A black hole is simple and clear, at least according to the model proposed in 1963 by Roy Kerr; his model of a clear, smooth black hole is now the currently accepted paradigm. But a group of scientists led by Thomas Sotiriou, a physicist of the International School for Advanced Studies (SISSA) of Trieste claims that black holes are way “dirtier” than previosuly believed.
According to the traditional model, black holes are defined by only two parameters: mass and angular momentum (rotation velocity). That’s it; no size, no temperature, no nothing – just mass and angular momentum tell you everything you can know about a black hole. Everything that came from the progenitor (the star which collapsed into the black hole) is gone, no memory of it is retained – nor of anything else.
In 1963, during a simple renovation in the town of Derinkuyu, a cave wall was opened, revealing a passage way to an underground city, thousands of years old, extending more than 280 feet deep. Derinkuyu is 11 stories, with 15,000 little ventilation shafts that bring air to even the deepest of levels.
Turkey is home to some of the most interesting archaeological digs around. One of the most intriguing would have to be the underground city at Derinkuyu. Of all of the underground cities found in Turkey, the Derinkuyu underground city is the largest.
It is unknown exactly why the city was constructed. Archaeologists have found evidence that the city could be sealed off from the inside by means of a series of large stone doors. The stone doors are approximately one meter to a meter and a half in height. They are between 30 and 50 cms thick and weigh between 200 and 500kg. Each of the 11 floors in the city could also be closed off independently of one another.
In a mind boggling act, spiders are capable of “ballooning” themselves using silk strands and fly for miles, both in altitude and distance. Small and big spiders alike can do this, although smaller ones are capable of traveling further, and scientists have long theorized the mechanisms of spider ‘flight’. Peter Gorham at the University of Hawaii tested a theory that dates back from the early 1800s, first proposed by Charles Darwin himself, which states that the spiders achieve their amazing lift through electrostatic means. His findings support this theory, explaining the mysterious and peculiar spider flight behavior which has puzzled scientists for so long.
While off the cost of Argentina a few tens of miles away sailing in the infamous HMS Beagle in the 1830s, Darwin perplexedly recalled how the ship was flooded with spiders as if they had dropped from the clouds.
“I repeatedly observed the same kind of small spider, either when placed or having crawled on some little eminence, elevate its abdomen, send forth a thread, and then sail away horizontally, but with a rapidity which was quite unaccountable.” C. Darwin.
At the time Darwin thought spiders used their silk to catch thermal air currents to carry them to considerable height, and this conventional wisdom was used to explain it for years. Darwin also proposed “electrostatic repulsion” played a role in the fanning of the threads, but this theory was dismissed by biologists in favor of the thermal air currents theory.
A team of researchers at the Wyss Institute of Biologically Inspired Engineering at Harvard University has found a way to self-assemble complex structures out of bricks smaller than a grain of salt. The new method could help solve one of the major challenges in tissue engineering: creating injectable components that self-assemble into intricately structured, biocompatible scaffolds at an injury site to help regrow human tissues.
It doesn’t look like a highly skilled killer, but that’s exactly what it is; the sand cat, which is the only felid found primarily in true desert, and has a wide but apparently disjunct distribution through the deserts of northern Africa and southwest and central Asia.
They can easily live in areas far away from water, and even though they drink water when they can, they get enough hydration just from their prey.
