Is SETI worth it?

[scotth]

Why do you assume that we need to use forces to communicate at a distance? I communicate with particles --- well, they're usually called "pieces of paper" --- all the time. Similarly, much of my communication is done with much smaller particles called "electrons." I don't see any particular reason that I can use electrons for communications and not (assuming sufficiently advanced technology) mesons, neutrinos, yadda yadda.

More to the point --- communicating via EM specifically does not imply that the EM is detectable as a communication at a distance. For example, I can use a laser (which is, of course, an EM signal) to communicate between two points without having anyone else pick up the beam outside of the direct line-of-sight, since a laser beam is directional. As another example, since the bandwidth of any channel is limited, I will probably want to compress data before I send it --- a really good compression system will yield data that's indistinguishable from noise.

Our hypothetical aliens may be communicating using a directional, highly compressed signal carried by a stream of high-speed mesons. SETI would never find that.

Communicating with particles in this context is a difficult, hazardous, and generally stillborn idea. Sufficiently advanced technology would not make them a good choice.

While it is interesting to think about closed beam (laser in your example) communications, it would never be used for broadcast communications and certainly not for radar. The whole point of radar is to search for things you don't know are there. And therefore largely transmitting at nothing at all.

And radar signal will never be encoded like you suggest. Putting alot of modulation on a signal spreads its spectrum and greatly reduces the range at which it can be detected. That is why a radar signal will always be only modulated just enough to make it easy to recognize in the background noise.

You are coming up with classes of communication that would not be useful to look for, but the existance of these would not in any way preclude the existance of more easily detectable RF.

 

[Batman Jr.]

Lasers do have the advantage of being able to carry more information than radio waves. As far as the problem of their narrow broadcasting field, couldn't an array of lasers reconcile this predicament?

Originally posted by scotth

You are coming up with classes of communication that would not be useful to look for, but the existance of these would not in any way preclude the existance of more easily detectable RF.

You didn't read my post yet, did you? A mind sufficiently disparate from a human's may come up with certain methods of communication before RF. If such a method is superior in the opinion of the alien to RF, then it may very well preclude RF. What you fail to grasp is that concepts of complexity and simplicity and pragmatism are all relative.

 

[scotth]

You didn't read my post yet, did you? A mind sufficiently disparate from a human's may come up with certain methods of communication before RF. If such a method is superior in the opinion of the alien to RF, then it may very well preclude RF. What you fail to grasp is that concepts of complexity and simplicity and pragmatism are all relative.

I did, and I thought some of what I put in there rebutted it... but here it is specifically.

When you are guessing about communicating with or even detecting another civilization, you have to consider what you know in common. Another technical civilization would have figured out the same things about the universe that we have in order to achieve technology.

Where your arguement goes off course is that it posits that there is some reasonable way of sending data without wires that uses something besides the EM spectrum. As far as we can tell today, nature simply doesn't provide another useful tool for the job.

Like I said before, every thing that we can see going on in the universe is neatly covered by 4 forces and a small stack of particles. Particles are not useful for communications. That leaves the forces, and only one of them is useful, and that is electromagnetism.

It doesn't matter how differently they think, or how different their culture may be, or whether would could ever even understand them. If you want to send signals without wires, EM radiation is the way to do it.

 

[Batman Jr.]

EM can be manipulated in a multitude of ways each to different effects. Lasers and radio waves are both EM, but require different apparatuses in utilizing them as mediums for communication. You assume that I'm excluding EM entirely, which I'm not.

Originally posted by scotth

When you are guessing about communicating with or even detecting another civilization, you have to consider what you know in common. Another technical civilization would have figured out the same things about the universe that we have in order to achieve technology.

You still haven't told me how you know this. Consider a composer and a less musically inclined computer scientist attempting to train a computer to compose for him based on certain mathematical algorithms. The composer's thought processes in creating a piece of music are mostly subconscious, almost as if he were merely taking dictation for a symphony which resided in his mind's ear. The computer scientist, however, must completely reverse engineer music down to its most fundamental terms in teaching the computer what the composer takes for granted. In this scenario, the composer is required to know less than the computer scientist despite the fact that they have the common aim of just getting a new piece of music written! By your logic (if you assumed yourself to be the computer scientist), Erich—he's the man with the bowtie on your left—ought to have understood the exact mathematics governing music. Otherwise, it would have been impossible for him to have written Die Tote Stadt, the film score to The Sea Hawk, etc.

 

[scotth]

EM can be manipulated in a multitude of ways each to different effects. Lasers and radio waves are both EM, but require different apparatuses in utilizing them as mediums for communication. You assume that I'm excluding EM entirely, which I'm not.



You still haven't told me how you know this. Consider a composer and a less musically inclined computer scientist attempting to train a computer to compose for him based on certain mathematical algorithms. The composer's thought processes in creating a piece of music are mostly subconscious, almost as if he were merely taking dictation for a symphony which resided in his mind's ear. The computer scientist, however, must completely reverse engineer music down to its most fundamental terms in teaching the computer what the composer takes for granted. In this scenario, the composer is required to know less than the computer scientist despite the fact that they have the common aim of just getting a new piece of music written! By your logic (if you assumed yourself to be the computer scientist), Erich—he's the man with the bowtie on your left—ought to have understood the exact mathematics governing music. Otherwise, it would have been impossible for him to have written Die Tote Stadt, the film score to The Sea Hawk, etc.

EM is EM. That is the situation.

To put data on it, it must be varied in some way.

You can turn it on and off.
You vary the amplitude.
You can vary the frequency.
And you can shift its phase.

That is it. Its that simple.

If you detect EM radiation that is changing in one or more of the above aspects in such a way that it could not be caused by nature, you probably have a signal created by another intelligence.

Your analogy to creating music doesn't illuminate the situation at all.

 

[Thomas]

Scotth,

If you think EM is the best solution for interstellar communication, I would have to say that you're quite wrong. Quantum communication, based on the 'spooky action-at-a-distance' as Einstein called it, is far the best solution we know of today. EM is a joke compared to quantum communication:

Seth Shostak from the SETI institute says:

Could quantum messaging dominate interstellar communication? Could this be the preferred way to get in touch with unknown cosmic beings? If so, it offers an appealing resolution of the famous Fermi Paradox, which asks "if the Galaxy is teeming with intelligence, why don’t we see evidence for it everywhere?" Perhaps the evidence is everywhere – washing over us right now in a shower of quantum-encrypted messages.

It is most likely that this is the way aliens would try to communicate with us, there is nothing that can interfere with these signals, and they happen instantly, no travel needed, spooky action-at-a-distance.
Even the most powerful transmitters we use today, can only be detected 50 lightyears away, and the odds for being 'heard' within this range, is minimal. Actually it would require an antenna to be 1,000 feet in diameter. With perfected quantum communication systems, distance becomes irrelevant.

I think that if there is someone out there, we're gonna find out when we have perfected quantum communication.

Source for the quote

 

[Thomas]

By the way, I voted yes, although I belive they are looking for the wrong signals as I said in my previous post. But I like the philosophy behind SETI, and quantum communication is belived to be in our hands within the next 10-15 years. I indeed think it's worth the try.

 

[Batman Jr.]

Originally posted by scotth

Your analogy to creating music doesn't illuminate the situation at all.

In my analogy, the computer scientist has certain prerequisites for creating music and the composer has others. Your statements allude to your thinking that everyone must have the same prerequisites in achieving the same things. I was attempting to provide a specific and tangible counterexample to this notion.

The point I was trying to make to begin with is that there is no set linear path that technology always follows.

There is an optical SETI program that succors the radio wave one, so that's good. In contrasting lasers and radio waves, I had meant to specify that I wasn't talking about lasers in the radio spectrum. I apologize as that got a little convoluted.

However, I cannot so readily dismiss the possibility of more unconventional forms of deep space communication.

 

[Thomas]

There is an optical SETI program that succors the radio wave one, so that's good. In contrasting lasers and radio waves, I had meant to specify that I wasn't talking about lasers in the radio spectrum. I apologize as that got a little convoluted.

What's the point? They wouldn't be sending anything with such primitive signals anyway. It's like if I tried to send you this message in a bottle through the Atlantic ocean. And that's even a poor analogy, because both the internet and the message-in-a-bottle takes time, quantum signals don't.

 

[Rob Lister]

What's the point? They wouldn't be sending anything with such primitive signals anyway. It's like if I tried to send you this message in a bottle through the Atlantic ocean. And that's even a poor analogy, because both the internet and the message-in-a-bottle takes time, quantum signals don't.

The problem with 'quantum signals', at least as you describe them, is that they cannot be used to convey intellegence at speeds greater than c; doing so would violate causality.

edit: clarification. Also to add: But their great for encryption.

 

[Thomas]

The problem with 'quantum signals', at least as you describe them, is that they cannot be used to convey intellegence at speeds greater than c; doing so would violate causality.

They do violate causality. That's what quantum mechanics do. Determinists like Einstein claimed to the day he died that the QM theory would have to be flawed, and there are still objections to this day. I don't understand QM, actually noone really does because it conflicts with common sense, but it works anyway. That's the ugly part about it. Experiments have been made where particles have been, hold on, teleported.

And other experiments have been conducted where quantum communication have been verified over small distances. But in theory it doesn't matter if the distance is 1000 lightyears, or 2 feet. One particle knows what the other one is doing, it's quite weird, but it works. Or put in another way, if you look at one particle, you'll know the state of the other particle.

 

[scotth]

Scotth,

If you think EM is the best solution for interstellar communication, I would have to say that you're quite wrong. Quantum communication, based on the 'spooky action-at-a-distance' as Einstein called it, is far the best solution we know of today. EM is a joke compared to quantum communication:

Just what is in this, indicates you don't understand this at all.

This would still be EM communications. What they are actually discussin is quantum encoding of photons (EM).

And it changes not one thing about my arguments about detecting things like broadcast or radar leakage.

 

[scotth]

They do violate causality. That's what quantum mechanics do.

No, they don't. Period.

 

[Thomas]

No, they don't. Period.

Excellent argument, but Here

 

[scotth]

Further problem with quantum communications scheme.....

The sender would have to hit the recipients position exactly for the message to be found. When I say exactly, I mean very exactly. The receiving system would have to be place at exactly the intersection of where the quantumly entangled photons are to meet.

 

[Thomas]

Just what is in this, indicates you don't understand this at all.

This would still be EM communications. What they are actually discussin is quantum encoding of photons (EM).

And it changes not one thing about my arguments about detecting things like broadcast or radar leakage.

From the same source as above:

These two scientists have been researching quantum information theory for a while. Their trick is to forego conventional electromagnetic signals (light or radio) – made up of large, organized "waves" of photons – in favor of individual, quantum-entangled photons.

If I have misunderstood something here, then you are welcome to explain, but I gotta go for now. Stay cosy.

 

[scotth]

Excellent argument, but Here

This is a pretty out of date article.

It has been demonstrated quite well that it is impossible to use any of these tricks to pass information at greater than the speed of light.

I'll see if I can dig up an article on that.

 

[scotth]

From the same source as above:



If I have misunderstood something here, then you are welcome to explain, but I gotta go for now. Stay cosy.

Quantumly entangle photons are still photons. Photons are EM. Photon are the particle the mediates the Electromagnetic force.

 

[Thomas]

I see now that you're right, quantum entanglement would only be used for encryption in this case, an illusion deprived again.

But Shostak could have a point, that this could be the preferred method for another civilization to communicate, with quantum-cryptation, and we therefore can't 'hear' anything yet.

But you know, not to be a nag, but QM do break causality/determinism. Atleast that's how the picture looks now. Spooky action-at-a-distance breaks causality. That's what I been seduced to belive anyway, although I think it sounds rather akward.

 

[Rob Lister]

Spooky action-at-a-distance breaks causality.

No, it doesn't, at least not until you can use it to convey intellegence at speeds greater than c, which you can't, because that would violate causality. Talk about circular!!! But in this case it's necessary.