Upped The Drake Equation...?

[Jack Knave]

Just finishing Nick Lanes book "The Vital Question" and in a footnote he says that "Data from the space telescope Kepler suggest that 1 in 5 sun-like stars in the galaxy have a earth-sized planet in the habitable zone, giving that projected total of 40 billion suitable planets in the Milky Way." for life to start and progress.

That must up the Drake equation?

What he sets out in the book also makes the start of organic life a reasonable possibility.

I also heard on BBC Inside Science radio programme that not only are there the four bases to DNA but they have now created some more and are planning to produce some bacteria adding in these additional bases to the other four, with the hope that they create bacteria to help deal with man's pollution and problems........can't wait 

[Shaker]

Fascinating as all this is, we have to be on our guard against a sort of parish-pump parochialism - Earth-like planets entail Earth-like life, and for as much as we know other forms of life may be very, very, very different to any of the kind with which we're familiar on this one isolated example. Though very considerably less reactive than carbon it's been suggested that ET life could be based on silicon, for example. Far harder to get going, but given a big enough stage and long enough time, does "far harder" really have much traction left in it? I say no. 

Still, we have to start looking somewhere. It's inevitable that we're going to look based on the parameters and conditions with which we're conversant.

[Hope]

Fascinating as all this is, we have to be on our guard against a sort of parish-pump parochialism - Earth-like planets entail Earth-like life, and for as much as we know other forms of life may be very, very, very different to any of the kind with which we're familiar on this one isolated example. Though very considerably less reactive than carbon it's been suggested that ET life could be based on silicon, for example. Far harder to get going, but given a big enough stage and long enough time, does "far harder" really have much traction left in it? I say no.

Seem to remember hearing, on a BBC show perhaps, that there are 5 or 6 possible bases on which life could start.  As you say, silicon is one, but I can't for the life of me remember what the other suggestions were?  Is the idea that Group 4 elements might be the best bet for such developments?

[Jack Knave]

Fascinating as all this is, we have to be on our guard against a sort of parish-pump parochialism - Earth-like planets entail Earth-like life, and for as much as we know other forms of life may be very, very, very different to any of the kind with which we're familiar on this one isolated example. Though very considerably less reactive than carbon it's been suggested that ET life could be based on silicon, for example. Far harder to get going, but given a big enough stage and long enough time, does "far harder" really have much traction left in it? I say no. 

Still, we have to start looking somewhere. It's inevitable that we're going to look based on the parameters and conditions with which we're conversant.

Lane mentions silicon and then pretty much follows you on discounting it.

[Udayana]

So, suppose there were beings on one of these planets with the same level of technology as we have, would they be able to detect signs of life on Earth?

[Shaker]

So, suppose there were beings on one of these planets with the same level of technology as we have, would they be able to detect signs of life on Earth?

Certainly, yes. We've been, in effect, pumping signs of intelligent human activity into space for upwards of a century, in the form of radio waves and (in ye olde dayyes) television signals. These have been expanding in a sphere or shell around the earth ever since at the speed of light; any civilisation within that sphere with the means of detecting such signals - one like ours, as you say - could certainly pick them up.

[Udayana]

Yes, but what about the distance? I don't think any of the earth like planets we have found are close enough to be able to pick up our television signals. We could send/receive strong signals sent for the specific purpose of advertising presence.

Googling, it seems we can now detect water on exoplanets, but will not be able to detect life, assuming it was there, for another decade or so.

 

[Shaker]

Yes, but what about the distance? I don't think any of the earth like planets we have found are close enough to be able to pick up our television signals.

Yes, that's perfectly true - the point I made in my previous post was that any planet within that signal-sphere with technology at least equal to ours would be able to pick up on those signals.