50 Years of Seeking E.T.

[IndianaGreen]

50 Years of Seeking E.T.

It's been almost 50 years since scientists first came up with the idea of looking for radio signals from extraterrestrial civilizations - and although there have been a couple of curious blips, we haven't yet definitively heard E.T.'s cosmic call. Now the experts in the search for extraterrestrial intelligence, or SETI, are wondering whether we've been looking in the wrong places for the wrong kinds of signals.

Or maybe we just haven't been looking long enough.

All of those possibilities are considered in "Confessions of an Alien Hunter," a new book from Seth Shostak, the SETI Institute's senior astronomer.

<snip>

Over the decades, the strategy for SETI has by necessity been dictated by a cosmic Golden Rule: We look for communication in the channels that we use to communicate. A generation ago, that might have been the analog television signals that carried "I Love Lucy" out to the cosmos. Today, Drake speculates that the aliens might be transmitting digitally, with lasers instead of monster radio antennas.

During a weekend talk in Seattle, Drake pointed out that the just-completed National Ignition Facility can focus the light of 192 lasers to create a pulse that lasts just a few nanoseconds but far outshines the sun. "Those lasers can make pulses of light which are visible to very small telescopes all across the galaxy," he noted.

Shostak theorizes that E.T. might have two types of transmitters going: one that flashes such pulses of light toward a long list of target planets that might be habitable - including us - and another "low-power, omnidirectional broadcast that tells you how to join their book club, or whatever." For that reason, SETI searchers have started conducting surveys for those tiny flashes of light as well as for sustained radio traffic.

http://cosmiclog.msnbc.msn.com/archive/2009/05/04/1921655.aspx

[applegrove]

1. I know the odds are against me but I simply do not believe there are aliens out there.

I know the Universe is a gazillion times bigger than I can possibly imagine but I think we are alone. I just do.

[Mz Pip]

2. The distances

are so vast that even if we do get a signal, by time we receive it that civilization may have been extinct for eons.

[applegrove]

3. It is all so unbelievable. I'll buy whatever the scientists say but only up to the point they can

prove it to me.

[Orsino]

7. What do you think is keeping all the other possible planets sterile?

And why do you think it spared Earth?

[applegrove]

8. I'm willing to say there may be "life" on other planets but I just don't think there are thinking

beings who make stuff like radio waves. I'm sure if I talked to a physicist for about two minutes he would change my mind. But I just don't believe in aliens.

[Orsino]

9. Well, same question, then.

What do you think is preventing the development of intelligence on other worlds, and what's our loophole?

[applegrove]

10. I agree the odds are against me. I know that there are gazillions of galaxies out there.

And then there could be life. I go for those odds. But out of the billions and billions of life forms on earth...this planet somewhere develops mammals and then develops apes then humanoid type beings. I just think the odds of that are more remote. I can see evolution taking place on another planet far away. Maybe they would evolve the same lichen as we have here out of all those odds. But out of all the things that evolve on this one amazing planet the odds of it being a thinking, technology using animal have to be pretty small.

But then you say there are even more galaxies. And I still say until some physicist sits me down and lectures me on the err of my ways I just don't believe in aliens. I'm sorry. I have my limits. That is just me.

[Skittles]

5. I'd hate to think we are IT

that is truly a hideous thought :o

[krispos42]

4. Or...

...the aliens have warp drive and don't use interstellar radio communications, but "message sloops" instead because they're dozens of times faster than waiting decades for a radio signal.

[Skittles]

6. awesome read

:thumbsup:

[TZ]

11. Very nice.

I always want to say that if aliens are visiting this planet all the time as many claim, why aren't we picking up any kind of obvious footprint?

[Phoonzang]

12. *sigh* SETI finding nothing means exactly nothing because

1.)Most of our "emissions" dissipate after a few light years. Unless you have very sensitive electronic ears (which we don't right now), you won't be able to detect leakage.

2.)We use spread spectrum technology right now...why wouldn't ET? If you spread a signal out across multiple frequencies, you could intercept one and not get anything from it.

3.)You have to be looking at the right place at the right time. I think Shostak compared it to two hunters firing their rifles in a forest and having the bullets connect. They have to be sending a signal at us at the exact same time we're looking in their direction. This means that they'd have to know we are here....and with the whole dissipation of signals problem, that might not be very likely.

There's many more explanations as to why we're not getting signals but, I'm not going to list them all.

Fact is, the galaxy could be swarming with intelligent life and we'd have no idea, so there's no need to get into all these nihilistic rare-earth and "ohhh we're so very special" theories.