Um espelho que reflecte a vida, que passa por nós num segundo (espelho)

Ago 13


Reducing cost and risks


It takes six to nine months to get to Mars using traditional propulsion technology.


But when astronauts eventually take the trip, it would be significantly cheaper and safer for them to hibernate through the vast majority of it, like bears waiting out the winter.


"One area would be in radiation shielding," he said. Astronauts "will almost always be contained in one spot. You could significantly increase the radiation shielding over this small area and reduce the dosage they're taking over the mission."


Cooling down


Bradford's team is trying to leverage and extend medical advances in therapeutic hypothermia, which seeks to prevent tissue damage during periods of low blood flow by lowering core body temperature.


For every drop of 1 degree Fahrenheit in body temperature, metabolic rate decreases by 5 to 7 percent, Bradford said. The researchers are aiming for a 10-degree drop during manned Mars missions, or a 50 to 70 percent reduction in metabolic rate.

That's a big drop.


The longest anyone has remained in a medically induced hypothermic torpor to date is about 10 days, Bradford said. But that's likely not an upper limit, he stressed; rather, it's a reflection of the low medical need to keep people in such states for prolonged periods of time.


"We're trying to give [the medical community] a need, or a rationale" to push the 10-day record out to 30 days and beyond, and to look for any possible attendant complications.


Challenges ahead


"Typically, you have to have these very slow rotation rates, because spinning too fast makes people sick," he said. (Rotation rate dictates the magnitude of the induced gravitational force.) "Because they're not conscious, they obviously won't be susceptible to disorientation, and we think we can actually put them on a much faster rotation."


"There's a lot of research on black bears — they hibernate for five or seven months, and they experience very little muscle atrophy," Bradford said. Scientists "are trying to understand why that is. Are body processes tricking the muscles into thinking they're active? So we're looking at that."


Early days


At the moment, Bradford said, the strategy looks promising. He thinks it should be possible to put astronauts into a torpor state by the mid-2030s — the same timeframe NASA is targeting for its first manned Mars mission.


"I don't think it's quite as far-fetched as some people may think," Bradford said. "My goal would be to have something here in 20 years, and I think a lot of the research and experimentation stuff could begin even sooner."


As an example, he said that hypothermia therapy experiments could begin on the International Space Station at pretty much any time.


Bradford also sees potential in the longer term, saying that the hibernation approach could make it easier to establish and sustain a permanent Mars colony.



publicado por Produções Anormais - Albufeira às 21:40

A Estrela (Morta) companheira do Sol


Desde há muitos anos que os estudiosos e especialistas da História da Terra tentam encontrar uma explicação lógica e credível, que clarifique duma vez por todas as razões fundamentais que estiveram na base das extinções maciças de seres vivos, que o nosso planeta terá eventualmente sofrido desde a sua formação até aos dias de hoje.


Uma das explicações possíveis poderá estar na existência duma estrela companheira do Sol – NEMESIS – que na sua órbita cíclica de aproximação à nossa estrela poderia afectar a órbita doutros corpos celestes, desde logo afectando os mais afastados do nosso Sistema Solar e posteriormente os localizados no seu interior – por exemplo na nuvem de OORT e na cintura de KUIPER – podendo-os lançar numa rota de colisão com o nosso planeta. Como estrela ou planeta anão (dwarf star/dwarf planet) NEMESIS – com uma órbita larguíssima e exterior ao nosso sistema e com um cíclico provável de milhares senão mesmo milhões de anos – e caso se comprove a sua existência, pode representar o fim dos tempos e o início doutro tempo e a explicação para alguns dos fenómenos que a Terra tem sofrido ultimamente.


É certo que tudo isto pode ser apenas ficção cientifica conspiracionista, ainda por cima agora que os Republicanos atacam violentamente, sucessivamente e de todas as formas possíveis a (medíocre) administração Obama, equiparando-o ao Anti-Cristo – talvez por ser negro como poderia acontecer por ser mulher: até o cometa ISON poderá ser o encoberto NEMESIS.


No entanto muitos cientistas não acreditam nessa teoria – que assenta na ideia de que o Sol pertence a um sistema binário – recusando-se a reconhecer a sua existência, até porque essa Estrela Anã (Dwarf Star) nunca foi até hoje observada.



The argument for Nemesis


In the early 1980s, scientists noticed that extinctions on Earth seemed to fall in a cyclical pattern. Mass extinctions seem to occur more frequently every 27 million years. The long span of time caused them to turn to astronomical events for an explanation.


In 1984, Richard Muller of the University of California Berkley suggested that a red dwarf star 1.5 light-years away could be the cause of the mass extinctions. Later theories have suggested that Nemesis could be a brown or white dwarf, or a low-mass star only a few times as massive as Jupiter. All would cast dim light, making them difficult to spot.


Scientists speculated that Nemesis may affect the Oort cloud, which is made up of icy rocks surrounding the sun beyond the range of Pluto. Many of these chunks travel around the sun in a long-term, elliptical orbit. As they draw closer to the star, their ice begins to melt and stream behind them, making them recognizable as comets.


If Nemesis traveled through the Oort cloud every 27 million years, some argue, it could kick extra comets out of the sphere and send them hurling toward the inner solar system — and Earth. Impact rates would increase, and mass extinctions would be more common.


The Kuiper Belt, a disk of debris that lies inside of the solar system, also has a well-defined outer edge that could be sheared off by a companion star. Researchers have found other systems where a companion star seems to have affected the shape of the debris disks.


The dwarf planet Sedna lends further credence in the eyes of some to the existence of a companion star for the sun. With an orbit of up to 12,000 years, the planet presents a puzzle to many. Scientists have suggested that a massive object such as a dim star could be responsible for keeping Sedna so far from the sun.


Though some scientists find the Nemesis theory plausible, others do not.


“The Sun is not part of a binary star system. There has never been any evidence to suggest a companion. The idea has been disproved by several infrared sky surveys, most recently the WISE mission. If there were a brown dwarf companion, these sensitive infrared telescopes would have detected it”. (David Morrison, Astrobiology Senior Scientist, October 17, 2012)


(The Argument for Nemesis: imagem e texto –

publicado por Produções Anormais - Albufeira às 18:46

Agosto 2013






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