h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I'm new here so I may have missed it, but has any thought been given here to the desirability of announcing our prescence to the universe? I.e., if ETI exists, and I believe it must, how do we know that it will be of a friendly disposition? I can hear the groans from here but no-one as yet has convinced me of this. Quite simply, how do we know that any aliens discovered will not percieve us as a threat?

Well, let us start with the basics then. Earth sends out a whole lot of electromagnetic radiation. All those TV and radio signals we have spills out into space. So any alien civilisation looking at Earth will quickly be able to spot there is life on there and find us. The difference with the SETI program is that instead of just blabbering things into space like we do now, we say "We come in peace". Having seen any of our TV programmes they may not believe us.
But the important thing is, if they are listening they already know we are here. So what we have to do is tell them we have peaceful intentions.

Te important thing about the SETI programme, is that the message that SETI sends into space will be of a form that it might be possible for another civilisation to decode.

All of the garbage that is currently floating around in the ether is totally unintelligible.

As Xanatic says, an ETI will already know we are here if they are listening. They just can't understand what we are saying.

Thks for your reply.

OK I understand what you are saying now. We are trying to forestall any possible antagonism. It seems obvious now when put like that. But that begs a second question, namely how do we do that? I'm not arguing the point now, but how can we be sure that other intelligences understand that we are peaceful? Also, if we judged ourselves superior to others,how do we know that we wouldn't try to take advantage of that? But that's a different thing altogether.

Thanks again for taking the time to reply. TORG (Terry)

The answer to that question would probably be "We're doing our best". We are trying to make messages that an alien intelligence would understand, and be able to tell about ourselves in that message. And they should be able to see from there wether they like us or not.

As for who is superior, that is a good question. It could very well end up with one species taking advantage of the other.

Thanks for replying.

Yes I understand now. I would love to know though, how we are trying to do this when we don't know who we are talking to. Any ideas where to find this?

Thanks again for replying.

TORG (Terry)

There's a book out on the subject, got it for x-mas this year. I can't remember the name right now but I will go home and find out. It has everything you need to know about SETI. Different codings they use, wavelenghts they use and such. It is a bit boring though, too much like a technical manual.

Just remembered it. It is called Beyond Contact and is by Brian S McConnell. You can find it on Amazon.

As I understand it, the seti@home project is analysing data collected by the radio telescope at Arecibo.
We are listening for them, I don't know if that would announce our presence to them.
The question of *if* we find intelligent life out there *what* would we do about it, remains as a "cross that bridge when we come to it" - possibly the people at the seti@home base, berkeley edu, may produce a poll for all the contributors.
I'd like to think so.

"Please complete the following questionaire"
We have found intelligent life in XX area of the galaxy.
Do we:
(a) Send them a signal, letting them know we are here, and hope they pick it up in 60-100 years {whatever} and pray they realize it's a friendly "Hello"; then wait 60-100 years for their {hopefully friendly} reply, and pray we can decipher it.
(b) Ignore them.

I don't think there is very much to worry about - we have been sending out radio messages for about 100 years, which means that only inhabitants on stars within a radius of 100 light-years have had a chance to intercept our signals. That's not actually that many stars, and when you start taking into account the probability of intelligent, technologically enabled civilisations existing on any of those stars, it makes the chances of winning the lottery on two consecutive occasions high by comparison.

Our own milky way galaxy is so big it would take 150,000 years for a radio signal to go from one end of it to the other, so as the years go by the chance of interception increases, but the distance between us and the interceptor would also be increasing, thereby limiting very much the likelihood of an invasion force being assembled!

Of course, I am assuming that faster than light travel is not possible, but there you go.

A few messages has been sent out into space, but it is mainly listening yes. Apparently they are planning to send out another message to commemorate some SETI jubilee. But at the moment they are working on making a code that would be able to be read by everybody in the universe.

I recently read a book about the development of the human species that contained a chapter on this question.
I think the author was speaking tongue in cheek, but what he said made sense. Here goes...
If we send out radio signals to another planet, we are hoping that they will receive them.
To receive the signals these *aliens* must have developed similar receiving technologies to our own
In order to have developed similar technologies, they must also have evolved in much the same way.
If they have evolved in much the same way, then they will behave in much the same way we would if we encountered a less developed civilisation.
Namely, they would either wipe us out via their superior technology, weaponry and diseases. Or they would exploit us for all we were worth.

As you can see, it seems to make sense - well I think it does. But you can't really take it too seriously.......Or can you?

Well, not of that made sense I think. I'd love to hear the guys arguments for all that.

All another civilisation need is to discover radiowaves and a bit of simple mathematics. Doesn't matter how they evolved.

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I don't think this is right since light (and by extension, radio waves) is a fundamental component of of the universe. Look at how many light capturing devices we have - eyes, antennae, parabolic dishes, photographic plates, CCD's... - it's easy to capture light. Therefore, you could possibly develop other means to capture this using completely different technologies and approaches, thus implying that evolution of the technology and therefore the evolution of the beings developing the technology would be different.

But I agree with one thing - for an *alien* civilisation to capture and properly interpret the messages involves far too many "ifs", therefore to make it practical, millions (possibly billions) of star systems might need to be reached before we got a good match, and the distances involved then are so vast, how could they possibly even imagine a threat from us? And if they did see us as a threat (another if), what exactly could they do to eliminate us? A big directional laser or something, which takes 10,000 years to cross the void between us? Why bother?

Fair criticism, but it is worth bearing in mind that aliens could be exactly that - alien. Just because the universe is interpreted by us through light and sound waves, etc.Who's to say that another type of life form should use the same means to understand the concept of space and time.
I know this is getting far fetched now, so I'll sit down and have another

Well, light is something you'd expect in a lot of places and which a life form would be likely to know about.

That's just a typically humanistic approach on all this. If you can't be objective and take into account the perspectives of all lifeforms in the universe then please take a back seat.
Sorry, just got very sarcastic

I will say though that certain creatures have been found at the bottom of the sea, where they never have any contact with light, and take all their energy from the earth's surface. It's best not to take for granted only those things that we receive through our own senses.

Yes, and so far those ocean dwelling organism haven't invented satellite dishes yet.

What is meant is a species that has achieved a certain level of technology, they will probably know about EM waves. Even though we cannot sense them, we still learned about the invisible part of the EM spectre.

Fair enough, I suppose until crustations get themselves into space, then we'll just have to go on what we can/have achieved then.

Sure there is light way down there. There's heat, there is cosmic radiation, there are radioactive rocks going "crackle", there is magnetism, radio waves can penetrate down there - lots of light. Light is not just the visible wavelengths we see, it is a whole spectrum of electromagnetic waves from radio to high energy gamma rays, and it is absolutely everywhere in the known universe.