The image shows an impression by David A. Hardy of a possible scene from a moon orbiting the extra-solar planet in orbit around the star HD70642. The planet has a mass about twice that of Jupiter and orbits the star in roughly six years, with a nearly circular orbit of more than three times the Earth-Sun distance. The star HD70642 is a 7th magnitude star in the southern constellation Puppis, and has properties very similar to that of our sun. The similarity in appearance of the extra-solar planet to Jupiter arises because the planets have a similar mass. The possible existence of the moons has been inferred from our knowledge of the planets in our own solar system and from theories of planetary formation—they have not actually been detected.
The 'orbit' diagram shows the size and shape of the star HD70642 orbit compared with the orbits of planets in our own Solar System
Illustration of the Doppler Wobble Technique.
Astronomers looking for planetary systems that resemble our own solar system have found the most similar formation so far. British astronomers, working with Australian and American colleagues, have discovered a planet like Jupiter in orbit round a nearby star that is very like our own Sun. Among the hundred found so far, this system is the one most similar to our Solar System. The planet's orbit is like that of Jupiter in our own Solar System, especially as it is nearly circular and there are no bigger planets closer in to its star.
"This planet is going round in a nearly circular orbit three-fifths the size of our own Jupiter. This is the closest we have yet got to a real Solar System-like planet, and advances our search for systems that are even more like our own," said UK team leader Hugh Jones of Liverpool John Moores University.
The planet was discovered using the 3.9-metre Anglo-Australian Telescope [AAT] in New South Wales, Australia. The discovery, which is part of a large search for solar systems that resemble our own, will be announced today (Thursday, July 3rd 2003) by Hugh Jones (Liverpool John Moores University) at a conference on "Extrasolar Planets: Today and Tomorrow" in Paris, France.
"It is the exquisite precision of our measurements that lets us search for these Jupiters - they are harder to find than the more exotic planets found so far. Perhaps most stars will be shown to have planets like our own Solar System", said Dr Alan Penny, from the Rutherford Appleton Laboratory.
The new planet, which has a mass about twice that of Jupiter, circles its star (HD70642) about every six years. HD70642 can be found in the constellation Puppis and is about 90 light years away from Earth. The planet is 3.3 times further from its star as the Earth is from the Sun (about halfway between Mars and Jupiter if it were in our own system).
The long-term goal of this programme is the detection of true analogues to the Solar System: planetary systems with giant planets in long circular orbits and small rocky planets on shorter circular orbits. This discovery of a -Jupiter- like gas giant planet around a nearby star is a step toward this goal. The discovery of other such planets and planetary satellites within the next decade will help astronomers assess the Solar System's place in the galaxy and whether planetary systems like our own are common or rare.
Prior to the discovery of extrasolar planets, planetary systems were generally predicted to be similar to the Solar System - giant planets orbiting beyond 4 Earth-Sun distances in circular orbits, and terrestrial mass planets in inner orbits. The danger of using theoretical ideas to extrapolate from just one example - our own Solar System - has been shown by the extrasolar planetary systems now known to exist which have very different properties. Planetary systems are much more diverse than ever imagined.
However these new planets have only been found around one-tenth of stars where they were looked for. It is possible that the harder-to-find very Solar System-like planets do exist around most stars.
The vast majority of the presently known extrasolar planets lie in elliptical orbits, which would preclude the existence of habitable terrestrial planets. Previously, the only gas giant found to orbit beyond 3 Earth-Sun distances in a near circular orbit was the outer planet of the 47 Ursa Majoris system - a system which also includes an inner gas giant at 2 Earth-Sun distances (unlike the Solar System). This discovery of a 3.3 Earth-Sun distance planet in a near circular orbit around a Sun-like star bears the closest likeness to our Solar System found to date and demonstrates our searches are precise enough to find Jupiter- like planets in Jupiter-like orbit.
To find evidence of planets, the astronomers use a high- precision technique developed by Paul Butler of the Carnegie Institute of Washington and Geoff Marcy of the University of California at Berkeley to measure how much a star "wobbles" in space as it is affected by a planet's gravity. As an unseen planet orbits a distant star, the gravitational pull causes the star to move back and forth in space. That wobble can be detected by the 'Doppler shifting' it causes in the star's light. This discovery demonstrates that the long term precision of the team's technique is 3 metres per second (7mph) making the Anglo-Australian Planet Search at least as precise as any of the many planet search projects underway.
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Contributing yet another strand to the patchwork of overseas Chinese speech and customs were the Hakkas, latecomers to the southernmost provinces, moving into Fukien and Kwngtung in two separate migrations: during the tenth century and the twelfth and thirteenth centuries. The Hakkas whose name means `guest families' have been described as the gypsies of China, people who live side by side with speakers of different dialects in enclaves scattered across six southern provinces, without a homeland of their own. They were a rugged lot, and even their women had to be hardy. Little wonder that the Hakkas were the only Chinese to refrain altogether from binding their daughters' feet into the `golden lilies' that were de rigueur everywhere else. One thing Hakka women were not was dainty.
Men moving across great distances into an unknown landscape, assailed by the hostility of settlers who have preceded them, band together; and if Hakkas were (and still are) thought a very clannish people, they had good reasons to be. The banding-together took a palpably defensive form, in communal living and communal housing Their dwellings, still to be seen today in a border area in Fukien province, are extraordinary constructions, rising out of the countryside like veritable fortresses, gigantic, multi-storied, round. They are built to a circular plan, with a thick outer wall of tamped earth pierced by tiny squint-holes, presenting a resolutely sealed and embattled look to the world. In the walled complex, an entire community, numbering six to seven hundred inhabitants, could be concentrated.
It was no easy matter to live among the Cantonese, to contend for land and water. Feuds were easily ignited in such an atmosphere, and there evolved a tradition of armed fighting between the migrant and the settler. We read of a period of prolonged fighting between the two in the years 1855-67, a war in which about half a million people are said to have lost their lives. It is not hard to see why the Hakkas emigrated to Nanyang [South-East Asia]. In China they were pushed on to marginal land, hilly country rejected by those who had got there first.
[from Sons of the Yellow Emperor : The Story of the Overseas Chinese by Lynn Pan, Mandarin Paperbacks 1991, page 16]
Here are some pictures of traditional Hakka round earth builidings (click to get a higher resolution version).
Round Earth Building
This type of building is round in shape and divided into three classes, small, medium and big. The small ones are usually 2 to 3 stories tall with a single ring. The medium dwelling is usually 3 to 4 stories tall with a large inner open space (single ring) or double rings. The large round building is usually 4 to 5 stories tall consisting of as many as three rings.
The very small round building has about 12 to 18 rooms, the small ones have 21 to 28 rooms, the medium ones have about 30 to 40 rooms, the large ones have about 42 to 58 rooms, and the super large round buildings have about 60 to 72 rooms.
Two-third of the round building are 3 stories high and hold roughly 20 families or 100 people. The round earth building is a "group-oriented" residence, usually with one main entrance. Its wall is usually around 1 meter thick. The main entrance door is padded with iron sheet and is locked by 2 horizontal wood bars. The wooden bars retract into the walls in order to open the door. In the event the wood bars are sawed through, the locking mechanism is still intact.
Inside the entrance is a huge central courtyard where all the doors of the rooms and inner windows are open to. At the ground level except the hall and the staircases, the rooms are used as kitchens and dining rooms. The rooms on the second floor are used for storage. The rooms on the 3rd level are used as bedrooms. The rooms in each level are identical. In front of each room, there is an open round hallway and usually there are 4 staircases to move from one level to another. Thus each family occupies one vertical units with lower level as kitchen, 2nd level for storage and miscellaneous use and 3rd level and above used as bedroom. Sometime there is no open round hallway. Instead, every family has its own private staircase. A typical room is about 10-13 square meter in size.
The larger round earth building has room around 15 square meters. The windows facing outside tends to be small, with the window size at the outer wall smaller and the window size at the inner wall larger enabling wider surveillance from the inside. It is extremely hard for outsiders to come in through the windows. There is usually no window at the ground level. While the round building is fairly large, it has an inner ring, which is like a round building within a round building. For round building that built earlier than 15th century, they have other defensive features that would counter siege. It is said that during Ming dynasty as Japanese pirates intruded the coastal areas, they always leave the Hakka's Earth Buildings area alone.
[Hakka - An Important Element of Chinese Culture]
The world's first bicycle was developed by a Japanese feudal lord in 1732, a model recently created on the basis of a Edo-Period drawing has suggested.
A 30-centimeter-long scale model of a bicycle designed in 1732.
Toshio Kajiwara, 60, a former bicycle company technical adviser, analyzed the drawing of a "newly-developed, boat-style ground vehicle," and Kenjiro Kawakami, professor of industrial archeology at Tama University of Arts, created a 1/5 scale model.
"Our discovery that a bicycle with pedals existed in Japan in the 1730s has drastically changed the history of bicycles," Kajiwara said.
It has been widely believed that the first bicycle was invented in France in 1861.
"The pedal structure of the 'newly-developed, boat-style ground vehicle' is identical to that of bicycles. However, it did not spread throughout Japan probably because most of the roads in the country were bumpy at the time," Kawakami, president of the Japan Industrial Archeology Society, said.
The drawing is in a document compiled by Kuheiji Hiraishi (1696 to 1771), the lord of the Hikone feudal clan in Shiga Prefecture. It is preserved at the Hikone Municipal Library.
The document says that a so-called "boat-style ground vehicle" developed by a farmer living in the Kodama district of Bushu (currently the Saitama Prefecture city of Honjo) became popular in Edo (Tokyo).
It shows that the vehicle could climb up slopes. One of Hiraishi's retainers living at the clan's Edo residence reported the vehicle to the lord who was also a scientist.
Since the vehicle's mechanism was unclear, Hiraishi designed his own boat-style ground vehicle and built it in 1732, the document says.
The vehicle comprises of a boat-shaped wooden body, a single front wheel and two rear wheels. The pedals are connected to a disk that resembles a flywheel with an iron rod similar to a crankshaft.
The document claims that it ran at about 14 kilometers per hour.
[Mainichi Shimbun]
