A Friend wrote in rec.arts.tv:
Is that according to only 1970s or 80s research.
A Friend wrote in rec.arts.tv:
Is that according to only 1970s or 80s research.
Four things:
And, for light & quiet reading, I suggest Fredric Brown: The Wavaries, and The Fourth Profession by Larry Niven.
Peter Wieck Melrose Park, PA
Getting into government conspiracies? :)
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It's hard enough to communicate with Voyager when two dishes converge. Horizontally omni broadcast has low energy and complex signals. Forget it.
Greg
I'd always suspected so. But is there any respectable research to back up this figure of 1.5 light years?
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OH, so they are still in anticipation of the Kardashians. Mikek
We know the signal strength (inverse square law), and we know a lot about noise received from space. When the noise is drowning the signal, you cannot receive the signal. So, yes, we know the reception quality for a given transmitter power and distance. To reach twice as far you need 4 times as much power, and as distance increases, you quickly lose that game.
The problem with communicating with Voyager is on the uplink side, not the downlink side. Even at Voyager 1s distance and current power output of a few 10s of watts, in the appropriate spectrum Voyager 1 is a blazing beacon far outshining most other objects of interest studied by radio astronomers.
I think it's possible to do much better than 1.5 light years, if you can make some assumptions about what area of the spectrum you're looking in, and what kind of patterns you're looking for. It's not like there aren't ways to recover periodic signals/signals with structure that have been corrupted by noise.
But these very clever aliens have worked out how to use galactic scale gravitational lensing to survey the comms of lesser inteligencies.
So even if we could do 3 light years, there's still nothing much within that radius that we could expect to communicate with. Why did all that effort go into SETI, then? Surely all the nerds that ventured into that, or granted the SETI nerds spare time on their idling computers to analyse the data obtained from the world's radio telescopes must have known they were wasting their time!
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Bollocks. Lensing more noise/weak signal does not change the ratio, and does not make for better reception. And your lensing works only over millions of light years. Which leaves you micro-micro-micro watts of received power.
I take your point about the scale over which lensing works. But why is the effect not similar to using a high-gain aerial, which is common enough?
Mike.
I think the idea wasn't to scan for ET's version of "I Love Lucy", it is/was to look for much higher power signals, from more advanced civilizations, broadcast with the express intent of alerting systems like SETI.
i.e. not trying to overhear ET's conversations, but listening for trumpet blasts.
Whatever. I appreciate N Cook's suggestion was just a joke which some here seem to have overlooked. The idea is a total non-starter if anyone tried to do it in practice, which I very very very much doubt.
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A suitably advanced gregarious civilization capable of directing "trumpet blasts" like that probably already has sufficiently powerful space-based imaging to directly look the planetary surfaces of any inhabited worlds within say 50 light years down to maybe several hundreds of meters resolution, evaluate the civilizations they see there, and decide whether they look like a species worth contacting, or not.
STILL PRETTY QUIET 'ROUND HERE
If you're going to start using gravitational lensing for your telescope it's probably "easiest" to just directly image planetary surfaces in the area of the visible spectrum. i.e. just literally spy on them visually.
And you definitely don't need millions of light years of distance to leverage lensing, you just need to get your telescope up an out of the Sun's gravity well and out to a focal point of the gravity lens of the Sun itself to get enormous amplification; in the visible spectrum we're talking amplification factors on the order of 10^10.
About a third of a light-year away is where you'd need to be; to get there in a reasonable time (less than a human lifetime) you'd need an engine that could push the carrier vessel up to an average of around 1 million mph.
So all of those specialist scientists who run SETI are completely wasting their time! You should email them ASAP.
-- Shaun. "Humans will have advanced a long, long way when religious belief has a cozy little classification in the DSM*." David Melville (in r.a.s.f1) (*Diagnostic and Statistical Manual of Mental Disorders)
Guys and gals:
PLEASE!! Look up "Pathetic Fallacy".
Now. Apply it to any sort of ET from any sort of source, near or far.
With "Humans" as the objects to which 'feelings' are attributed.
This discussion needs to take place on the level of what actually is, not s ome sort of pseudo-science based on the incredibly arrogant position that a ny sort of ET (again) from any source, near or far, has the slightest thing in common with humans. Repeat, we have more in common with a garden spider than any conceivable ET, from any source, near or far.
Peter Wieck Melrose Park, PA
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** That must be your other name.** Apply literary term to ETs ?
** Not one bit arrogant. ** You have more in common with spider on crack.
Wot a pathetic f****it.
..... Phil
Off your meds again?
Peter Wieck Melrose Park, PA
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