|
|
|
|
| SCIENCE & TECHNOLOGY |
|
|
|
Ancient Greek city
digitally recreated
This
Universe Trends |
|
|
Ancient Greek city digitally recreated
A submerged
ancient Greek city, from the heroic era portrayed in Homer’s Iliad, is being ‘raised’ from the bottom of the Aegean. Using cutting edge underwater survey equipment and site reconstruction software, archaeologists and computer scientists have joined forces to map and digitally recreate a Bronze Age port which was swallowed by the waves up to 3000 years ago. It’s the first time that a submerged city has ever been fully mapped in photo-realistic 3D. The entire city — covering 20 acres — has been surveyed in ultra-high definition, with error margins of less than three centimetres. The survey was carried out by an archaeological team from the University of Nottingham. The original name and political status of the site is a complete mystery. The evidence so far suggests that it flourished between 2000 and 1100 BC, peaking in size in the two century period, 1700-1500BC, and being abandoned about a century before the end of the millennium. It’s conceivable that, at its peak, the city was a commercial or political satellite of the ancient Minoan Civilization which flourished on the island of Crete 80 miles across the sea to the south. For most of its final few centuries, it probably functioned as a major port of the Mycenaean civilization — and may well have been one of the more important population centres of the Kingdom of Laconia (Mycenaean era Sparta), the state associated in Homeric legend with King Menelaus and his adulterous Queen, Helen, whose famous decision to run away to Troy with her Trojan lover is said to have triggered the Trojan War. Certainly the site would have been a flourishing town with around 2000 inhabitants at the time traditionally associated with Menelaus and the war (said to be around 1200BC). It would almost certainly not have been Bronze Age Laconia’s major political centre which is thought to have been 60 miles further north. But it may well have been that Kingdom’s premier port for trade with Crete, the Aegean islands and Anatolia. Led by marine archaeologist, Jon Henderson of the University of Nottingham’s Underwater Archaeology Research Centre, the survey team has so far located scores of buildings, half a dozen major streets and even religious shrines and tombs. The entire drowned city lies four metres below the surface of the Aegean, immediately off the coast of the eastern peninsula of southern Greece’s Peloponnese region. At the heart of the city was a 40 metre long 20 metre wide plaza. Most of the houses had up to a dozen rooms. One larger building also had substantial storage facilities for imported foodstuffs. The city sunk beneath the waves during a series of earthquakes which caused land in that immediate area to subside relative to sea level, probably in the earlier first millennium BC. “Surveying the city has been a unique operation. It’s one of the few places on earth where, as a marine archaeologist, you can quite literally swim along a drowned street of an ancient city or look inside a submerged tomb,” said Dr. Henderson. “The detailed information we’ve been able to obtain through the survey is giving us an unprecedentedly detailed view of what a Bronze Age Mycenaean era city looked like,” he said.
— The Independent
|
||
|
This Universe What is the reason for the curved shape of rainbow? Why is it not straight? Come the rainy season and we have millions of fresh young people captivated by the beautiful spectacle of a rainbow. The happening of a rainbow is a phenomenon that lifts the human spirit. It also creates an urge to understand the reasons behind this spectacle. Some people think that understanding such things takes away the romance of the experience. I disagree. For me understanding increases the romance manifold, while imparting it a joyous spring. Let me try to give an answer to your question in a way that does not require a deep knowledge of the science of optics. We all know that following is true: l
A rainbow is seen only after it has been raining. This suggests that tiny water droplets still hanging in the air might have something to do with the formation of a rainbow. It is easy to see that these droplets cannot be lined up in any fixed direction. l A rainbow is seen when we stand with the back of our head towards the sun — it is in a direction opposite to the sun. In fact, the only line that we can define in this phenomenon is that which joins our head with the sun. l The only way the spherical droplets of water can send us some coloured light is if the white light of the sun falling on them is broken up into colours as by a prism and is reflected back in our direction. l The only preference open to these droplets is to favour some angle with respect to the direction of the incoming rays of the sun; that is the same as the line joining the back of our head and the sun. l Therefore, democracy and lack of favouritism would demand that the droplets that send us more light are those that lie in an arc around the “our head-sun” direction, That has to be circular in shape — we just intercept half of that in normal rainbows. Any other shape, including a line, is not feasible. In short, rainbows exist because of a preference in favour of a specific angle that depends on the properties of water and shape of droplets. This is the so-called “angle of minimum deviation” while passing through a prism. For water droplets this happens to be about 42 degrees. If the rays emerging from the drop on the return journey happen to suffer a total internal reflection on the front side, they will go through a similar path and come out after another circular trip and emerge at a larger angle. These photons, though reduced in number, would form a secondary rain bow. Since they undergo an additional reflection the colour scheme of the secondary rainbow will be opposite to that of the primary one. Also this secondary bow will lie outside the primary one. Why do small insects and some types of flies always appear in the night around a glowing bulb or tube? Why don’t they appear in daylight? I think some years ago I had answered this. I am trying to recollect what I might have said at that time. I hope I can remember. I suppose that these flying insects have a travelling urge at night. For this they often use the moon particularly the full moon for guidance. They might want to get as close to the moon as possible, but that is not their intention. They use the moon only for guidance and for this they keep their “telescope” pointed to the moon. They learnt this method of navigation many generations ago when there was not much distraction by artificial light sources. So the trick was to keep the only light source, the moon, in the same direction with respect to the direction in which they are migrating. Nowadays, when the guidance is provided by a shining lamp close by they keep revolving around that lamp. They are not actually anxious to incinerate themselves but only using it as a sign to go there way, they end up committing immolation. A very sad story of a ‘shama’ and a ‘bhanwara’. Readers wanting to ask Prof Yash Pal a question can e-mail him at palyash.pal@gmail.com
|
||
|
Trends LONDON: Scientists have mapped out the entire genetic map of the Black Death, a 14th century bubonic plague that killed 50 million Europeans in one of the most devastating epidemics in history. The work, which involved extracting and purifying DNA from the remains of Black death victims buried in London’s “plague pits,” is the first time scientists have been able to draft a reconstructed genome of any ancient pathogen. T. rex bigger than thought, and very hungry LONDON: Tyrannosaurus rex grew faster and weighed more than previously thought, suggesting the fearsome predator would have been a ravenous teen-ager, researchers said Wednesday. Using three-dimensional laser scans and computer modelling, British and U.S. scientists “weighed” five T. rex specimens, including the Chicago Field Museum’s “Sue,” the largest and most complete T. rex skeleton known. New stem cell method makes functioning liver cells LONDON: British scientists have developed a new stem cell technique for growing working liver cells which could eventually avoid the need for costly and risky liver transplants. A team of researchers led by the Sanger Institute and the University of Cambridge used cutting-edge methods to correct a genetic mutation in stem cells derived from a patient’s skin biopsy, and then grew them into fresh liver cells. NASA-backed space taxi to fly in test next summer CAPE CANAVERAL, Florida: A seven-seat space taxi backed by NASA to ferry astronauts to the International Space Station will make a high-altitude test flight next summer, officials said on Tuesday. Sierra Nevada Corp’s “Dream Chaser” space plane, which resembles a miniature space shuttle, is one of four space taxis being developed by private industry with backing from the U.S. government. TOKYO: It’s not quite a yellow submarine, since it’s destined for travel on top of the water, not under it. But the round yellow pod, christened “Noah” for the maker of the ark, could mean the difference between life and death in the case of another killer earthquake and tsunami like the one that hit Japan seven months ago, said its inventor, Shoji Tanaka.
— Reuters
|
