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Subject: ‘Astronomy’

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Megalithic monuments had an astronomical purpose

Posted in Archaeology, Astronomy, Famous landmarks, Prehistory, Space on Saturday, 15 February 2014

This edited article about Prehistoric astronomy first appeared in Look and Learn issue number 553 published on 19 August 1972.

Carnac,  picture, image, illustration
Original arrangement of stones at Carnac, Bretagne

It seems that Neolithic Man, who inhabited Europe about 3,500 years ago, was not the simple farming type that the history books would have us believe. Recent scientific research has shown that these people went to extraordinary lengths to solve the complex problem of the Moon’s motion and had an astonishing knowledge of astronomy and geometry.

Surveys carried out on Megalithic monuments in Scotland and France show that what seemed to be just geometrical patterns of stones were in fact observatories that were used for determining the Moon’s motion. From there findings it has been found these people had a far greater understanding of lunar astronomy than any of their descendants were to have for the next 3,000 years!

In the 18th century it was realised that Stonehenge, on Salisbury Plain, Wiltshire, was aligned with the mid-summer sunrise and was perhaps used on this day for religious or mystical rites. More recently one expert has suggested that the way the stones are arranged at this famous monument made it possible to predict eclipses of the Sun, an event which would have had a special and awe-inspiring significance for these early peoples.

To understand just how great the problems of building these observatories were for Neolithic Man it is important to know something of the Moon’s complicated motion through the sky.

To observers in Prehistory the most striking fact would be that the rising and setting points of the Moon change rapidly from night to night. In the Outer Hebrides, where most of the important Megalithic sites are found, it is possible for the Moon to rise and set almost in the north one day, and then two weeks later it barely manages to rise above the southern horizon for more than a few hours. When it does rise, it appears at different heights in the sky and over a period of 18.61 years goes through a full cycle of different positions and setting and rising points.

Only by constant observations over decades and even centuries could these early stone circle builders establish the reference points needed to construct their observatories.

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Caroline Herschel was the first female astronomer to achieve stardom

Posted in Astronomy, Historical articles, History on Tuesday, 21 May 2013

This edited article about Caroline Herschel originally appeared in Look and Learn issue number 261 published on 14 January 1967.

Caroline Herschel, picture, image, illustration
Caroline Herschel

In an observatory near Slough, a man peered through the eyepiece of a telescope. For 12 hours he had been hunched before his instrument. Beside him sat a pretty girl. Sometimes she would raise a cup to his lips, or put a piece of food in his mouth to prevent him fainting from hunger.

The man was William Herschel, one of the greatest astronomers of all time. The girl was his sister Caroline, and few men have had such devoted helpers.

It was common for William to watch the stars through the night while Caroline took down his notes as he could not leave the telescope for even a few seconds. Then, when he had fallen into bed exhausted at dawn, she would set to and rewrite the scribbled notes and calculations in her neat handwriting.

She was more than an assistant. She became an expert in astronomy and her first success in her own right came in 1798 when she published her ‘Catalogue of Stars’. In those days the woman’s place was considered to be very definitely in the home, yet Caroline’s book was accepted by scientists as a great work.

The crowning moment of her life came on 8th February, 1829, when she was awarded the Astronomical Society’s Gold Medal. Not only had she helped her brother in his achievements, but, using a telescope which he had made specially for her, she had discovered no less than seven new comets.

Her career as one of the first women astronomers ended at the great age of 97. She died on 9th January, 1848.

America built the world’s largest telescopes which looked into Deep Space

Posted in America, Astronomy, Historical articles, History, Philanthropy, Science, Space on Wednesday, 8 May 2013

This edited article about astronomy originally appeared in Look and Learn issue number 247 published on 8 October 1966.

Andrew Carnegie, picture, image, illustration
Andrew Carnegie in 1913

There can be few people who have not heard of the Palomar Reflector, which has a mirror 200 inches across. It is much the most powerful telescope in the world, and it has allowed astronomers to look further into space than they would ever have been able to do without it. It is known as the Hale Reflector, in honour of the man who planned it, but who died before it was completed: George Ellery Hale.

Hale was born in 1868, in Chicago. Astronomy was his boyhood interest, and at the early age of 23 he became famous for his invention of an instrument known as a spectroheliograph, used in studying the Sun. Even as a young man, Hale was far-sighted; he knew that if men were to probe into the depths of the universe, large telescopes would be needed. Unfortunately, such instruments are very expensive indeed. It did not seem likely that any Government would put up the money for a giant telescope, and so Hale looked around for someone who would be prepared to do so.

In 1892 he met Charles Yerkes, a millionaire who owned a large part of the city of Chicago. Yerkes could afford to pay for a large telescope, and he agreed to finance the project. It was decided that the telescope should be a refractor, collecting its light by means of a lens known as an object-glass; the optics were made by Alvan G. Clark, the world’s leading expert. Clark’s object-glass, 40 inches in diameter, turned out to be well-nigh perfect. The telescope was set up in a new observatory outside Chicago, named in honour of Yerkes – with Hale, naturally enough, as its first Director.

Within a few years the Yerkes 40-inch had more than justified the 34,900 dollars spent in building it, but Hale was not satisfied. His motto was ‘More light!’ and he knew that the essential thing was to collect the light from immensely faint, remote stars and star-systems. The 40-inch, powerful though it was, had its limitations, and Hale made up his mind to obtain something better.

There were hopeless difficulties in the way of making an object-glass more than 40 inches across. However, a reflecting telescope collects its light by means of a mirror instead of a lens, and there seemed every chance that a huge mirror could be made – if only the money could be found.

Again Hale was lucky. Andrew Carnegie, one of the few men as wealthy as Charles Yerkes, had set up a financial trust known as the Carnegie Foundation, and this trust agreed to finance a reflector with a 60-inch mirror. George Ritchey, at that time unrivalled as a mirror-maker, took charge of the optical work, and in 1908 the new telescope was ready. It was placed in an observatory on Mount Wilson, a peak in California, from which the observing conditions were particularly good.

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Human reasoning suggested Neptune existed, and in 1846 it was seen

Posted in Astronomy, Historical articles, History, Science on Tuesday, 7 May 2013

This edited article about astronomy originally appeared in Look and Learn issue number 245 published on 24 September 1966.

Leverrier, picture, image, illustration
Urbain Leverrier

One of the most remarkable detective stories in real life was solved on 23rd September, 1846. The detectives were astronomers, and they were looking for a mystery planet.

Ever since the planet Uranus had been discovered by Sir Frederick Herschel in 1781, astronomers had been puzzled by its strange behaviour. Other planets travelled round the sun in a regular path. Uranus, however, was inclined to wander. A German astronomer put forward a theory that Uranus’s irregular path or orbit might be caused by the pull of gravity from an unknown planet farther away from the Sun.

In 1843, John Adams, a mathematics student at Cambridge, worked out where the mystery planet probably was, and what its orbit might be like. At the same time Urbain Leverrier, a young French astronomer, was trying to solve the problem in exactly the same way. Both Adams and Leverrier sent their calculations to John Galle, a German astronomer who had one of the most powerful telescopes in Europe.

On 23rd September, 1846, Galle turned his telescope in the direction suggested by the calculations and observed the planet just where the mathematicians had said it should be. Its discovery was one of the greatest achievements of human reasoning.

Astronomers christened the new planet Neptune. It is the eighth planet in order of distance from the Sun. Neptune is 27,700 miles in diameter and 2,800,000,000 miles away from the Sun, around which it revolves once in 165 years. It is 2,900,000,000 miles distant from the Earth.

Galileo recanted beliefs he knew to be scientifically true

Posted in Astronomy, Historical articles, History, Religion, Science on Thursday, 11 April 2013

This edited article about Galileo originally appeared in Look and Learn issue number 222 published on 16 April 1966.

Galileo, picture, image, illustration

Galileo, now blind, lets a friend look at the stars through his telescope from the balcony of his study in Pisa, by Peter Jackson

Who first looked at the stars through a telescope? We cannot be sure; it may have been an Englishman named Thomas Harriott. Yet of the early telescopic astronomers, by far the greatest was an Italian mathematician named Galileo Galilei.

Galileo was born in 1564, the same year as Shakespeare. His father was a cloth merchant, but was able to send the boy to university, and Galileo at first meant to study medicine. He soon gave up this idea, and became fascinated by what we now call experimental science. For instance, he designed a pendulum clock, though he was never able to build one.

He was an excellent mathematician, and in 1589 became a professor at the University of Pisa. At Pisa there is the famous Leaning Tower, which is conspicuously tilted. It has often been said that Galileo went to the top of the tower and dropped stones off it, to show that a large, heavy stone would fall at the same rate as a lighter stone, and would therefore hit the ground at the same time. Actually this is nothing more than a story, but it is quite true that Galileo was busy working at problems of force and motion.

In 1592 he moved to another Italian university, Padua. By now he had become extremely interested in astronomy, and was certain in his own mind that Copernicus had been right in saying that the Earth moves round the Sun. This was not the official church view, and to support the Copernican theory was dangerous. At first, then, Galileo was wise enough to keep silent.

While still at Padua, Galileo heard some remarkable news. In Holland, a spectacle-maker named Lippershey had invented an instrument which would make distant objects seem to be close. He had, in fact, made the first telescope, and Galileo lost no time in making one for himself.

It was very small by modern standards, but powerful enough for him to see the skies more clearly than before. During the winter of 1609-1610 he made a series of spectacular discoveries which were to alter the whole course of astronomical history – and which brought great misfortunes upon Galileo himself.

The telescope was of the kind known as a refractor. It collected its light by means of a special glass lens known as an object-glass, and the image was magnified by a second lens, the eyepiece. The object-glass in Galileo’s first telescope was only one inch in diameter, whereas the largest refractor in the world today (at the Yerkes Observatory, in America) has a lens forty inches across.

Yet even so, Galileo discovered the mountains and craters of the Moon, the phases of the planet Venus, spots on the Sun, and the four moons of the giant planet Jupiter. He also found that the Milky Way, which stretches across the sky as a luminous band, is made up of vast numbers of faint stars.

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Uranus was originally named Georgium Sidus – the Georgian Star

Posted in Astronomy, Discoveries, Historical articles, History, Royalty on Friday, 5 April 2013

This edited article about astronomy originally appeared in Look and Learn issue number 218 published on 19 March 1966.

Sir William Herschel, picture, image, illustration

Sir William Herschel by John Cameron

It was nearly midnight on March 13, 1781, and Sir William Herschel was looking at the stars through his home-made telescope.

Suddenly he noticed in a corner of his lens a greenish-blue disc. There was nothing unusual about that. For centuries charts of the night sky had shown an object there, but astronomers had always classed it as a star.

Something made Herschel examine the disc more closely than anyone had done before. The more he looked at it, the less star-like it seemed. At first he thought it was a distant comet, but it did not behave like a comet.

Then the truth came to him in a flash. It was not a star and it was not a comet; it was a planet and part of the solar system.

Herschel called the planet “Georgium Sidus,” which is the Latin for “Georgian star,” in honour of King George III. King George was so flattered that in 1782 he appointed Herschel his private astronomer.

In 1850, however, the planet’s name was changed to Uranus.

Uranus is the seventh planet in order of distance from the sun, being 1,784 million miles away from it. The planet’s average distance from the earth is 1,680 million miles. It takes eighty-four years to travel round the sun, so that anyone born on Uranus would have a birthday only once every eighty-four years. But the planet rotates on its axis once in ten hours; this means that a Uranian day lasts for less than half as long as our earth day. Uranus is 30,900 miles in diameter and has five moons.

Tycho Brahe observed a rare supernova in 1572

Posted in Astronomy, Historical articles, History, Science on Tuesday, 2 April 2013

This edited article about Tycho Brahe originally appeared in Look and Learn issue number 217 published on 12 March 1966.

Kepler and Tycho Brahe, picture, image, illustration

Kepler and Tycho Brahe in the observatory in Prague by J Venturia

Tycho Brahe had no telescope – it had not been invented. But with his own eyes he mapped the night sky in astonishing detail

There have been many strange men in the history of science, but the oddest of all must surely have been the Danish astronomer Tycho Brahe. He was born in 1543, and died in 1601 after a life full of the most extraordinary happenings.

His father, Otto, was Governor of Helsingborg Castle in Denmark. While Tycho was still a baby, he was kidnapped by his father’s brother, and brought up away from his parents, but at least he had a good education, and on leaving school he went to the University of Copenhagen.

His uncle wanted to train him as a statesman, but young Tycho had other ideas; he was fascinated by science, and his only wish was to become an astronomer. Eventually he had his way, and went from Copenhagen first to the University of Leipzig and then to another German university, Rostock.

While at Rostock he had a quarrel with another student, and a duel was fought, ending when Tycho had part of his nose sliced off. He was not dismayed; he simply made himself a new nose out of gold, silver and wax, and apparently felt no ill-effects.

By now he had learned a great deal about astronomy, but his main career began in 1572, when he observed a new star in the constellation of Cassiopeia. Cassiopeia is a well-known group, and is easily found; it lies not far from the Pole Star, and its chief stars are arranged in the form of a rough W. In 1572, however, another star was seen, far outshining the others, and becoming so bright that for a few months it was visible in broad daylight.

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Copernicus died before the Church could punish him

Posted in Astronomy, Discoveries, Historical articles, History, Science on Wednesday, 27 March 2013

This edited article about Copernicus originally appeared in Look and Learn issue number 213 published on 12 February 1966.

Copernicus, picture, image, illustration

Copernicus observing an eclipse of the moon in Rome

The Earth upon which we live is a planet, moving round the Sun at a distance of 93,000,000 miles; the Sun itself is a star, much less luminous than many of the stars visible on any clear night. These facts are known to everyone, but they were certainly not known five hundred years ago. In those days, astronomers believed that the Earth lay in the centre of the universe, with the Sun, Moon, planets and stars revolving round it. This had been the view of Ptolemy, last of the great scientists of ancient times, and Ptolemy’s authority was so great that few people cared to question it.

One man who was not satisfied was Nicolaus Koppernigk, better remembered today as Copernicus. He was not a professional astronomer; he was a churchman, and he also practised medicine, but his main interests were in science – and it was he who took the first step in showing that Ptolemy’s picture of the universe could not be correct.

Copernicus was born at Thorn, on the River Vistula, in 1473, and spent some time studying in Italy before going back to live in his native Poland. While still a young man, he began to have serious doubts as to whether the Earth could really be the centre of the Universe, as he had always been taught. The main trouble, as he saw it, was that Ptolemy’s theory was so complicated. In science, a simple and straightforward picture is generally more accurate than a clumsy one, and at last Copernicus thought that he could see a way out of the difficulty. If the Sun were put in the centre of the Solar System, with the Earth and other planets moving round it, everything would fall into place.

Copernicus went on with his studies, and by 1533 he had almost finished writing a book, the title of which may be translated as “Concerning the Revolutions of the Celestial Bodies.” In this book, he laid down the principle of a central Sun and a moving Earth. Unfortunately, it would have been very unwise to publish it, because there would be strong opposition from the Church; and this would put Copernicus in an impossible position, since he was himself a priest.

The Church authorities would never bring themselves to believe that the Earth could be anything but the most important body in the universe. Copernicus knew this quite well, and so for many years his book remained unpublished. At last his friend Georg Rhaeticus, Professor of Mathematics at the German university of Wittenberg, went to stay at Copernicus’s home, and urged that the book should not be kept back any longer. After much persuasion, Copernicus agreed, and Rhaeticus took the book away to have it printed.

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Flamsteed House, the Royal Observatory at Greenwich

Posted in Architecture, Astronomy, Famous landmarks, Historical articles, History, London, Science on Wednesday, 20 March 2013

The Royal Observatory had been proposed in 1674 by Sir Jonas Moore and was commissioned the following year by Charles II.

Royal Observatory, picture, image, illustration

The Royal Observatory, Greenwich Park, Kent

The original building was designed by Sir Christopher Wren, possibly with the assistance of Robert Hooke. The first Astronomer Royal, John Flamsteed, was particularly irritated on discovering that the building was 13 degrees away from true North, due to having been built on the ancient foundations of Duke Humphrey’s Tower. The principal room was the Octagon Room, a magnificent space twenty foot high which also housed two ingenious Tompion clocks which only lost seven seconds a day.

Night work at Greenwich Observatory using the Great Equatorial Telescope

Posted in Architecture, Astronomy, Historical articles, History, London, Science on Wednesday, 20 March 2013

The Great Equatorial Telescope was mounted in 1859 by the seventh Astronomer Royal, George Biddell Airy, famous for ensuring that Greenwich became the favoured location of the prime meridian.

Great Equatorial Telescope, picture, image, illustration

Night work at Greenwich Observatory; the great Equatorial Telescope by William Bazett Murray

It was the first of these spectacular telescopes at Greenwich, and was housed in a specially designed observatory called the The Great Equatorial Building, also known as the South East Dome. After 1891 it was adapted and moved, before ending its scientific life in the nineteen-fifties when it was taken to the Observatory Museum in Sussex.