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Any thoughts on why SETI or other approaches have not yet made contact with alien civilisations?
Some possibilities:
1. All civilisations hitherto have managed to destroy themselves through warfare, or injudicious experimentation (e.g. black hole experiments).
2. The "goldilocks" theory applies to earth with avengeance i.e. earth is not just right for life, but it is about the only sort of planet that could be right for advanced life. If you then factor in that advanced intelligent multicellular organisms may themselves be "freaks of nature", one can see that earth type civilisations may, more's the pity, be extremely rare. And even if such life gets going, we know it could be extremely vulnerable to comet strikes.
Any other ideas.
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They have located us, transported themselves to our planet and are using advanced nanotechnology to mask themselves as the infiltrate our society?
Or maybe as a civilisation advances everyone learns to transcend matter and become beings of pure energy?
Come on to the Future
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Some good points there.
We already have technology that can effectively make military vehicles "invisible" (involves projection of the background image on to the front of the vehicle) and we are only a 2-300 years into an industrial revolution - think what might be produced 10,000 years hence.
Beings of "pure energy" may well be possible.
But all these civilisations ought to have produced zillions of radio signals before that and we ought to have received some by now, surely, since we are receiving from all parts of the galaxy/cosmos.
As a side line to this discussion, it's often said our original TV porgrammes like "I Love Lucy" from the 1950s are now 50 light years away from earth.
Is it true the signal will remain coherent over that distance or does it become diffuse and incoherent?
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Or maybe they might not be as adnced as us, and any alien civ within our historic radio sphere could just be developing still
Maybe we and another advanced civilization will notice each other once their radio signals reach us, in any case there arent any within 100 lights years so far.
Who knows ther might be many life bearing and habitable planets in our galaxy but only a hand full of intelligent civilizations spread out in it.
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Not all Alien civilizations will by default develop the same level or types of technology as us. In our region of the galaxy, civilizations may have never discovered radio waves or electricity. Its not incredibly unlikely. Only in the last two centuries have such technologies existed on Earth, a very short time compared with the thousands of years that our species has used much more primitive technology.
Many Alien world maybe in a medieval state of technology or even more primitive. The paradigm for technology may be completely different on an alien world due to its alien conditions.
An example would be that many central and south american civilizations became very complex, but never invented the wheel. There technological development was different to that of middle east/europe.
Truthfully, we may never know what form an Alien civilization will take. We can make good guesses based on our own history but we should never conclude that there is know one out there just because we haven't heard a radio-wave signal in the few decades that we studied this.
We should be patient and keep looking.
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There is probably only a short period of time from when a civilisation develops radio telescopes and when they stop using radio waves and move onto more advanced (neutrino the next step then quantum based???) methods. Plus, if we believe Ray Kurzweil and the like, aliens will have hit the technological singularity a century or two after discovering radio.
Use what is abundant and build to last
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Zhar -
Two points:
1. Our star is relatively young. There will have been billions of older solar systems around in the cosmos, so if it's relatively easy for intelligent life to evolve, it should have evolved in millions of those solar systems.
2. Doesn't matter if our signals are only 100 light years away. We should be bathed in signals by now, from those earlier-evolving solar systems.
Gregori -
It is completely incredible that an advanced civilisation wouldn't discover radio waves! Radio waves are part of one of the four fundamental forces of the universe. Even if they are discovered say 2000 years after an industrial revolution on a planet makes little difference in terms of what we will be receiving here in terms of radio signals.
Terraformer -
A good point. But surely all sorts of alien activity would simply generate radio waves, even if they weren't being used as a means of communication.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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But those radio waves would just be random static and so indistinguishable from the CBR.
Plus, why would aliens be using the same format as us? That's like me trying to post HTML into BASIC to try and detct whether the HTML is indicative of intelligence.
Those 'Billions of older star systems' will be too old and won't have the correct elements for even life, let alone alien life.
Off course, if we do find alien life, it will be definate evidence of a creator.
Use what is abundant and build to last
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For reference, this type of argument is what is called the Fermi Paradox or as Enrico Fermi said "Where are they?"
As you can see there are many explanations, they fall into two categories:
1. They don't exist - we are alone, the very first intelligence in the universe
2. We can't detect them - they are too remote / rare / hiding / undetectable by our sensors / we are too stupid to recognize them
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See also ...
Why is the Universe silent?
http://newmars.com/forums/viewtopic.php?t=5136
Fan of [url=http://www.red-oasis.com/]Red Oasis[/url]
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Gregori -
It is completely incredible that an advanced civilisation wouldn't discover radio waves! Radio waves are part of one of the four fundamental forces of the universe. Even if they are discovered say 2000 years after an industrial revolution on a planet makes little difference in terms of what we will be receiving here in terms of radio signals.
Its incredibley arrogant to assume they would.
Humans are pretty intelligent species, but for the most part of our existence on the planet, we hadn't relied discovered radio-waves, never mind using them for communication. Technology is not a linear path. Societies which have discovered and lost different technologies have come and gone. Concrete wasn't to be re-discovered until centuries after Romans first used it. The Egyptians maintained an advanced society that built monumental architecture without having discovered Iron/Steel etc etc
Who is to say an "industrial revolution" will even happen on another planet.
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My conclusion: We aren't alone in the universe, but we are alone in the galaxy. An alien civilisation would need warp drives to get to Earth, something that requires dismantling the home star and planets and turning them into energy, or tapping the Z-Point.
Any alien signal would just look like random junk to us. Here's an analogy: I get HTML (or some other programming language witten in english), and show it to someone who doesn't know english, let alone HTML. Even if they knew English, it would still look like gibberish to them. They'd need to know English and HTML to decode the document. We don't know the aliens language or their computer language, so we have no hope of knowing whether the signal we get is the product of an intelligent species, or simply the product of some random natural phenonomea. It's incredibly arragont to assume the aliens are going to be using the same language, the same computer language, and the same system we use for data (binary). By adding a third state in they could have more data in the same space.
Use what is abundant and build to last
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It is naive to think that advanced ET would be dependent on our radio emissions as the sole or even primary means of ascertaining our existence. Consider what is very likely to occur with us in the next few years:
Cataloguing celestial bodies that are of a size, composition and temperature similar to that of Earth with
> NASA’s Kepler mission (scheduled to launch in 2009), SIM Planetquest and Terrestrial Planet Finder, and ESA’s Darwin project, scheduled for launch in 2015
> Ground based telescopes with the equivalent of primary mirror apetures in excess of 20 meters including the Giant Magellan Telescope (24 meters), the Thirty Meter Telescope and the European Extremely Large Telescope (42 meters). All scheduled for first light from 2016 to 2018.
Identifying indications of biology with NASA’s Terrestrial Planet Finder, ESA’s Darwin and ground based telescopes, all of which will have an increasing ability to identify gasses (such as oxygen, ozone, methane and nitrous oxide) indicative of biology.
Although cost, completion and capability estimates of incomplete or unbuilt projects are always dubious, it seems likely that many of the goals of these projects will be met; especially considering all of the various technologies, funding sources and involvement of many different nations and institutions. In the next 15 years or so we will see the fruition of some of the understanding and capabilities of 20th century physics and technology in indentifying:
> Earth sized planets with a temperature and composition similar to that of Earth around thousands of nearby stars.
> Biology of a similar character and on a similar scale to that of Earth around hundreds of nearby stars.
In the last seventy years we’ve seen the invention of radio astronomy, charged-couple devices, adaptive optics, interferrometry, and space based astronomy amongst many other very major developments.
It’s hard to conceive that 2008 represents the ultimate in human understanding of physics and in technological deployment. Even with the most sparing extrapolation of the capability of 20th century technology, by 2100 it seems likely that these detection capabilities will have increased by orders of magnitude, as has been the case in the last seventy years.
Since the number of stars increases with the cube of the distance from Earth (within about 5,000 light years) and radiation decreases with the square of the distance, a ten fold increase in detection capability results in a one-hundred fold increase in candidate stars. The Giant Magellan Telescope will produce images up to ten times sharper than the Hubble Space Telescope.
A hundred fold increase results in data for ten thousand times as many stars. Thus by 2100 we would expect identification of
> Earth sized planets with a temperature and composition similar to that of Earth around tens of millions of nearby stars—detection beyond a thousand light years from Earth.
> Biology of a similar character and on a similar scale to that of Earth around millions of nearby stars—detection hundreds of light years from Earth.
We can also expect some qualitative improvements such as the ability to detect chlorophyll, gases produced by metal working (active on Earth for more than 8,000 years), coal burning (>3,000 years) and industrial gasses such as as chloroform (1840s), gasoline (1850s), kerosene, naphthalene and benzene (1860s), and DDT (1870s).
If we will be able to do this, advanced ET should be able to do a lot more, but, at the least, ET should be able to determine from many thousands of light years away and from hundreds of millions of star systems:
> The size, temperature and composition of Earth
> The existence of widespread biology on Earth
> The presence of technology.
Without reference to radio at all.
Bob
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Since life itself is such a fluke, probably only 1 planet in every Spiral Galaxy (the only Galaxy capable of supporting life - See Galactic Habitable Zone) has life. 1 in a 100 have complex life. 1 in a 10,000 have intelligent life. I doubt there is any complex life in Our local group, and we'd have to go billions of Light Years to find other intelligent life. We can't get their radio waves now because they've only just set off.
Only stars in the same category of the sun (K2 is it?) will be able to support life.
Use what is abundant and build to last
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“Since life itself is such a fluke, probably only 1 planet in every Spiral Galaxy (the only Galaxy capable of supporting life - See Galactic Habitable Zone) has life.”
We don’t know that life is a fluke. The fact that it arose on Earth apparently as soon as the water stopped boiling suggests that life may arise quite easily. And it has existed on Earth through huge solar, geologic, atmospheric and climatic changes over 4 billion years. Life on Earth arose easily and is very robust. Our own solar system contains at least one other planet and one moon where life may be, or have been, possible.
“Only stars in the same category of the sun (K2 is it?) will be able to support life.”
I don’t think this is correct. Stars smaller than the sun will have habitable zones closer to the star, but the stars will last longer—in most cases, much longer which will give time for many different processes to take place as the stars and their planetary family evolve.
Large moons orbiting gas giants beyond the habitable zone may provide a much larger population of abodes for life. There may be a trillion large celetrial bodies orbiting stars in our galaxy. That gives a rather huge range for biological experiment.
“1 in a 100 have complex life.” Maybe, or is it one in ten?
“1 in a 10,000 have intelligent life.” Maybe, or is it one in a hundred?
I’m glad you’re so certain about all of this. I’m not.
Bob
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It's all speculation, but so is every other idea to do with Intelligent Alien life so I don't really care.
Those other stars won't have the correct amount of Heavy elements for life. Take something as simple as a magnetic field that is neccersary for a habitable planet. Without metals there can't be a flowing conducter, without enough radioactive elements there can't be a flowing conducter. Of course that does not discount the possiblity of Interstellar Wanderers being caught by a star.
The problem with smaller stars is precicely that the planets have to orbit closer in. The planet will become tidal locked.
The orbit has to be nearly circuler in order to minimize the temperature swings. Add a moon/primary planet into that to stabilize its axial tilt.
The fact that Earth has life can't be extrapolated to other systems. The odds are so against life arising that exraterrestrial life in this galactic cluster will be clear and convincing evidence for a creator.
If we are looking for ET inside our Galaxy the first question to ask is: How many K2 (that *is* the suns spectral type?) stars are inside the galactic habitable zone that aren't Binaries (sure, a stable orbit could be maintained, but think of the radiation. And all those comets/asteroids flung your way. Tattionine must have been terraformed.) If there aren't any then we should give up looking for life inside this galaxy.
Next stop: Andromeda. I haven't mentioned yet how the galaxy has to be above a certain size to have stars that are like the Sun. Andromeda will definately have K2 stars in its Galactic Habitable zone, but we need a decent amount here and there to have a chance of just life.
So still no life. Let's go further afield to other clusters. Eventually we'll find Microbial life. Then eventually complex life. Finally, millions/billions light years from Earth, we'll find Intelligent life. That civilisation would have to be a Type 4 civilisation (the energy output of an entire cluster or supercluster, can anyone help at deciding the definition) to have a stab at getting to other Intelligent life, if they haven't given up the search. Of course that's discounting Instantaneus communications being picked up from other civilisations, something that could happen as soon as we switch our first recievers on. That point is many 100s of millions of years in the future. Assuming that the other civilisations are at the same level as us (whichis a reasonable assumption, given how old the universe is), we'll probably find out about them in a thousand years (when we switch our first Instantaneus receivers on).
So there you have it. A solution to Fermis Paradox.
The Drake equation - 'A way of compressing a large amount of ignorance into a small space', as one scientist put it.
Use what is abundant and build to last
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Correction - The Sun is a G2 star.
Use what is abundant and build to last
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“Those other stars won't have the correct amount of Heavy elements for life.”
Stars formed at about the same time and place as our sun will have similar elemental compositions regardless of spectral type. Stars formed more recently than our sun may have even larger amounts of heavy elements, again, regardless of spectral type.
“The planet will become tidal locked.”
This isn’t true. Both electromagnetic radiation and gravity decrease with the square of the distance. In the solar system Venus at .72 AU is not tidal locked, which would seem to give a lot of room for non-tidal locked planets in a habitable zone around a star. Large moons orbiting gas giants in or near the habitable zones, which could be the most common places amenable to life, would completely obviate any issue of tidal locking.
“The orbit has to be nearly circuler in order to minimize the temperature swings.”
I don’t think this is true either. Large bodies of water can stabilize temperatures for many years, and life has demonstrated that it can readily adapt to cyclically changing environments
“Add a moon/primary planet into that to stabilize its axial tilt.”
Again, this isn’t necessary as the examples of the relatively stable climates of Mars and Venus suggest.
“The odds are so against life arising...”
I can as easily, and, I think, with more justification say, “The odds of life arising are almost 100%.”
Bob
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The climate of Mars is stable because there isn't much of a climate in the first place. Venus' is stable because the massive atmosphere smoothe out any changes. Both planets are not conducive to life.
Those stars of different spectral type won't
give out the right amount of light for planets with life.
What about those periodic eclipses that gas giant orbiting moons will have?
Life does not, I repeat not, spotaneously arise even with all the right ingrediants in place. Poke a hole in a cell so all it's contents leek out into a Prebiotic soup (which, by the way, has no evidence for it). You now have all the ingrediants for life. Leave it for a few million years, expose it to heat and radiation, come back and what will you find? You certainly won't find a living cell. What you'll probably find is gunk formed by the DNA, Proties, and Amino acids breaking down.
Then you run into the problem of evolution, which is currently in crisis. Where did all that information come from. Even if it happens, most planets with life won't get beyond bacteria and primitive multicelluer.
Then assuming some of those planets get to complex life (ie. Beyond jellyfish) they've got to get to the stage at which intelligence is advantageus. Then they have to develop technologically.
In the solar system Venus at .72 AU is not tidal locked,
No, but it nearly is.
Use what is abundant and build to last
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The climate of Mars is stable because there isn't much of a climate in the first place. Venus' is stable because the massive atmosphere smoothe out any changes. Both planets are not conducive to life.
Those stars of different spectral type won't
give out the right amount of light for planets with life.What about those periodic eclipses that gas giant orbiting moons will have?
Life does not, I repeat not, spotaneously arise even with all the right ingrediants in place. Poke a hole in a cell so all it's contents leek out into a Prebiotic soup (which, by the way, has no evidence for it). You now have all the ingrediants for life. Leave it for a few million years, expose it to heat and radiation, come back and what will you find? You certainly won't find a living cell. What you'll probably find is gunk formed by the DNA, Proties, and Amino acids breaking down.
Then you run into the problem of evolution, which is currently in crisis. Where did all that information come from. Even if it happens, most planets with life won't get beyond bacteria and primitive multicelluer.
Then assuming some of those planets get to complex life (ie. Beyond jellyfish) they've got to get to the stage at which intelligence is advantageus. Then they have to develop technologically.
In the solar system Venus at .72 AU is not tidal locked,
No, but it nearly is.
The Miller Urey experiment, after :!: 1 WEEK :!: produced nitrogen bases. You know how many carbonaceous chondrites are red? That's organic compounds. Amino Acids. The basis of life. give life enough time, it will become multicellular. Give it a billion or 10 years more time, intelligent life will arrive. A marslike moon with an atmosphere orbiting a saturnlike gas giant, towards the warm part of the habitable zone, around a red dwarf, will have all of the time it needs and will probably get life. Fermi paradox: Intelligent life is self destructive.
-Josh
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“Those stars of different spectral type won't give out the right amount of light for planets with life.”
Those stars of different spectral type will give out the right amount of light for planets with life.
“What about those periodic eclipses that gas giant orbiting moons will have?”
An hour every few months?
“Leave it for a few million years...”
When was this experiment last performed?
“Then you run into the problem of evolution, which is currently in crisis.” ???
I guessed I missed that. What crisis?
“Even if it happens, most planets with life won't get beyond bacteria and primitive multicelluer.”
When it happens, most planets with life will get beyond bacteria and primitive multicelluer.
As for Venus being nearly tidally locked, a miss is as good as a mile.
Bob
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As for Venus being nearly tidally locked, a miss is as good as a mile.
That is what my second wife said. I think you are right.
Vincent
Argument expected.
I don't require agreement when presenting new ideas.
-Dana Johnson
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Actually the TV signals that escape to space don't endure for very long before they become background noise.
If intelligent life existed on the next closest start to us and had been beaming TV signals like we do, we couldn't detect them as more than background noise.
The belief that a radio bubble exists for 50+ years away from Earth is a myth.
At around 1ly TV signals become just background noise.
Unless some intelligent civilization has a very big radio dish and sends a very powerful signal right at us we would never detect them.
We would also have to be listening at that star with a very big dish when they send.
The galaxy might be a very noisy place with TV and Radio, but the distances from star to star far enough to make it just background noise.
Science facts are only as good as knowledge.
Knowledge is only as good as the facts.
New knowledge is only as good as the ones that don't respect the first two.
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The Freon bubble on the other hand has been broadcast 24/7 with a a 600 million square kilometer antenna in a 360 degree sphere for 80 years; informing everyone that we use refrigeration, have substantial electrical distribution and freight delivery systems, fractional horsepower electric motors, measures of some kinds of industrial activity, and lots of other implications.
Then there’s the chemical bubble broadcast for 150 years: chloroform, gasoline, kerosene, naphthalene, benzene, DDT and numerous others.
The coal burning bubble for over 3,000 years.
The metal working bubble for 8,500 years
And the agriculture bubble for 10,000 years.
Radio is not at all necessary.
Besides, advanced ET may have other tricks up their sleeves no one has thought of.
Bob
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