Is there anybody out there?
April 16, 2008Is there anybody out there? Probably not, according to a scientist from the University of East Anglia.
A mathematical model produced by Prof Andrew Watson suggests that the odds of finding new life on other Earth-like planets are low, given the time it has taken for beings such as humans to evolve and the remaining life span of the Earth.
Structurally complex and intelligent life evolved late on Earth and it has already been suggested that this process might be governed by a small number of very difficult evolutionary steps.
Prof Watson, from the School of Environmental Sciences, takes this idea further by looking at the probability of each of these critical steps occurring in relation to the life span of the Earth, giving an improved mathematical model for the evolution of intelligent life.
According to Prof Watson a limit to evolution is the habitability of Earth, and any other Earth-like planets, which will end as the sun brightens. Solar models predict that the brightness of the sun is increasing, while temperature models suggest that because of this the future life span of Earth will be ‘only’ about another billion years, a short time compared to the four billion years since life first appeared on the planet.
“The Earth’s biosphere is now in its old age and this has implications for our understanding of the likelihood of complex life and intelligence arising on any given planet,” said Prof Watson.
“At present, Earth is the only example we have of a planet with life. If we learned the planet would be habitable for a set period and that we had evolved early in this period, then even with a sample of one, we’d suspect that evolution from simple to complex and intelligent life was quite likely to occur. By contrast, we now believe that we evolved late in the habitable period, and this suggests that our evolution is rather unlikely. In fact, the timing of events is consistent with it being very rare indeed.”
Prof Watson suggests the number of evolutionary steps needed to create intelligent life, in the case of humans, is four. These probably include the emergence of single-celled bacteria, complex cells, specialized cells allowing complex life forms, and intelligent life with an established language.
“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.
Each step is independent of the other and can only take place after the previous steps in the sequence have occurred. They tend to be evenly spaced through Earth’s history and this is consistent with some of the major transitions identified in the evolution of life on Earth.
Source: University of East Anglia
Nov 05, 2009 |
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I commend his hard work on his formula, but it is far from complete and answers nothing.
There are what, 100 billion galaxies? Even if just one star has a potentially habitable planet per GALAXY, that's still 10 million intelligent civilizations.
I would start with the assumption that there is life throughout the ageless timeless universe and we are not Gods special creation although the universe might be.
Forgot about this article so soon?
Besides, in ten years we'll be using quantum computers communicating instantaneously with entangled electrons. How will anyone "out there" detect us?
SETI is like Roman astronomers peering into the night skies searching for signal fires. They'd be using the latest technology. How long did Humans use signal fires? A few thousand years at most. The Roman astronomers probability of success searching for signal fires, like ours using radio, would be zero.
It's not instantaneous, is it? (I would be extremely surprised and excited by the possibilities if this were the case) I'm under the impression that much like gravity, effects propagate no faster than the speed of light.
"spooky effects at a distance"
Instead of calculating the odds of life forming "out there," calculate the odds of the human eyeball evolving. Which parts came first? How about the "simple" single-celled organisms? How did those first ones survive the "primidoral soup"? Amino acids don't equal life.
What IS the speed of light? Since we now calculate the speed of light based on visual measurements, we're defining light's speed by the speed of light. That's the reason the speed of light has remained constant in recent history.
Time is based on light, and light is based on time; this sounds much like the circular reasoning behind dating fossils by strata and then strata by fossils.