I know I shouldn't write about this. I already spent two hours on Friday arguing about the same press release. But some days I just can't help myself.
Here are some thoughts... (in case anyone is bothering to read):
[quote]
The work is reported in the International Journal of Astrobiology.
[/quote]
Never heard of it. It's a Cambridge Journal which on the surface appears to be a good thing. It has only published FOUR volumes, though -- which is next to nothing -- but that has to be weighted against the fact that 'astrobiology', using that word is a relatively new field. E.g. your spell-checker won't recognise 'astrobiology'; it will recognise 'astrophysics'. Unlike most peer-review journals, they don't publish their impact factor. That in turn may be because the journal is too young. It's just call it 'untested'.
[quote]
Even with the higher of the two estimates, however, it is not very likely that contact could be established with alien worlds.
[/quote]
That is one fact that won't be evolving with time or with the new cool observations or simulations: the nearest extrasolar planet that I can find that is likely to be rocky, lies at 100 light-years. So
'high, how are you?'.....
'not too bad, you?' would take >2 typical human lifetimes. Without a strong violation of fundamental physics.
The following two are quite shocking:
[quote]
The current research estimates that there are at least 361 intelligent civilisations in our Galaxy and possibly as many as 38,000.
[/quote]
[quote]
... 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.
[/quote]
The maximum number of planets hosting intelligent life in the galaxy is 38,000 but in the whole Universe the maximum is 1,000,000? WTF? It would imply there are only 26 galaxies in the Universe. A number off by at least 10 orders of magnitude. It
is presented as 'recent estimates', I concede but to present the 2 numbers within 100 words must mean the journalist really can't have thought about what s/he had written.
[quote]
"It's a process of quantifying our ignorance," said Duncan Forgan, the University of Edinburgh researcher who carried out the work.
[/quote]
Indeed it is. I like this line a lot.
Every scientific news article should begin with exactly that statement. To drum it repeatedly into the heads of scientists and non-scientists together. That is exactly what all science is and people would do well to remember that.
[quote]
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.
[/quote]
To be quite clear, he did
not simulate planet formation in a volume the size of our Galaxy. If you put all the computers in the world together and dedicated them to solving that problem, they couldn't do it in a human lifetime. Either the resolution would have to be reduced, or the volume shrunk.
That is anyway unnecessary. You need to know the number of solar-type stars in the Milky Way: that's just 1 line of algebra. And couple an empirical relation about masses and orbital distances of extra-solar planets. It's really hard to see what he did.
[quote]
These simulated alien worlds were then subjected to a number of different scenarios.
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.
[/quote]
That's.... OK. Two scenarios. But it seems to be designed to keep the final number intermediate. Why not make life formation
and evolution both easy? [Because you get as many life-hosts as you get planets...?] Or make both hard? [Because you get zero, and we know there is at least one...?]
Ultimately I have always regarded these kind of numbers as a rather fun by-product of research, but nothing that's important. Certainly nothing that should be driving research directions. It's a bit annoying that they make it to mainstream. I suppose if the public likes it.... But it's only a crack at solving the Drake equation. In which there are still some whacking uncertainties. As is presented, here:
[quote]
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.
[/quote]
Quite. They can really drive the number from zero (OK, 1) to the number of stars. How life started and how it evolved? These are still really out there. In the land of speculation [even if the models are quite appealing]. While some numbers above [e.g. really good statistics on exoplanets] are maybe only 2 decades away, I can't see any way we could nail down statistics on actual life-formation and evolution [Or even figure it out here]. It would take... actually I don't know what it would take. I think we would have to go there...
See? I said nobody would read. If you got this far, send me a message to let me know... Nobody... ? OK. As punishment I will embed he Worlds funniest joke here and you will all have missed it.
I went to the zoo the other day and the only animal they had was one single dog
....
...
..
.
It was a shih tzu
And then I will go and get drunk.
hayes, Feb 7, 2009 @ 21:29
