Overused Silly Sci-Fi Science.

[dworth]

There are a number of questions that need to be considered re: intelligent life on other planets and whether we could talk to them:

How common are planets?
How common are planets suitable for some form of life to occur?
How often does life actually occur on suitable worlds?
How common are complex life forms compared to microbial organisms?
How often does intelligence arise?
How often does the existence of intelligent beings result in organised societies?
How often do said societies reach a level of technology capable of communicating with other worlds?
How long do civilisations last? The universe is 13.7 billion years old and humans have had the capacity to transmit information for barely more than a century. Perhaps countless civilisations have come and gone elsewhere before we reached this level.
What is the best way of communicating over interstellar distances? Is it radio, or is it something that we haven't thought of yet?

The answers to almost all of thosequestions are currently 'don't know' of course, as we only have our own example to go on, although one or two may get answered in the next few years (the data from the Kepler mission is producing some startling results and it appears that planets may be very common indeed). Maybe life is common or maybe it's rare. Maybe life itself is common but intelligence is rare. Maybe intelligence has taken 13.7 billion years to emerge and we are the first of many. We may be unique in the universe, but the truth is that we just don't know.

[jehane]

Originally Posted by WT Sharpe

Given that the Universe has been around for around 14 billion years, I don't think it's likely that we're the first to achieve our level of technology. Given that we've so far found no trace of any other civilization, I do think it highly likely that technological societies can only advance so far before they self-destruct.

I've always thought that it's highly likely that intelligent life exists elsewhere in the universe, however I don't think that it's necessary to have self-destruction of technologically advanced societies, even if that is apparently our way. Fermi's paradox makes a big assumption - that any alien society is *more* advanced than us. What if they are also sitting on their little mudball in the back of beyond wondering where *we* are? It doesn't help that we are essentially only looking for aliens just like us - corporeal beings who perceive reality in certain ways (eg 3 spatial dimensions) and communicate in the same ways (signals on particular wavelengths of the EMS).

[QuantumIguana]

One thing we have learned in recent years is that planets are common. That was suspected, but it was confirmed with the discovery of exoplanets. It's easy to detect Jupiter-sized planets, but hard to detect Earth-sized planets. We really have no idea how common life is, but we have discovered that life on Earth can exist in a far wider range of conditions than we had previously imagined. Just about anywhere you look on Earth, there is life. There is life in water hot enough to cook us, life that loves acid, life that loves salt, etc. Dig down miles into the crust, and you will find life in the rocks. I was watching a documentary recently, and it was talking about life on Antarctica. It looks lifeless, but break open the rocks and there is a thin green layer. The algae in the rock is frozen nearly the entire year, but for a few days each year, the rock is warmed enough for photosynthesis to take place.

Fermi's paradox makes another assumption, that an advanced civilization would have a single-minded dedication to spread throughout the universe. It imagines that colonists are sent out, and then that new colony immediately plans to send out colonists of its own. Such ambition makes building the pyramids of Egypt or the cathedrals of Europe look like a child stacking blocks by comparison.

I think we can conclude that no such species exists in our galaxy with an overwhelming drive to grow and spread through the universe. That doesn't mean that technologically advanced species don't exist. Perhaps when they reach a certain stage of advancement, they don't keep growing their numbers.

As Douglas Adams put it, "space is big". We haven't even scratched the surface. What would it mean for intelligent life to be "rare"? There are upwards of 100,000,000,000 galaxies with upwards of 100,000,000,000 stars per galaxy. That is many opportunities for life to emerge. One per galaxy would, I think, qualify as rare. So would four per galaxy. It would still be rare enough that it might be quite unlikely to discover them. But for Earth to be the only planet in the whole universe with intelligent life? Not quite impossible, but I think it would be astonishingly unlikely.

[Penforhire]

Several authors postulate the need for continuous growth (expansion into the universe) if life is to continue. I recall at least one who suggested that expansion would accelerate to near light-speed because of how resources get consumed. The alternative is reduced energy consumption to stay 'local' but alive (is a VERY slow-running uploaded self still "alive?"). Even Dyson ring/sphere/section energy collection doesn't work over billions of years. Your star runs out of fuel.

Along the Fermi lines, it is hard to imagine a continuously expanding alien race whose RF signature is so low-profile we haven't spotted it yet. I suppose one answer is to say they intentionally keep a low profile, so as to sneak up on their expansion targets. Another is to say that we DO see them but interpret them as natural, cosmological oddities like quasars. Another is to say the laws of physics vary enough across the universe that we don't see their society's emissions (and I don't believe science ruled this one out yet).

[QuantumIguana]

Fermi's paradox involves a species spreading out through the galaxy at in incredible rate. Such a species would have to have a single-minded devotion to expansion. A star's lifetime is very long. Humanity may have to move out of our solar system, but not for well over a billion years. We have great resources in our own solar system. If a species was somehow consuming its resources at such a prodigious rate that they needed to move on every few centuries, they would quickly run out of room to expand, they would use up the resources of the galaxy. I don't think such a wasteful species could ever exist.

The RF signature is very hard to detect. Right now, we could only detect an intense signature sent out with the intent of interstellar communication. The RF signature from Earth could not be detected from nearby stars. There is no reason to think that with the technology we have today that we could eavesdrop on the RF signals from alien civilizations. Stars just drown everything out.

[Penforhire]

The scale is billions of years, not hundreds. The question posed is why, after 14 billion years of existence, don't we see anyone else? The star problem is still real in that time scale and requires constant expansion (or alternate power sources) to overcome.

I agree that the RF signature of civilization is in the noise but we broadcast signals to see if we're alone. Are we the only species that would do that, or have SETI-like receivers looking for it?

[sbroome]

I was confused by the time travel in the latest Star Trek, it seems like Nero had travelled through time in a way that his people weren't actually dead.

[dworth]

Maybe they don't use radio for interstellar communication? If you've managed to create the great sci-fi trope of FTL travel, the quickest way to give someone a message is to go there in person and tell them.

[QuantumIguana]

The lifetime of a star is billions of years. There might be a species that has had to flee the death of its star, and there is a slight possibility of a species that has had to flee the death of a second star, but a species that has had to do this over and over again, and in the process filling up the galaxy? The universe isn't old enough for that.

Fermi's paradox doesn't involve billions of years. One of the claims that Fermi's paradox makes is "If interstellar travel is possible, even the "slow" kind nearly within the reach of Earth technology, then it would only take from 5 million to 50 million years to colonize the galaxy." That would involve species sending out new colonies, and those new colonies in turn sending out more new colonies in a very short period of time. It is more likely that intelligent species that survive for long periods of time don't have an overwhelming compulsion to expand, and instead live within their means. Our solar system contains a vast amount of resources to exploit.

I don't know that alien species would be any more inclined to beam an intense signal at us just in case we might be listening. We have sent out signals, but not for very long periods of time, and then only sporadically.

[Steven Lyle Jordan]

Hmm... this thread went from "overused silly sci-fi science" to "serious speculation on sci-fi science." I'm not sure now whether to join into the latest discussion or to mention something about telepathy...

[WT Sharpe]

Maybe something about telepathy would get this thread back on tract. It does seem to have drifted far afield, not that I think anyone minds too much, since both topics are generally of interest to the same people.

[Freeshadow]

I think telepathy belongs in the serious branch
Startrek puts prewarp species in contact quarantine.
I belive in reality it is rather pre-psi and so we are left out of contacts.
why? just look how many ways for misunderstandings are given the ways of communication we use: verbal written and symbolic.
hell we have serious intraspecies comm problems.
just check some of the language themed threads for interesting examples.
keeping this in mind communication with beings we have even a lesser or no common ground to start from is next to impossible (thus extremely overused: the universal translator gadget) I think that development of controlled psi abilties is a basic requirement of inter species contacts.

[Ekaros]

Telepathy is also silly, some form of energy which we haven't discovered? Im not saying some races couldn't communicate with magnetic, electric fields or by radio. Still, whole telepathy and faster than light is a stranger...

Interstellar radio is also an issue. It all comes to signal to noise and bandwith. Amount of information you can transfer is limited.
C = B log_2 ( 1+ {S}\{N})
Capacity, Bandwith, Signal and Noice power...
If I have understood above right, the signal power is limiting factor. And it lowers in inverse square of distance. S = P/(4 pi r^2)... Thus at huge distances the capacity to transfer information get's very low.

[QuantumIguana]

Discussions of silly science and real science go hand in hand. Some of the science that gets labeled as silly isn't so silly after all. It's not difficult to imagine an alien species that has telepathy, they could have evolved biological radio. As for humans having telepathy, it is on the silly side unless there is some good reason given.

[Penforhire]

Very true. I see where today's research on quantum particle entanglement is bringing the idea of telepathy or other instant-over-any-distance communication into the realm of the possible. Maybe our minds just got entangled there for a while?