It would also be rather a shame if the galaxy's 100000 sentient species were all listening and not broadcasting.
Andy
That could be a possibility. If they are likely to exist.
Regarding SETI, DG seems to be confusing the SETI@Home Project with any search for ETI. SETI is the generic name for the search and has been ongoing since the early 60's if one only considers an organised search for electromagnetic signals. Its a bit facieous (sorry spelling!?) to suggest SETI has only been ongoing since 1999 as that is patently not the case. EVEN UC Berkley couldnt subscribe to that premise.
I've been looking at my SETI@Home account, I registered in 2002. I have to admit I stopped frequently doing the SETI number crunching a couple of years ago when I started to do more research into astrobiology and the possibility of intelligent civilisations out there. At first, my faith in ETI was very strong especially due to the WOW! signal.
But, one only has to consider the SETI 'farm' of headless pc's that DG ran to show how almost futile SETI@Home is. Consider this example;
20 headless pc's presumably running 24/7/365. If one assumes SETI@Home only sent each of the headless pc's one unique data packet per day, over a period of the nearly 10 years subscribed to the project, that means crunching almost 200 years worth of data ie 1 data packet per pc (20 pc's) per day times 10 years.
Now, a headless pc used solely for SETI@Home and not using its processing power for anything but that, should be capable of completing at least 2, 3 or 4 SETI data packets per day. Let's be conservative and say each headless pc did 2 SETI data packets per day and that each of these data packets were unique to each of our headless pc's ie one of the headless pc's in this group was not checking a SETI data packet one of the other pc's was or had already worked on.
This means almost 400 years worth of data has been crunched ie 2 data packets per pc (20) per day times 10 years. If the headless pc's managed 3 data packets each per day, you would be looking at getting on for 600 years of data.
So, in this example, we have a lower assumption of 200 years of data searched upto an higher assumption of nearly 600 years worth of data. In other words, using a single pc would have taken from, say, the year 2000 to 2200 or 2600 for the top end of the scale.
Yet despite this not a single verified SETI signal has been found in that data. Not only that, this example of headless pc's isnt rare. SETI@Home are not keen on the multiple headless pc approach used by a number of people in the project partly due to the 'credits' they give out. However I dont really see their objection as it gets far more data crunched than if each person only had one pc doing the work.
And yet still SETI fails to find a verifiable candidate despite these multiple headless pc's and other users. The nearest it has got is one signal SHGb02+14a which SETI@Home itself discounts.
Taken in this context and with people leaving the project due to disillusionment at finding nothing, its easy to see why SETI@Home resorts to sending begging emails to users no longer in the project and asking them to return.