) of the photons which compensates exactly for the red-shift effect on the spectrum frequencies. Now in a static universe the photon density remains constant (absorption by matter is negligible in the Universe at the present epoch) and it is this fact that causes the trouble for the TLT.
Another alleged way out of the difficulty is to assert that when the CMB radiation formed billions of years ago in a static Universe it had a non-Planckian spectrum but due to the effect of the 'tiring' of light it just happens to be passing through a phase that makes it at present appear Planckian to a very high degree of accuracy. Some judicious fine-tuning on the initial non-Planckian spectrum could achieve this. Again, this is poor scientific methodology. A variant on the above is to simply assert that the CMB radiation loses its initial characteristic Planckian spectrum by the TLT process only to regain it by so-called re-thermalisation which suggest as a mechanism the same graphite whiskers in inter-galactic space at work as were put forward to explain the CMB radiation within the framework of the classical Steady State Theory.
The most extreme suggestion put forward to 'explain' the pure Planckian spectrum of the CMB radiation within a static Universe where the TLT applies is simply to assert that the radiation is not cosmological but is, say, a feature of our local galaxy cluster. This is very difficult to accept because of the problem of explaining how such radiation would thermalise in such a low density environment.
It would appear that the TLT can no longer be put forward as a serious contender for an explanation of the Hubble red-shift. Attempts to keep it alive mean adding on additional postulates, analogous to Ptolemy's increasing number of epicycles introduced to keep the Earth-centred universe intact and explain the fine detail of planetary motions.
In this respect tired-light cosmology is in good company since modern cosmology suffers from its own equivalent of epicycles!
Sir Norman Lockyer 1836 — 1920
by Mike Frost
In the first twelve years I lived in Rugby I estimate, conservatively, that I must have walked down Sheep St approximately 1200 times — it is one of Rugby's two pedestrianised shopping streets, running from the clock tower at the town centre to Rugby school. Every single one of those 1200 times I failed to notice a plaque fixed to the wall of No 3 Sheep St, next door to the Three Horse Shoes Coaching House, on what is now the HFS loans shop. Only when the plaque's existence was pointed out to me did I stop to read it. This is what it says:-
In Commemoration of
Sir Norman Lockyer
Born in this house
May 18th 1836
Died August 20th 1920
Who was he? What is he famous for? Well, fortunately, Rugby library have a copy of his biography, written by his family (T.Mary and Winifred.I.Lockyer) and published in 1928. After failing to spot his memorial for twelve years, the least I can do is tell you about his remarkable life.
Joseph Norman Lockyer was the son of Joseph Hooley Lockyer, founder of Rugby's literary and scientific society (and a friend of Matthew Arnold, Rugby School's famous headmaster) and Anne Norman, daughter of the squire of Cosford, a small village outside Rugby. During Lockyer's childhood the family moved first to Leicester, then settled in Kenilworth. Lockyer showed promise at school and eventually joined the War Office as a clerk. In 1858 he observed an annular eclipse of the Sun from the water tower at the Crystal Palace, his first recorded interest in the field which was to become his speciality - solar observation.
Lockyer had the fortune to come to astronomy at the time when a new observational tool became available - the spectroscope. Others used the spectroscope to investigate the spectra of stars in the night sky, but Lockyer took up the technically trickier task of investigating the spectrum of the Sun; in particular to try and obtain the spectra from different portions of the solar disk.
To give some idea of the extent of knowledge at the time, during the 1850's and 1860's there was a major debate as to whether or not the features seen during total eclipses - the soft white glow of the corona and the fiery red prominences - belonged to the Sun or to the Moon. Lockyer's first major scientific discovery, in 1868, was to obtain separate spectra for the prominences and chromosphere, showing once and for all that these belonged to the Sun. He was not the only one to make such a discovery - in a remarkable co-incidence, the French Academy of Sciences received notification of the discovery from two separate scientists - at the same meeting; from Norman Lockyer and from the distinguished French observer Jules Janssen. There was no unseemly squabble over precedence (although Lockyer had made the observations first, publication was simultaneous) and the French academy struck a medal commemorating both men.
Lockyer was not content simply to prove that the chromosphere was solar in origin. He carried out experiments to determine what caused the bright lines observed in the solar spectrum. Each line corresponded to the "burning" of a different element (for example, the orangey-red of streetlights is indicative of a spectral line corresponding to burning sodium). Lockyer and his assistants were able to reproduce in the laboratory every one of the lines observed in the solar spectrum - except for one. Norman Lockyer made the bold suggestion that this was caused by an element not found on Earth - which he named after the greek for Sun, "helios". Helium did indeed turn out to be a new element, the second lightest after hydrogen, and indeed the second most abundant in the universe. Because of its lightness and its inability to form compounds, almost all the helium present at Earth's formation has long ago escaped into space. Helium was not chemically isolated on Earth for another twenty five years - it's a great tribute to Lockyer and Victorian science that its existence was correctly deduced from astronomical observations. When William Ramsay discovered helium terrestrially in 1895, the first person to analyze it spectroscopically was - you guessed it - Lockyer.
Lockyer was keen to bring his discoveries to a wider audience. By all accounts he was an excellent public speaker, and delivered talks to enthusiastic audiences all over the country. He contributed articles on popular science to "The Reader", a journal of the day, and when this folded he decided to launch a new journal dedicated entirely to the "natural" sciences. So was born Nature, which quickly moved from being a journal of exposition to a publisher of original research. Today Nature is arguably the most important research journal in the world - the one in which scientists try and announce dramatic new findings. My M.Sc supervisor published in Nature when his team thought they had photographed the centre of our galaxy, the Milky Way. Unfortunately, as I proved in my M.Sc, they hadn't.
There is really only one way to get really good spectra of the outer atmosphere of the Sun. You have to blank out the photosphere, the visible disk, and to do that you need a total solar eclipse. For the next thirty years Norman Lockyer, latterly in the company of his son, Joseph, attended a remarkable series of solar eclipses.
These days, to go and see a total eclipse, you pay a ridiculous sum of money to Explorers Travel, turn up at Heathrow, and let the tour company handle the rest. It wasn't so easy in Lockyer's day! His first eclipse was in the Mediterranean Sea south of Italy in 1870. Lockyer, the most eminent solar scientist of the day, requested the loan of a warship from his nominal employer, the War Office. The War Office refused, saying that the Admiralty charged too much for the hire of a warship. Lockyer, showing a better grasp of economics than governments then and since, complained that the money was merely being transferred from one branch of government to another, and accepted instead the offer of a lift from the warship carrying the American eclipse expedition. Of course, once it was realised that Lockyer was travelling with a foreign party, Prime Minister Palmerston intervened and secured the services of HMS Psyche. Lockyer, his wife, and the rest of the party, travelled by train to Sorrento to join the Psyche.
Let Mrs Lockyer tell you what happened next.
"...we were enjoying the soft, balmy air and brilliant sunshine, our beautiful little ship steaming at 14 knots - a shock and a crash, and we were immovably fixed on a sunken rock. Not a sound afterwards; all were silent until the Captain's voice ordered the boats to be lowered; then, turning to the observers, he said, 'Do not fear; I will get you and your instruments off safely.' In less than five minutes some of us were being rowed to the shore, which was a matter of some difficulty owing to the immersed lava rocks and not seeing a landing place. At last a native fisherman shot a boat from behind rocks and our sailors took us safely into the little creek.... our trim little vessel [was] a complete wreck, in this short time half filled with water and settling on one side"
Fortunately no-one was hurt, and remarkably all the scientific equipment was rescued. Unfortunately, the gods did not continue smiling through the eclipse. After all the tribulations of Lockyer's voyage, the sky was cloudy on eclipse day and all that was glimpsed was a second and a half of totality. Lockyer was not even allowed to return promptly to England; instead he proceeded to Malta for the court martial of the officers of the Psyche. Lockyer spoke in their defence, which probably counted in their favour; nevertheless, the officers were degraded for losing their ship.
Lockyer's party may have had an eventful journey to their eclipse, but it pales before the adventures of his friendly rival Janssen, who found himself besieged in Paris by German armies, a long way from the track of totality. Before he left England, Lockyer made strenuous attempts to secure safe passage for Janssen through the German lines - but Janssen had other ideas. He had promised to carry important government documents out of Paris, and, being a man of honour, could not bring himself to do this under German protection. Instead he made a daring escape by hot air balloon!
The next total eclipse - December 1871 in Imperial India - was more successful. Lockyer based himself in Ceylon (now Sri Lanka), in "a ruined fort, with crowds of natives and a solitary house amongst the coconut trees. Observations were almost ruined when fires were lit as a sacrifice to the sun god Rahu". Lockyer missed the next eclipse, in Siam in 1875, but observed the 1878 eclipse from a Union Pacific railroad car in America, and then subsequent eclipses in Egypt (1882), Grenade (1886), Lapland (1896), India (1898), Spain (1900) and Majorca (1905).
In addition to his expeditions around the world, Lockyer founded his very own solar observatory in South Kensington, London. In 1887 he published "The Chemistry of the Sun" which put forward a radical new theory, "the dissociation hypothesis". The detail of this has been found wanting, but the heart of the theory remains valid; within the Sun atoms become ionised, splitting off their outer electrons into a sea of particles or "plasma". Experimental data on atomic structure was still twenty years off, but Lockyer was beginning to grasp the essentials.
Likewise the other great theory he championed, the "meteoritic hypothesis", has now been superseded. Lockyer believed that much of the structure of the universe was a result of meteoritic bombardment - comets, asteroids and even planets were formed by the accumulation of meteoritic debris. This is not far from current theories of formation for the smaller bodies of the solar system. But Lockyer was of the opinion that the meteoritic hypothesis even explained the formation of galaxies, and was convinced that the spiral nature of the Andromeda nebula was evidence of meteoritic infall. In this he was completely wrong. The Andromeda "nebula" is actually a galaxy like our own Milky Way, much bigger and further away than Lockyer ever realised, and the spiral structure is the result of a density wave causing star formation.
One further aspect of his spectroscopic research deserves mention. When, in 1883, there was a spectacular series of sunsets, it was Lockyer who analyzed their spectra and pinned them down to dust from the explosion of Krakatoa. Lockyer was firmly of the opinion that volcanic and meteorological events on Earth were driven by the solar cycle, and he produced papers showing correlations. The meteorological correlation is still a live topic, but volcanic events are now thought to be independent of the solar cycle.
Don't let me give you the impression that physics, and solar physics in particular, was Lockyer's sole concern - he had a wide range of interests. He wrote a memoir on Tennyson (an old friend) for example, and even published what he claimed was the first ever written set of rules for the game of golf. But science was never far from his mind. On holiday in Greece in 1890, he wondered if there was any astronomical significance to the alignment of greek temples. Subsequent holidays saw him visiting the Pyramids (of course), Stonehenge and many other stone circles around Britain. Lockyer was one of the very first people to investigate astronomical alignments for ancient monuments is acknowledged as the founder of archeao-astronomy. He was also the first person to note in print the curious alignment of Stonehenge, Old Sarum, Salisbury cathedral and the Clearbury Ring iron-age fort. In 1925 Alfred Watkins documented the existence of many other such "ley-lines" around Britain. I am sure Lockyer would not have been happy with the way in which his carefully observed prehistoric alignments seemed to have been hijacked by crop-circle and UFO enthusiasts.
By the age of seventy six, you might have thought Norman Lockyer would be ready for retirement. Instead, he took on the scientific establishment. South Kensington was hardly an ideal place for a solar observatory, and the authorities proposed relocating to Cambridge. Lockyer believed that the proposed site in Cambridge was too close to the city lights, and proposed to found a new observatory in opposition. He decided on Sidmouth in Devon, as the best site available in Britain. The Lockyer observatory was first opened in 1912 but was soon shut because of the demands made by the first world war. It wasn't until 1919 that the observatory opened properly. Norman Lockyer died the next year.
The Sidmouth observatory remains to this day, although it has had a chequered history. During the 1930's the observatory, under the stewardship of Joseph Lockyer, Norman's son, became a research centre of international renown. However, as the years passed, the equipment became more and more out of date. Solar research continued until the 1950's and some geophysical research until 1980, then the observatory fell into disrepair. In 1984 it was proposed to demolish the observatory and build housing. Fortunately, the people of Sidmouth were determined to keep the site free of development. The BAA held an out of town meeting in Sidmouth at which it was resolved to try and re-open the observatory to the public.
In 1985 ownership was transferred to East Devon council, who sold off some of the site, including the old library, and used the proceeds to renovate the observatory and instruments. The site is now run by the Norman Lockyer observatory society as an educational establishment. There's a planetarium, meteorology station, radio station (call sign GB2NLO) and several telescopes open to the public - of most interest to our society, the NLO possesses an equatorially mounted twin tube 10 inch refractor made by Thomas Cooke of York. This was the instrument used by Norman Lockyer in South Kensington. They also have a 6.5" refractor and siderostat also made by Cooke.
In October 1997, I was able to pay a visit to the Sidmouth observatory, with the kind assistance of George Wilkins, of the Norman Lockyer society, who showed me round. The observatory is on top of a hill, to the east of Sidmouth, well away from the town. Even though the grounds have been reduced, there is still plenty of space for parking and picnicking, and even a slate sundial, in which the observer plays the role of gnomon. The main building contains a library, radio room, meeting room, kitchen facilities, and a display of memorabilia. The old Mond telescope dome, part of the main building, now contains a Goto planetarium, originally owned by Exeter University, which George Wilkins demonstrated to me. The McClean 10 inch refractor and Kensington Cooke refractor have their own domes.
It is very good to see Norman Lockyer's name live on in such a practical fashion - he would certainly have approved of his association with popular astronomy. Equally, the journal Nature remains a very strong testament to his support for professional research. His scientific legacy is mixed. Some of his most cherished ideas read today as nineteenth century science, swept away by twentieth century discoveries, in particle physics and astronomy. It would be unfair, however, to categorise him simply as a Victorian "man of science", contributing to many fields but shining in none.
I think Norman Lockyer deserves to be much better known as a founder of solar physics. And above all, we should commemorate him as the joint discoverer of the "solar element" helium. If Rugby can have statues for William Webb Ellis, Rupert Brooke and Thomas Arnold, surely we could put one up for Norman Lockyer!
"Life and Work of Sir Norman Lockyer" T.M.Lockyer and W.L.Lockyer (MacMillan, 1928)
"Sir Norman Lockyer's contribution to science", G.A.Wilkins (Quarterly Journal of the RAS,35, p51-57,1994)
"The Norman Lockyer observatory restored", T.Ward (Astronomy Now, 1990)
"Norman Lockyer observatory", leaflet
"In search of ancient astronomies", ed E.C.Krupp (Penguin, 1984)
A PORTABLE DRIVEN CAMERA MOUNT
THAT CAN BE USED ON A
PHOTOGRAPHIC TRIPOD FROM ANY LATITUDE.
By Geoffrey Johnstone
A modification to the Hague camera mount is described that has proved
itself with a standard lens and short exposures with very fast films.
Photographs of the night sky can be very successful with a standard lens of approximately 50mm, using a fast film and exposures of no more than 20 seconds to prevent trailing of the stars. However just by increasing the exposure time to one, or even better 2 minutes, together with very fast 1600 ISO slide film dramatic results can be produced, from a dark site. During the recent apparition of comet Hale-Bopp I was able to take some photographs from Central Wales where there was very little light pollution. Using a simple driven camera mount, a 45mm f2 lens together with Fujichrome 1600 and a 2 minute exposure produced some spectacular slides. When enlarged the prints showed excellent grain structure even up to 8 x 10 inches. A forthcoming trip to Australia to visit relatives during july and August meant that I needed some means of taking photographs of the night sky with exposures up to 2 minutes, and since I was travelling in south Australia and Queensland I needed a driven camera mount that could also be used in varying latitudes, one that would pack easily, weigh little, and cost next to nothing. The only possibility appeared to be the Haig Mount, named after George Haig who first described it. This is also known as the Scotch mount, perhaps more correctly as Scottish mount, as it is not Whisky driven, the hinge mount or the Screw Drive. The Hague mount characteristically consists of a large block of wood about 300mm x 80mm x 100mm sawn at one end to the observers latitude. Fixed to the angled end is a short plank 300mm x 150mm x l2mm and hinged at one end is an identical plank, 291 mm from the hinge end in the fixed plank is an undersize hole through which a 1/4" Whitworth bolt is screwed. This bolt acts on the second plank such that one turn of the screw per minute will advance this part at the sidereal rate. A ball and socket camera mount is attached to the moving board so that the camera can point at any part of the sky. While working excellently the disadvantages of this arrangement for my purpose, is the overall size and weight, and because of this cannot be used on a standard camera tripod. Apart from size there is a further problem caused by the screw passing through an undersize hole, in the bare wood, tending to make the action rather jerky. Firstly I thought these problems could be solved by using a captive bolt instead of the undersize hole, although in practice two bolts were needed one on each side to keep the bolt moving in a straight line. Secondly two narrow pieces of wood were used in place of the two short planks, and thirdly the large block of wood was dispensed with altogether to be replaced by the tripod head itself. Since the exposures were intended to be short, the tripod head could be tilted to the appropriate latitude with a detachable sighting rod adequate for alignment on the pole. Furthermore by reversing the tripod head the mount could be used either in the northern or southern hemispheres. One further modification was made, which in the diagram is referred to as a strengthening bracket, and this was needed to prevent sideways movement of the moving piece of wood relative to the fixed piece, although it could still allow exposures up to five minutes. Haig recommended that the bolt be turned in time with the second hand of a watch, but I preferred to count the seconds, moving the bolt after each five second interval, as I considered a five or ten seconds error in two minutes to be insignificant, and this proved to be the case. The camera mount was a total success and provided a record of the southern Milky Way beyond what was possible using a 20 second exposures, with a fixed camera, and much fainter than naked eye visibility. Prints from the slides could be joined together to make a strip of the entire southern Milky Way. A4 photocopies could similarly be joined to make a poster more than a metre in length. Since returning to Britain I continued the project by photographing the northern Milky Way from North Wales. Despite a high wind this too was successful with exception that there was considerable sky glow presumably from the industrial midlands. I am sure the mount could be further modified to include a small telescope to make polar alignment more accurate, thereby allowing exposures of more than two minutes, although in this country there are few site where this would be possible.