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comment by kleinbl00
kleinbl00  ·  4551 days ago  ·  link  ·    ·  parent  ·  post: The Light of Alien Cities
I read an article over 20 years ago that held forth that if we really were looking for ET, we needed to be looking at laser light in the visible range since that's what any sensible civilization would do. Hell, 35 years ago Niven and Pournelle put that idea forth in "The Mote in God's Eye."

I read an article 10 years ago that said "well duh lasers are passe we should be really looking for pulsed microwave emissions."

It might have been Seth Shostak who pointed out that SETI is one of the most "fashionable" sciences, in that it's driven by whatever the prevailing fashion is at the time. Percival Lowell, for example, was looking for canals on mars not just because he didn't bother to look up the Italian word "canali" but also because big damn canals were the engineering marvel of his era. So yeah. I'm right there with ya when you point out that this article is about looking for space LEDs.

At the same time, it's a "free" search. You don't need extra gear and you can piggyback on existing or proposed telescope missions. There are two parts to observation: "what are we looking at" and "what are we looking for." The "at" is booking time, but the "for" means "which instrument package do we strap on" at worst.

I read an interesting article in Scientific American a couple years ago about searching for extraterrestrial flora. The author pointed out that with next generation scopes we could theoretically be able to detect life on other planets simply by looking for that star's equivalent of "chlorophyll green." The trick, according to the article, was in knowing what color that would be depending on the star.

It's all spectra, after all. It just depends on what you do with it.





mk  ·  4551 days ago  ·  link  ·  
Yeah. You would think that given our rate of development, we might be a bit more adventurous with our extrapolations. Then again, a large contingent of us believe that this entire universe was created for us.

One thing that really excites me about SETI are the possible surprises that await us. If we are lucky enough to detect other intelligence out there, I am certain that we will have to do some serious reassessing of our current situation.

That's why even though this hypothesis seems misguided, I am all for collecting more information on extra-solar systems and planets. Every bit of data is a clue, and we'll probably find valuable information where we didn't expect it. Even the lack of a signal is good data.

kleinbl00  ·  4551 days ago  ·  link  ·  
I wouldn't mind seeing the whole thing re-assessed from a non-idiotic point of view. The fact that the foundation for SETI is the Drake Equation robs them of credibility in my opinion.
mk  ·  4551 days ago  ·  link  ·  
Yes, I always thought the Drake equation was pretty much worthless.

It is interesting that SETI just looks at the hydrogen line frequency. At least they did last time I checked. http://www.setileague.org/askdr/hydrogen.htm But IMO the reasoning for that is a bit better than city lights.

kleinbl00  ·  4551 days ago  ·  link  ·  
Well that was a fucking wormhole. From hydrogen emission lines to the Wow! signal to pulsars mistaken for SETI contacts to a Joy division album and then back to refresh myself on the Kardashev scale.
Jay  ·  4547 days ago  ·  link  ·  
Using lasers for star to star comms.... you have to be able to aim and hold your laser pointer at where the receiving planet will be in (insert X number of years hence here), with a degree of accuracy requiring not only knowledge of where that star is gonna be when your beam gets there, but also where in its orbit the receiving planet is gonna be at that time, cuz unless you up the output power to type II levels to afford a less focussed beam that's still detectable, you're gonna have a beam narrow enough that you won't be able to fill an orbit, much less a whole planetary system. This is accuracy so damn perfect we can't even approach it. But again, coherent light seems to be a pretty obvious thing to look for out there, just in case, don't it?
mk  ·  4547 days ago  ·  link  ·  
I think everything is worth looking at. But I bet if there is interstellar communication, we aren't privy to the medium yet. If we found a way to communicate that was much better than what we currently have, I am sure that we would send signals with this new medium. And, as any improvement will probably be of higher fidelity, lower energy, and possibly faster, we wouldn't bother with flashing laser lights.
kleinbl00  ·  4547 days ago  ·  link  ·  
I'll bet coherence is a real bitch to hold over light years of interstellar hydrogen.