Probability of ET Life Arbitrarily Small, Say Astrobiologists
The Drake equation is one of those rare mathematical beasts that has leaked into the public consciousness. It estimates the number of extraterrestrial civilisations that we might be able to detect today or in the near future.
The equation was devised by Frank Drake at the University of California, Santa Cruz in 1960. He attempted to quantify the number by asking what fraction of stars have planets, what fraction of these might be habitable, then the fraction of these on which life actually evolves and the fraction of these on which life becomes intelligent and so on.
Many of these numbers are little more than wild guesses. For example, the number of ET civilisations we can detect now is hugely sensitive to the fraction that destroy themselves with their own technology, through nuclear war for example. Obviously we have no way of knowing this figure.
Nevertheless, many scientists have attempted to come up with a figure with estimates ranging from a handful of ET civilisations to tens of thousands of them.
Of the many uncertainties in the Drake equation, one term is traditionally thought of as relatively reliable. That is the probability of life emerging on a planet in a habitable zone. On Earth, life arose about 3.8 billion years ago, just a few million years after the planet had cooled sufficiently to allow it.
Astrobiologists naturally argue that because life arose so quickly here, it must be pretty likely to emerge in other places where conditions allow.
Today, David Spiegel at Princeton University and Edwin Turner at the University of Tokyo say this thinking is wrong. They've used an entirely different kind of thinking, called Bayesian reasoning, to show that the emergence of life on Earth is consistent with life being arbitrarily rare in the universe.
At first sight, that seems rather counterintuitive. But if Bayesian reasoning tells us anything, it's that we can easily fool ourselves into thinking things are far more likely than they really are.
Spiegel and Turner point out that our thinking about the origin of life is heavily biased by the fact that we're here to observe it. They point out that it's taken about 3.5 billion years for intelligent life to evolve on Earth.
So the only way that enough time could have elapsed for us to have evolved is if life emerged very quickly. And that's a bias that is entirely independent of the actual probability of life emerging on a habitable planet.
"In other words, if evolution requires 3.5 Gyr for life to evolve from the simplest forms to sentient, questioning beings, then we had to find ourselves on a planet on which life arose relatively early, regardless of the value of [the probability of life developing in a unit time]," say Spiegel and Turner. #
When you strip out that bias, it turns out that the actual probability of life emerging is consistent with life being arbitrarily rare. In other words, the fact that life emerged at least once on Earth is entirely consistent with it only having happened here.
So we could be alone, after all.
That's a sobering argument. It's easy to be fooled by the evidence of our own existence. What Speigel and Turner have shown is the true mathematical value of this evidence.
Of course, that doesn't mean that we are alone; only that the evidence can't tell us otherwise.
And if the evidence changes then so to will the probabilities that we can infer from it.
There are two ways of finding new evidence. The first is to look for signs of life on other planets, perhaps using biogenic markers in their atmospheres. The capability to do begin this work on planets around other stars should be with us in the next few years.
The second is closer to home. If we find evidence that life emerged independently more than once on Earth, then this would be a good reason to change the figures.
Either way, this debate is set to become a major issue in science in the next few years. That's something to look forward to. - technologyreview
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Unexplained sighting at Daytona Beach, FL
I was vacationing in Daytona Beach sitting on the shore of the ocean July 24th 2011 at 3 in the morning. I started getting a creepy feeling about being in the ocean with sharks and stuff at night and was trying to figure out if they would be more active at night. After a lot of deliberation I decided to get out and go sit with the other people I went to the beach with. I was with my sister Rachel, her friend Kenley, and someone that was a friend of a friend named Jess who lived an hour from this spot. All of us saw this. After I sat down with them, my sister started freaking out because a huge roach was running all over her legs. We were all laughing at here and I looked out over the ocean as we had been doing prior to that and noticed what at first appeared to be a lantern. It was a distant bright orange light that was pretty far off in the distance over the ocean. I thought it was some boat that was coming up closer to shore because a storm had just went through. I said out loud to everyone else, "What the hell is that?" and everyone just sat there staring at it. It slowly moved across the ocean and lined up straight with us which would have made this thing if floating on the ocean go against the current. It wasn't bobbing so it would had to have been a massive boat. But someone said something about how bright it was and almost as if on cue it seemed to get brighter. It started getting bigger and by the end of this part of the sighting it almost looked like the moon fell and started floating on the ocean. It was crescent shaped and had another piece right above it and looked like something was in front of it but it was fairly bright outside for it to be as late as it was and I didn't see anything near this thing. I attempted to take a picture of it but this thing wasn't picking up on my camera. It sat in front of us for quite some time before it started to lift in the air very slowly. When it lifted (about an inch from my perspective) off the water line it started shrinking rapidly and ended up the size of a star that you would normally see on a clear night. Then in the blink of an eye it shot up into the sky. By the end of all this I was so overwhelmed that my eyes started watering and I couldn't say anything but, "What the hell was that!". All the ladies I was with started screaming and were as excited as me. - MUFON CMS
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Close encounter of the unknown beings
March 1979: Arrived at Joshua Tree National Monument on a Friday evening to camp and do some rock climbing for the weekend. It was very windy and cold and the sun had set. We set up camp with a small 2-man tent (without windows)and were sitting inside discussing what to do about dinner since it was too windy to light the camp stove.
We had only been in the tent about 10 minutes when a soft whirring (hard to describe) sound flew directly over the tent and stopped what sounded like 20 to 25 feet away. As we looked at each other, asking simultaneously "did you hear that", we could hear foot steps approaching from the direction the strange noise had stopped. They were clearly discernible as bipedal walking on the decomposing granite as it came toward the tent. The foot steps circled the tent twice and stopped at the zipper door and proceeded to sniff the entire zipper (the door was an inverted T). Then nothing. I probably don't need to say we were thoroughly frightened out our wits.
Not exactly sure how long we sat listening but seemed like forever that we sat waiting for that door to open or at least hear more footsteps but we heard nothing. Finally whispering to each other we decided to make a run for the car which was only 10 feet away.
We unzipped the door and ran on the count of three, jumped in the car and locked the doors. We turned on the lights and looked around and saw nothing. After we calmed down, we got out the flashlights and started looking around for anything including footprints, there were only ours from setting up the tent. We headed out the direction that the sound came from and the only thing we found was a set of three round depressions in the gravel approximately 10-12 feet apart in a triangular pattern, also with no footprints around them.
Don't really know what to think. - MUFON CMS
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Man attempts DIY hernia surgery using butter knife and lit cigarette
A man is recovering in hospital after attempting surgery on himself using a butter knife.
Police say the 63-year-old Glendale man cut into himself with a six-inch butter knife in an attempt to remove a protruding hernia from his stomach.
The unnamed man was found on Sunday and taken to Los Angeles County-USC Medical Center.
According to Sargent Tom Lorenz, Police who arrived at the man's house came across a gruesome scene.
The man was found lying naked outside on a lounge chair with the handle of a knife protruding from his stomach.
Amazingly, as they waited for paramedics to arrive, the man pulled the knife out and shoved a cigarette inside the open wound.
Speaking to the Glendale News Press, Sargent Lorenz said the man's wife told him her husband had 'become frustrated' with the hernia and 'wanted it out'.
He added: 'Out of frustration, he tried to cut it out.'
Speaking to the paper, surgeon Sam Carvajal said the DIY surgery had probably caused more harm than good.
He said: 'It is absolutely impossible for someone to fix their own hernia.'
Dr Carvajal said most hernia patients don't actually suffer that much pain, leaving him to conclude the patient was suffering, 'some amount of psychosis.' - dailymail
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