Alone In A Crowded Milky Way (scientificamerican.com) 472
Basic extrapolations suggest that if there are other spacefaring civilizations in the Milky Way, they could spread across the entire galaxy with surprising speed. Why, then, have we found no irrefutable evidence of aliens visiting Earth? Popular answers to this puzzle -- that we are alone, that interstellar travel is impossible, that aliens are hiding from us -- all rest on assumptions that verge on implausibility.
Drake equation (Score:2)
No data (Score:5, Insightful)
The Drake equation [wikipedia.org] suggest that many alien civilizations should exists.
No, it does not because there are far too many unknowns. In particular, the probability to evolve intelligent life. The problem is that we only have a sample size of one which is self-selected to produce intelligent life so we don't know really know how likely it is to happen, all we know is that it is possible. Armed with this information we cannot make any prediction about the probability of even life elsewhere in our galaxy, let along an alien civilisation.
For example, suppose life does evolve quickly in the right conditions but the odds of it evolving to the multi-cellular stage is about one in 10^12 for any billion year period of the galaxy. Suddenly, even if you have 100 million habitable planets with the right conditions, even one civilization seems unlikely. However, if that probability is only 1 in 10^6 per billion years then the galaxy is teeming with intelligent life. Until we start visiting other star systems the only thing we know about this probability is that it is not zero.
Re:No data (Score:5, Interesting)
This, it's quite possible we're the only intelligent life in the universe. Of all of Earth's species, it's only produced a handful that could be considered "intelligent," and from what we've seen so far, intelligent species tend to do things that reduce the number of intelligent species on their planet to 1 or 0. Evolution tends not to favor the production of the relatively huge energy-guzzling brains that make species intelligent.
Here's another idea, what if abiogenesis is startlingly unlikely? A creationist stats professor buddy of mine tried to use math to prove that abiogenesis was improbable to the point of impossibility, thus proving the existence of GAWWD. He did have a point that the odds were strongly against it happening, but obviously it happened...so, what if we're just incredibly lucky to have had all the molecules dance in the right way on Earth to have any form of life?
Re:No data (Score:4, Interesting)
It's not just intelligence but intelligence that gets into technology in a big way.There's lots of intelligent animals that will never become too technical, dolphins, birds that aren't equipped for tool making, octopuses that don't pass any knowledge on (no parental care) as well as living in an environment where technology is hard.
Even the various Homo species have spent most of their history without getting too technical with even currently various groups that were/are quite primitive as in stone age technology.
Good point about having no idea about abiogenesis as well, but even if common, it took the Earth being stable for billions of years before intelligence could evolve, a lot has to go right.
Re:No data (Score:5, Interesting)
This, it's quite possible we're the only intelligent life in the universe.
A discussion like this, rife with unknowns, begs a particular question that is often ignored or never asked. The biggest question is, are we actually that intelligent? Or, would a (hypothetical?) spacefaring civilization classify us as intelligent in the same way they think they are?
We have developed technology unimaginable even a few generations ago, but we are a long way from achieving interstellar travel, so it is a huge stretch to label ourselves "spacefaring." For heaven's sake, we've sent a few people to the moon a handful of times which, I don't need to remind anyone here, is a minuscule fraction of the distances that are relevant here, while we have no prospects for expanding beyond Earth in the foreseeable future. And technology can not be the only measure of intelligence. Look at all the grief we've caused ourselves over the millennia, and what we are doing now: we are on the brink of war around the globe, billions of humans are malnourished and food insecure, and we conduct ourselves differently behind closed doors than we do in public view, often submitting to our animal instincts that we otherwise repress and abhor in others. We are destroying our planet and everything on it, while too many of us (I'm guilty) sit back and enjoy a privileged Western life, all while espousing on the virtues of equality and sustainability.
It is possible, although no fun, to think that something like the zoo hypothesis is plausible, less because we are being protected per se, but rather we are being excluded from the galactic party because we are not worthy, or capable. Star Trek technology is still a long, long way off (if it is all possible at all), but we are even farther from achieving so many other things that are likely requirements for going interstellar and being accepted by evolved and advanced societies. We need to fix our society and take care of business on Earth, and we are doing a poor job.
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Building civilizations and developing technology is a massive step up from just having life and it takes many random characteris
Re:No data (Score:5, Insightful)
>A creationist stats professor buddy of mine tried to use math to prove that abiogenesis was improbable to the point of impossibility, thus proving the existence of GAWWD
More likely his proof was deeply flawed. Most such proofs fail in one of two ways - by drastically overestimating the amount that needs to be accomplished at once, or by drastically underestimating the size of the laboratory.
There are 10^21 kg of water on Earth, and 10^25 molecules of water in a kg. In the "invisible" first half-billion years of Earth's existence (where the crust has all been subsumed) there are 10^16 seconds, and a gas molecule will collide 10^10 times per second at STP (couldn't find information on liquids I'm not sure if the greater molecular density or lower molecular speed would dominate, but I would guess they mostly even out.)
So, that's in the ballpark of 10^67 potential chemical reactions with water molecules between when the Earth started supporting liquid water and when the first geologic records show that life already existed. That's plenty of experimental room for 10 independent one-in-a-million chances to all occur simultaneously, 10,000 times over.
And you don't need to create life - just reasonably robust, imperfectly self-replicating chemistry. Once you have that, evolution would likely take it the rest of the way to something we'd recognize as life.
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No, it does not because there are far too many unknowns. In particular, the probability to evolve intelligent life.
It is not just intelligent life. It is the ability of that intelligent life to create a technological civilization. For instance, marine creatures, e.g. dolphins, could be highly intelligent, our peers even, but living in the oceans means that a lot of the drive to develop technology, e.g. fire, agriculture, huts and so on, simply isn't there or is impossible.
On the other hand, it is becoming increasingly clear that animals can be quite intelligent, e.g. dolphins and ravens, and industrious, e.g. beavers, s
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Not necessarily - we might be a rare exception that developed spaceflight before we encountered the carrying capacity of our planet. Numerous island species here have evolved to self-regulate their population in the absence of predators, where overpopulation is the greatest threat to survival. It might be that intelligent species normally evolve similar self-regulation before they become spacefaring. Especially given the fact that our planet is already almost too large for rockets to be able to get us to
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Another possible explanation is that we live in a simulation [wikipedia.org], as such other civilizations are not created for optimizations purposes (i.e. 2x or more computing power to run two instead of just humanity).
Yet another possible explanation is that we are all living on the back of a turtle. Basic extrapolations fall apart on the cosmic scale, since it is turtles all the way down, where the other civilizations live on their own turtles. Extrapolations don't work on the subatomic scale either, since the turtles are so close to each other that they start fighting and quantumly entangle themselves.
We will only discover these civilizations when we develop inter-turtle space travel.
We might also discover that th
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It has long been known that the turtles bend spacetime in proportion to the mass that they carry, so the turtles themselves get cancelled out. Basic algebra.
Re:Drake equation (Score:5, Interesting)
The aliens all got plastic beer pack holders stuck around their necks and died painful deaths!!!
But seriously, we're intelligent enough to create amazing gadgets and crazy big buildings and structures but we're doing it in a totally out of control unsustainable manner which is poisoning us all already and this will only get worse if we keep letting idiots run our countries.
We are rapidly wiping out all other species, I read in the news that a great extinction event is about to happen. That is wrong, the extinction event is not about to happen, it IS happening right now, we've already wiped out a sizeable percentage of other species and we're doing that faster and faster. The way we're going we'll wipe ourselves out pretty soon. Whether it be by run away global warming or by dead land due to pollution and over-farming or by a pathagen which spreads rapidly and leaves only remote tribes that'd never be able to recreate the technological progress that we just went through.
The other possibility is that we'll try something in physics that wipes us all out in one go, scientists weren't completely sure that the 1st atom bomb wouldn't kill us all, that didn't stop them from trying it to find out!
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We are also wiping out ourselves at the pace we are holding right now.
Few are around that are skilled and equipped to survive in a world that's tougher than it is today. Many of the gadgets that we have aren't going to survive for more than a few years either.
Re:Drake equation (Score:5, Insightful)
Or perhaps the speed of light really IS a limit that you cannot breach, and getting even close to it requires so much power that you cannot do it, even harnessing the power of an entire sun. So thus interstellar travel is limited to maybe 4 light-years range (meaning a trip there and back, at the insanely fast speed of 0.1c, would take 80 years, and a single question and answer communication would take 8 years. For us, that's exactly 1 star we could reach. What are the odds that that singular star has life? Pretty damn slim.
It's probably nothing "grandiose" like a "Great Filter", but probably something really mundane such as the speed of light, and basic physics.
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Re: Drake equation (Score:4, Interesting)
Orbit of Mercury is about 70 million km from the sun [space.com]; assume we put our Dyson swarm at that range. That means the spherical surface of that orbit would be (4*pi*R^2) ~6.1E16 (61,000,000,000,000,000) square kilometers (61 quintillion square kilometers).
You have mentioned that it should be a swarm with a lot of satellites; let's assume you use just one satellite per 10,000,000 square kilometers (that is a bit bigger than the land area of the Continental US) [bymap.org]. With that density of coverage (1 per size of the US), we need 6.1 billion satellites.
Assuming 6 billion satellites, each being 1 km square, and 1mm thick, that is 1000 cubic meters of satellite. Assume we use silicon (solar collection, electronics, etc). The density of silicon and silicon dioxide is about 2.5 grams per cubic centimeter [researchgate.net]. That is about 2500 kg per cubic meter; meaning each satellite will need 2.5 million kg of silicon.
Since we have about 6 billion satellites, we will need around 15 trillion metric tons of silicon to build the swarm. We produce about 700,000 tons of silicon a year [earthmagazine.org], so we would need about 21 million years of current production to harness enough silicon.
Let's assume we ramp up production of silicon by a factor of 1 million. So now, in 21 years, we will generate all the silicon we need. Of course, there is energy needed to lift it to orbit! It takes about 33 MJ of energy [wired.com] or about 9.1 kWh, to take 1 kg just to low Earth orbit. We have 15 quadrillion kg of silicon to move, so we need just shy of 140,000 petawatt-hours of energy. The world uses about 157 PWh total, annually [wikipedia.org], so we need about 900 years worth of 100% of our power consumption to do the lift.
And note, this is just to get to orbit, nothing about actually breaking Earth's orbit and positioning around the sun. Nothing about metals, or other materials needed like copper or aluminum. And we're not even talking about replacement of failures, yet. Assuming just a 0.1% failure rate, you need to replace around 6 million satellites a year. And this is a Dyson swarm with a coverage of just 0.00001% of a sphere with the radius of Mercury's orbit. And I assume we can ramp up our silicon production by six orders of magnitude, AND we can increase our total power generation (just for lift, mind you - not for actual satellite assembly) by a factor of 50. Yeah - that's pretty optimistic, to say the least.
So there's my math - how about yours?
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You used ridiculous assumptions there, like that you would build on a planet and then launch to orbit. Why would you do that?
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As Drinkypoo stated - you've made a lot of ridiculous assumptions with those calculations - you wouldn't start building something on the scale of a Dyson sphere until you already had a thriving space-based economy that of a scale that renders Earth-based industry completely irrelevant.
And why would you build it out of silicon? Silicon is relatively heavy, rare, not very strong, and doesn't even make that great of solar panels compared to theoretical alternatives. Not that you'd need the surface of your co
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So the solution is to assume we have science capabilities that we don't even know exist - or can exist, we use materials that we know we cannot make (graphene). And that material is terrible for reflection in the visible spectrum (and is essentially invisible to UV - UV passes through it, meaning it's a terrible mirror.
And that setup - focused mirrors and collectors - is considerably more complex than just using silicon to make solar collectors in the first place.
I chose 70,000,000 km as that's the orbit
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Graphite really is a terrible reflector of light (visible), and is highly transmissive to UV. So it sucks for being a reflector of solar energy. And where would the collectors exist? Will they handle 700+ deg C differentials (bright versus dark side), which will be magnified by your approach of condensing energy from multiple mirrors to fewer collectors?
As far as a Dyson sphere, that would NOT be at Mercury's orbit, but around Earth's orbit, which is a LOT bigger. And note that my math was for a 0.00001
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It's not just a matter of speed. Aside from radiation there is the existence of random debris floating around. If your space vehicle is traveling at 0.1 c even a small rock packs an incredible punch. And if you want to send a space vehicle with a primer for building a self sustaining modern civilization in a different star system (i.e. carrying millions of people), it is going to be huge and will hit some of the debris.
Building and equipping such a ship is an extreme expense that is unlikely to ever pay its
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For your solution to be valid it would require that all members of all species capable of interstellar colonization believe that interstellar colonization is not a good idea. The moment that a small portion of a single species think it is a good idea then it becomes likely that it happens.
If it was that easy, why are we still Earth-locked? There are millions of people who wants us to colonize the solar system, including at least one billionaire, and yet we haven't even sent people to another planet in our own solar system. Small groups cannot raise the resources needed. Interstellar colonization is many magnitudes more expensive than colonizing Mars or Venus, and likely to be an endeavor requiring a full and dedicated effort from our entire planet for millennia. A small rag-tag group of hero
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You are conversing with a space nutter. He is talking something that is theoretically possible but absolutely impracticable. You will never convince him that he is wrong. Leave him alone to enjoy his dreams.
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One thing that is left out of these thought scenarios is economics. Economics assumes that individuals are rational actors, which admittedly is an overly-strong assumption. But rational concerns at least *constrain* individual choices, which make economic theory useful.
If we assume that technological civilizations are *rational*, then economics can be used to model their behavior as well. These models all assume that if a large set of civilizations gain the capability to build interstellar vessels it's vi
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Forget planets for a moment - if you're a spacefaring species that wants more land, you'll likely create something like O'Neill cylinders or other space habitats long before you seriously consider colonizing other stars - among other reasons, space habitats remain within the influence of the existing civilization and produce additional wealth within the existing trade networks. And once you've got a few thousand years of building and maintaining an ever-growing swarm of such space habitats under your belt,
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So where is that computer? Who created it? Why?
Well gee, aren't those exactly the same questions that are asked about "god"?
Advances in science and technology (Score:5, Insightful)
Another plausible explanation is that having gone through all of 200 years of technological civilization we don't really know anything. On a billion-year time scale, we're dreadfully ignorant. Aliens could be zipping back and forth in front of us and we just don't know how to see them yet.
Re:Advances in science and technology (Score:5, Insightful)
The problem with SETI and similar methods of detecting civilizations beyond earth is that trying to capture radio signals leaking from such civilizations can only propagate at most a few dozen light years. Unless some distant civilization actually know we're here and uses a high powered form of communication like a laser beam we won't hear it. Presuming the la s of physics make FTL travel impossible, we won't be having any aliens paying us a visit either.
Re: Advances in science and technology (Score:5, Interesting)
No, the problem is you are viewing the problem through human eyes and intelligence. There may be species that hibernate naturally, there may be ones based on silicon, shit, they could be just like us but so evolved the technology doesn't even register to us.
It's like any sci-fi program made 40 years ago, you look at it now and think, see how cute, they didn't even know about digital storage back then. But they were trying hard to think about the future, but as all things, they were constrained by the tech and thinking of the time.
Now imagine a race that had a 500k year headstart on humans, but don't have a natural tendency to prey on themselves.
What could humanity look like in 100k years? What tech could exist? I leave it to you to ponder, but stop looking at alien civilisations through a human perspective, it's just so narrow...
thanks (Score:2)
Well put
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Re: Advances in science and technology (Score:2)
The universe is a big place (Score:4, Insightful)
Even the galaxy alone is impossibly huge. Maybe the aliens simply have better things to do than go slumming with the humans.
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Mostly harmless.
Re:The universe is a big place (Score:5, Funny)
Even the galaxy alone is impossibly huge. Maybe the aliens simply have better things to do than go slumming with the humans.
Right, what everybody always forgets in this discussion location, location, location. The earth is located far out in the uncharted backwaters of the unfashionable end of the Western Spiral arm of the Galaxy, not exactly prime real estate. On top of that humans are widely known among the older civilisations as the hillbillies of the galaxy. Combine a bad location with noisy, messy, unhygienic, opinionated, xenophobic and stinky neighbours with a distressing tendency towards solving problems by shooting at them and who would ever want to live in this neighbourhood?
Re:The universe is a big place (Score:5, Interesting)
The earth is located far out in the uncharted backwaters of the unfashionable end of the Western Spiral arm of the Galaxy, not exactly prime real estate.
Right on! We're like the Alabama hillbillies of the galaxy.
Except for one tiny little problem with the urban galactic center: More stars means more supernovae to irradiate you and blow off your atmosphere, more chances to get blasted with gamma ray bursts, and higher chances to have a wandering star come through and throw your planet off into the cold, dark void of space.
Sure, denser concentrations of stars theoretically means you'll have a greater chance of life popping up near there, but there's also a greater chance of that life getting obliterated at some point too.
Are we worth contacting? (Score:5, Insightful)
The fact we don't have a centralized world government may be reason enough to avoid the whole situation. And what about the religious aspect. Would a highly religious race spread the word or have their own morality stop themselves from telling a planet with a multitude of religions, "You've wrong."
Why would they even settle on planets (Score:4, Informative)
Asteroid belts have so much more material to construct habitat with, at near zero launch costs. Some of them have high concentrations of metals and rare earth minerals because they originate from the core of planetary dissolution events. So, you don't need to settle distant planets for raw material.
Really, the argument for 'archipelagos' is just the theory that von Neumann machines populate the galaxy for no purpose. The question remains, why would they build their own factories on hostile, deep gravity wells instead of barren moons?
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Based on what we can see when we look out into the universe, stars are the most likely energy source for any civilization. We also know that solar winds clear a lot of space out around stars, so there's going to be a balance between finding low mass objects to mine with being close enough to the star to extract enough solar energy to run your stuff.
As to why one would build a factory in a hostile, deep gravity well: Safety. If it's got an atmosphere that won't kill you, you don't need to be so paranoid abou
nobody wants to talk to a bunch of savages (Score:2)
who would want to communicate with people that are violent. selfish and greedy, our civilization and societies are far too immature and unethical
I'm sure the extraterrestrials know that contact with a lesser species could be detrimental to us, I'm thinking they study us as we study primitive cultures and with the same need to preserve isolation
the upper class has kept us in economic slavery for too long, that's the main thing that we need to change
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Man isn't Advanced Enough to Ask Right Question (Score:2)
After RFTA and looking at the comments here it feels like everybody who is making a comment (including the author's of TFA) don't know enough other than to guess or state beliefs.
It doesn't seem like we've progressed sufficiently in the past 70 years to be able to properly validate/invalidate Fermi's original paradox or make a reasonably accurate model of how civilizations evolve, grow and colonize.
alternatively (Score:2)
There are two obvious possible answers (Score:4, Interesting)
One possible answer is "the great filter", i.e. technological societies tend to self destruct. Perhaps nearly always self destruct. We've currently got so many potential methods that it's hard to count them.
Another is that after spending several centuries traveling in interstellar space, planets no longer appear to be reasonable places to live.
And there's nothing wrong with combining the two answers.
Another answer may be that most forms of life can only live in a fairly narrow niche environment, and it may be too difficult for them to even take over their own planet. E.g., elephants would have a hard time with space flight. But you could think of that answer as a part of the "great filter".
You don't need one simple answer to the question, when it may really be a complex of many different answers. But my real belief is that space adapted civilizations don't find planets attractive.
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Gamma ray bursts (Score:2)
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Great article, but evolution & morality are ch (Score:3)
Not specifically addressed in this great article, but almost certainly dealt with as parameters in the many simulations considered, is that evolution occurs in very rapid fits and spurts as environments change [wikipedia.org].
Settling another planet - or just hanging out in space for a millennia on the way to a planet - would certainly produce some interesting new species that will no longer be human, and will thus have very different values and motivations.
From the article, emphasis mine:
These radically different approaches highlight the challenges of making meaningful statements about interstellar migration. There are always a lot of big assumptions in any study like these. Some are reasonable and easily justifiable, but others are trickier. For example, all scenarios involve guesses about the scope of the technology used for interstellar travel. Furthermore, when the species is “along for the ride” rather than sending out sophisticated robotic emissaries, the most fundamental assumption is that living things can survive any kind of interstellar travel at all .
It is almost certain that if anything survives interstellar travel, it will very quickly bear little similarity to the original organism that set off on the journey.
If biological organism like us are to travel, the variability in environments -even during transit- would very quickly lead to many different species. Even if fully synthetic self-replicating AI probes were to expand throughout the galaxy, if their information processing 'AI' had enough similarity to our biological brains, even they would evolve into unrecognizable probes over time. Units of ideas and units of biological information evolve in nearly identical ways (memes) [wikipedia.org].
Rather than using Pitcairn Island as an example of exploration across the galaxy, it might be safer to assume that we are late to the expansionist game, and the realistic scenario of settling other worlds would more closely match the interaction between the Spaniards and the Incas.
As the article mentions, expansionist civilizations hiding from each other might be the most prudent thing to do:
There is also what I like to call the paranoia scenario: other civilizations are out there but are hiding from one another and refusing to communicate because of some kind of cosmic xenophobia.
Or, given our own history and enough time, our children will come home to [eat | conquer | subjugate | educate] us.
Space is vast, time moreso (Score:2)
We need to focus on not merely distance but also time. Both are vast. How long will a civilization survive? 10kyears? Broadcast for maybe 1k?
That is less than one-millionth of the age of the universe; even considering it might take half the universe age to have 3G stars to make heavy elements. There may be/have been other civs out there, but there is no reason to assume any sort of time synchronicity. Star Trek ain't real, folks.
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Too many unknowns (Score:3)
Separate from the question of how often technological civilizations evolve and last, is the question of limits of technology and intelligence. How advanced can civilizations be? Is it like modern civilization vs the Romans, like modern civilization vs paleolithic hunters, or possibly modern civilization vs ant colonies? If the last we might not even recognize alien civilizations right here: ants living in a crack in the cement, won't know that they are living on an airport.
Then there is the question of where civilizations will go. Paleolithic man often lived near water holes - modern man rarely does. Maybe planets are not interesting to advanced civilizations. Maybe most intelligent life lives in brown dwarf star atmospheres.
Then there are all the reasons that civilizations aren't contacting us, ranging for zoos (prime directive), to lack of interest, to predator civilizations that are even as we speak, destroying our civilization with weapons we can't recognize - like gassing rabbits in their burrows.
Interstellar distances aren't a huge impediment, imaginable technology can get to something like 0.1C, and there is no particular reason to believe other species (or robots) will have lifspans like ours.
Its fun to speculate, but I don't see any way to put probabilities on it. Still, its an extremelly important question and worth continuing to investigate
Extrapolate from evidence, not sci-fi (Score:3)
Star Trek is not real. We need to extrapolate from actual evidence, not science fiction fantasies. Here is the actual evidence.
We only have one example of a species with human level intelligence. That species has existed for about 200,000 years. For 99.9% of that time, it didn't even have a way to get off the ground. It still has never gone beyond its own moon. It currently has no credible way of traveling to another star any time in the foreseeable future.
That's the evidence. Maybe humans are really unusual, but more likely we're typical of intelligent species. No E.T.s have come to visit us. Are we supposed to be surprised? Why? That's totally consistent with the evidence. Humans can't travel between stars, so it's hardly surprising if other species can't either.
Sure it's fun to fantasize. Maybe some future scientific discovery will enable us to travel at close to the speed of light without needing crazy amounts of energy. Maybe we'll figure out a way to extract energy from empty space. Maybe we'll give up on sending humans and just send robots, and who cares if it takes them 10,000 years to get there? But these are just fantasies. If we're going to reason based on actual evidence, 100% of the species we know about can't travel between stars and quite likely will never be able to. We shouldn't be surprised if other species are the same.
Re:They have it backwards (Score:5, Insightful)
You seem to have confused interstellar travel and faster-than-light travel. They are not the same.
Re:They have it backwards (Score:5, Interesting)
Re:They have it backwards (Score:4, Interesting)
If you could actually travel fast enough to make the time dilation significant, I imagine there would be an entire market of people who would like to see what the future is like.
There are also a lot of people who would like to say adios to Earth and her populace and go start over somewhere new.
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Getting to high gamma (time dilation) is extremely difficult - the mass ratio of the rocket (even for a matter / antimatter rocket) becomes extremely large. If you accelerate at 1 G for 20 year you would be at a very high gamma, but your starting mass ratio would need to be something like e^20 - a very big number.
If you try to accelerate at 1G with external power sources (laser sails, etc) the power required to maintain one G in the rocket frame grows as gamma.
Getting to 0.1C looks technologically reason
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Interstellar travel is an one-way-trip. You will never be able to return home.
This has not stopped us from sending rovers to other planets and probes into interstellar space.
Even if you survive it due to life support systems, cryogenics or other methods, ...
You are assuming biological life that evolved on a planetary surface. Civilizations likely transition to cybernetics once they develop AGI. A cybernetic mission could adapt well to space, self-repair, and has an unlimited lifespan.
A roundtrip through the galaxy at 0.1 c will take half a million years
That is 0.0004% of the lifetime of the Universe.
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This has not stopped us from sending rovers to other planets and probes into interstellar space.
But the product of that endeavor (information) is returned in a relatively timely manor. And that's all we really wanted anyway. A bunch of worn-out robot parts are worthless.
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Re:They have it backwards (Score:4, Insightful)
It'll take thousands and thousands of years to reach another star.
We have thousands and thousands of years.
We have millions of years.
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We may, in fact, be homo sapiens for just another few hundred thousand years.
"We" means any spacefaring civilization originating on Earth. That is not necessarily, and most likely won't be, homo sapiens.
With progress in genetic modification and cybernetics, we are transitioning from Darwinian evolution to intelligent design, which progresses a million-fold faster.
We can design our descendants to be well adapted to space. We can transfer our intelligence to the digital realm.
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Civilizations likely transition to cybernetics once they develop AGI.
Just like civilizations transition to pigments once they develop paint.
Other reasons to go (Score:2)
I think you're limiting yourself when you're just considering business cases.
There is also the desire to just find out what's over there. Humans often move on never intending to come back, so whether you could or not might not feature so large in your decision making process.
Consider also the idea of ensuring the survival of the species. For some humans, the idea of their genes continuing is of paramount importance. Wouldn't motivate me, but might others.
These are just two that came readily to mind.
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Yes...and no (Score:2)
Now we can certainly hope that future technology will make this a lot easier to achieve (and I frankly think it is even li
Re:Yes...and no (Score:5, Insightful)
1000 years ago, a trip to the moon could have been described that way - the cost in resources being insanely high, and therefore unlikely to ever happen.
Oddly enough, last year was the 50th anniversary of the first such trip.
So, let's extrapolate to 22020 (20K years down the road) - are you really so confident that you know what we'll be capable of then?
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1000 years ago, a trip to the moon could have been described that way - the cost in resources being insanely high, and therefore unlikely to ever happen.
Oddly enough, last year was the 50th anniversary of the first such trip.
And it was so expensive and complicated to do, it's been done exactly 5 more times since that first trip.
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Current projections are that it will take centuries to get to even a nearby star system and the cost in resources to build a generation ship capable of doing that would be insanely high, so high that it is unlikely ever to happen.
So live longer. Done.
We can't visit nearby star systems because we're still more primitive than a tree in many ways.
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It's not impossible, just very slow. There are at least hypothetical methods that could accelerate a spacecraft to some significant fraction of c. It wouldn't make much difference to folks back on earth but time dilation means it might not be so bad for the adtronauts.
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They indeed have it backwards. It might not be impossible, but it is indeed highly impractible to travel interstellar. Sure, we can send some probes that take fifty years to even leave our solar system. But sending humans requires sending a closed, sustainable ecosystem that has to be able to go on for millenia before reaching nearby stars. Such an ecosystem will have a huge mass that will use a lot of Earth's resources to just give it escape velocity. And since there is no economic benefit of such an endea
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Name one of these benefits
You might be making incorrect assumptions about which parts of the species we load onboard those rockets [wikipedia.org].
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Clearly there isn't going to be warp drive or anything like it, ever. Power requirements aside, it just doesn't work. So you would need multi-generational colony ships with renewable supplies of fuel, food, water and oxygen. Considering how little chance there is that you could actually find an inhabitable planet comparable to Earth, heading out on a slow ship is probably untenable. On top of that, most planets that have life will probably still be at microbial stage of evolution, and the number that have a
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Power requirements aside, it just doesn't work. ...
Folks, it is called science Fiction, for a reason.
The reason that your comment is science fiction is that you made it up (fiction) and that you blather about stuff presumed to be sciencey.("science")
You don't know what the list of things that you don't know are, so you can't possible even know what is possible, and what is not possible. And if you were smarter, smart enough to consult contemporary science, you would learn that the unknown isn't known. But then you wouldn't know everything, you'd have to accept being ignorant and just not knowing, but you'r
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So you turn away from religion saying it's stupid and illogical to have a big guy with a beard to worship as a god, only to have a void in you that now you need to fill with aliens.
Who tend to be small and hairless. Interesting.
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Belief in aliens is as stupid and illogical as belief in god.
There is a key difference between a belief in god and asking a question of why we have seen no other alien civilizations in the Universe. People that belief in god have no evidence of one existing - there is set of 0 of known Gods. People that ask questions about alien civilization have evidence of one existing (us) - there is set of 1 of known civilizations.
The question of "aliens" is to be understood as "Are we unique, and if so why".
Re:Belief in aliens (Score:4, Insightful)
not true, there is some empirical evidence for higher realities and divinity, NDEs, miracles, etc, not to mention philosophy and theology, funny how the thought of higher realities closes some minds ... just saying
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Only if you define "some" as "none".
funny how the desperate desire to be special and have a purpose in life closes some minds to reality ... just saying
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Belief in god: super-intelligence that supersedes the laws of nature and, in most cases, basic logic, yet still gives a shit about humans for some reason.
Belief in aliens: the possibility that the processes that created us also occurred at least once somewhere else.
Yup. Clearly the same thing.
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Belief in aliens is as stupid and illogical as belief in god.
Believing in aliens is simply thinking that what's happened here on Earth has also happened somewhere else, that there's microbes, plants and animals on other planets seems likely. It's true that we're fantasizing about what future technology they might have, but if aliens with warp drives are implausible it's because warp drives are implausible. We're extrapolating what we could do with a million or billion years worth of science when we can't reasonably predict what life will be like 50 years from now.
Re:Simple explanation (Score:4, Informative)
Except for inconvenient existing evidence such as fossil record that shows that the species that you see evolved here, and the inconvenient non-existent evidence such as anything that support your theory except a quick rewrite of Chariots of the Gods.
Unsupported isn't out of the box. It's just unsupported.
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The most simple explanation is that we are part of an expanding intergalactic civilization.
Why not? An advanced civilization decides to test its origin theory, and seeds planets in similar solar systems with prokaryotic and/or eukaryotic cells to what, if anything, develops.
It could just be a way to spread or continue organic life for an advanced civilization on the brink of destruction. Maybe they've discovered that initiation of life from dead matter is the bottleneck.
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Perhaps this amazingly advanced civilization has a rather small minority of critical thinkers in its population, with a majority still clinging to the origin theory long established by religious worship.
GP's is simply an interesting theory. Dissecting the intentions of a life form born on another world is thoughtful exercise, nothing more.
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Re:An often overlooked problem: the CMB. (Score:5, Informative)
The wavelength of the CMB is about 6 mm. If we redshift it by a factor of about 1100, it represents a temperature of 3000 K, the temperature it origins from. That would be at a speed of 99.9999 percent of the speed of light (or about 1 millionth below the speed of light). That means that we have a time dilatation of a factor of about 1000. A trip across the galaxy would feel like a 25 year long travel.
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