Number of alien worlds quantified..

Number of alien worlds quantified

We are likely to be listening for a long time, even if there are many worlds
Intelligent civilisations are out there and there could be thousands of them, according to an Edinburgh scientist.

The discovery of more than 330 planets outside our solar system in recent years has helped refine the number of life forms that are likely to exist.

The current research estimates that there are at least 361 intelligent civilisations in our Galaxy and possibly as many as 38,000.

The work is reported in the International Journal of Astrobiology.

Even with the higher of the two estimates, however, it is not very likely that contact could be established with alien worlds.

While researchers often come up with overall estimates of the likelihood of intelligent life in the universe, it is a process fraught with guesswork; recent guesses put the number anywhere between a million and less than one.

"It's a process of quantifying our ignorance," said Duncan Forgan, the University of Edinburgh researcher who carried out the work.

In his new approach, Mr Forgan simulated a galaxy much like our own, allowing it to develop solar systems based on what is now known from the existence of so-called exoplanets in our galactic neighbourhood.

These simulated alien worlds were then subjected to a number of different scenarios. If alien life forms do exist, we may not necessarily be able to make contact with them, and we have no idea what form they would take

Duncan Forgan
Edinburgh University

The first assumed that it is difficult for life to be formed but easy for it to evolve, and suggested there were 361 intelligent civilisations in the galaxy.

A second scenario assumed life was easily formed but struggled to develop intelligence. Under these conditions, 31,513 other forms of life were estimated to exist.

The final scenario examined the possibility that life could be passed from one planet to another during asteroid collisions - a popular theory for how life arose here on Earth.

That approach gave a result of some 37,964 intelligent civilisations in existence.

Form and function

While far-flung planets may reduce uncertainty in how many Earth-like planets there are, some variables in the estimate will remain guesses.

For example, the time from a planet's formation to the first sparks of life, or from there to the first intelligent civilisations, are large variables in the overall estimate.

For those, Mr Forgan says, we will have to continue to assume Earth is an average case.

"It is important to realise that the picture we've built up is still incomplete," said Mr Forgan.

"Even if alien life forms do exist, we may not necessarily be able to make contact with them, and we have no idea what form they would take.

"Life on other planets may be as varied as life on Earth and we cannot predict what intelligent life on other planets would look like or how they might behave."




http://news.bbc.co.uk/1/hi/sci/tech/7870562.stm

Ughh, I'm surprised they were able to slip that into a journal article.

The number of alien civilizations really can't be estimated with any accuracy. It's all based on guesswork, and to pull out a number like 361 is just silly. You could just as easily end up calculating that there's no life in the galaxy, or life on every second star. The problem is that we really don't know how easy it is for life to start, and without that we can come up with any number we like.

That said, it's still fun to speculate. I'm just surprised they actually put those numbers in a journal.

Seems like I read or saw something the other day where scientist had put everything together to create life in an experiment and had created something. But if we did put things together and found out how easy or hard it would be, couldn't that give us a clue as to the likelihood of life on other planets?

Looking at it from a creationist or a scientific stand point, it's hard to believe what we have here on Earth is it as far as life.

Creationist: Why would God only incubate one pee-tree dish? (Cute metaphor huh? )

Scientist: With all the planets, stars, solar systems in the universe, even if the odds are that of a lottery, how can it be that we are the only winner since the big bang?

CarolinaHound wrote:Seems like I read or saw something the other day where scientist had put everything together to create life in an experiment and had created something. But if we did put things together and found out how easy or hard it would be, couldn't that give us a clue as to the likelihood of life on other planets?

Yeah, I think he created some amino acids or something, which are the building blocks of proteins. It was a big step in the right direction.

Looking at it from a creationist or a scientific stand point, it's hard to believe what we have here on Earth is it as far as life.

Creationist: Why would God only incubate one pee-tree dish? (Cute metaphor huh? )

Lol. I like that. I've often wondered why a creationist thinks god created such an enormous universe (100 billion stars in our galaxy alone) and all for the sake of us, here on Earth, who are going to face the rapture before we ever colonise another planet anyway.

Scientist: With all the planets, stars, solar systems in the universe, even if the odds are that of a lottery, how can it be that we are the only winner since the big bang?

The thing is, though, that the odds may be much worse than even the lottery. It's possible that it's so hard to create life that it's only ever happened once, and even that was a fluke. Who knows? It would be kind of depressing if that turned out to be the case, if we were the only ones in this universe.

It would be sad if we are the universe has to offer in the way of life. Rather depressing.

Kazza wrote:Ughh, I'm surprised they were able to slip that into a journal article.

The number of alien civilizations really can't be estimated with any accuracy. It's all based on guesswork, and to pull out a number like 361 is just silly. You could just as easily end up calculating that there's no life in the galaxy, or life on every second star. The problem is that we really don't know how easy it is for life to start, and without that we can come up with any number we like.

That said, it's still fun to speculate. I'm just surprised they actually put those numbers in a journal.

Isn't it true to say that in many areas of physics, the best you often have is guesswork, albeit educated guesswork?

I am sure you can think of a number of examples when this would apply.

CarolinaHound wrote:It would be sad if we are the universe has to offer in the way of life. Rather depressing.

Would it?

Why?

It would make all life unique, and that would be pretty amazing, anyway, no?

From a creationists view, I heard one speculate that the creator(s) had in fact chosen three planets were they thought life was sustainable.

Apparently there are vague ref's to the search for a suited planet for life, mentioned in the bible. Something about god saying 'the soil/earth was good'...

Anyway, the idea is that on these three planets, there is a sort of race going on. The population which 'wins' shall have all the secrets of the universe revealed to them.

Sounds like another empty incentive.

The Ghost Of Yeah Well Fi wrote:

CarolinaHound wrote:It would be sad if we are the universe has to offer in the way of life. Rather depressing.

Would it?

Why?

It would make all life unique, and that would be pretty amazing, anyway, no?

All life is unique anyway. Even each individual life. A beings life is like a fingerprint, none exactly a like. Each life has it's own little twists and turns.

So what would there to be depressed, as you said?

Just that I aways wanted to wake up to seeing a lizard woman or something in my window. I've always had a thing for those green and blue alien women on Star Trek. If there aint no aliens that aint likely to happen... Unless kazza and his boys get jiggy with those amino acids and make some sort of boogie woman.

CarolinaHound wrote:Just that I aways wanted to wake up to seeing a lizard woman or something in my window

Get some Peyote.

And Salvia.

Your dreams shall come true.

The Ghost Of Yeah Well Fi wrote:

CarolinaHound wrote:Just that I aways wanted to wake up to seeing a lizard woman or something in my window

Get some Peyote.

And Salvia.

Your dreams shall come true.

Na, last time I did that i woke up with a werewolf woman.