While SETI is busy searching for signals from alien civilizations, there are scientists who think we can find proof of advanced extraterrestrial life much closer to home - namely in our DNA!
The downside with leaving behind alien artefacts is that they will not survive for millions of years. A coded message hidden in our DNA, on the other hand can be saved for a very long time.
The coded message would only be discovered once the human race had the technology to read and understand it.
This unusual and thought provoking idea comes from Professor Paul Davies, from the Australian Centre for Astrobiology at Macquarie University in Sydney.
Paul Davies is not very supportive of SETI. Davies believes it is wrong to assume that extraterrestrials who may be hundreds of millions of years ahead of us technologically will have chosen to communicate by radio. There are other means of communication, he point out.
So, what future technologies might enhance the search for extraterrestrials?
"I think we need to get away from the idea of leaving this to a small and heroic band of radio astronomers and try and spread the burden across the entire scientific community. I think all the sciences can contribute, and I'll give you some examples.
It could be their machines or their probes or robots or something of that sort that they could well have come a very long time ago, and in this game you've got to think not in thousands or even millions of years, but hundreds of millions or billions of years, so it's that sort of timescale we have to think on, and the question is, would any trace remain of alien activity, say in our solar system, after-let's pluck a figure out of midair-100 million years?
If you came back in another 100 million years from now would any trace of human activity remain?
The answer is not very much, but there are some things that we could look for.
If ET did pass through the solar system obviously didn't stop for 100 million years what would we find?
Well there are some things like nuclear waste. If you dumped nuclear waste that will certainly survive for that length of time. We could go look for that. Any sort of large scale mining or quarrying activities would leave scars although they might be buried beneath rock strata would still be discernible to a geologist doing a survey. We could look for that too.
And then there is one other idea that is crazy, but it's dear to my heart and this comes back to the message in the bottle concept, so up to now SETI has been involved in looking for messages that are being deliberately beamed at us and as I've explained that's pretty unlikely, but there is another type of messaging of which the beacon is an example.
It's a one way message. When you put a message in a bottle and throw it into the sea you don't think to yourself "Well, I expect a reply."
It's you don't know if anybody is ever going to find it and certainly don't know who is going to find it, so it's just sort of left to its own devices.
Perhas we must look for alien
messages in our DNA.
Well in the same way we might imagine that an alien civilization might
have put a message in a bottle for anyone who might find it
and that anyone could be us, could be human beings, so where is the
bottle and where is the message?
I'm open to suggestions. One idea I've had is that maybe the bottles
are living cells, terrestrial organisms and that the message is encoded
Viruses are continually infecting organisms on Earth and uploading their
DNA into the genomes of those organisms, so there is a well understood
for getting information into DNA. We're littered with it.
Our own genomes have got huge amounts of this junk that has climbed onboard from viruses over evolutionary history, so if viruses can to it ET can do it and it seems to me that we could in addition to scouring the skies for radio waves with a message encoded we could scour terrestrial genomes, which are being sequenced anyway, to see if there is a message from ET encoded in it. You know, it could be some striking string of nucleotide bases, the famous four letter alphabet that is the language of life, the A's, G's, C's and T's in the DNA.
It might just spell out some sort of message that would attract our attention.
Now of course this is a crazy idea.
I'm not actually suggesting that there really is a message from ET in genomes. What I'm saying is that is the type of thinking we need. Maybe it is no more crazy than expecting it to be etched into radio waves coming from the sky," Davies said.
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