Is there anybody out there...

Hi.  It's been a while. Sorry about that, I've not really  had anything worth saying for a while (like that's ever stopped me before!).  But, here I am!  I'm sitting watching 'Through the Wormhole, with Morgan Freeman' on Discovery (you are reading this in Morgan Freeman's voice now, aren't you. That's ok, I'm trying it in his voice, so it's all good), and it's talking about the possibility of sentient life elsewhere in the universe.   Unsurprisingly, it's widely believed amongst astrophysicists that it's a nailed on certainty that there is life elsewhere in the universe. In 1960 an astrophysicist named Frank Drake came up with an equation designed to estimate the number of extraterrestrial civilisations which may be out there.

The formula he designed is:

Now, I'm not going to lie, that means absolutely nothing to me.  Fortunately... Wikipedia to the rescue!

R^* = the average rate of star  formation per year in our galaxy

f_p = the fraction of those stars that have planets

n_e = the average number of planets that can potentially support life per star that has planets

f_ℓ = the fraction of the above that actually go on to develop life at some point

f_i = the fraction of the above that actually go on to develop intelligent life

f_c = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space

L = the length of time for which such civilizations release detectable signals into space

So, are we any the wiser? I'm certainly not! So, I'll summarise the summary I read - even at it's most conservative, the Drake Equation hypothesises that there are tens of thousands of civilisations in our own galaxy - if you applied it to the universe at large, well, the number could be so large as to be essentially meaningless (sadly, a bit like my waistline!).

I've had an interest in space for as long as I can remember.  I had a little telescope that I would pack up, take it into the forest behind where I stayed (it was a more innocent time back then!), because there was a hill in the forest which was clear of trees at the top, so when it was a clear night, not too cold, I'd wrap up and go an stargaze for a while. Good times.

I don't believe in a lot of things - I don't believe in ghosts, telekinesis, religion, the flying spaghetti monster, that aliens have visited earth, but I do believe there is intelligent life elsewhere in the universe. I also believe that telepathy is theoretically possible (if you think about it - brain activity is essentially electrical, therefore it's a reasonable assumption that thought is like an electrical signal, or a radio signal, with each of us having our own unique 'frequency' - there's a good chance that some people either share 'frequencies' or can adjust theirs, but that's a topic for another time!).  So, back to the ET thing...

You will note that whilst I said I believe in the probability of intelligent life in the universe, I don't believe they have visited Earth. There is just nothing out there to support that argument. There is no clear evidence of any kind of visitation, there are no planets within hundreds of light years which are even vaguely close to being considered potential candidates for life, and given that light speed is apparently an immutable limiter of the universe, it's going to take our ET neighbours hundreds, if not thousands of years to make the trip.  Are they really going to come all this way just to shove a probe up the backside of 'Cletus from Kentucky' (or Shug fae Ballingry)?  I find it very unlikely. I also find it unlikely that we are going to  have any visitors any time soon, if ever.

There is, however, a school of thought that the seeds of life on Earth were, themselves, extraterrestrial in origin. The theory is called 'panspermia' and it suggests that the primordial organic substances were brought to Earth on one, or many, of the meteorites which peppered the incipient Earth.  It sounds far fetched, but there appears to be evidence to support the theory - meteorites have been found to have organic substances in their core. For example, the Murchison meteorite, discovered in Australia in 1969 was found to contain both common and uncommon amino acids (which, convention dictates I must now call 'the building blocks of life'), whilst in 2009 an amino acid glycene was found in a comet by a probe.

So, next time you are out looking at the stars, stop for a second, look up, and wave - you never know who might see it - in a few thousand years time!