Is there anybody out there?

Apr 16, 2008

Is 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

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User comments : 15

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2.3 / 5 (6) Apr 16, 2008
Rubbish. Bollocks. Garbage In, Garbage Out.

I commend his hard work on his formula, but it is far from complete and answers nothing.
3.5 / 5 (4) Apr 16, 2008
I'm not sure I follow his logic. If the chance of intelligent life forming is less than 0.01% in four billion years, that means for every 10,000 planets that have a habitable life of 4 billion years, you'll develop life on one of them, on average.

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.
4 / 5 (5) Apr 16, 2008
I used to work on the NASA SETI project. The calculations about how many intelligent species exist have always been replete with open guesswork and speculation. The original idea of the calculations was merely to demonstrate that life was worth looking for. Watson's paper is slightly interesting (similar calculations were made decades ago), however the "Garbage In, Garbage Out" comment is valid -- especially because readers are likely to be mislead by the Watson's statements. Among the "flaws" in his assumptions are certain to be that we have very little idea of how other forms of intelligent life might evolve.
3 / 5 (4) Apr 16, 2008
I think they are assuming this is based on Earth like planets specifically.
2 / 5 (4) Apr 16, 2008
What a small to mind to think that his equation describes the proliferation of life in the universe.

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.
1.8 / 5 (4) Apr 16, 2008
If time and space is infinite, there is only the 100% probability that we are not the only intelligent beings to HAVE existed. To discover any accurate probability, we must first understand the size of time and space. To presume understanding, only displays ignorance. To presume non-understanding, displays the ability to learn.
4.3 / 5 (3) Apr 17, 2008

Forgot about this article so soon?
4.3 / 5 (4) Apr 17, 2008
The other silly mistake, imo, is that he acts as if sentient beings will die when their planet's environment gets mean (over the millennia). Perhaps someone should point out certain abilities that smart beings have that might help them overcome those difficulties, like artificial environments and space travel.
5 / 5 (1) Apr 17, 2008
We are in an old arm of our galaxy. We have an old star for it's type. We are in the last quartile of life on our planet. If we consider just earth like planets around earth like suns, WE are likely to be the "elder race." And we've had interstellar communications capabilities for only a hundred years or so. The probability of finding nearby, similar, intelligent life at our stage of development or higher is slim indeed.

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.
not rated yet Apr 17, 2008
Besides, in ten years we'll be using quantum computers communicating instantaneously with entangled electrons.

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.
not rated yet Apr 17, 2008
No, its not instantaneous--still speed of light.
not rated yet Apr 17, 2008
Entanglement creates instantaneous effects.
"spooky effects at a distance"
not rated yet Apr 17, 2008
Look up EPR, Alain Aspect, John Bell. The action can be thought of as occurring instantaneously if you like, but it precludes information being sent faster than light. The 'faster than light' way of looking at it can be moderately useful in a hand-waving sort of way, but unfortunately it can be extremely misleading.
not rated yet Apr 19, 2008
It's funny how the supposed "evolution" is simply accepted now, even though there is less evidence for it and more evidence against it since Darwin wrote his incredibly racist "Origin of Species."

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.
not rated yet Apr 19, 2008
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.

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.