St Dunstan, the Devil and a pair of tongs

 

In the convent of the Holy Child Jesus at Mayfield in Sussex is a pair of tongs which tradition claims was the property of the great Saxon churchman St Dunstan, who was Archbishop of Canterbury from 960 to 978. However, this cannot be true, because although the Monastery stands on the site of Mayfield Palace, where Dunstan lived when he was Archbishop of Canterbury, the tongs were certainly not made before the 13^th century, some 300 years after Dunstan’s death.

Many stories were told about the piety of Dunstan and his conversion to Christianity, and some of these make mention of rumours that he had occult powers and may even have dabbled in black magic.

After his conversion by St Alphege, he divided his time between spreading the message of the Gospels and working as a blacksmith at Mayfield. The legend concerning his thwarting of the Devil comes from this time.

One day, so the story goes, the Devil was so enraged by the work that Dunstan was doing as a Christian that he disguised himself as a beautiful young woman and set about seducing him.

Dunstan did not even look up as he worked at his anvil, while the Devil danced around the room. At one point, the dance became so animated that the devil’s skirts rode up to reveal the hooves on his feet, which might seem a bit strange given his otherwise immaculate impersonation of a young maiden.

Dunstan promptly seized a pair of red-hot tongs from the forge and clamped them onto the Devil’s nose. His screams could be heard up to three miles away as he fled from the forge. As he flew through the sky he caught sight of the springs of Tunbridge Wells, swooped down, and plunged his nose into the water.

To this day, the spa water of Tunbridge Wells still tastes of sulphur!

© John Welford

Were the Dogons visited by aliens from outer space - or somewhere closer?

People who are keen to believe that aliens from outer space have visited Planet Earth at various times in our history sometimes point to the Dogon people of Mali (West Africa) as evidence of such a visitation.

This is because the Dogons appear to possess certain pieces of astronomical knowledge that they could never have worked out for themselves. In particular, they are very well informed about the star Sirius. This was reported by a French anthropologist named Marcel Griaule who studied the Dogon people during the mid-20^th century and wrote about them in 1946.

The Dogon people knew that Sirius was a double star, with one of the pair taking 50 years to orbit the other. This was extraordinary knowledge, given that the companion star is too faint to be seen with the naked eye and the Dogons did not have telescopes to look through.

What explanation could there have been for this knowledge? Surely they must have been visited at some time by aliens who lived on a planet that orbited one of the Sirius stars?

Or might it have had something to do with the team of astronomers who had visited Mali in 1893 to view a solar eclipse?

© John Welford

Exploring the Summer Triangle

The Summer Triangle is the name given to an area of the night sky that contains several features of interest for the amateur astronomer.

Out On The Lawn

In 1933 W H Auden wrote a poem (“A Summer Night”) that begins with the lines:

Out on the lawn I lie in bed

Vega conspicuous overhead
In the windless night of June …

Leaving aside the merits of the poem – and there are many – nobody could fault Auden’s astronomical knowledge. On a clear night in June, if you lie looking up at the stars on an English lawn in June you will hardly fail to be aware of the prominent star Vega, which is the fifth brightest star in the entire sky. 

Vega forms one of the extremities of what is known as the Summer Triangle, the other points being Altair and Deneb. The Triangle is what is termed an “asterism”, by which is meant an arrangement of stars other than an officially recognised constellation. Altair forms the lowest point of the triangle, with Vega to the top right and Deneb at the top left.

All three stars are also members of constellations: Vega is in Lyra (The Lyre), Deneb in Cygnus (The Swan) and Altair in Aquila (The Eagle). Each named star is the brightest in its constellation.

An Optical Illusion

It is easy to imagine that the constellations and asterisms seen with the naked eye represent actual associations of stars that are relatively close to each other. However, this is rarely the case, because what we are seeing are stars along certain lines of sight when viewed from Earth. A star can be many times further away from us than its apparent neighbor, and the Summer Triangle provides an excellent example of this fact. 

The closest of the three stars to Earth is Altair. It is 16.7 light years away, which means that we are seeing it as it was 16.7 years ago. Vega is 25 light years away but appears to be somewhat brighter than Altair. That is because Vega is considerably more luminous than Altair, which is a main sequence dwarf star – as is our own Sun. Altair is 11 times more luminous than the Sun, but Vega is 52 times more luminous and therefore appears brighter than Altair despite being considerably further away.

Even more striking is the case of Deneb. It appears to be three times fainter than Vega, but that is because it is nowhere near as close. It has been estimated that it could be between 1,550 and 2,600 light years away, and would be invisible to the naked eye were it the same sort of star as Vega or Altair. However, Deneb is a white supergiant star with a diameter 200 times greater than that of our Sun and it is 200,000 times more luminous. Were Deneb to be at the same distance from us as is Vega, it would appear so bright that it would cast shadows at night and be visible in daylight!

The Milky Way

If the sky is dark and the Moon not shining, a viewer of the Summer Triangle will not fail to be impressed by the sweep of the Milky Way crossing the Triangle between Vega and Altair. It is even more impressive when viewed through a telescope.

This “river” is the combined light of the many millions of stars that form part of our galaxy. The tilt of Planet Earth means that viewers in the Northern Hemisphere can only look “outwards” whereas in the Southern Hemisphere you would look “inwards” towards the heart of the galaxy. That is not a great limitation as far as northern viewers are concerned, because our Sun lies in one of the outer swirls of the galaxy (the Orion Arm) and there is plenty to see that is in the same swirl as ourselves and in swirls even further out, such as the Perseus and Cygnus Arms.

Albireo

This star is just to the left of a line drawn between Vega and Altair and about halfway along that line. It can be seen with the naked eye, but even a modest telescope will reveal it to be a double star with strongly contrasting components in terms of color – Beta Cygni A is amber and Beta Cygni B is blue-green. It has been suggested that Beta Cygni A is itself a double star, making Alberio a triple-star system.

However, the jury is still out over whether Alberio represents a true double/triple, with the components orbiting a common centre of gravity, or whether this is an optical double with Beta Cygni A and Beta Cygni B merely being seen along very close lines of sight.

Epsilon Lyrae

If there are questions about the composition of Alberio, there are none about Epsilon Lyrae, which lies quite close (visually) to Vega. This is a genuine “double double”, with the two main components also being doubles. You would need very good eyesight – or modest binoculars – to resolve the main division, but something much stronger in terms of telescopic power to see the system in all its glory – around 200x magnification in a four-inch aperture telescope should do the trick!

The impression that these stars are sitting on top of each other is easy to gain but somewhat misleading. The Epsilon Lyrae system (which probably contains more than the four stars indicated above) is 162 light years away, which is 6.5 times further away than Vega. The fact that it is possible to resolve the components at all using standard ground-based equipment must mean that they are at some distance from each other. Each of the two doubles are around 120 AUs (astronomical units) apart. Given that an AU is the distance from Earth to the Sun, that distance takes you considerably beyond the orbit of any known object in the solar system – the most remote object discovered to date is at 103 AUs and Pluto is almost cheek by jowl with the Sun at an average distance of 39.5 AUs!

The distance between the two main pairs in Epsilon Lyrae is on a completely different scale, at 10,500 AUs. When seen in the context of its own star system that sounds like a vast distance; however, when one considers that the distance to the Sun’s nearest star neighbor, Proxima Centauri, is 268,000 AUs, the Epsilon Lyrae stars sound to be almost touching each other!

Nebulas M57 and M27

Two impressive planetary nebulas can be seen in the Summer Triangle. A nebula looks like a fuzzy star when seen through low-resolution equipment, but a better telescope will reveal its true nature, namely the expelled outer layers of an ancient red giant star that reached the end of its life as a giant and continued as a white dwarf.

M57, which is known as the Ring Nebula, is about halfway between Vega and Alberio, slightly to the right of an imaginary line between them. A three-inch aperture or larger telescope will reveal the dramatic colors of what has been described as a “celestial smoke ring”. M57 is 2,300 light years away from us.

Alberio lies halfway between M57 and M27, which is known as the Dumbbell Nebula. It is brighter and larger than M57 and closer to us at 1,360 light years. It is easier to spot than M57 and was in fact the first planetary nebula to be identified. It has been calculated that the original red giant star threw off its outer layers about 14,500 years ago, leaving its core behind as a white dwarf star that is the largest such star discovered to date.

Time spent with a moderately powerful telescope pointed at the Summer Triangle will be well rewarded!

© John Welford

All aboard the starship to Proxima Centauri!

Let’s suppose that – 100 years hence, maybe – it is decided that Planet Earth is no longer inhabitable and the human race will have to decamp to another planet if it is to survive. After much debate it is concluded that Mars is far from suitable so the journey will have to take a lot longer – to the next nearest planet that could sustain human life, namely one that orbits Proxima Centauri B, some four light years away.

OK – we know that light can make the journey in four years, but no spacecraft could possibly travel at anything like that speed. Indeed, the best we can imagine given the propulsion technology available to us is around 700,000 kilometres per hour, which means that the journey would take around 6,300 years!

Is that feasible? Let’s imagine what that would involve. Of course, if a spacecraft left Earth with a journey of that length in mind, the astronauts who began it would die of old age before they had gone even a fraction of that distance. The only option would be for a whole community of people to set off in a very large spaceship that could not only sustain life for thousands of years but enable them to breed new generations of people as they went along.

An awful lot of new generations! If you estimate that a new generation arrives on average every 25 years, that is more than 250 generations that will be born, live and die during the voyage. It is now 2018 – 6,300 years ago our ancestors by 250 generations were living in 4282 BC, when agriculture was first being developed in Mesopotamia and the Indus Valley, metalworking was in its infancy in some parts of the world and the Pyramids and Stonehenge were still thousands of years into the future!

Can you imagine what it would be like to spend your whole life on a vast starship whizzing through space, knowing that you had absolutely no choice in the matter and that you would die exactly where you had been born, your only real function being to produce the right number of babies to keep the community in perfect balance? 

Presumably it would be essential to develop virtual reality to the extent that people could lead entirely artificial but realistic lives, maybe similar to that of the hero of “The Truman Show”? Otherwise everyone would surely lose their minds!

There is also the question of preventing disease from wiping out the community before it gets to where it’s going. That will imply the thoroughgoing screening of all the “starters” to make sure that there are no genetic imperfections that could lead to fatal or debilitating conditions emerging several generations down the line. It will also mean that some of the community will have to learn medical skills as they go along – presumably from previous generations or from a highly sophisticated library.

How much lifestyle choice will the voyagers be allowed to have? Suppose that a substantial portion declare themselves to be gay and refuse to breed? Should this be a genetic trend that is screened out at the outset, or would that mean introducing a form of eugenics – extreme social engineering – that is morally indefensible?

And who will enforce the rules down the generations? How will they do it, and what sanctions will be at their disposal?

Hm! A lot of questions! So is the idea even remotely conceivable? It may surprise you to learn that there are people who have given serious thought to these issues and produced computer models for the ideal starship community – apparently you start off with 49 men and 49 women and that is what you get at the end! 

It sounds crazy to me – what do you think?

© John Welford

Psyche could reveal secrets about Earth

There is a small minor planet, only 210 kilometres across, that could unlock some of the secrets of our own planet. This is Psyche, which orbits in the asteroid belt between the orbits of Mars and Jupiter. 

There is a lot that we don’t know about the origin and inner structure of Earth. In particular, we do not know exactly how the planet came to be formed or what the composition is of its solid metal core. We cannot examine this directly because it is surrounded by thousands of kilometres of molten metal and magma. 

So where does Psyche come into the picture?

Observations of the asteroid reveal that it is composed almost entirely of solid metal, and there is nothing else in the solar system – as far as we know – of which this can be said. The implication is that Psyche is a remnant of a former planet that was once considerably larger, but was so battered about by collisions with other objects that all the outer layers were knocked off to leave only the solid metal core. Could this therefore be similar to what lies at the heart of Planet Earth?

Astronomers are keen to send a probe to Psyche to find out. A launch date for a mission to Psyche has been set for 2022, with the destination reached in 2026. 

The spacecraft will be equipped with a range of instruments to enable the nature of Psyche’s gravity to be established, which will in turn allow deductions to be made about its composition and structure. There will also be a gamma ray and neutron spectrometer on board, which will be used to discover the exact range of metals of which Psyche is composed. It is thought that the main elements will be iron and nickel, but there is a distinct possibility that silver, gold, palladium, copper and iridium will also be present.

The purpose of the mission is to gain knowledge, from which inferences will be made about Earth’s interior. The assumption is that the early solar system contained many similarly composed lumps of metal, most of which coalesced and ended up as planetary cores.

However, there is also room for speculation about how such a world might be a source of future benefit to mankind in terms of its content. All that metal, just sitting there doing nothing! An estimate has been made of what Psyche might be worth in terms of monetary value, and it is a truly staggering figure,  namely ten quintillion dollars – a one followed by nineteen zeros!

If anyone imagines that all that metal could be transferred to Earth and the value realized, they need to think again. For one thing, the idea is pure fantasy. For another, the value of something like gold depends on its scarcity – make vast quantities of it available and it will no longer be valuable!

© John Welford

Arsonist birds

Eyewitness accounts from Australia have suggested that certain species of bird of prey practice a food-finding technique that involves spreading fire with the intention of driving prey to where it can more easily be caught.

What they do is visit an area where a fire is taking place (usually started by natural means such as a lightning strike), take burning sticks from the fire and then drop those sticks in a non-burning area which then catches fire. Small mammals and birds flee the fire and are then caught by the raptors, which are mainly black kites, whistling kites and brown falcons.

A report cites the evidence of a firefighter in Northern Territory who was fighting a blaze near a uranium mine when he saw a whistling kite – only 20 metres away – take a burning stick and drop it on the other side of the road from the fire. This caused a new fire to break out. The witness reckoned that at least seven new fires were caused by the kites.

Another firefighter reported a similar event in which hundreds of kites swirled above a wildfire and were able to start new fires in grassland 50 metres away. 

It is believed that such action is quite common, especially when it appears that the original fire is unlikely to spread or will soon be extinguished, meaning that no more prey will be forced out unless the birds take matters into their own beaks and ensure that fresh fires break out.

There is evidence that this behaviour is not limited to Australia, with reports of similar incidents coming from Asia, Africa and the Americas. It is quite possible that wildfires that were thought to have been spread by the wind, or even by human arsonists, may have raptor birds as the culprits.

It has also been suggested that spreading fire in order to catch prey may be something that birds have done for hundreds of thousands of years. Indeed, using fire to gather food may be something that predates the existence of human beings. Raptor birds evolved millions of years before humans did, and may have “tamed” fire long before any of them clapped eyes on a human.

© John Welford

The Great Comet of 1680

The comet that appeared in the sky in November 1680 has two main claims to fame. It was the first to be discovered by telescope and the first to have a known orbit. 

It was found by accident by Gottfried Kirch, a German astronomer, when he was actually observing the Moon through his telescope, but as it approached closer to Earth it became clearly visible to everyone as it streaked across the sky. 

The orbit was calculated by Isaac Newton who made use of his new theory of universal gravity, publishing his results in his “Principia Mathematica” in 1687. 

The Great Comet was seen twice – once as a morning phenomenon as it headed towards the Sun and later in the evenings as it made its return journey towards the outer regions of the Solar System. Newton was the first person to appreciate that these appearances were of the same comet. It had previously been assumed that comets travelled in straight lines, passing through only once. Newton’s discovery that comets travelled round the Sun in parabolic curves was what enabled Edmund Halley to predict that the comet named after him would return every 76 years.

Robert Hooke, the English physicist, noticed a stream of light issuing from the comet’s nucleus. This was the first description of the emanation of jets of material from active areas.

The Great Comet will not be seen again in the lifetime of anyone alive today. Its orbit takes it into the outer regions of the Solar System and it will not return for more than 9,000 years!

© John Welford