“Complex life is separated from the simplest life forms by several very unlikely steps and therefore will be much less common. Intelligence is one step further, so it is much less common still,” said Prof Watson.
His model, published in the journal Astrobiology, suggests an upper limit for the probability of each step occurring is 10 per cent or less, so the chances of intelligent life emerging is low – less than 0.01 per cent over four billion years.
When will alien life be proven http://www.paddypower.com/bet/novelt...-existence2020
What about signals from an technologically advanced extraterrestrial civilization? The SKA will be so sensitive that that it will be able to detect signals comparable in strength to television transmitters
operating on planets around the closest stars to the Sun. The SKA will be able to search for “leakage” signals from other civilizations for the first time. And it will expand the volume of the Galaxy that can
be searched for intentional beacons by a factor of 1000, using a wider range of frequencies than attempted before. The detection of such extraterrestrial signals would forever change the perception of humanity in the Universe.
“Complex life is separated from the simplest life forms by several very unlikely steps and therefore will be much less common. Intelligence is one step further, so it is much less common still,” said Prof Watson.
His model, published in the journal Astrobiology, suggests an upper limit for the probability of each step occurring is 10 per cent or less, so the chances of intelligent life emerging is low – less than 0.01 per cent over four billion years.
The latest estimates figure 1.6 rocky earth like planets per star(and climbing) in our own milkyway galaxy, If Watson is right with his calculations thats a lowly 160,000 intelligent life forms in just our galaxy alone.
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Graphene, still cool stuff. (This time a graphene oxide membrane to be exact.)
Quote:
When a metal container was sealed with such a film, even the most sensitive equipment was unable to detect air or any other gas, including helium, leaking through.
But when the researchers tried the same with water, they found that it evaporated without noticing the graphene seal. Water molecules diffused through the graphene-oxide membranes with such a great speed that the evaporation rate was the same whether the container was sealed or open.
...
Dr Nair said: "Just for a laugh, we sealed a bottle of vodka with our membranes and found that the distilled solution became stronger and stronger with time. Neither of us drinks vodka but it was great fun to do the experiment."
...
"The properties are so unusual that it is hard to imagine that they cannot find some use in the design of filtration, separation or barrier membranes, and for selective removal of water."
The latest estimates figure 1.6 rocky earth like planets per star(and climbing) in our own milkyway galaxy, If Watson is right with his calculations thats a lowly 160,000 intelligent life forms in just our galaxy alone.
And that's an upper limit, with a lower limit of 1.
Even with 160,000, the amount of empty space that would be left in the galaxy is astounding. That's 160,000 out of 480,000,000,000 planets. Even with travel at the speed of light, and communications at the speed of light, we would likely never know they exist. They would be too far away for us to ever reach.
Factor in the fact that the center bulge of the galaxy is where the majority of stars exist, and the likelihood that the entire region is so bathed in radiation as to make it uninhabitable - the galactic habitable zone. Add to this the fact that we know almost nothing as to the cause of the Cambrian Explosion - the rise of true multi-cellular life, and that 160,000 becomes a really, really high estimate. I am very skeptical about this, and am glad that someone out there that is respected is throwing cold water on the idea that our galaxy is teeming with life. There is zero scientific evidence that there is any life of any discernible type outside of earth, and to suggest not just otherwise, but that the universe is teeming with life - especially intelligent life - is not very scientific.
My guess - there's only one life form that has any kind of intelligence whatsoever. Unless you count Dolphins. Even with these weirdly optimistic calculations, there had to be a time when there was only one. What if that time is now?
And that's an upper limit, with a lower limit of 1.
Even with 160,000, the amount of empty space that would be left in the galaxy is astounding. That's 160,000 out of 480,000,000,000 planets. Even with travel at the speed of light, and communications at the speed of light, we would likely never know they exist. They would be too far away for us to ever reach.
Factor in the fact that the center bulge of the galaxy is where the majority of stars exist, and the likelihood that the entire region is so bathed in radiation as to make it uninhabitable - the galactic habitable zone. Add to this the fact that we know almost nothing as to the cause of the Cambrian Explosion - the rise of true multi-cellular life, and that 160,000 becomes a really, really high estimate. I am very skeptical about this, and am glad that someone out there that is respected is throwing cold water on the idea that our galaxy is teeming with life. There is zero scientific evidence that there is any life of any discernible type outside of earth, and to suggest not just otherwise, but that the universe is teeming with life - especially intelligent life - is not very scientific.
My guess - there's only one life form that has any kind of intelligence whatsoever. Unless you count Dolphins. Even with these weirdly optimistic calculations, there had to be a time when there was only one. What if that time is now?
Uninhabitable for what? Humans? If that is the case, you wouldn't be the first guilty of anthropocentrism.
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And that's an upper limit, with a lower limit of 1.
Even with 160,000, the amount of empty space that would be left in the galaxy is astounding. That's 160,000 out of 480,000,000,000 planets. Even with travel at the speed of light, and communications at the speed of light, we would likely never know they exist. They would be too far away for us to ever reach.
The distance is more a problem for communication, and less so for detection. I will say that ignoring some more exotic solutions and with the exception of the immediate neighborhood, interstellar travel for purposes of colonization is less of a problem than for anything that would require you to report back to your home planet for. A trip to Kepler-22b (thought to be a candidate for life) at a constant acceleration of 1G would take us about 12 and a half years ship time, but just over 1000 years would have passed on Earth by the time you got there. To send a radio message back to Earth would take another 1000 years, which would be impractical. A similar trip to the Andromeda Galaxy would take just 29 years for the travelers, but more than 2.5 million years would have passed on Earth; by then, our planet might be very different.
Quote:
Originally Posted by Knalus
Factor in the fact that the center bulge of the galaxy is where the majority of stars exist, and the likelihood that the entire region is so bathed in radiation as to make it uninhabitable - the galactic habitable zone. Add to this the fact that we know almost nothing as to the cause of the Cambrian Explosion - the rise of true multi-cellular life, and that 160,000 becomes a really, really high estimate. I am very skeptical about this, and am glad that someone out there that is respected is throwing cold water on the idea that our galaxy is teeming with life. There is zero scientific evidence that there is any life of any discernible type outside of earth, and to suggest not just otherwise, but that the universe is teeming with life - especially intelligent life - is not very scientific.
Huh? The only possible ways* for us to discern the existence of extraterrestrial life at present are:
1) Analog signals from an intelligent civilization.
2) Discovery of extraterrestrial life in our solar system, say for example on Europe or Encyladus.
3) It comes to us.
We're attempting #1 and #2, and the arguments for #3 being a present reality are unconvincing in my opinion. Your argument is in effect:
We've not yet discovered extraterrestrial intelligence, therefore to merely suggest that there might be life outside our solar system, not even intelligent life, somewhere else is unscientific. However, we can use what we do know to make a guess. Based on the amount of time life took to arise on Earth, Lineweaver and Davis estimate at least 13% of inhabitable planets go on to develop life. In other words, the pro-ET conjecture is a better one than the anti-ET conjecture based on what we know so far.
Quote:
Originally Posted by Knalus
My guess - there's only one life form that has any kind of intelligence whatsoever. Unless you count Dolphins. Even with these weirdly optimistic calculations, there had to be a time when there was only one. What if that time is now?
The problem with this is, of course, that other locales have had an enormous head start on us - billions of years worth.
*If I've missed anything else we could currently do, please correct me.
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Pretty much every new discovery relevant to the debate increases the likelihood of intelligent life existing elsewhere. In the last few years we've discovered silicone-based life here on earth. We've discovered key organic compounds (amino acids to RNA compounds to DNA compounds) in space. The number of goldilocks planets that we know of has increased exponentially, and the more we know about life and in particular extremophiles, the more likely it is that some forms of life could live (and possibly evolve) outside the goldilocks zone in special circumstances. Even amongst the other forms of life that we're share the planet with, we're finding that many hallmarks of intelligence (from tool-usage to self-awareness to sophisticated language) are far more common than we thought even a decade ago. It's amazing how much our knowledge has grown in the last decade, and while we're probably a long way off from the discovering extra-terrestrial life, let alone advanced life, every related discovery makes it more likely that there's life out there.
Pretty much every new discovery relevant to the debate increases the likelihood of intelligent life existing elsewhere. In the last few years we've discovered silicone-based life here on earth. We've discovered key organic compounds (amino acids to RNA compounds to DNA compounds) in space. The number of goldilocks planets that we know of has increased exponentially, and the more we know about life and in particular extremophiles, the more likely it is that some forms of life could live (and possibly evolve) outside the goldilocks zone in special circumstances. Even amongst the other forms of life that we're share the planet with, we're finding that many hallmarks of intelligence (from tool-usage to self-awareness to sophisticated language) are far more common than we thought even a decade ago. It's amazing how much our knowledge has grown in the last decade, and while we're probably a long way off from the discovering extra-terrestrial life, let alone advanced life, every related discovery makes it more likely that there's life out there.
Which is why I think it is far more likely that intelligent life will discover us rather than us discovering it.
Last edited by Flash Walken; 01-27-2012 at 11:59 PM.
And that's an upper limit, with a lower limit of 1.
Doubtful, We just started finding planets and so far mostly planets that are big because the instruments we have can't find too many earth like planets. Trust this! It won't be long before it a lot easier.
Because of the way stars form I suspect solar systems like ours are the norm and 1 or 2 planets would be rare.
Quote:
Originally Posted by Knalus
My guess - there's only one life form that has any kind of intelligence whatsoever. Unless you count Dolphins. Even with these weirdly optimistic calculations, there had to be a time when there was only one. What if that time is now?
After drilling for two decades through more than two miles of antarctic ice, Russian scientists are on the verge of entering a vast, dark lake that hasn’t been touched by light for more than 20 million years.
Scientists are enormously excited about what life-forms might be found there but are equally worried about contaminating the lake with drilling fluids and bacteria, and the potentially explosive “de-gassing” of a body of water that has especially high concentrations of oxygen and nitrogen.
[ . . . ]
If microbes are found in Vostok, the discovery would have particular significance for astrobiology, the search for life beyond Earth. That’s because Jupiter’s moon Europa and Saturn’s moon Enceladus have deep ice crusts that scientists think cover large amounts of liquid water warmed by sources other than the sun — just like Vostok.
Let's just hope they don't find any black oil.
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WASHINGTON — International astronomers said on Thursday they have found the fourth potentially habitable planet outside our solar system with temperatures that could support water and life about 22 light-years from Earth.
The team analyzed data from the European Southern Observatory about a star known as GJ 667C, which is known as an M-class dwarf star and puts out much less heat than our Sun.
However, at least three planets are orbiting close to the star, and one of them appears to be close enough that it likely absorbs about as much incoming light and energy as Earth, has similar surface temperatures and perhaps water.
The new rocky planet, GJ 667C, orbits its star every 28.15 days — meaning its year equals about one Earth month — and has a mass at least 4.5 times that of Earth, according to the research published in Astrophysical Journal Letters.
So when they come across planets like these, does it help with SETI determining where to point their dishes? For example, if there is intelligent life on the planet from the article that has been broadcasting signals for at least 22 years, is it as simple as pointing a radio dish in that direction to listen?