Tuesday, May 22, 2012

Newly Discovered Diprotodon Fossil Gives Hint at Extinction of Ancient Marsupials

Ancient Marsupial Fossil Suggests Climate Change A Cause of the demise of Megafauna
Scientists at the South Australian museum (Adelaide, Australia) are hoping the discovery of the fossilised remains of a giant marsupial might be able to provide them with further insights as to what led to the demise of Australia's megafauna, animals as diverse as hippo-sized Wombats, predatory Thylacines, giant Koala bears and Monitor Lizards twice as big as Komodo Dragons.
Giant Marsupials - Diprotodontids
The giant marsupial in question is a Diprotodon, a strange and diverse group of mammals unique to Australia. Diprotodontids are an extinct family of marsupials, the majority of which were plant-eaters and some evolved into giant forms becoming the largest mammalian herbivores the continent has ever seen. The first Diprotodontid fossils are known from Eocene deposits and they may have persisted until around 45,000 years ago.
Palaeontologists have puzzled over why the Australian megafauna died out. It has been proposed that hunting and the burning of forests by the first human settlers on the continent hastened the demise of these large animals, however, rapid climate change may also have played a prominent role.
Giant Prehistoric Animal From Australia
The fossils of the three metre long Diprotodon were found at the remote Collinsville Merino Stud, a substantial sheep and cropping station approximately eighty miles north of Adelaide. The fossils were discovered in mid 2010 when Paul Cousins, a sheep station worker, came across the fossils eroding out of a riverbank whilst on a camping trip with his family. He took some of the exposed fossilised bones to a local museum knowing that they represented the remains of a prehistoric animal but he was unsure whether or not they had discovered a dinosaur. Museum staff identified the specimens as Diprotodontid fossils and a team from the South Australian museum was dispatched to excavate the rest of the fossil material still embedded in the ground.
Associate Professor Rod Wells of the South Australia museum commented that over 500 man hours had already been spent excavating and preparing this specimen and he asked for more field volunteers to help with the excavation. The fossils have been dated to around 120,000 years ago, a time when people had yet to reach Australia, according to most palaeoanthropologists. The fossil matrix, the sediment in which the material was found, may provide clues to the extinction of Australia's unique megafauna.
Sediment Suggests Extinction due to Climate Change
The sediment in which the bones of this large, plant-eater were deposited are very finely grained. The fossils were discovered by the Cousins family in a creek bed that was eroded by seasonal flooding and exposed. The strata in the immediate vicinity of the fossil material, as it is so fine suggests a hot, dry and windy environment. The Australian scientists have speculated that this large animal may have died in a prolonged drought or fallen into a dried up river channel, the carcase would have been washed down to its final resting place in later, seasonal flooding.
This suggests that the climate may have been more extreme 120,000 years ago with very dry periods followed by intense, seasonal rains which may have caused extensive flooding. The location of this fossil material adds to the debate as to whether climate change played a significant role in the extinction of a lot of Australia's unique, native fauna.
Harsh environments and rapidly changing climatic conditions would have affected large animals at the top of the food chain to a greater degree than smaller animals. The larger species of Diprotodontids may have been struggling to survive and then with the advent of the first human settlers, they were finally driven to extinction.
Palaeontologists Hoping to Find More Fossil Remains
Rod Wells has suggested that the more fossil sites such as the Collinsville location that the scientists explore so they will be able to build up a more complete picture regarding the climate of Australia during the Pleistocene Epoch. Such data will help them to understand why these huge animals perished along with the other amazing megafauna that once roamed the outback.

Tuesday, May 8, 2012

Is It Possible To Travel Backwards in Time?

Einstein based his entire theory of relativity on two simple assumptions, one about predictability of optical experiments irrespective of lab conditions and the other about constancy of velocity of light in fundamental system/empty space.
Thereafter, Einstein fantasized a space ship travelling along a straight line for further construction of his theory. He assumed a scenario in which space ship can be potentially accelerated to the velocity of light.
It is a common experience that when matter is heated by supplying energy to its atoms and molecules, it results in increase of kinetic energy of its atoms and molecules and increasing kinetic energy of atoms and molecules is associated with not only increasing temperature but also increasing velocity of constituent atoms and molecules. This increasing velocity of atoms and molecules is necessarily associated with change of one or the other kind. Ensuing change may be physical, chemical or nuclear reaction and may be essentially nonlinear in character. Physical change often consists of nonlinear change of state from solid to liquid to gas to plasma state and may be even thereafter. Appropriate chemical reactions, again essentially nonlinear in character commonly occur depending on nature of interacting entities and conditions of the experiment. Very high velocities of atoms and molecules are associated with thermonuclear reactions such as nuclear fusion of Hydrogen into Helium at 50,000°K.
Exact nature of change can only be empirically known and is rationally unpredictable. In most general terms, nature of change can be attributed to nature of interacting entities.
But Einstein arbitrarily assumed that increasing velocity of the said space ship shall lead to reduction in speed of time measuring devices such as clocks and watches in order to compensate effects of increased velocity. Einstein stated "A moving clock, no matter what its construction, runs slower than an identical clock that is at rest." Einstein never bothered to explain as to why frequency of a pendulum in linear motion changes when in the equation of simple pendulum length of the pendulum and gravity are the only two variables determining its frequency/time period. Moreover why should errors of observation determine behavior of the observed, i.e. why incorrect recording of time by clocks and watches should have a bearing on behavior of time itself and properties of matter?
Einstein's arbitrary conclusions were extended to Biological domain leading to speculation that one day using a device designated as time machine; it shall be possible to travel backward in time.
Time is linearly progressive. This is the inherent nature of time. No experimental conditions or errors of observation can have a bearing upon intrinsic nature of time. Therefore, it shall never be possible to travel backward in time. Hence time machine is nothing more than science inspired fantasy which shall never materialize.
Backward travel of time by any stretch of imagination, if ever becomes feasible than it is bound to lead to many absurd situations and universal chaos. Imagine the following scenarios:
1. A time traveler goes back to times of Jesus and is able to persuade Pontius Pilate not to crucify Jesus. Consider its impact upon subsequent world history and turmoil it will create in the contemporary world.
2. A time traveler in India travels back to Mahabharata period and is able to persuade Pandavas not to indulge in the game of chess with Kauravas or is able to persuade Duryodhana not to insult Draupadi by removing her saree. Alternatively, another time traveler is able to persuade Duryodhana to justly give Pandavas their share in the kingdom. Imagine impact of these backward journeys in time upon subsequent Indian history and changes it will lead to, in contemporary Indian society.
3. A person meets an accident, fractures several bones, is put in time machine, backward travel in time restores his health. A novel technical innovation, yet to be discovered, shall be used to rehabilitate the person in contemporary world. This technology may be employed to treat a large number of ailments.
4. A person has left for his heavenly abode; his dead body is put in time machine, the person comes to life and is than rehabilitated in the contemporary world by some novel technology yet to be discovered.
5. Consider impact on world history of abortion of Hitler's mother while Hitler was still in the womb!
Clearly, there can be countless number of such examples providing ample food for thought to science fiction writers for infinite generations to come. But it is self-evident that the mere feasibility of backward travel in time is bound to lead to countless absurdities that would disrupt natural order and precipitate universal chaos. Such universal chaos is bound to be in conflict with universal instinct to exist. This will jeopardize existence of universe itself of which we all are a part.
Hence, backward travel in time is nothing but a pure fantasy of scientific origin devoid of any foundations in fact and logic. However, this is without prejudice to rational predictability of past based on our understanding of natural laws and intrinsic nature of things and events.