Crowd-Funded Radio Beacon Will Message Aliens 196
astroengine writes "In the hope of uniting people around the globe in a long-duration project to send a radio 'message in a bottle' METI (Messaging Extraterrestrial Intelligence) signal, a crowd-funded project utilizing a refurbished radio telescope in California has begun its work. Lone Signal is a project initiated by scientists, businessmen and entrepreneurs to set up a continuous radio beacon from Earth. To support the operations of the Jamesburg Earth Station radio dish in Carmel Valley, Calif. (a dish built to support the Apollo 11 moon landing in 1969), a crowd-funding effort has been set up so that for a small fee, users can send images to the stars. If you're content with sending a text message, your first message is free. The radio dish's first target is Gliese 526, a red dwarf star 18 light-years from Earth, but the project will be considering other stellar targets believed to be harboring habitable worlds."
I sure do hope.... (Score:5, Funny)
I sure do hope they get this right. It would be a shame if it turned out they created a intergalactic message like this [shutterstock.com].
Re:I sure do hope.... (Score:5, Funny)
Don't worry. I'm just going to send a copy of the book "How to Serve Man"
Re: (Score:2)
That will screw will my plans to base a cookbook on them.
Planetary Resources Arkyd-100 Space Telescope (Score:3)
It's great that Slashdot is giving coverage to the above story, but how come they're not giving timely coverage to the fact that Planetary Resources has announced a new Stretch Goal for their existing Kickstarter campaign:
http://www.kickstarter.com/projects/1458134548/arkyd-a-space-telescope-for-everyone-0 [kickstarter.com]
They're promising that if the new $2M fund-raising goal is crossed, they'll use the extra funds to upgrade their Arkyd-100 Space Telescope to search for exo-planets. This is a fantastic idea, especially gi
Re: (Score:2)
Probably because you either haven't submitted the story or because your submission has been voted down by the readers.
Re: (Score:2)
It's great that Slashdot is giving coverage to the above story...
Hasn't Adolph Hitler beaten them to it by about 80 years?
Re: (Score:3)
Re: (Score:2)
Insightful and hilarious. Thanks!
you joke, but... (Score:5, Insightful)
Fortunately, what with the speed of light being what it is, this shouldn't be of any immediate concern.
Also, I think there's a recent 'obligatory' xkcd that's quite on-topic here if anyone wants to whore some karma. In the what if section.
Re: (Score:2)
> I know he catches some flak for this, but Stephen Hawking has it right.
No he doesn't.
In 10 years you will have proof that a) we are not alone, b) they look very similar to us, c) our fear of _them_ keeps them away as they know the true human potential whereas we are still ignorant & blind.
Re: (Score:2)
Re: (Score:3)
Even the presence of an industrial civilization has been given away by sudden changes in the atmospheric composition over the last 150 years.
It could be that the cleaning up of the mess industrialization caused could be the signal that our brains have ripened enough to be quite the delictable delights for the discerning alien palate. As for nuclear weapons, chances are they would be seen as the equivelant of bows and arrows to any civilazation far enough advanced.
Re: (Score:2)
It could be that the cleaning up of the mess industrialization caused could be the signal that our brains have ripened enough to be quite the delictable delights for the discerning alien palate. As for nuclear weapons, chances are they would be seen as the equivelant of bows and arrows to any civilazation far enough advanced.
Odds are, their palates are rather undiscerning, and we would be more or less like chicken nuggets to them. [youtube.com]
Re: (Score:2)
Though I am a believer in science, I'm not as convinced as you are that our current science has so far exceeded the limatations of our intelict that it is unfallable.
Re: (Score:2)
You're correct that the available weapons have considerable power, and that they render the surface of the earth hazardous where used. I do wonder about the possibility of an advanced space faring civilization having weapons that are more subtle in effect that could be used to their advantage. For example, something akin to the neutron bomb: kills the people, but does far less damage to the ecosystem and infrastructure. There may well be other effects that could be harnessed to produce a similar outcome
Re: (Score:3)
that makes us a pretty formidible foe if push comes to shove.
See, here is where I think many are either failing to see or ignoring/dismissing an important real-world factor.
Given that;
1> Unless they're in some space federation/have regular interstellar contact with others they are just as clueless as we are as to how an alien race might react to detecting them with zero data.
2> Given [1] above, there is realistically a 50/50 chance on whether or not they will react with hostility just as they see the same odds from their side regarding humanity.
3> Given [1]
Re: (Score:2)
I'm not so sure that intentionally and pro-actively revealing our presence is such a great idea.
You are about 129 years to late to be worrying about that.
Unless you find a way to run out 130 light years and disrupt Marconi's transmissions and all that followed, you would be better off trying convince those alien bad guys that we're really a swell bunch of party loving life forms who like fire works. Mostly harmless.
Re:I sure do hope.... (Score:4, Informative)
That is a myth more or less. Those transmissions would be damn lucky to make it to Pluto let alone another star. Maybe to Alpha Centauri if there is a kilometer scale dish there.
Transmitting a signal to another star is non-trivial, uses a huge amount of power, and isn't likely to happen with unintentional leakage. You pretty much have to either aim a beam at a target or have an omnidirectional transmitter with truly immense power.
James Benford, along with his twin brother Gregory Benford (Timescape etc) has written some fascinating papers on the subject from the POV of the sender [arxiv.org] and the receiver. [arxiv.org] Very well thought out stuff and required reading for any amateur METI projects. But this won't be the first intentional METI transmission anyway. Alexander Zaitsev [wikipedia.org] has sent a number of messages at various targets already using a 70 meter radio telescope in the Ukraine. Those were relatively brief transmissions though. This project will be transmitting continuously. A pretty big difference, although one that would only matter to a pathetic, cowardly species.
Re: (Score:2)
A pretty big difference, although one that would only matter to a pathetic, cowardly species.
Pathetic and cowardly species? How about a species whose bottom line is survival in a very big and uncaring universe?
*You* might be willing to bet the survival of all life on Earth on a completely-alien species' good will, that may not even be carbon-based, never mind having an intelligence that shares a sense of right & wrong, with absolutely no evidence, but I'm not so sure everyone else is OK with that. Or should be OK with that.
Here's a thought: We may have already been hit by another intelligent sp
Re: (Score:3)
Any species with the capabilities of "sending big rocks" wouldn't fear dinosaurs and rodents, nor fail to notice that their diabolic plan had failed so miserably.
Re: (Score:2)
Any species with the capabilities of "sending big rocks" wouldn't fear dinosaurs and rodents, nor fail to notice that their diabolic plan had failed so miserably.
They wouldn't even have to know for sure there was even any life. Just pick planets that are likely candidates for life to develop. As long as there is not sufficient time between strikes for life to develop intelligence and a technological civilization, they're safe.
Also, sending a "big rock", as in many miles in size, wouldn't be necessary. When you've got literally centuries to gain velocity, the size of the rock needed to create an extinction-level event decreases dramatically. Humans have the technolog
Re: (Score:3)
It's pretty much inevitable that someone is going to do this on any planet with intelligent life of the sort that can build radio telescopes. Short of a planetwide police state to detect such projects and eliminate them there's really not much that can be done to stop them.
The chances of there being any intelligent life on a star within 100 or even 250 ly are astronomically small and 18 ly is so close that any highly advanced species would probably already have detected the oxygen/nitrogen/methane/water vap
Re: (Score:3)
There is certainly considerable merit in what you write. But allow me to present a different perspective for the sake of the argument. Consider the Fermi paradox [wikipedia.org] and our observations of the universe so far. Although it is known that the universe is a very big place indeed, and it is thought that there must be many potentially habitable planets, in our very early and limited efforts we have yet to detect one apart from earth. It may be that they are rare, which would make life rare. If that turns out t
Re: (Score:3)
Fermi Paradox concludes that we shouldn't even exist, because the aliens should be already here before we had a chance to appear. It's extremely improbable that aliens are common enough for some of them to come here, but still rare enough for none be here already, as the Sun is quite young, and our galaxy could be colonized in just a few millions of years with ships moving in plausible speeds (the kind of speed the project Orion would acheve). Or, TLDR, there is likely nobody out there.
Even then, this thing
Re: (Score:2)
Don't let it bother you because there is absolutely nothing that can be done to stop these sorts of projects. Anyone with a an advanced physics degree can figure out how to build a klystron or gyrotron and a small parabolic antenna based on existing documentation.
I'm not sure why you claim there is no upside. The upside is obvious. Although it is very unlikely we cannot completely rule out the idea of not just life, but intelligent life of the sort that builds radio telescopes living at some nearby star lik
why transmit drivel? (Score:2)
instead of text messages which have no inherent means of even being understood, why not transmit useful information about ourselves that we would wish aliens to send to us: pictures, society structure, arts, science...this was done to limited extent with the "pioneer plaque"; that's the direction we should be thinking
Re: (Score:3)
Re: (Score:2)
How would an alien decode the .jpeg, .bmp, or whatever else we send them.
Let's just send out BluRay streams. Everyone in the galaxy knows that these have to be licensed + players constantly updated, so the aliens will know what to do.
Re: (Score:2)
How would an alien decode the .jpeg, .bmp, or whatever else we send them.
Let's just send out BluRay streams. Everyone in the galaxy knows that these have to be licensed + players constantly updated, so the aliens will know what to do.
In the 18 years it will take for the signals to reach the alien civilization on Gliese 526, the MPAA's reach will include the entire Galaxy, and relations with the alien civilization will be soured when each member of their society is fined $150,000 and extradited to the USA for punishment after receiving the and decoding the movie stream.
Re: (Score:2)
You've got to read Year Zero by Rob Reid. It deals with just this sort of situation only with music instead of movies. Very clever and funny science fiction.
Re: (Score:2)
You don't compress the image, you present pure sequence of pixels with scan line and frame completion markers as on the Voyager Golden Record. Have a look at it, the instructions to "play" the disk are engraved on the disk and are crystal clear even to young teen: I was 13 when I first saw it and system was obvious.
Sure, start things out with your pulses, then go to diagrams and pictures like the Voyager Golden Record
Re: (Score:3)
You don't compress the image, you present pure sequence of pixels with scan line and frame completion markers as on the Voyager Golden Record. Have a look at it, the instructions to "play" the disk are engraved on the disk and are crystal clear even to young teen: I was 13 when I first saw it and system was obvious.
Sure, start things out with your pulses, then go to diagrams and pictures like the Voyager Golden Record
Crystal clear? Really?
http://en.wikipedia.org/wiki/File:The_Sounds_of_Earth_Record_Cover_-_GPN-2000-001978.jpg [wikipedia.org]
Re: (Score:2)
yes, that is trivial to understand the basic binary numbering system employed, play direction, and demarcation of scan line and frames.
what would be hard to comprehend, on the other hand, is that business in lower left quadrant of location of earth by bearing to pulsars.
Re: (Score:2)
yes, that is trivial to understand the basic binary numbering system employed, play direction, and demarcation of scan line and frames.
what would be hard to comprehend, on the other hand, is that business in lower left quadrant of location of earth by bearing to pulsars.
I can't even pick out the 1's and 0's in that top waveform. Are the waveforms below it related to the top one? Why is the first part of the wave a perfect and uniform triangle wave followed by a clear and steady zero-level, then it degrades into a much noisier signal? What do I, I- and II mean? Do I rotate the disk clockwise or counter clockwise to read it?
Re: (Score:3)
oh dear.
I I- II are one, two, three. - is zero
you should now be able to answer the rest of your questions.
Re: (Score:2)
Why is the first part of the wave a perfect and uniform triangle wave followed by a clear and steady zero-level, then it degrades into a much noisier signal?
This knowledge is lost along with the analog television. Clear and steady zero level is blanking interval, and the "noisier signal" is the analog video of the scan line.
If you rotate the disk backward you will get the image flipped, and the sequence of the frames inverted (assuming that the recording is done in a spiral, and thus has only two ends
Re: (Score:2)
Who decides what's "useful"? How do you fund it?
This project solves BOTH of those problems at once.
The same scientist(s) who came up with the "hailing message" with enough basic information to help the Aliens decode and understand the message.
What good is sending thousands of random tweets? What are the aliens going to be with messages like "I luv aliens" and "f1rst post!". Even sending the contents of a random novel would be better since it would give a coherent sample of text that aliens could analyze to try to learn our language -- sending a large body of unrelated short messages (in multiple language
We should stop this (Score:5, Interesting)
I am hereby setting up a crowd funded effort to bomb and destroy this radio dish. I don't want any aliens appearing on my front doorstep. We've all seen the movies, this never ends well.
Seriously though, it seems to me incredibly arrogant and self centred for a private group of people to try and contact aliens, because the potential results of aliens turning up could be catastrophic, and that's a decision that all mankind should make together, not some private group.
The only reason I'm not concerned is that I think this has precisely a zero point zero chance of success.
Re: (Score:2)
When was the last time "All Mankind" agreed on anything at all whatsoever, let alone whether or not to try to contact aliens?
We've been sending out transmissions for decades now, much stronger than this. What harm can another few do?
Most importantly, aliens won't detect us because of our signals...they will detect us based upon the signatures we've left on our atmosphere, which is how we are most likely going to detect life on other planets.
Re: (Score:2)
What harm can another few do?
...that The Beverly Hillbillies hasn't already...
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Maybe this is the solution to the Fermi paradox, all the other aliens are hiding on their planets pissing themselves about imagined invaders too.
Re: (Score:2)
that's a decision that all mankind should make together
Good luck getting a unanimous vote. Aside from that's it's still one group imposing their will on another.
I still don't think opening it up for every message is a great way to run it, though.
Re: (Score:2)
I am hereby setting up a crowd funded effort to bomb and destroy this radio dish. I don't want any aliens appearing on my front doorstep. We've all seen the movies, this never ends well.
Seriously though, it seems to me incredibly arrogant and self centred for a private group of people to try and contact aliens, because the potential results of aliens turning up could be catastrophic, and that's a decision that all mankind should make together, not some private group.
The only reason I'm not concerned is that I think this has precisely a zero point zero chance of success.
Who the hell are you to stop them?
Talk about "incredibly arrogant and self-centred"...
What are you doing to do about the past 100 years of radio broadcasts (including high powered military radars) emanating from our planet? If the Aliens are looking for us, they don't need us to emit a beacon to find us.
Re: (Score:2)
leakage is a bit different than drinking from the firehose
Re:We should stop this (Score:5, Informative)
Those radio broadcasts are unlikely to even make it to Alpha Centauri with reasonable sized recieving antennas. With planetary scale antennas it might be possible. The military radars are another story, but they would be randomly aimed and relatively infrequent and not transmitting any sort of coherent message.
This wouldn't be the first attempt at METI. Alexander Zaitsev has sent a number of messages to various stars including Gliese 581 using his 70 meter RT-70 radiotescope located in Yevpatoria, Ukraine. He is the chief advocate for METI among professional astronomers and makes his case well [arxiv.org] I think.
His messages were relatively brief however and are unlikely to be noticed even if there is an intelligent civ at one of his chosen targets. What would new is the idea of a full time, dedicated transmitter sending messages out 24/7/365 aimed for long periods, like say 6-12 months, at a single target so that if anyone is there listening there would be at least some chance of them noticing our signal.
Re: (Score:2)
I believe scientists already have a program like this, and it involves several countries.
Well you are wrong. There is no long term METI program anywhere in the world. This would be the first full time, long term attempt at METI / ASETI.
On top that that since radio and tv broadcasts having been in service that too is getting beamed into space. And if Aliens have been listening to those, they are pretty much going to stay away.
They haven't because those signals are pretty much indistinguishable from noise even at a few light years away. Also, I think alien cavemen would be pretty interesting to us. At least some aliens would find us intriguing enough to study and maybe attempt to communicate with. The fact that we are so primitive and stupid might make us more interesting, not less.
Dangerous!! (Score:2)
I have an uneasy feeling with this.
OK, maybe I just read/watched too much bad Science Fiction.
Nevertheless, the message I'll send will be:
"Nothing to see here, move along!"
Re: (Score:2)
Howabout,
"Hi, Do you have good taste? We'd like to serve you!"
Re: (Score:2)
I have an uneasy feeling with this.
Hook up the NSA Prism into this, that will keep the aliens away.
Good Idea, or Not? (Score:2)
Something tells me... (Score:2)
It will be more like a scantily-dressed 18-year-old female yelling "Here I am! Come get me!" in the middle of an ocean, with nothing but said ocean in sight.
Re: (Score:2)
I sure hope they moderate these... (Score:2)
Re: (Score:2)
Because other people will send out messages entirely different and opposite to that. So the Aliens will see reasonable messages and unreasonable ones, leading them most likely to do nothing more than be exceedingly amused.
goatse (Score:3)
enough said
Re: (Score:2)
"I didn't think there was a Nebula over there... Who's sending that to us?"
Get Your Space Lizard Snacks! (Score:2)
Language barrier (Score:2)
It's hard to see how there's anything useful in sending disjointed messages without at least providing a primer on English or whichever Earth language the messages are going to be in. Something like transmitting all of Wikipedia and Project Gutenburg so there's a big enough sample of the language so they have a chance of deciphering it.
Re: Language barrier (Score:3)
This all assumes that large-scale interstellar space travel is economically feasible for a sufficiently advanced civilization.
It's just as likely that it isn't (eg sending the Lizard Armada to another star requires way more energy than the Lizards are willing to spend, even if we are delicious) and therefore we as a species are safe wrt being eaten.
Proper lead account for? (Score:4, Interesting)
Rookie error #3: Point the radio transmission directly at the star.
Unless the target is moving directly toward or away from us relatively speaking, pointing it at the star will target where the star was 36 light years before the transmission will arrive. If it -is- moving directly toward or away, are they accounting for Doppler?
Re:Proper lead account for? (Score:4, Insightful)
Of course, rookie error #1 is getting involved in a land war in Asia and rookie error #2 is going in against a Sicilian when death is on the line.
All kidding aside, I'm not sure I like this idea. It's not really a good idea to announce your presence in an area where the natives could be restless and you could be considered "tasty".
Re: (Score:2)
Rookie error #1 - pedantic posting about stuff he doesn't understand.
Stars move slowly, and radio transmissions (even relatively tight beamed ones) spread out the farther they get from the source - and 18LY is a very long way away.
Not to mention the dangers of assuming too much from a very simple statement - like exactly where the antenna will be pointing.
Re: (Score:2, Informative)
It's a 30-metre antenna. If they're transmitting radio waves with (say) 3 cm wavelength, the beam will be 0.001 radians ~= 0.05 degrees across. For the star to get out of this beam before the signal arrives, it needs to be travelling at over 0.001 of the speed of light, which is ridiculously fast for a star. So, pointing straight at the star isn't a problem.
Doppler shifting isn't a problem, either. It's only important if your transmitter and receiver have been tuned to exactly the same frequency; and al
Danger! Keep away! (Score:2)
I'm all for METI as long as it's honest.
Let's send them (Score:2)
Codebreaking challenge? (Score:2)
They should release the binary contents of the haling message and message content as a codebreaking challenge and see if anyone here on earth can decode it.
Re: (Score:2)
Re: (Score:2)
Here you go: 01101000 01110100 01110100 01110000 00111010 00101111 00101111 01110111 01110111 01110111 00101110 01111001 01101111 01110101 01110100 01110101 01100010 01100101 00101110 01100011 01101111 01101101 00101111 01110111 01100001 01110100 01100011 01101000 00111111 01110110 00111101 01000100 01000101 00101101 00111000 01111001 01001111 00110011 01100110 01101110 01001010 00110100
Those are going to be some pretty pissed off aliens, maybe they really are going to come and destroy us.
Re: (Score:2)
Has anyone of those people ever thought about (Score:2)
Re: (Score:2)
What if they are predators? (Score:5, Insightful)
Can the senders please make sure that if those guys are predators, the rest of us are safe. Thanks.
As a side note, I tend to feel strangely unsure that such things are a good idea when unknown extraterrestrials receive more attention than starving 3rd world fellow terrestrials.
The jungle is a dangerous place (Score:2)
The deep ocean is a dangerous place. The jungle is a dangerous place.
To think whatever might be lurking in deep space is all warm and fuzzy, ready to submit to our dominion, or tenderly treat us like children, eager to school us in the secrets of the universe, seems a bit naive.
Re: (Score:2)
The deep ocean is a dangerous place. The jungle is a dangerous place.
To think whatever might be lurking in deep space is all warm and fuzzy, ready to submit to our dominion, or tenderly treat us like children, eager to school us in the secrets of the universe, seems a bit naive.
You'd have a much better chance of thrusting your hand in the ocean at random and retrieving a fish than pointing a radio telescope at a random star system and finding an intelligent civilization
Re: (Score:2)
Professor Donald Kessler: We know they're extremely advanced technologically, which suggests - very rightfully so - that they're peaceful. An advanced civilization, by definition, is not barbaric.
Martian Translator Device: We come in peace! We come in peace!
Re: (Score:2)
An advanced civilization, by definition, is not barbaric.
So what is the Skynet, not an advanced civilization or not barbaric?
There could be civilizations that don't even realize that chemical compounds may interlink to support life. There could be civilizations to which we are microscopic creatures; or the other way around. We destroy bacteria in most places where we come across them, and if they attract our attention we just do it faster.
There may be civilizations that define the word "barbaric" dif
Re: (Score:2)
You seem to have lost the movie reference, so let me clarify...
Woosh!
Yeah, I think that's the sound of their guns.
Re: (Score:2)
Don't run! We are your friends!
Re: (Score:2)
Ack ack!
Why contact them? (Score:2)
Re: (Score:2)
Do you have any idea how unlikely it is that there is someone listening at Gliese 526 or any other target less than100 light years from us? I'm guessing that you don't. BTW, Hawking is simply wrong about this issue.
Einstein was right (Score:2)
Monsters are coming (Score:2)
No license is trust license (Score:2)
No license means the owner concede no right at all to the user. This is in fact an unspoken trust license: do whatever with it and trust me to not sue you.
This should drive corporations away because of the legal risk and just keep end user that do not care about IP laws
Did anyone else read the title as (Score:2, Funny)
Crowd-funded radio bacon?
Re: (Score:2)
let me start another project (Score:2)
They stole my project. (Score:2)
What they are doing is similar to what I want to do.
1. Build minimum 350 kW, 10 Ghz, long pulsed, pulse position modulated, Klystron / Gyrotron.
2. Build parabolic dish 20 meters or larger in diameter. Ideally at a latitude where your most important target star passes right above (at your zenith).
3. Aim dish at Gliese 581 or other interesting targets within 30-50 ly.
4. Profit ???
5. After round trip time, if you are still alive, listen for a response.
We do need to make a profit in order to sustain the operating costs in order to keep doing it."
Ruh roh. I wonder what their "operating costs" are. Just
Gold Here! (Score:4, Insightful)
Or perhaps.... Hey Spike! Wanna go dig up some bones?!
The reply (Score:2)
This is a new phone, I don't have anyone's numbers. Who's this?
Stupid idea (Score:2)
1) No idea if they will be nice. Simply no way to tell.
2) What makes them think they can speak for me, or for the rest of humanity for that matter?
Re: (Score:2)
I always preferred this [abovetopsecret.com] explanation
Anyway, I'm glad that these guys are doing this. That way when the inevitable alien invasion occurs, we'll know /exactly/ who to blame.
(cue pedants reminding us that Earth has been spewing out radio signals for over a century).
Re: (Score:2)
why does'nt our moon have life?
It may, there could still be dormant microbes leftover in the garbage we've left behind.
http://www.bbc.co.uk/learningzone/clips/bacteria-survive-nearly-three-years-on-the-moon/9931.html [bbc.co.uk]
Re: (Score:3)
Why do I have this indelible image in my mind... a bunch of Indians come together and crowd-source wood to build a big bonfire on the shore - hoping it may be a guiding beacon to travelers coming from far out at sea.
Anytime two societies meet, it usually doesn't end well for the less advanced one. They could possibly come in star ships...we can barely put a man in orbit.
An Alien civilization that can cross the Galaxy in a Starship to come see us is probably not going to find any natural resources or living space that they can't already find elsewhere. There'd be little reason to take over Earth, unless they see us as a threat, and that's doubtful.
Re: (Score:2)
That makes so much sense...
On the other hand travelling to the New World wasn't profitable the first voyage either.
Re: (Score:2)
Most of terrestrial communications on VHF and above is done with antennas that don't radiate much into space. HF and longer wavelengths reflect from ionosphere and don't leave Earth. Most unintended transmissions don't have enough power to be detected outside of the Solar system, and they don't employ noise-resistant coding.
However if you take a 60 dBi dish [setileague.org], shove a kilowatt or ten into the feed, and slowly modulate the signal with error correction codes [wikipedia.org], that transmission might be detectable from a larg
Re: (Score:2)
I read somewhere that using current technology we would be able to detect some very powerful military radars (like used in antiballistic missile systems) from over 100 light years away... if it was pointed at us.
Re: (Score:3)
I've actually done the math (link budget calculations) and a 30 meter radio telescope is actually large enough to reach quite a bit further than Alpha Centuari. With an adequately powerful transmitter (a minimum power output of something like 300 kW with sufficiently long pulses (>= 0.3 milliseconds) and a sufficiently narrow band signal Gliese 581, at 20.3 ly, is well within its reach. With a megawatt you could get even quite a bit further than that. At least out to 50-60 ly. Of course a lot depends on