Folks, "they" are out there...but by now probably aren't even using RF for comms....although those old old signals might just started arriving any day now from their long interstellar voyage..

This discussion is general in nature.....do you think ET has dropped RF for communication and now user another way? If so, what form? Light? Something sub atomic?

We're so primitive probably in our own way, not sure it's good practice to focus just on RF energy. Our technology just got here and we're just babies...

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Folks, "they" are out there...but by now probably aren't even using RF for comms....although those old old signals might just started arriving any day now from their long interstellar voyage..

This discussion is general in nature.....do you think ET has dropped RF for communication and now user another way? If so, what form? Light? Something sub atomic?

We're so primitive probably in our own way, not sure it's good practice to focus just on RF energy. Our technology just got here and we're just babies...

At present we humans know of two methods of communications. One uses electro-magnetic energy, the photon. The other uses gravity waves.

We, in common usage make a distinction between RF and light, but only the frequency is different, they are both carried by photons.

As for gravity waves, the power levels needed to transmit are so far off the chart, I can't actually see any civilization doing so. Remember at present we have only been able to observe multi solar mass black holes. To grab such a mass and shake it in a way to transmit is rather a wasteful use of energy which could produce a much stronger stream of photons.

I'm rather sure searching for photons is the way to go.

Quantum entanglement sounds interesting.

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Quantum entanglement sounds interesting.

Yes. But it doesn't work as a better or faster way of communication then using radio waves. Just to set up such a line takes much more times than to transmit some kind of message. One could think that some aliens have for some billion years ago somehow transported entangled particles to Earth and already "communicating" with us. Sorry, that doesn't work either because you cannot eavesdrop on entangled particles...

Don't see this as a way of communicating. Equivalent to flipping a coin. How do we change the spin of an electron and how do we keep track of it's entangled partner to even identify it. How do we send it to where we want to go. Looks to me flipping a coin makes more sense. more quantum mumbo jumbo

More to the point I think is that the power levels required to communicate over the likely distances are very great. If as I strongly suspect intelligent life evolves very rarely (and may last only a short time after it evolves), then the mean distances to the nearest sources will be large, probably on the order of a thousand light-years. (The Milky Way is about 100,000 light-years in diameter).

If you have any background in RF engineering, you realize that the power levels required at that distance to produce a usable signal at a telescope the size of Green Bank is huge. That is why such telescopes are intended to study exploding stars, gas clouds, etc. that produce enormous energy outputs that dwarf anything we can do.

When you scratch just a little below the surface, the SETI folks also realize that, they just don't bother to mention it very much. What they are really assuming (or hoping) is that said intelligent life will be so considerate as to set up large beacons that will radiate out huge amounts of RF energy, conveniently in our direction, over time periods of at least thousands of years to have any hope of our detecting it.

Right. In fact, any intelligent civilization that lasted that long probably did so by figuring out how to hide their presence from possible invaders. They are probably the universe's experts in cloaking technology. The chances that they would jeopardize their existence just to say hello to us is not that great. I think I will use my crunching energy elsewhere. We need to keep our own civilization going.

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Hyperwave relay anyone?

Most likely, it would be too expensive for advanced civilizations to hide themselves. There is a very real possibility that civilizations don't hang around very long, though. Earth's history involves several mass extinctions, so if SETI finds the universe to be unusually empty in the next 20-30 years, we should anticipate that we will have a limited ability to survive any significant portion of the universe's history.

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Philosophies:

• Intuitionist
  
• Moral functionalist
  
• Humean about motivations
  
• Panpsychist leaning; optimistic about combination problem
  
• Agnostic; sympathetic to prime movers
  

Here's a thought.
We don't know what the impact of receiving a signal would have on our species. The possible reactions range from enlightenment to self-immolation and we have no reason to assume we're anything but average. If life is as abundant as we hope that means our galaxy is full of other species at varying stages of their own evolution.
So let's say that we had the capability of broadcasting a signal thousands of light-years. Maybe some bit of technology we think everyone should have or simply a "we are here" announcement. Knowing there is a chance that that signal might be an extinction-level event for whoever receives it, would it not be an insanely irresponsible act to send it?
Maybe the reason we hear nothing is simply because it's a really, really bad idea.

The best "first contact" signals started to leave Earth about 100 years ago. It is not possible to decipher any message in these signals without knowing a lot about the sender, their "natural time cycle", the sort of language they use and so on. However, given a good enough receiver system it should be possible to detect those signals. Now consider the reverse....

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

Maybe the reason we hear nothing is simply because it's a really, really bad idea.

It may also be that, if there is something out there that is very far advanced from us, they've decided that their "beacon" should be in the most advanced form of communication that they have, something we have yet to develop or even theorize about, so that any civilization that can detect them is similarly advanced technologically, and thus hopefully past the risk of self-immolation.

But of course, we'll never know unless we listen. All the speculation we can do is never a substitute, as we really have no idea if or what we will find.

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The universe has a speed limit for matter. We are matter. Potential invaders are matter.

Even if we find a way to transform us - regular matter - into some "thing" that goes faster than the speed limit, there will need to be the inverse machine on the other end to transform the "thing" back into ordinary matter. Having to move that machine to the other place kills any scheme to go faster than the speed limit.

I don't think we or they have much to worry about from an invasion standpoint.

If we got a signal tomorrow, perhaps it would spur us to finally do something about our trashing of our spaceship.