Did The Sky At Night Solve The Drake Equation Paradox?

[Colmc54]

The episode 'Playing with a clockwork universe' can be viewed on the Sky at Night web site, just not yet according to my latest check. In the programme it emerges that our Sun has travelled around a thousand light years from where it formed. The astronomer also said that as well as the evidence from study of the proper motion of galactic stars that supports the above, the make-up of stars (aka metallicity -obtained from stellar spectroscopy) makes the Sun unique among our galactic neighbours.

The Drake equation is 'a probabilistic argument used to arrive at an estimate of the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy'.

The paradox is that so far we have heard no alien communications from other advanced intelligent species in our galaxy.

Could it be that the reason we haven't is because we have travelled so far away from our sibling stars and are now surrounded by neighbouring stars that lack the elements, a long list of which are vital for the evolution of intelligent life?

Maybe if we survive and keep listening for another thousand years might we begin to hear from other worlds?

[jomifl]

As Earth is the only planet that we know of that bears intelligent life we really don't know what spectrum of chemicals is necessary for the evolution of intelligent life. Perhaps the reason that we haven't heard from our neighbours is that they are talking too quietly or target their radio comunications too precisely for us to detect.

[bibblebub]

it will be interesting to see what new data is obtained about KIC8462852 in the new year

[Jonathan-Joe]

Drake's equation did not consider the distribution of various types of star around he galaxy (possibly it could be tweaked for different areas). This, even though Drake would have been aware of (for example) Population I and Population II stars. So his estimate is as valid as ever for the galaxy as a whole.

[Colmc54]

Thanks. I was actually going to say 'as we know it' at the end of the fourth paragraph!

Yet we have learned a lot about the elements essential for evolving an organism possessed of a brain advanced enough to discover how to invent space communication and develop the technology to enable it.

The probability of life, let alone intelligent life evolving, is highly unlikely if metals like Cobalt, Manganese, Selenium... aren't there to be included in the enzymes and coenzymes that are responsible for making them perform their vital roles. http://sciencelearn.org.nz/Contexts/Just-Elemental/Science-Ideas-and-Concepts/The-essential-elements

[Colmc54]

Regarding KIC8462852;

http://www.space.com/30855-alien-life-search-kepler-megastructure.html

Has anyone measured the metallicity of the star yet?

[jomifl]

We can only speculate as to what elements are necessary for the development of life. Under different conditions such as pressure and temperature it is anybody's guess. I suspect that organisms on Earth evolved to use what was available and elsewhere they would do the same.

[Colmc54]

I'm not so sure. Life here exists n all kind of extremes but only if the organic chemistry can evolve into biochemistry and then life e.g. extremophile bacteria.

It might make for good science fiction but I wonder what other element other than carbon could form the backbone of all the molecules that need to behave the way they do to create life, whatever the temperature or pressure.

Has any scientist proposed a plausible substitute for carbon? I remember an old episode of Star trek when they discovered sentient rocks i.e. silicon based life hmm I'm sure there's a joke in there somewhere.

The only kind of non-carbon based life we might be likely to hear from out there could be self- replicating and evolving AI descendants originally created by intelligent organic life-forms.

If we last long enough we might even be able to stop killing each other for long enough to put a few out there ourselves!

[jomifl]

Life elswhere in the universe might exist in scales of time and space quite different to life on Earth. If that is the case the elements apparently necessary for life on Earth might be inappropriate.

[Colmc54]

I suppose that as long as there remain gaping holes in our understanding of the Universe, there is a case for not ruling anything, however implausible it may seem to to us at this time.

However there is also a case, when large financial commitments are being made by governments in the search for evidence of ET life, for at least for now confining ourselves to looking for evidence for the only type of life we can be sure exists and thus is more likely to be discovered.

[Old_Geezer]

I'd have to go look up details but I don't think there is a paradox is there ? IIRC most of the stuff in the equation were estimated/guessed and could be way off.

[EDDIE51]

Colmc54, Carbon is the ONLY Element that can form the long chains necessary for the complex compounds that are needed to make life .
Any life anywhere in the universe will have to be Carbon based.

[Colmc54]

Well thanks for agreeing with me.

Also I have read of our failure to detect extraterrestrial communications from other civilizations being referred to as the Drake equation paradox. In one book on famous equations it states that some have suggested that the reason for the silence is in the equation itself where one of the terms relates to the probability that an advanced civilisation will develop nuclear/thermonuclear or other such weapons of mass destruction and having used them will become set on a course leading to extinction and not the stars.

[Colmc54]

Sadly the Sky at Night episode in question is still not available to view on their website. Earlier in the episode there was a feature on astrology that may have led to it being pulled after complaints from astrologers.

There is more but here's a lead to a clip on my phone from the night of the broadcast. https://www.flickr.com/photos/124207905@N04/21881236953/in/dateposted/