Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: jellyjan on 27/01/2008 10:54:24
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I know the subject may seem slightly immature but there are two questions behind this topic.
1) How could we possibly scientifically communicate with aliens?
2) What else besides light can travel through space(vacuum)?
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I do not think we can communicate with aliens to any great degree unless they have similar senses to us and live in a similar environment.
We have 'alien' creatures living amongst us with well developed senses such as Chimpanzees and dolphins but we can only have very limited communication with them.
All things can move thru space!, electromagnetic radiation at the speed of light and objects with mass at any speed up to that limit
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Basic mathematics is something common to all lifeforms with advanced technology so the generally accepted route to communication is via mathematics. this allows the generation of basig symbols which are developed and elaborated to enable communication. This would apply to any lifeform however it was constructed. A good example of this process is described in the book and film "contact" by Carl Sagan.
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Greetings Earth people- 4467832256?
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Basic mathematics is something common to all lifeforms with advanced technology so the generally accepted route to communication is via mathematics. this allows the generation of basig symbols which are developed and elaborated to enable communication. This would apply to any lifeform however it was constructed. A good example of this process is described in the book and film "contact" by Carl Sagan.
But if they had neither sight nor hearing, how could we communicate the mathematics to them, or vice versa? It's not easy to tap Morse code on someone's arm if they are 10 squillion miles away.
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Doesn't Voyager 1 have a naked scientist type logo on the side and there is some mathimatical progression involved somewhere. This was done incase some aliens came across it.
Voyager 1 is a real hero. It's still going and is expected to keep sending back data until at least 2020...that's 43 years after it launch! I'll be happy if my 76 merc lasts that long.
is that your phone number Opus? if it is, I'm phoning you tomorrow.
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Doesn't Voyager 1 have a naked scientist type logo on the side and there is some mathimatical progression involved somewhere. This was done incase some aliens came across it.
Voyager 1 is a real hero. It's still going and is expected to keep sending back data until at least 2020...that's 43 years after it launch! I'll be happy if my 76 merc lasts that long.
There are all sorts of things on Voyager, but you are correct. It does have that Leonardo DaVinci Naked Scientists thingy on it. However, if our aliens have neither sight nor hearing, they wouldn't be able to perceive any of the stuff we sent.
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We cannot even be sure how large the aliens would be. Is the voyager going to look like a speck of sand, or like something the size of a mountain, in which case, at what scale will they view what they see (maybe they will pay more attention to the surface texture of the metal than to the symbols writ large on the side).
As has been mentioned - mathematics is a logical connection between things, but although we do have a domestic set of symbols we conventionally use to describe mathematics, these symbols are by no means universal, but merely inventions of our own. The underlying relationships may be universal, but if they don't understand the symbols, then the relationships we may believe they describe are meaningless to them.
In any case, one of the problems with mathematics is that it is too universal (in the nature of the relationships - not in the symbolism). Meaning is derived from understanding large similarities combined with small differences. If all things are totally similar, there is no meaning. This is the difference between DNA, which has lots of irregularities, and so lots of information; and a simple polymer, that has no irregularities, and so no meaningful information.
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I think the problem with communicating with aliens (without two way interactive communication) is a little like the questions of whether there is a God. We need to send them something that demonstrates that there is intelligence out there in the universe (i.e. us). The problem is not unlike our looking out to the universe around us, and arguing whether the complexity/simplicity of that universe is proof of a Godlike intelligence, or is just proof of our own intelligent understanding of natural phenomena. So too, if an alien life were to see the voyager craft floating in space towards them (or even crashing down upon their heads - for it may indeed be a space hazard for them), they could argue endlessly as to whether the complex patters on the craft really represent alien intelligence (i.e. us), or whether it is just a natural phenomena they have to find an explanation for.
Ofcourse, the dichotomy between intelligence and natural is not that simple, and much of what is regarded as intelligent or unintelligent is probably down to prejudice. Honey bees can manufacture sophisticated, and mathematically elegant, hives - yet we do not accord them a high intelligence.
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There has been threads on radio communication over vast distances and the calculations show that transmitters thousands of times more powerful than we have now would be required.
Even the SETI groups admit that aliens would not be able to hear our flea power transmissions and they are relying on aliens having much more powerful ones.
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There has been threads on radio communication over vast distances and the calculations show that transmitters thousands of times more powerful than we have now would be required.
Are you sure about this?
I have absolutely no doubt that this is true of narrow spectrum transmissions, but I am thinking of very wide spectrum transmission with massive data redundancy allowing effective reconstruction even when the signal to noise ratio is minute (after all, the problem with distance is not that the signal will not reach the distance, only that the signal to noise ratio would be so extreme that you would need a very complex level of signal processing to obtain any useful information with those signal to noise ratios).
Ofcourse, as for SETI - the point is, unless they know how to decode the encoding mechanism, it may well not be possible for them to understand the signal even though they would be receiving it.
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We cannot even be sure how large the aliens would be. Is the voyager going to look like a speck of sand, or like something the size of a mountain, in which case, at what scale will they view what they see (maybe they will pay more attention to the surface texture of the metal than to the symbols writ large on the side).
Actually, if we assume basic life processes as being similar to ours then we can. We do have some idea about upper and lower size limits. Any creatures of fly size would be, necessarily, limited in brain power (numbers of cells / memory elements) and, for engineering reasons, they would need to build ships around the size of human's space ships in order to leave a planet of Earth-like size.
Also, there are upper limits to size, based on strength of materials available for skeletons etc.
Evolutionary processes would probably produce successful species on a not-too-dissimilar size to us on any planet which could support similar biochemistry.
That is unless they are based on some bizarre chemical basis which we haven't though of yet. Which is not impossible, of course.
I could imagine a range of body masses spanning a ratio of, perhaps, ten to one? Certainly not more than 100:1.
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If we took a ludicrously optimistic case of an Earth sized planet orbiting a Sun type star in the 'Goldilocks' zone say ten light years away and received coherent signals from it of such strength that a one bit per second communication channel could be set up.
Assuming they were transmitting something like a 'CQ' what could we do about it, we can no longer afford to buy time on large telescopes now that we waste our money on wars!
How many twenty year contacts could be run before any meaningful information could be exchanged, all we could glean is that at least there are 'Aliens' out there that can build radio equipment
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Actually, if we assume basic life processes as being similar to ours then we can.
I don't like assumptions - but then, I suppose the real problem, and one that has never been properly answered, is what do we define as life? It may be that you could argue that we define life as being composed of processes like ours, and if it was not of processes such as ours, we would disqualify it from being called living.
We do have some idea about upper and lower size limits. Any creatures of fly size would be, necessarily, limited in brain power (numbers of cells / memory elements) and, for engineering reasons, they would need to build ships around the size of human's space ships in order to leave a planet of Earth-like size.
I don't actually believe the human animal is that bright at all - it is human society that is intelligent.
So the question should not be about whether a fly could be as intelligent as a human, but whether a society of flies (or similar sized life form) could be as intelligent as humans.
Bear in mind that the human being is not themselves a monolithic entity, but just a collection of cooperating cells. Not flies, but bees, are also strongly cooperative, and so can achieve far more than any single bee or fly could attain on their own (although their is no doubt that the number of cells in a human society exceeds the number of cells in a single bee society).
If a living entity could find novel ways of cooperating at a cellular level, then maybe what we consider an animal might not even exist, yet the collective intelligence of all those cells could still be leveraged.
We presently assume that life can only exist on Earthlike planets (we have changed out mind on this several times). Certainly, it is reasonable to assume that Earthlike life could only exist on an Earthlike planet - but then, we are back to what we consider to be life?
I am not sure whether I accept your limitation on the size of a spacecraft. It rather depends on what criteria you are using.
Certainly, if one is talking about present rocket technologies (and there has been much debate in other threads about whether rockets are really an ideal technology for space launches), the smaller the rocket, the less fuel needs to be carried, and so you have a feedback of being able to even further scale back the size of the overall rocket.
There might be issues about the degree of protection that a small spacecraft may offer its occupants - but that also depends on how much protection they need.
Even within our own experience, we do produce much smaller launch vehicles for unmanned launches (although the smallest are not likely to reach orbital altitudes). Ofcourse, we have ourselves been limited to existing human scale technologies to achieve that. I would ask that if we were able to use nano-scale technologies, is it really the case that we could not create very much smaller launch vehicles for nano-scale or micro scale payloads?
Also, there are upper limits to size, based on strength of materials available for skeletons etc.
Yes, but that is because skeletons were evolved to handle Earth's gravity, and to produce life forms of a given scale within that gravity.
Trees, that do not rely on bone, are capable of growing much higher. Even life that does rely on bones, in particular, marine life, is also not so constrained on size.
I would think it as likely that the real limitation on size probably has less to do with structures (other structures can be used) as the availability of energy, which if radically different from that available on Earth, would imply a much hotter environment, which would preclude the development of Earthlike life.
I could imagine a range of body masses spanning a ratio of, perhaps, ten to one? Certainly not more than 100:1.
Not sure what you mean by this?
Blue Whales are up to 170 tonnes, and heavy as I may be, I am still well under 1% of that body mass.
If you are saying that you cannot imagine something 100 times heavier than a Blue Whale, I am not even sure that is true, but the limiting factor, in my opinion, is not the size of a single animal, but rather the amount of total biomass an environment can sustain (which goes back to my question about energy, as well as the amount of space available), and what proportion of that biomass can reasonably be vested in one organism (bearing in mind that the organism must feed on something, and if it feeds on other organisms, then there must be a substantial proportion of the biomass of the planet vested in the food organisms - and the only way around this is if even the largest of organisms were lithotrophs, but then, is this evolutionarily viable?).
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No earth-being turnipsock- I'm trying to communicate mathematically!
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Trees, that do not rely on bone, are capable of growing much higher. Even life that does rely on bones, in particular, marine life, is also not so constrained on size.
But they don't need to carry enough muscle to move them around!
Blue Whales are up to 170 tonnes, and heavy as I may be, I am still well under 1% of that body mass.
Woops - I forgot about sea organisms. However, their technology could be a bit limited if, as with humans, they need fire to get started.
Not flies, but bees, are also strongly cooperative, and so can achieve far more than any single bee or fly could attain on their own (although their is no doubt that the number of cells in a human society exceeds the number of cells in a single bee society)
This is true, but there are many more possible interconnections between the cells of a complex brain than between the brains of 'simple' individuals. I think this is relevant where sophisticated ideas and tasks come into play.
There is something else to consider about aliens. The more different they are, from us, the less 'interested' we would be in what they had to say to us. It is probably true to say that, if they looked a lot like us, we would be much more empathic (or, possible suspicious). The conspiracy theorists would just love it if they looked like people dressed up.
Initial 'messages', would have to be extremely simple - prime numbers sent in binary form or musically related frequencies. etc. etc.
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Although on a much smaller scale than communicating with aliens dozens of light years away I have had a taste of it trying to make travel arrangements in Melbourne.
Although E.mails zip across in under a second the 11 hour difference in local time means that one never gets a reply in less than 24 hours.
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Trees, that do not rely on bone, are capable of growing much higher. Even life that does rely on bones, in particular, marine life, is also not so constrained on size.
But they don't need to carry enough muscle to move them around!
But human beings have been moving trees around with their own muscles since many millennia.
True, it would take a fair amount of muscle to get a tree to run for any distance at 30mph, but simply moving around at a very slow pace would not take that much muscle, and as I said, we humans have provided the muscle to do that for some time (long before we invented the steam engine).
As I said, I don't really believe the limiting factor is structural, but energy - it takes a lot of energy to move a tree, and one or two trees can be moved by the odd animal (elephants do it quite well), but to supply every tree with the power to move would require a good deal of energy (one elephant per tree in the world would be an infeasible undertaking).
Woops - I forgot about sea organisms. However, their technology could be a bit limited if, as with humans, they need fire to get started.
Why did we need fire?
Certainly, the industrial revolution required fire; and even the bronze age revolution did require fire.
It is conceivable that a submarine life could have used submarine volcanoes or even mid oceanic vents as an alternate heat source.
There were two things that we have that whales lack. Firstly, we have fingers (so any marine intelligent life would have to develop appendages that could have a similar dexterity to our fingers - octopuses are not that bad - maybe the closest, but still some way off).
Then, what really does distinguish us from whales. The most important things is our weakness. We had to use our brains simply because we lacked the brawn to do otherwise. This is why an intelligent life form cannot be the largest life on the planet - if it had that much brute force on its side, it would never have the driving force to need to develop any substantial technology.
This is true, but there are many more possible interconnections between the cells of a complex brain than between the brains of 'simple' individuals. I think this is relevant where sophisticated ideas and tasks come into play.
It is not the number of connections that matter, it is the speed of information transfer that matters (not that, in the design that life uses on the planet, for that too, it is still true that bandwidth is better for shorter distances than for longer ones).
Moving away from carbon based cellular life, and looking at electronic components, it is still true that components that are connected with short pieces of wire can sustain higher transmission bandwidth than components that are separated by longer distances (e.g. by wireless networks); but nonetheless, there are advantages also to having components are are more widely dispersed that communicate over lower bandwidth transmissions.
Even with regard to carbon based cellular life, while it is true that cells that are in intimate proximity to each other have a much higher information bandwidth, the logical conclusion to this is that a single organisms that contains the same number of cells as 6 billion humans should have more intelligence than 6 billion humans that are separated from each other, and have to use relatively low bandwidth communication (e.g. speech) to communicate with each other. Clearly, the evidence seems to be the contrary, that there is an optimum balance between have small blocks of cells with high speed communication between them, and those blocks then more widely dispersed, and using low speed communication between the individual blocks. Exactly what defines where this optimum unit size lies is not something I would claim to properly understand, but I have no reason to believe that the size of a human being necessarily defines that optimum (it must to some extent depend on what the relative difference between the speed of communication between adjacent cells and more widely separated bodies, and anything that effects the relationship between the speed of those two levels of communication must impact upon the ideal unit size for an individual unit).
There is something else to consider about aliens. The more different they are, from us, the less 'interested' we would be in what they had to say to us. It is probably true to say that, if they looked a lot like us, we would be much more empathic (or, possible suspicious). The conspiracy theorists would just love it if they looked like people dressed up.
Indeed - this goes back to what I was saying above - if it is very unlike us, we would probably disqualify it as life, even though it may well function similarly to life in an abstract sense.
Initial 'messages', would have to be extremely simple - prime numbers sent in binary form or musically related frequencies. etc. etc.
So if you received a set of pulses that amounted to a primary number in binary form, how would you know it was from a living entity (or, more precisely, from an intelligent living entity). Many things, such as the patterns of petals on a flower, use the Fabroccini numbers - does that prove flowers are intelligent? Are prime numbers somehow more intelligent than Fabroccini numbers?
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Hi guys,
I think communication with the far reaches of the multiverse are far more attainable than physically getting around the cosmos. I picture some sort of video conferencing with far removed neighbors.
I do some 3D chat at http://www.cybertown.com/main_ieframes.html (http://www.cybertown.com/main_ieframes.html). This involves the use of avatars. Since trying this type of limited virtual reality, I feel that this type of communication would be a basis for interstellar interaction.
My best guess is that signals carrying information would be far easier to send to far reaches of the cosmos, than physical travel. Somehow I see this type of faster-than light-communications as involving the sending of signals via extra dimensions.
First contact would be most interesting. I am sure the first non-random signal we receive will be very strange in content indeed.
I imagine there will be quite a learning curve in both species reaching some common communication exchange. But if this happens, then some sort of exchange of virtual realtiy chat platform could be shared. Instead of going to Zula Prime in the Nth galaxy or them coming here, we meet in our computers and assume avatars.
We can recreate a virtual earth environment for them to explore and they could create a Zula Prime virtual environment to check out. They can show us what they look like by their avatars and we do the same.
Cheers.
Saganist
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Organisms evolve to fit their surroundings in competition with other organisms. OK you can move a tree with human muscles but that's not a big organism; it's a small organism doing some work on a big object. Humans can also run around, defend themselves and chase prey. A 10m human would be no use as a predator; it would have to photosynthesise and would need no brain. 'Intelligence' develops where it is necessary / advantageous; carnivores and omnivores do better when they are intelligent. 'Too much' intelligence is wasted on herbivores so they don't tend to be that smart -just be strong or run fast, which isn't a good starter for 'civilisation' or technology.
Where there has been evolution in isolation - Australia / Galapagos Islands / the sea etc. we find that species develop in parallel fashion, with predators and prey all taking up equivalent roles. There are certain optimum arrangements for given circumstances and these are what develop favourably. There is no reason to suppose that carbon-based life on another planet with 'Goldilocks' conditions would end up developing in a wildly different fashion. I agree that you can dream up all sorts of life forms but Chemistry has to rule. You need complex molecules for 'life' and there is nothing quite so useful as Carbon for this under Earthlike conditions. Is there evidence of alternative complex molecules existing under wildly different conditions in the same way as we can detect the presence of Methane etc. all over the place?
Speculation is only worth while when it is based on a hint of reason or we'll have fairies at the bottom of the garden.
Wales and Fingers: We didn't do well BECAUSE we had fingers; our evolutionary path gave us rudimentary fingers and a crude ability to use them, all in the same process and we ended up with what we have now. Whales' ancestors actually DISCARDED what could have been fingers when they took to the sea and needed flippers, not hands. It seems that organisms. once committed to a particular path, carry on in that direction, changing only when circumstances change radically.
Potential candidates for Alien civilisations need to have gone through similar processes to what we have been through and in similar timescales, too. Any 'top' organism has to reach a level before there is some extinction event which gives another organism the chance to get to the 'top'.
What do I mean by 'top'? I suppose I mean to be successful reproducers and to want to and to be able to communicate with other similar organisms. There are loads of other prolific species which don't give a monkey's about the others except as potential danger of dinner.
I guess it is that majority that we should be looking for, but we will have to go there to find them; they wouldn't have invented Radio.
On the subject of brain size, there is a definite upper limit on human brain size and that is imposed by the restrictions of the female birth canal and on the necessity of having and supporting a skull to protect it whilst we are walking about.
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Organisms evolve to fit their surroundings in competition with other organisms.
Agreed, but all that means is you cannot say how an organism will evolve until you know the environment.
OK you can move a tree with human muscles but that's not a big organism; it's a small organism doing some work on a big object.
That is not the point I was making - only that it is not beyond nature to create muscles capable of moving trees (ofcourse, why would a tree have such muscles itself is another matter).
Humans can also run around, defend themselves and chase prey. A 10m human would be no use as a predator; it would have to photosynthesise and would need no brain.
Trees don't run around, and humans may not have attained 10 metres in height, but various dinosaurs have various claims of size that exceed that (exact maximum sizes seem somewhat mired in controversy - the largest complete seems to be a Brachiosaurus at around 12m tall, but various partial finds of sauropods have been speculated to be up to 18m tall, and 40m long).
Nature can, in the right conditions, be extrely diverse.
'Intelligence' develops where it is necessary / advantageous; carnivores and omnivores do better when they are intelligent. 'Too much' intelligence is wasted on herbivores so they don't tend to be that smart -just be strong or run fast, which isn't a good starter for 'civilisation' or technology.
This is a common stereotype, but I'm not sure how valid it is - but again, it depends on what you consider to be intelligence.
Certainly, animals that have a wider range of food sources will tend to have more curiosity, because they will try new things to see if they are edible. This has nothing to do with whether they specifically are hunters or not.
Snakes, which are obligate carnivores, are certainly not more intelligent than elephants, which are pure herbivores. Whether a gorilla (which is a herbivore) is less intelligent than a chimpanzee (which is an omnivore), I am not sure about. Chimpanzees do seem to have the greater curiosity, but then we come down to whether curiosity is a measure of intelligence?
One think I believe one may reasonably say about that which we recognise as intelligence, is that it is a social phenomenon: which is why elephants, who though herbivores, are highly social and highly intelligent; while snakes, which are obligate carnivores, lack any social structure, and lack much in terms of intelligence.
Another factor that is relevant would be life expectancy. There is no point in spending 10 years teaching a juvenile the skills of life, if they only have an 11 year life span.
Where there has been evolution in isolation - Australia / Galapagos Islands / the sea etc. we find that species develop in parallel fashion, with predators and prey all taking up equivalent roles. There are certain optimum arrangements for given circumstances and these are what develop favourably.
The islands may have been isolated insofar as animal migrations were concerned, but they were not environmentally isolated - they still had the same wider environment to cope with. Also, even their isolation, insofar as it did exist, was only very transient in evolutionary terms (most of these places were not isolated at the time of the dinosaurs, so they still shared a lot of common history with the rest of the planet, even if the most recent part of that history was slightly divergent).
There is no reason to suppose that carbon-based life on another planet with 'Goldilocks' conditions would end up developing in a wildly different fashion. I agree that you can dream up all sorts of life forms but Chemistry has to rule. You need complex molecules for 'life' and there is nothing quite so useful as Carbon for this under Earthlike conditions. Is there evidence of alternative complex molecules existing under wildly different conditions in the same way as we can detect the presence of Methane etc. all over the place?
I am willing, in the absence of specific evidence for alternatives, to accept carbon as the basis of alien life (at least - and this is a key point, for initial alien life).
The main issue is that while the thing we associate most with life is carbon, in fact carbon alone would simply not be enough. We have a complex mix of carbon, hydrogen, oxygen, phosphorous, ..., all the way down to trace amounts of iron and chromium. All of these are critical for life as we live it, but if the ratio of the abundance of these lesser elements was different, then what difference would that make to the life as it existed?
For instance, as has been discussed on a number of other threads on this forum, the importance of vitamin D to all animal life (I don't believe it only applies to vertebrates, or even with the inclusion of animals with exoskeletons, although I may be wrong about this). What vitamin D does is help manage the transport of calcium. What would happen on a planet with more, or less, calcium than exists on our planet?
Bear in mind that the conditions on Earth are not mandated by our being 93 million miles from a medium sized star - they are as much to do with the conditions that formed our moon, which might have been very different elsewhere in the universe.
Even on this planet, just a few tens of millions of years ago, oxygen levels in the atmosphere were much higher than they are today (and earlier on, no oxygen was at all), so all of this makes an enormous difference to the amount of energy available for life, and so what kind of life can exist.
Speculation is only worth while when it is based on a hint of reason or we'll have fairies at the bottom of the garden.
The fact of the matter is we do not have any hint of reason that extraterrestrial life exists at all, so taking that logic, one could argue that all speculation, of whatever form, concerning extraterrestrial life is futile, otherwise we might have fairies at the end of the garden.
The questions we are asking are not "does extraterrestrial life exist?", much less are we asking "what form does extraterrestrial life take?", the question is "what are the limiting parameters that might dictate the possible forms that extraterrestrial life might take?". We are indeed working largely with an absence of evidence, so does this, in your view, make the question futile?
Wales and Fingers: We didn't do well BECAUSE we had fingers; our evolutionary path gave us rudimentary fingers and a crude ability to use them, all in the same process and we ended up with what we have now.
Whales' ancestors actually DISCARDED what could have been fingers when they took to the sea and needed flippers, not hands. It seems that organisms. once committed to a particular path, carry on in that direction, changing only when circumstances change radically.
Yes, but without those rudimentary fingers, we would not have learnt to manipulate objects, and with that ability to manipulate so we developed evolutionary pressures to become ever more dexterous in our manipulations. Had we not manipulated in the first place, there would be no basis upon which the evolutionary pressure could have applied.
Yes, whales needed flippers more than they needed fingers, and this limited their ability to develop tools (although not so much their ability to develop language).
Potential candidates for Alien civilisations need to have gone through similar processes to what we have been through and in similar timescales, too.
You have yet to show any evidence for this statement.
Certainly, there does need to be a similarity in the processes, but similarity in a broad sense, and similar in a specific sense, are two different things. I am not saying you are wrong, only that the statement seems to lack specific evidence, and so I would take it as merely speculative (given what you said earlier about drawing conclusions in the absence of evidence).
Any 'top' organism has to reach a level before there is some extinction event which gives another organism the chance to get to the 'top'.
What do I mean by 'top'? I suppose I mean to be successful reproducers and to want to and to be able to communicate with other similar organisms. There are loads of other prolific species which don't give a monkey's about the others except as potential danger of dinner.
Very few for which this statement is absolute, although there is a wide degree of variation to the extent that it is true of different species.
It is said there are about as many rats in the country as there are humans, and probably even more mice. Both of these animals can communicate and socialise well. Both mice and rats tend to thrive in the presence of man, which is why their population sizes tend to be proportionate to the human population.
On the subject of brain size, there is a definite upper limit on human brain size and that is imposed by the restrictions of the female birth canal and on the necessity of having and supporting a skull to protect it whilst we are walking about.
You are ofcourse talking about a placental bipedal animal. For a quadruped, or marsupial, or even an egg laying animal, that statement is totally false.
Yes, there are good evolutionary reasons why greater intelligence is more common in placental animals - mostly because placental birth is already such a high investment that a parent makes in its offspring, that they are the group of animals that were most likely to further increase their investment in their young by giving them a long training period. If, in another environment, there was a marsupial or egg laying animal that was also forced, for other reasons, to place a high investment in their young, it might be that they would have formed an even larger brain over time.
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This is all interesting enough but it is not helping us to converge on some sort of final statement on the matter.
The original question involved communication with other lifeforms. That implies Technology, which implies a Need for technology on the part of the lifeform. Trees get no net advantage from developing technology. Neither do cows, or most other herbivores. It is only when you need to be inventive because of competition that you start to develop significant culture and technology. Is it really just chance that made the hominids progress at technology where the apes didn't? Or was it because of their particular niche in the ecology of a couple of million years BC?
We seem to be the 'smartest' so far, in this respect and (post hoc, I admit) we can sort of explain why. Our technology outshines the technology of any other organism we know, by a huge factor; we are clearly a bit of an exception. What has made us exceptional? Luck; being around at the right time and being around long enough, before some extinction event, to get as far as we have. One hefty asteroid and things could all be back where they started - tiny creatures running about in the forest amongst the ruins of Homo Sapiens' world.
I, personally, think we are much more likely to come across some humble lifeform, relatively near than end up having a conversation with an advanced one a really long way away.
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Lots of excellent points there anothersomeone- made me think.......
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The trouble is (and this is where we got sidetracked before), you are using different concepts, and blithely assuming they all are unavoidably interlinked.
You are talking about intelligence and technology as if they were one and the same thing. You are also assuming that all technology will inherently lead to telecommunication, or that telecommunication need be associated with other technological advances.
Being 'smart' is about being 'smart' in the context of your environment - there has been much debate about how 'smart' dolphins are (and in fact, arguably, whales and dolphins are capable of telecommunication, if you allow that sending information over hundreds, or thousands, of miles using sound amounts to telecommunication - in an underwater environment, the use of radio would be a technological backward step.
If you want to simply constrain the discussion to radio frequency electromagnetic transmissions (which is all that we seem to be looking for at present), then we should constrain ourselves to that, without asking how intelligent, or 'smart', or even 'civilised' the organism making the transmission is.
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The only meaningful conversations across interstellar distances would be between 'aliens' that had a much longer lifetime than us and a vastly different concept of time.
There is a remote chance that if we were in the right position between two systems that were communicating we might eavedrop on such a conversation but would we recognise it as such ? as the data rate would be very low by our standards
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There is one unicersal way in which all beings that we consider intelligent could communicat. If we found aleins that we considered intelligent there is an extremely high probability that they would know about atoms. Thus we could communicate using atoms. Both us and the aliens would need to be able to detect various atoms. We could then develop a language like this
Hydrogen could be the equivalent of Hello.
If we detected Hydrogen being emitted by an alein this would be 'Hello'. However this would requiere both side to be coincidently using this metheod.
Another possibility is that because of the extremely long time scales of the universe it is also extremely likely that any aleins we encounter will be millions possibly even billions of years a head of us in terms of technology. Such an advanced species will most likely have encountered other life and may have ways of communicating with aleins.
Yet another way that would be a little more difficult is using the positions of stars. If we send them data with the position of a particular constelation with positions of that constelations stars relative to earth and sent them data of earth's position relative to their locations and maped out the stars we gave them relative to their position we could use various grouping of stars as communications. for instance:
Equuleus star constellation means the equivalent of 'Hello'
Another way we could communicate with aleins is by communicating using universal constants. However this may be a bit more risky because many universal constants are constantly changing. Such as the grvitational Constant which has changed some over extended periods of time.
Another way, which would be unblievably difficult and requiere computers so powerful that its like nothing we can imagine. In about 600 hundred years it has been predicted that we will have computers that will be able to simulate the universe. Also this last one here is pure theory. Now using this computer we would enter everything we know about these aleins that is naturally occuring about them, such as their quivalent of DNA and the environment of their planet, moon, star, or whatever other object they live on then have a the computer run a simulation giving data on all possible combinations of what this species could come up with. And I am everything down to at least one of these simulations would give us the exact date they discovered the atom. Then amoung this data would be there language. Then this next part would take a very very very long time depending on their computing power and wether or not they are attempting to communicate with us to, which if we know about each other they may be interested in doing so. We will send them a steady stream of all this data we communicated from our simulation then if they responded using lets just say radio waves to keep it simple we would look for that peice of data amoung our database from the simulation and match it up. At that point we could confirm that to be some kind of a word. After that this process would be reapeted until we discovered many more of their words or rather word equivalent. Then once we have a reasonable number like at a point that we stop discovering additional words then we start sendng the words back to them that we discovered in random orders. Then we wait for a response. If the response sent back contained the same words only in a different order then we could know that their response was the correct order of the words. We keep on doing this until we get more snetances. Then we plug these sentances back into the data we got from the simulation. The simulations would have picked up the positions of the aleins lifeform at everystage of their timeline. We then try and look for situation in which one of these sentances that are correct was spoken by one of the aleins when first interacting another another alein after a period of time. Such as a 'Hello' you may give to a co-worker when arriving at work. Then after all that we will have successfully discovered what is MOST likely some sort of a greeting. At least in theory. However this metheod requires that the aleins have a greeting perhaps the aleins do not greet each other.
I can think of many other possible communication methods and at the same time I can think of holes in any of the above communication methods. That is why if we truly wished to communicate we would need to attempt hundreds of methods.
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The only meaningful conversations across interstellar distances would be between 'aliens' that had a much longer lifetime than us and a vastly different concept of time.
There is a remote chance that if we were in the right position between two systems that were communicating we might eavedrop on such a conversation but would we recognise it as such ? as the data rate would be very low by our standards
The problem is that this leads to something of a paradox.
Ignoring the lifespan of an individual organism (not sure it is as critical as you suggest - but I'll get back to that later), but you are correct that they must have a different notion of time, insofar as they can send a transmission, and wait a couple of centuries or more for a reply, and regard that reply as still pertinent, it implies that not a lot has changed over the couple of centuries or more to allow the continued pertinence of the answer. This is in marked contrast to what we imagine a high technology society to me doing. It would imply that we might be dealing with a society that was once rapidly developing, but has reached a plateau, or else a society with a far longer period of technological gestation than we have had. It implies a society that is inherently conservative, where social change is extremely slow.
As I indicated above, this need not tell us much about the lifespan of an individual organism, only of a social entity. In an ultra conservative society, it is quite plausible for a man to send a message, and know that his grandson will receive the reply, and know exactly what kind of life his grandson will live (for his grandson will in all probability inherit the social position he himself holds today), and so the reply will be meaningful to the family (in such a society, it is the family that holds a place in society, rather than the individual), even if the particular family member who sent it is long dead by the time the reply returns.
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There is one unicersal way in which all beings that we consider intelligent could communicat. If we found aleins that we considered intelligent there is an extremely high probability that they would know about atoms. Thus we could communicate using atoms. Both us and the aliens would need to be able to detect various atoms. We could then develop a language like this
Hydrogen could be the equivalent of Hello.
If we detected Hydrogen being emitted by an alein this would be 'Hello'. However this would requiere both side to be coincidently using this metheod.
Another possibility is that because of the extremely long time scales of the universe it is also extremely likely that any aleins we encounter will be millions possibly even billions of years a head of us in terms of technology. Such an advanced species will most likely have encountered other life and may have ways of communicating with aleins.
Yet another way that would be a little more difficult is using the positions of stars. If we send them data with the position of a particular constelation with positions of that constelations stars relative to earth and sent them data of earth's position relative to their locations and maped out the stars we gave them relative to their position we could use various grouping of stars as communications. for instance:
Equuleus star constellation means the equivalent of 'Hello'
Another way we could communicate with aleins is by communicating using universal constants. However this may be a bit more risky because many universal constants are constantly changing. Such as the grvitational Constant which has changed some over extended periods of time.
Another way, which would be unblievably difficult and requiere computers so powerful that its like nothing we can imagine. In about 600 hundred years it has been predicted that we will have computers that will be able to simulate the universe. Also this last one here is pure theory. Now using this computer we would enter everything we know about these aleins that is naturally occuring about them, such as their quivalent of DNA and the environment of their planet, moon, star, or whatever other object they live on then have a the computer run a simulation giving data on all possible combinations of what this species could come up with. And I am everything down to at least one of these simulations would give us the exact date they discovered the atom. Then amoung this data would be there language. Then this next part would take a very very very long time depending on their computing power and wether or not they are attempting to communicate with us to, which if we know about each other they may be interested in doing so. We will send them a steady stream of all this data we communicated from our simulation then if they responded using lets just say radio waves to keep it simple we would look for that peice of data amoung our database from the simulation and match it up. At that point we could confirm that to be some kind of a word. After that this process would be reapeted until we discovered many more of their words or rather word equivalent. Then once we have a reasonable number like at a point that we stop discovering additional words then we start sendng the words back to them that we discovered in random orders. Then we wait for a response. If the response sent back contained the same words only in a different order then we could know that their response was the correct order of the words. We keep on doing this until we get more snetances. Then we plug these sentances back into the data we got from the simulation. The simulations would have picked up the positions of the aleins lifeform at everystage of their timeline. We then try and look for situation in which one of these sentances that are correct was spoken by one of the aleins when first interacting another another alein after a period of time. Such as a 'Hello' you may give to a co-worker when arriving at work. Then after all that we will have successfully discovered what is MOST likely some sort of a greeting. At least in theory. However this metheod requires that the aleins have a greeting perhaps the aleins do not greet each other.
I can think of many other possible communication methods and at the same time I can think of holes in any of the above communication methods. That is why if we truly wished to communicate we would need to attempt hundreds of methods.
All sorts of possibilities exist, but as you have subtly indicated, they are only meaningful once there is an agreed code as to how one should use these symbols. If a word (whether it be a hydrogen atom, or the position of a star, or anything else) that we believe says "I come in peace", they interpret to mean "I will kill you", then you have problems whatever you are using (even assuming they and us do ascribe any meaning at all to particular tokens).
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What will they make of The Beatles' "Across the universe" - an all-out declaration of war???? Have NASA really thought this thru??
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What will they make of The Beatles' "Across the universe" - an all-out declaration of war???? Have NASA really thought this thru??
the aliens might already be fans of 'earth music'...
http://en.wikipedia.org/wiki/Voyager_Golden_Record (http://en.wikipedia.org/wiki/Voyager_Golden_Record)
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----There has been threads on radio communication over vast distances and the calculations show that transmitters thousands of times more powerful than we have now would be required.
Are you sure about this?-----
Absolutely. You can calculate received signal to noise ratio given transmitter power, frequency, receiver noise figure, bandwidth, aerial gains and distance. There are even on-line 'calculators'.
I am familiar with boucing signals off the Moon with large antennas arrays and 400 - 2000 Watts of power at mid VHF. Path loss is over 250 dB and special transmission techniques are used these day which improve the situation by a few dB only. Signals are pretty weak. There is a limit to which special transmissions and processing at the receiver end can improve the situation.
Path loss over just one light year at 150 MHz is 336 db ... another 86 db which is 400 Million types greater in power times.
So you would need 400 Million times more power than the minimum 400 Watts for the Earth-Moon-Earth path....with the same antennas. = 160 Billion Watts (about double the output of all the UKs' power stations?) ....for just one light year to get a weak signal. The antennas would melt in seconds.
The problem of using lower power and large dishes or arrays is the narrow beam angles. It make the chances of two aerials being aligned by chance extremely small.
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There is a limit to which special transmissions and processing at the receiver end can improve the situation.
This is the key issue I was wondering about. Are these theoretical limits, or merely technological limits?
Bear in mind that we are talking about radio signals that may have to travel several hundred light years, thus to receive a reply would take twice that, so if the message too 1 year to transmit, that may mean a signal that might take 10 seconds worth of actual transmission, and the rest of the year merely sending error forward correction signals, that is a massive amount of redundancy that can be introduced into the signal, and so a very high noise immunity.
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I would have though once a signal is well below the noise there is nothing you can do no matter what you do. Integration of a period of time will have its limits.
There are suggestions that the only way you could communicate would be to float huge dipoles (1.5 Million km) which have massive aperture in space and use carrier frequencies of the order 0.1 Hz. Data rates would be very slow indeed. Very large dipoles would have very wide acceptance angles and collect a signal of the order a dish of the same diameter working at VHF and higher.
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I would have though once a signal is well below the noise there is nothing you can do no matter what you do. Integration of a period of time will have its limits.
I don't see this is the case.
Noise is the random fluctuation of a signal. Information is a meaningful variation from that randomness.
If you look at the noise as a series of events over a period of time, then the signal you are looking for is a subset of those events. The likelihood of the noise being inseparable from the signal is dependent on how probable is it that the events you are looking for are created by random chance within the noise you are receiving. The larger the number of possible events are in what you are viewing, then the less likely that any single event is one of the events you are looking for, so the greater your certainty that the signal you are receiving is meaningful and not merely a manifestation of random noise. Thus, if one has one years worth of signal, that signal amounting to 1 billion events per second, then you have 3.155x1016 events; which, if they are treated as binary events, are 23.155x1016 combinations of events. If one is looking for 10 seconds worth of signal within that one years worth of transmission, then one is looking for any one of 21010 combinatorial events within a space of 23.155x1016 possible combinatorial events.
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Take it from from there are no working systems which can rescue signals which are well below the noise.....and we are talking 60 - 80 - 100 dB ++ below noise. 100 dB is 10 billion times in power terms below noise. You can dream up fanciful schemes to extract a tiny bit of info from a signal with massive redundancy and take a 1000 year to do but it wouldn't be much use would it?
There are other problems with long distances which space agencies have to deal with. Even at the record distance we have received a signal fom a spacecrft which is only 1/600 of a light year signals tends to arrive garbled due to group delay. There are very slight differences in the speed of popagation at different frequencies so bits of a signal (which apart from sinple 0n-off keying - Morse has a spreed of frequencies) arrive before others.
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Take it from from there are no working systems which can rescue signals which are well below the noise.....and we are talking 60 - 80 - 100 dB ++ below noise.
Not doubting this, but that is a technological limit, not a theoretical limit.
You can dream up fanciful schemes to extract a tiny bit of info from a signal with massive redundancy and take a 1000 year to do but it wouldn't be much use would it?
But as has been said above, if you are dealing with hundreds of light years distance, you are not talking about real time two way communication, whatever you do - the limitation is not about getting the signal through, it is simply about how long the signal takes to get there. It is more like sending a letter to Australia in the days of clipper ships , or maybe more like the Pope trying to communicate with the Emperor of China in the Middle Ages - probably even worse than that. It is not as functional as we use radio communications today, but if it is the best you have available, but if it the best you have, it is still better to use it than not to.
There are other problems with long distances which space agencies have to deal with. Even at the record distance we have received a signal fom a spacecrft which is only 1/600 of a light year signals tends to arrive garbled due to group delay. There are very slight differences in the speed of popagation at different frequencies so bits of a signal (which apart from sinple 0n-off keying - Morse has a spreed of frequencies) arrive before others.
Agreed - so you have to make compensations for that either on the transmission or receiver side (this is something that network engineers have had to deal with continually - reshaping signals).
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It is getting too esoteric and too 'science fiction'. I am just making the point that huge transmitter powers would be needed to communicate at distances of the order of one light year never mind hundreds of light years.
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It is getting too esoteric and too 'science fiction'.
If we are talking about interstellar communication - ofcourse its science fiction - we don't do it, so however we might do it must be regarded as science fiction with regard to current capabilities. The only issue is to understand what is plausible and what is implausible science fiction.
I am just making the point that huge transmitter powers would be needed to communicate at distances of the order of one light year never mind hundreds of light years.
I am just not convinced that that is the only way (although clearly it is one way) of achieving that end.
Incidentally, no matter how big the transmitter, it makes not the slightest difference for the group propagation problems (in fact, that is probably not totally true, as increasing signal strength to the point where the signal could change the properties of the medium it is passing through, could make it worse).
On the other hand, it does not appear that group delay is so bad a problem that we cannot temporally resolve signals from millisecond duration pulsed quasars, although this clearly we would hope for better signal resolution than that if we are trying to transmit real communication signals.
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Group delay is a separate question and there is a considerable difference between the 'rough note' pulsar etc and a communications signal.
To think there could be any technique that could retreive signals which are millions of times below noise...not only receiver noise but cosmic noise is a bit like me saying that I could make my ordinary car do 100,000 MPH and 50,000 MPG (at the same time). Anyone looking towards Earth would also be looking at our Sun and receive its radio noise.
At some point there will be no signal..at some distance..when there are just no electrons being stimulated in a aerial by our Earth transmitter.
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Group delay is a separate question and there is a considerable difference between the 'rough note' pulsar etc and a communications signal.
http://en.wikipedia.org/wiki/Pulsar
Owing to their extraordinarily rapid and stable rotation, MSPs can be used by astronomers as clocks rivalling the stability of the best atomic clocks on Earth. Factors affecting the arrival time of pulses at the Earth by more than a few hundred nanoseconds can be easily detected and used to make precise measurements.
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To think there could be any technique that could retreive signals which are millions of times below noise...not only receiver noise but cosmic noise is a bit like me saying that I could make my ordinary car do 100,000 MPH and 50,000 MPG (at the same time).
Who is talking about 'ordinary'?
We are talking about what could be done with novel technologies, not how we can convert what we have today to achieve this.
Anyone looking towards Earth would also be looking at our Sun and receive its radio noise.
This is true, but it is all about the discussion about signal to noise. Ofcourse our sun will contribute to the noise, but that is not to change the nature of the underlying problem. Ofcourse, the majority of that noise will also be out of band, but there is no doubt that it will contribute to noise across the spectrum.
At some point there will be no signal..at some distance..when there are just no electrons being stimulated in a aerial by our Earth transmitter.
So what would be happening to the photons in the wave? Do the photons lose their energy? To what would they lose their energy?
Yes, the number of photons you detect would reduce, but it will never go to absolute zero.
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I think too much emphasis is being put upon the dispersion of the signal, the aliens that I visualise communicating over tens of light years would be quite happy to use a bit rate of 10^-6 bps which would enable the use of very narrow band receivers (computer simulated) to recover a much weakened signal.
I don't think we that have a 'snow balls chance in hell' of eavesdropping on such communications let alone joining in!.