Designed with convenience for the traveller in mind, the Tabula Peutingeriana is an early road map which charts in astonishing detail the highways and byways of the imperial Roman world.

A few days late, certainly, but over the weekend we celebrated the Chinese "mid-autumn" festival (it's actually spring here), better known as the Moon Cake festival. Leading a group of young children and adults with paper lanterns illuminated we set out to wander the streets of Moonee Ponds and draw the stares of curious neighbours.

Admiration of the moon is one of the important features of this festival but while gazing up at the moon, one can only wonder how old Wu Kang is getting along.

Wu Kang was a shiftless but clever fellow who changed jobs constantly. He started out as a farmer but quickly grew bored and decided that farming was not enough of a challenge for him. So he apprenticed himself to a furniture maker but on being told by his master that in another three to five years, he would be able to make a reasonable furniture, he gave up. He then went to work in shop but again grew bored, so once again he gave up and decided instead to study to become an immortal.

Wu Kang went to live in the mountains where he begged an immortal to teach him. First the immortal taught him about the herbs used to cure sickness but after three days his characteristic restlessly returned and he asked the immortal to teach him something else. Therefore, the immortal tried to teach him chess but again after a short time his enthusiasm waned.

Wu Kang was then given the books of immortality to study. Naturally, Wu Kang became bored within a few days, and asked if they could travel to some new and exciting place. Angered with Wu Kang's impatience, the master banished Wu Kang to the Moon Palace telling him that he must cut down a huge cassia tree before he could return to earth.

Though Wu Kang chopped day and night, the magical tree grew back with each blow. Even now, If you look up at the face of the full moon, you will see him still chopping away at that cassia tree.

As promised, I have finally gotten around to implementing a news feed for this blog. For those into the finer technical points, I decided to use the ATOM format instead of the better known RSS.

I've also added a link so that you can subscribe to this site using Bloglines.

Human head lice come in two genetically distinct varieties, one that is distributed worldwide and another that is found only in the Americas. Examination of the DNA of both types of lice has suggested that they probably diverged from a common ancestor nearly 1.2 million years ago and have remained separated for most of the time since. This result has leads to some fascinating implications regarding the trajectory of human evolution.

Firstly, this divergence happened quite early, around the time when our ancestors split off from our cousin species, homo erectus. Secondly, given that lice are parasites that have evolved to live exclusively on their human hosts, the two almost identical-looking strains were probably separated by the speciation of the humans themselves. Finally, when the lice did come back into contact this would have been when the two species of human came back into contact, perhaps as recently as 25,000 to 50,000 years ago.

This is quite a statement. It means that modern humans may have got infested by the second species of lice through direct contact with another species of human being, either by touching, fighting, cannabalism, mating or all of the above. Regarding the mating question, the researchers are now thinking of looking into the genetic histories of crab lice which can be only sexually transmitted. However despite this possibility, they are also supporting the dominant theory that when modern humans came into contact with other species, they completely replaced them.

There are also other interesting things to come out of the genetic data. Studies of human DNA have suggested that modern human evolution may have passed through a "bottleneck" where the entire world's population was found to have been descended from a population around 100,000 years ago that had collapsed to a total of less than 10,000 individuals. This was presumably because of some natural disaster or disease outbreak which had nearly wiped out the entire species. This bottleneck is also reflected in a similar collapse evident in the DNA of the world-wide variety of lice but not in the American one (which is thought to have been associated with the archaic human strain).

The fact that second kind of lice is restricted to the Americas, for me, also throws this possible discovery of homo erectus bones around a lake in Mexico into an even more interesting light.

More information on this research into lice DNA can be found in this press release from the University of Utah site.

"Some day they will have color photography," predicted Mark Twain to a friend in 1907. It was a prediction that was bang on the money, in fact a little late, because Auguste and Louis Lumière had already invented the Autochrome process back in 1904.

The Chinese calendar is based on a sexagesimal cycle (60 years) which is based on the combination of a ten year cycle (the Heavenly Stems) and a twelve year cycle (the Earthly Branches). Traditionally when a person has lived to his sixtieth year he is said to have completed one "life span" and the reckoning of his age starts again. Many people are familiar with the twelve year cycle of the Earthy Branches because these are associated with the twelve animals of the Chinese horoscope (Year of the Rabbit, Year of the Horse etc.) however it is the sexagesimal cycle which is considered far more important by the Chinese in fortune telling and dating.

Cycles of ten and twelve crop in several places in Chinese dating and I was reminded of this the other night during the Moon Cake festival. In Western thinking, the Moon's cycle, which was the original basis for the length of a month, is divided into four phases: New Moon, First Quarter, Full Moon, Last Quarter. These quarters loosely correspond to our notion of a week (which divides a month into approximately four parts). The ancient Chinese settled on a cycle of three phases known as "upper week", "middle week" and "lower week", where a "week" in this case is ten days long. I can't help but think (perhaps spuriously) that the cycle of ten suns being associated with the cycle of the moon, go some way to explaining some of the curious symbolism in the famous tale of Change Er.

Di Jun, the God of the Eastern Sea and Xi He, the Sun Mother had ten sons, each of whom glowed as a radiant sun. Each week Xi He would take her children to the Valley of Light in the distant East where she wash them in a lake and dry them in the branches of an enormous mulberry tree there which is known as Fu Sang. Then, one at a time, she would permit one of them to make the journey across the sky in a chariot pulled by six dragons. Each sun-child would travel to across the to sky to the far West, to the mountain of Yen Tzu and in this way the light from each of their bodies was able to give just enough warmth to the world down below them.
After a time, however, the suns became quite bored with this daily routine and wanted to play with each other in the sky. They decided one day that all ten of them should journey across the sky together. Unfortunately, the combined heat of all these suns in the sky at once scorched the world below and caused the earth to crack. All of the rivers ran dry and the people and animals began to die. The great Emperor Yao pleaded with Di Jun and the gods of heaven to save the earth from this calamity.

At first, Di Jun called for his sons to return to their mulberry tree but the boys were enjoying themselves so much that they paid absolutely no heed to his requests. Angered by their insolence, Di Jun called for his best archer, Hou Yi to help frighten them into submission. The mighty Hou Yi descended from heaven and landed upon the Kun Lun mountain. He drew a white arrow from his quiver and inserted it into his red bow but rather than merely frightening them, he then proceeded to shoot down the misbehaving suns one at a time.


Hou Yi's swift and unerring arrows shot down nine of the suns but Emperor Yao requested that he spare the life of the last one so that the world would still receive just enough light and warmth. The divine archer had saved the world but when Di Jun learnt what had happened to his beloved children he grew very angry and cursed Hou Yi, banishing him from heaven and exiling him to live as an ordinary mortal upon the earth.
Terrible though his fate was for an immortal, Hou Yi made the best of it. After all, for his extraordinary efforts he had earnt the devotion and gratitude of all the many people on the Earth as well as the heart of beautiful woman by the name of Chang Er whom he married.


One day, Hou Yi journeyed back to the Kun Lun mountain where he intended to visit a friend. There he met Xi Wang Mu, the Queen Mother of the West and out of respect for her he built a beautiful palace made of jade and fragrant timber. Touched by the obeisance of Hou Yi and impressed by his other good acts, she rewarded him with some pills made from the Elixir of Immortality, a gift which would enable him once again to live forever. Knowing that regaining his immortality would mean that he would outlive his beloved wife, Xi Wang Mu explained that she had given him enough elixir for the two of them. She also warned that before taking the pills they would need to purify their bodies through fasting and praying for twelve months.


Hou Yi went home and told to Change Er about the wonderful gift that the Queen Mother had bestowed upon them. He was determined to keep the precious elixir safe from harm so he wrapped it in silk and placed it in the roof of his house. Unfortunately their conversation was overheard by one of Hou Yi's servants, a wicked a treacherous man whose name was Feng Meng and his heart was so filled with envy that he decided to steal for himself this elixir of everlasting life.


One day while Hou Yi was out hunting for game, Feng Meng who was acting as his attendant attacked and killed him. Wasting no time, the evil Feng Meng returned to his master's home and accosted Change Er demanding that she immediately hand the elixir over to him. Chang Er guessed the fate of her loved one and when Feng Meng threatened her with violence she, without a moment's hesitation, swallowed the pills herself so as to deny the murderer his reward.


Chang Er at that moment became an immortal but, because she had taken a double dose of the elixir, also became lighter than air. She began to float off the ground and when Feng Meng rushed towards her, she flew out of the window and climbed higher and higher into the sky. In this way she travelled up into the heavens before finally settling on the Moon, it being the lowest point of heaven and closest to her beloved Hou Yi.


There she remains to this day, living in her palace on the barren and icy world and still mourning for her lost Hou Yi. People who remember her burn incense and make offerings on her behalf every year on the eight full moon.

Change Er on the Moon Patricia Lu-Irving

I should point out that this is only one version of this popular story and it is by no means the authoritative one, I just happen to like it the most. Being a folktale that has grown up around some visual imagery rather than a literary text, the story has developed a wide range of variations. Like the intricate variations that crop up in the rules of mahjong from place to place, this one comes in a great many permutations and combinations. The only things that tend to remain constant are the names of the characters, especially Hou Yi and Chang Er.

Sometimes the tale becomes a critique of the haughtiness and selfishness of the beautiful Chang Er who stole the elixir from her great and pious husband and was sent to the moon in punishment. In these versions, she earns the additional penalty of losing her beauty by being transformed into a ugly three-legged toad. Other versions emphasise the vanity of power where Hou Yi becomes king and gradually develops into a megalomaniacal tyrant. As with so many despots in China's history, Hou Yi becomes obsessed with his mortality and in an echo of Emperor Qin Shi Huang Di, he attempts to procure the elixir of ever lasting life. Chang Er then recognises the danger of her husband obtaining immortality and in a selfless act steals it and swallows the elixir in order to keep it out of his reach. This version ends with Hou Yi, while enraged by his wife's disobedience, watching in despair as she floats up into the heavens. Impotently, he fires off his famous arrows, trying to shoot her down but of course to no avail.

Yet others claim that Chang Er too was originally divine but was banished from heaven for breaking a porcelain jar in the Jade Emperor's palace. These tales usually hinge around Chang Er's disappointment at being forced to live on Earth and tend to be critical of her motives and behaviour.

With all these versions, the image I can't resist is of a massive "Chinese whisper" with the tale being told and retold by countless parents to their children over the course of hundreds of years, the story changing minutely each time.

In all cases the outcome of the story is the tragedy of separation and longing. For whatever reason Chang Er must spend an eternity in isolation separated from her husband and the world. The Moon is seen as, while unquestionably very beautiful, a barren and frigid world and, in fusion with other folktales, she must content herself with only the companionship of a jade rabbit that is always pounding the elixir of immortality and a woodcutter forever chopping away at the cassia tree.

For those interested at looking at other versions of the tale, you could start with these:

http://www.chinapage.com/Moon/moon00.html
http://www.scils.rutgers.edu/~kyfoo/chinese/Chang_E.html
http://www.wku.edu/~yuanh/China/changebenyue.htm
http://www.chinahotelsite.com/city/china_fastival.html
http://www.newcastlechinatown.co.uk/nct/festival/mythology_Chang_E.php
http://ias.berkeley.edu/orias/2003/myth/yi.doc
http://www.painsley.org.uk/re/signposts/y8/1-1creationandenvironment/c-china.htm
http://www.tuvy.com/chinese/info/lady_chang_er.htm
http://www.interlog.com/~fccs/mid.htm
http://china.tyfo.com/int/ent/music/festival/mid-autumn/legend.htm
http://www.jadedragon.com/archives/celebrations/autumn.html
http://www.windows.ucar.edu/tour/link=/mythology/ten_chinese_suns.html&edu=elem
http://www.paralumun.com/chinesesun.htm
http://csa.union.rpi.edu/csanew2/MidAutumn/storiese.html#Changer
http://www.china.org.cn/english/features/Festivals/78311.htm

Mapping the stars has always been an essentially part of astronomy but the 17th and 18th centuries was a golden age of the star atlas in which utility was intertwined with incandescent artistry. Based on ancient constellations as systematised by Ptolemy, the star atlas borrowed many elements from contemporary cartography and merged them observational data of unprecedented accuracy.

There's one born every minute.

Just a reminder that on Tuesday, 26th of October, Cassini will pass within 1,200 km (746 miles) of Saturn's giant moon Titan. This will be the closest encounter with the mystery moon before the Huygens space probe is launched into its atmosphere early in January.

This is Eta Carinae, the seventh star of the southern Carina constellation and the most massive and luminous star known in our galaxy. It's 100 times as massive as our sun and 5 million times brighter. Its diameter is about the size of Jupiter's orbit and it is extremely unstable. Currently it is in the process of rapidly exhausting its fuel supply and is on the brink of self-destruction. It could collapse into itself and form a black hole at any moment.

Eta Carinae is also interesting because it's probably the only star in the night sky that could conceivably kill you.

When it was first catalogued by Edmond Halley in 1677, it was an unremarkable star barely visible to the naked eye. But since then it's brightness has fluctuated wildly. In the mid-nineteeth century, Eta Carina briefly became the second brightest star in the sky before falling back to near invisibility. Since the fifties, the star's luminosity has been steadily increasing again and in the late nineties suddenly doubled in brightness.
Stars of this enormity do not last very long because the intensity of their gravitational fields leads to a rapid consumption of their fusable hydrogen. Eta Carinae has, at most, only a few million years to go but it could just as easily self-destruct tomorrow. When that happens a star would normally explode as a supernova but such a massive star as this one has the additional possibility of collapsing in on itstelf and turning into a blackhole.

Such an event would release an incredible amount of energy in the form of a highly focussed beam of gamma rays. If the Earth happened to be on the path of such a beam, there is a little doubt that it would totally devastate life on this planet. Perhaps it was gamma ray bursts like this that in the past caused one or more of mass extinctions that scar the Earth's history.

The theory behind hypernova gamma ray bursts is that they are radiated from the poles of the star but judging from measurements of the star's radial velocity and the shape of its equatorial disk of debris, it appears that the closest pole is pointing away from us us by at least 47 degrees. If true, this should (hopefully) dramatically attenuate the amount of radiation that would be due to arrive in our direction and at worst only disrupt our satellite communication systems.

Nevertleless, you probably wouldn't want to be a astronaut on a space walk at that moment.

If you take a look at the solar activity icon in the left hand column you should be able to see that there's a lot of activity going on right now on the Sun's surface. Currently there are six active sunspots, the largest is nearly 10 times wider than the Earth [link]

UPDATE: Apparently there has been more sunspot activity in the last 70 years than at any other time in the last 8000.

NASA's raw image database is getting thrashed at the moment¹ which is not surprising considering that Cassini is doing a flyby of Titan. The last worthwhile image to be published on the site is this one taken of the other day.

Eyes on Xanadu

This image taken on Oct. 24, 2004, reveals Titan's bright "continent-sized" terrain known as Xanadu. It was acquired with the narrow angle camera on Cassini's imaging science subsystem through a spectral filter centered at 938 nanometers, a wavelength region at which Titan's surface can be most easily detected. .. Surface materials with different brightness properties (or albedos) rather than topographic shading are highlighted... The origin and geography of Xanadu remain mysteries at this range. Bright features near the south pole (bottom) are clouds.

The remains of a hitherto unknown species of tiny 1 metre-high human beings, have been discovered on Flores, in Indonesia. The bones have been dated to as recently as 18,000 years, ten thousand years more recent than the last Neanderthal skeleton and some may be as recent as 13,000 years old. Based on what is known about modern human migration to the neighbouring islands and the Australian continent nearby, Homo sapiens may have co-existed with these little fellas for tens of thousands of years.


This story is so astonishing, I'm just going to quote it at length.

Scientists Find Ancient Hobbit-Sized People

Skeletal Remains Reveal Human Species That Measured 3-Feet High

Once upon a time, on an isolated island of Indonesia, there lived a colony of little people -- very little people.

Not only did anthropologists find the skeletal remains of a hobbit-sized, 30-year-old adult female, in this fairy-tale-like discovery they also uncovered in the same limestone cave the remains of a Komodo dragon, stone tools and a dwarf elephant.

Subsequent finds of other similarly sized, 3-foot-tall humans with brains the size of grapefruits in a cave on the Indonesian island of Flores suggest these 18,000-year-old specimens weren't a quirk of an ancient hominin, but part of an entire species of miniature people whose existence overlapped with that of modern Homo sapiens.

It takes a certain rat-like mind, I think, to bomb a city. It's all that sense of aloofness from the hellish reality on the ground that enables an elite pilot to describe the devastation they create in terms such as "surgical" or "clinical". Just drop that payload and go home.

It's a mindset that just chills me to the bone.

Anyway, it seems that technological evolution has a way of bringing things to their natural conclusion: rat brains grown on electrodes for flying fighter planes.

Thanks, Drew.

There's far from a consensus amongst experts about the meaning of the discovery of Homo floresiensis, the diminutive hobbit people of Flores. The main question is whether the sophisticated stone tools found in the proximity of the tiny skeletons were made by the creatures themselves or were made by humans that may have co-existed on the island.

The problem lies in not having any evidence of modern human occupation until around 12,000 years ago, about a thousand years after the most recent bones. The other problem is that the tools seem too big and heavy to be the sort of thing used by small humans and, given their grapefruit-sized brains, whether they were intelligent enough to make them in the first place.

Modern humans are known to have inhabited neighbouring regions for around 50,000 years and were even able to sail all the way to Australia, so the chances that two species met are very high. Perhaps the tools were left by humans whose remains are buried elsewhere. An even grimmer idea is that perhaps the tools were left by humans who hunted and butchered the hobbits for food.

See: Experts split over human Hobbit remains