Extraterrestrials Probably Haven't Found Us - Yet 588
kasparn writes "The Guardian today has a story about the Danish astrophysicist Rasmus Bjoerk, who recently conducted simulations on how long it will take to colonize the Milky Way. The basic idea is to send out probes in different directions (including various heights above the galactic plane). He estimates that it will take some 10 billion years to explore 4 % of the Milky Way. Since the age of the Universe is of the same order, his conclusion is that aliens can't have had time required to find us yet."
Forgot one thing... (Score:2)
I should hope so... (Score:5, Funny)
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Actually the cylons will find us first (Score:4, Interesting)
Actually the "cylons" will find us first, it is far cheaper to send robotic explorers out. Then if anything interesting is found send the "manned" missions.
Re:Actually the cylons will find us first (Score:4, Insightful)
I'll refer to my second sentence: "Then if anything interesting is found send the "manned" missions." Do you realize how much nothing is out there, where is the "fun" in finding another dead rock just like so many others? Forget the romantic fantasy of spaceflight, it will be uncomfortable, boring, and stressful. With robots doing the scouting there will be a greater number of interesting things for the manned missions to investigate, possible more than could be sent out. Now if manned missions did the initial exploration, the people would largely see nothing of particular interest. I think you are vastly overestimating the novelty of finding another dead rock in space, sure it would interest us, but a generation born after such discoveries become commonplace?
Actually it is a major point of debate, scientists favoring a large number of robotic missions, politicians favoring a handful of manned missions. Manned missions are multiple orders of magnitude more expensive.
Eat at Earth (Score:5, Funny)
I am sure their galactic physicians will recommend they don't eat too many humans from the Northwestern Continent due to cholesterol or something, but that they can eat all the yellow humans from the east they want, even if they will be hungry again in a few parsecs.
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Unless these alieens are doing the Kessel Run, of course.
Regards,
--
*Art
That's assuming... (Score:2)
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I think if you're going to go through the trouble of writing a paper like this it would be interesting to consider an FTL scenario as well. Say compare the numbers for 1/10c, c, and 10c. But then again, what would the realistic assumption be on speed?
Re:That's assuming... (Score:5, Interesting)
1. That they can't develop PROBES that travel faster than 1/10th the speed of light.
2. That probes of this form that would keep running long enough would be so massively expensive that even the most ambitious race would only be able to build 8 of them (He does address this complaint, and also considers 200 probes instead of 8, and von Neuman machines instead of static probes, neither of which drop the figures below 4x10^6 years to explore a mere 4% of the Galaxy).
3. He doesn't even consider non-material, photon-based probing methods, which would increase the rate of exploration by a factor of 10.
Re:That's assuming... (Score:5, Funny)
You mean looking at stuff through a telescope?
Re: (Score:3, Insightful)
You could look for an oxygen/carbon-dioxide atmosphere, but then you're just making assumptions about what sort of life you're looking for...
Re:That's assuming... (Score:5, Insightful)
You don't understand. (Score:3, Insightful)
Doesn't matter. Light only travels so fast, and we've only been here, what, 10,000 years? Nobody further than 10,000 light years away could have possibly found us yet. And a 10,000 light year sphere is well less than 4% of the galaxy.
This whole study is kind of dumb, because it doesn't matter that you can explore 4% of the galaxy in 4 billion years when we've only been here f
Based on poor assumptions (Score:4, Insightful)
Re:Based on poor assumptions (Score:5, Insightful)
Re:Based on poor assumptions (Score:5, Funny)
(That said, I totally agree with you.)
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c/10 is 30,000km/s. The article makes the assumption that alien civilizations have advanced enough that their spaceships are 1,000 times faster than ours - not unreasonable.
Re:Based on poor assumptions (Score:4, Informative)
No, it is quite unreasonable. The Cassini probe is going 32km a second (71,000mph / 115,000kph). That is more than a thousand times faster than the record less than a hundred years earlier.
We pretty much already have the technological capability to get a small probe up to c/10. We have the knowlege and basic designs to do it... it is already "mere" enginering and $$$$ problem for us today. If we simply chose to allocate several gigabucks to do it, we could with absolute certainty get something up to c/10 within 10 to 20 years.
Assuming our civilization doesn't implode in one way or another in the next few hundred years, getting well over c/10 is a certainty. The only uncertainty is whether the speed of light really is an inviolate limit, or whether some unimagined phyisics will have us exploring the universe way beyond the speed of light.
But looking at his paper I see that the real problem with his figure isn't his c/10 speed limit, but his laughable assumptions and exploration strategy of tiny fixed number of probes zig-zaging between stars almost one at a time. Even with conservative assumptions.... assuming just 0.5c and an interstellar civilization manufacturing just one probe per year... and assuming a reasonable strategy... the entire Milky Way could be explored in just a few million years.
With more reasonable assumptions, the entire exploration rapidly becomes light-speed limited. After the initial local exploration, an advanced technology civilization could mass produce replication-capable miniprobes or microprobes and use a maximized galactic search strategy. Send those probes out on a straight line courses directly to the various sectors of the galaxy... with the worst case probe taking between 150,000 years and 225,000 years to reach the opposite side of the galaxy. Within a handful of years the probe locates an uninhabited rock and sets up an automated factory to send out a few million miniprobes or microprobes, which scout all of the stars in that sector within about 20,000 years. Elapsed time: less than a quarter million years to get a probe to every star.
And really you only need the tech and pay the $$$$ to make and launch *one* such replicator miniprobe. After that, the entire exploration proceeds automaticaly and "for free". We will probably have this technology within a hundred years. Some time within the next 10,000 years... hell lets call it some time in the next 100,000 years of civilization... someone can and will do somthing like this (if we are still around). Once anthing remotely like this gets started, it doesn't much matter how you tweak the assumptions. The most it does is add in a small multiplier factor to the timeline. It is almost inconceivable that we (assuming we are still around) will not have probed every star in the Milky Way within a million years from today.
10,000 years or 50,000 years of technology and manufacturing is an insignifigant blip in the analysis. That technology level and time span means that a civilization can and will trivially produce the resourses needed to explore at a stbstantial fraction of the speed of light. Actual strategy and behavior only accounts for a small constant multiplier. the defining factor is the speed of light, and it locks down the final answer somewhere between 160,000 years and just a few million years. His result of needing 10 BILLION years to explore just 4% of the Milky Way is comical.
The only real question is whether the speed of light really is inviolable. If that falls, then I say we only need between 100 and 1,000 years of technology and then we explore at close to the limit of whatever that new physics makes possible. If we can explore and *get answers* at far faster than the speed of light, then there is vastly more incentive to actually do so.
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Fine assumptions, poor conclusion (Score:4, Interesting)
No one knows what aliens are going to look for in a planet. Our planet could be written off as an inhabitable nitrous sphere. They might be non-carbon based life forms. They could have progressed technologically much faster than we did as you suggested. By assuming aliens match our capabilities, he made an unstated assumption that was key to actually understanding the conclusion.
A more fitting conclusion from his work would be that it would take US 10 billion years to search a small portion of the Milky Way for life at our current technology levels.
Re:Based on poor assumptions (Score:5, Informative)
- Obtain a good enough understanding of space-time to create wormholes to any destination you want.
- Make a list of all destinations you are aware of.
- Send a probe to all of them, evaluate each destination and scan for more destinations from there.
- Go to step 2.
Space ships are just such a small-planet-with-water way of thinking.SURVEY (Score:5, Funny)
How would you prefer to travel?
a. A blue Police Box that can traverse space and time, with a hot British former 'teen star' that is obviously in love with your weirdness.
b. A big ancient ring that can take you anywhere where there is a corresponding ancient ring, but you keep bumping into Egyption dog people who try to kill you.
c. A large dinner shaped spaceship that does warp factors, but you get to shoot at klingons and make sexy time with green chicks (remember its all about the Journey!) Just dont get assimilated by Bjork!
d. Travelling with the Robinson family and a stupid robot that shouts "Danger" long after it stopped being funny. Oh and a pedophile.
e. In a ship that can make the Kessel Run in less than twelve parsecs - With a great big hairy Wooky and a gay robot.
e. Spending time on the only ship to have survived an attack by robots with KITT in their face, where it is a daily battle to stay alive.
f. On a moon that was flung out of orbit by a massive thermonuclear explosion initiated by the build up of magnetic radiation, which there is much debate as to it being caused by global warming.
g. Traveling across universes with a guy that looks like Mike Moore, where each new universe you 'slide' into is exactly like being on LSD.
h. On a ship with a dorky hologram an evolved cat, a computer with an IQ of 6000 and a very stupid robot, but every day is hilarious!
I. The space shuttle. (yawn)
Re:SURVEY (Score:4, Informative)
On a ship shaped like a sleek running shoe, perfectly white and
mindboggingly beautiful... (if you can stand the manic ship's computer and the terminally depressed robot).
Re:SURVEY (Score:4, Funny)
I'm sorry, I didn't read past your first option. Where do I sign up?
Re:SURVEY (Score:4, Informative)
Re:Based on poor assumptions (Score:5, Informative)
1/10 c: 3.263e29 tons
Even then this seems absolutely ridiculous. If you used a matter/antimatter reaction so that your propellant was pure electromagnetic radiation (thus your exit velocity is c), you'd get these results
1/10 c: 1.105 tons
Of course, these are not adjusted for relativity, since I don't know any simple equations to do that. I would imagine (as a wild-ass guess) that the 1/10 c estimates are close, but the
Basically all I'm saying is that 1/10 c seems fairly reasonable. It's not feasible given our current technology, but its within reason. If you start looking at things like space-time warpage, then we have no idea on any usage or capabilities, so any kind of theory based on it gets even further and further from reality.
By the way, I am a rocket scientist, but only a student, and not a physicist at all, only an interested amateur.
Re:Based on poor assumptions (Score:4, Insightful)
Why do you assume that any sane civilization would send out macro-sized probes?
Nanoscale or even microscale probes would completely change the economics of space exploration. And they would avoid the very serious problem of atomic abrasion that occurs at and above 0.1c.
That's why I laugh when people spot human-sized UFO craft. If there are UFOs here, they're microscopic.
I laugh at people who say things like that (Score:4, Insightful)
Assumptions are just that, assumptions. You can laugh all you want, but to me, it just shows one more scientific dogma. The attitude of "knowing it all" is sadly very prevalent here on Slashdot, and probably why so many spend time writing here, instead of discovering new stuff.
The problem is lack of creativity. In 0.5 seconds, I thought of nano-UFOs. Send one, or trillions of those, and let them dig into a moon or planet to rebuilt itself into a fully fledged macro-sized "UFO". Or, maybe if you want to "recreate yourself in your own image", why not send out organic "bombs"? Etc. etc. There are so many possibilities when you dont restrict your mind.
Just because you cant think of it, doesnt mean it isnt possible or thinkable. Please free your mind! There is so much more to know than we already know! And instead of giving focus to more effective ways to kill people, why not science of life?
Re:Based on poor assumptions (Score:4, Funny)
That's why *I* laugh when people think we haven't solved the issue of atomic abrasion. Teflon was named after our home planet, after all. Ha ha ha...
Puny human!
Re:Based on poor assumptions (Score:5, Insightful)
But the bad assumption remains: rocket technology. Like I said, who's to say they haven't gone further with physics, or pursued a different, or completely unthought-of (to us) means of travel?
No kidding. "If we put a thousand horses on a carriage, it still won't be fast enough to lift from the ground. But if we could discover the rumoured winged horse, we can do it."
Something tells me that we're a couple of paradigms away from comprehending galactic distances as attainable. Propellant propulsion systems are to interstellar travel what horses are to flight.
Duh (Score:5, Insightful)
Sheesh, talk about "proof by lack of imagination." This is supposed to answer the Fermi Paradox?
You can't explore a galaxy with a handful of probes. 72 probes??? First of all, if you're going to do it that way, you'd create hundreds of thousands of probes, if not millions of probes (mass production would reduce the cost). Second, you still probably wouldn't do it that way. You'd wait until you had the technology to make self-replicating probes, and the galaxy could potentially be explored in thousands of years.
Not impressed by this guy's argument.
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Funny I thought the galaxy was 100k ish light years across. So it would take half of that if we started at the center and the probes moved at light speed. It would take the same half of that to get the final results back so the minimum time is 100k years, without going faster than light.
The galaxy is 30,000 light years across. I actually thought of that after I posted, but I figured "thousands" covers everything up to a million. :)
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Re:Duh (Score:5, Funny)
Negative. I find your argument untenable. I am in agreement with the Danish monkey-being. Probabilities of non-human life spreading through the Galaxy and discovering primitive monkey-beings in Sol System are minimal. Probability is on the same order of probability of a F'narthag slime-weasel evolving wings and taking flight. It is also highly improbable that extraterrestrial beings would colonize the pathetic planet Earth and blend into the primitive monkey-being society. They would be forced to hide in internet discussion groups and the tech sector so that they are mistaken for geeks when they display lack of monkey-being social skills.
Re:Duh (Score:5, Informative)
Bingo. As usual, Wikipedia has a good article [wikipedia.org] on the topic.
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Re:Duh (Score:5, Funny)
Not impressed by this guy's argument.
He is probably just assuming that the aliens have a pretty much exact parallel to NASA.
Re:Duh (Score:4, Insightful)
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Uh-huh. And how many self-replicating probes traveling at .1 c have you developed?
The fact that we can imagine self-replicating interstellar probes doesn't mean they are practical or possible.
Re:Duh (Score:4, Insightful)
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Re:Duh (Score:5, Funny)
So I guess you are both wrong.
Self replicating probles will doom us ... (Score:4, Funny)
The Galactic Lottery (Score:5, Funny)
Plus he's not taking into account multiple alien races. So that's like double 4% which is almost 8%. Do that a few hundred times and you get 108%. This guy clearly doesn't understand math.
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Re:The Galactic Lottery (Score:4, Funny)
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Good news is: (Score:2)
Wrong, wrong, wrong (Score:5, Interesting)
This figure is based on some very reasonable assumptions. Colony ships travel at much below the speed of light. Each colony gets a thousand years of development time from first colonization before it starts sending out its own colony ships. As you can see, even though it seems quite "slow", thanks to the magic of exponential growth, the entire galaxy is colonized in short order.
We won't merely be discovered if aliens exist - we'll be colonized. That's the most likely scenario for running into aliens. If they never spread beyond their home planet, they'll just be one star out of trillions - but if they do start colonizing, we'd find them everywhere.
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Unless they're nearby already (Score:2)
So it would take 10 billion years to visit 4% of the Milky Way. In theory, if there are any aliens within the nearest 4% to us, they may have had time to visit us. Realistically, let's say the nearest 2%, to allow time for intelligent life to evolve and develop space travel. 2% of the galaxy is still a pretty big space, though you'd think we'd have seen some evidence of an alien civilization that (relatively) nearby.
Well, DUH! (Score:4, Insightful)
That's why you have to make the probes self replicating.. utilizing in-situ resources to make more probes at each star they visit, the growth becomes exponential and it only takes a few thousand years to search the entire galaxy. And seeing as we're visiting all these stars anyway, how about looking for planets that don't have life on them, but have nice suitable conditions for starting life on them. Cover a virgin planet with a wide variety of Earth lifeforms and fly on.
Re:Well, DUH! (Score:5, Insightful)
So, yeah, you can't explore the galaxy in only a few thousand years.
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Hopefuly they don't need to see any Earth-based SciFi to know that self replicating probes are a phenomenally *bad* idea.
Wrong (Score:3, Funny)
How close minded can one be? (Score:2, Insightful)
Under what time frame? If an alien race has had advanced technology for 100,000,000 Trillion years, then they'd have plenty of time (and would probably have technology more advanced then sending out physical "probes"). It doesn't see likely from what we know, but I don't think we actually know that much.
Why is it that scientists think that only what we can achieve is possible? It's like us looking for aliens using our tech
Re:How close minded can one be? (Score:5, Funny)
when they show up, please ask them how they survived the big bang.
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That would be a neat trick, considering that as far as we can tell the universe is only on the order of 10 billion years old. Though 100 Quintillion years with high technology is probably long enough to figure out time travel, so I suppose this could still work.
Re:How close minded can one be? (Score:4, Funny)
Holy shit, Tom Cruise posts on Slashdot!
I once worked out (Score:5, Funny)
When they do find us . . . (Score:2)
Only 10% the speed of light? (Score:2)
Self-Replicating Probes? (Score:2, Insightful)
More than one... (Score:4, Insightful)
I'd be careful with all those probes (Score:2)
Some potentially invalid assumptions? (Score:3, Interesting)
2. The ET search is not targeted.
3. The ETs are not much closer to Earth and found us by luck, early in their search.
At any rate, while the math is interesting, it just shows that we're not likely, as in snowball's-chance-in-hell likely, to have been found already. From a logical point of view, though, one cannot say that we haven't been found yet.
As far as we know for certain, the Vogon construction fleet could be circling our system as we type these responses... though the chance of that being the truth is small enough that we could very well see an Improbability-driven ship come in for a landing at JFK or LAX.
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Actually he is claiming that extraterrestrial probes can travel 1000 times faster than our probes.
So far propulsion systems are not following Moore's law and there is no evidence that they ever will.
This is a simulation made using guesses I would say that it is very interesting.
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Yes, and? (Score:2)
Maybe he could then go on to propose that these people "self-replicate" and create more people to look for the needle? That would make it go faster. However this obviously would cause problems because inevitably they would end up competing for resources or start forming unions to demand that they only need to look at 3 needles at a time.
how many colonies of aliens? (Score:2)
this reminds me of Thomas Aquinas (Score:2)
What's common in both viewpoints? Obviously one is real and the other is fictional, but what they have in common is that they both make predictions that we can't possibly do something in the future, so basically assuming no new technologies or scientific understanding.
I call BS (Score:3, Informative)
A more rational approach is exponential: You colonize a solar system. Then from that system you launch probes at anything reachable. Then you colonize everything reachable that qualifies. Rinse and repeat.
The main disc of the galaxy is about 100,000 light years across. Assume 10% light speed for probe travel time, light speed for information return and 50 years for each new colony to build infrastructure to a point where they can launch probes. You'd have 90% of the galaxy explored in three or four million years -- almost 4 orders of magnitude less than this fellow's estimate.
Just reported... (Score:4, Funny)
It has been done already (Score:5, Insightful)
One of these Turing machines reached Earth about 4 billion years ago. It first had to start by building very simple amino acids, then it graduated to proteins, then to RNA and then to DNA, and then these DNA machines built bodies around them and started using natural selection to evolve into more and more capable organisms. The final aim of these DNA structures is to build powerful radio beacons and send the information back to the original aliens who created these molecules and scattered them to the (solar) wind.
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do the physics, it's about DE-celeration (Score:3, Insightful)
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These are NOT self-replicating probes (Score:3, Insightful)
I think the real debate should be about self-replicating probes. Is the author assuming that every civilization capable of building these is automatically freaked out by potential doomsday scenarios, to the extent that none will be built? Even if it is foolish, I found that it pays to expect more foolishness in the universe rather than less.
Probe Droid? (Score:3, Funny)
I think we've got something, sir. The report is only a fragment from a probe droid in the sol system, but it's the best lead we've had.
We have thousands of probe droids searching the galaxy. I want proof, not leads!
The visuals indicate life readings.
It could mean anything. If we followed every lead...
But, sir, the sol system is supposed to be devoid of humaoid forms.
That's it. The humans are there.
There are so many uncharted worlds...
That is the system! Set your course for the sol system. General, prepare your men!
Nothing to do with the Fermi paradox. (Score:4, Interesting)
1. It's incredibly stable. It's launching an exploration program using probes that are going to take billions of years to get a result back to the original civilization. It expects to be around to pick them up.
By the same logic:
2. Individual members are incredibly long-lived, or the society is static and conservative enough that individual goals are submerged. They expect that the people around in a few billion years still care about the stuff they're doing, AND they care about the people who'll be around then.
The technology he's postulating is also very advanced.
3. Large scale space-based industry is routine enough for them to build probes capable of refuelling themselves using the raw materials in an as-yet-unexplored solar system, with surplus fuel to launch and recover the sub-probes. If they can do that, they can do the same thing in their own solar system.
If the probes are cheap by their standards, there's no reason not to keep building them indefinitely. So let's say they're expensive. Let's say it takes this civilization a hundred years to build a probe. Why do they stop after 800 years? They're long-lived, stable, conservative, so assuming they have the will to do it in the first place why would they stop building probes? As the author notes, probes break down.
So what happens when you add another probe into the search every century, indefinitely? Well, after a million years you've got 10,000 probes out there. Now you're looking at a search time measured in millions rather than billions of years, and it only takes millions of years to do it.
But why are they doing this? Looking for planets to colonize, perhaps? If they're just looking for civilizations they'd do much better depending on "signal intelligence".
But if they've got the ability to send out colonies, even the most conservative long-lived space-based civilization is going to figure out eventually that they don't actually need habitable planets to support a permanent colony. It's riskier without habitable planets, but even if the planetless colony is 10 times less stable than the home system you're still better off with your civilization in two baskets. And before long (in the terms of this civilization) you've got a roughly spherical shell of colonized star systems, expanding as fast as they can reach new systems. At 0.1C colonizing (not just exploring) the galaxy is going to take mere millions of years.
On the other hand, what if the self-replicating probes are members of the designing species themselves?
So either this level of technology is impossible to achieve, or we're back to the question of why no species has done it yet. There's lots of plausible answers, of course, but this paper sheds no light on them.
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Well, yes.
They are called the French and they across the pond.
=)
(Sorry, couldn't resist!)
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Re:Heh (Score:5, Funny)
Eventually these probes came home (Score:3, Funny)
Face it, we're not going to meet aliens, because they've already been destroyed by their own creations.
Re:Heh (Score:4, Funny)
Re:Heh (Score:4, Interesting)
Re:Heh (Score:5, Informative)
He found that even if the alien ships could hurtle through space at a tenth of the speed of light, or 30,000km a second, - Nasa's current Cassini mission to Saturn is plodding along at 32km a second - it would take 10bn years, roughly half the age of the universe, to explore just 4% of the galaxy. His study is reported in New Scientist today.
No mention of colonization there.
Plus
Mr Bjork confined the probes to search only solar systems in what is called the "galactic habitable zone" of the Milky Way, where solar systems are close enough to the centre to have the right elements necessary to form rocky, life-sustaining planets, but are far enough out to avoid being struck by asteroids, seared by stars or frazzled by bursts of radiation.
So there's that too. Looks like you should have taken a look at the article first.
Why about self-replication? (Score:4, Informative)
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Maybe in a few decades, we will learn that we need to be more circumspect, and try and hide better from alien races.
Until then, a probe doesn't need to stumble upon us, it might be able to
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Which I don't say is impossible -- just that counting on ID in a classroom, where you have to teach science is pointless and merely to make Fundies happy.
I think that humans, in a few more decades, may very well want to "seed" nearby planets with modified earth DNA. The compulsion to do so will be hard to ignore. We could create food or useful organic crops on Mars and Venus -- or just experiment without ecological disaster on earth (or test ways to fix ecological
What context?! (Score:5, Funny)
Average weight of humans up... sounds like and interstellar Hansel and Gretal
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Not really.
You need to allow for the mass extinctions in the Earth's past.
If the mass extinction 250 million years ago (Permian-Triassic) had not occurred then intelligent life may have evolved on this planet over 200 million years ago.
It would be quite possible for an alien race to be hundreds of millions of years more advanced than us just due to luck.
Irrelevant to the Fermi Paradox (Score:5, Interesting)
The study in question does not even address the Fermi Paradox in any meaningful sense, much less "resolve" it. In fact, if this study is being offered as a resolution of the Fermi Paradox then it suggests the researcher does not understand why the Fermi Paradox is a paradox at all.
The fundamental difficulty with any explanation offered for the complete absence (so far) of any sign of other intelligent life in the universe is that the proposed explanation has to be universally valid.
The span of time for colonization, or dispersal of replicating probes, or of building vast telescopically detectable artifacts is so great that even one single exception from any proposed explanation would be capable of generating ubiquitous evidence in a tiny fraction of the life of the Universe.
Simply describing some model for exploration, and then arguing that this model won't do the job says nothing about other models. This study apparently does not consider the geometric growth that occurs with any exploration program that uses some form of replication of explorers, for example. If replication is thought to be impossible then the study would have the high hurdle of convincingly demonstrating this. (The material evidence of life on Earth seems to argue persuasively against it though.)
Arguments that "interstellar travel is impossible" would qualify for explaining why alien artifacts aren't being found locally (but do not address communication signals or telescopically detectable artifacts), but require convincing arguments that this is indeed true. On the contrary, physics does not seem to make this impossible at all, just very costly and slow. Too costly and slow for anyone to bother? Not even one single civilization?
The Fermi Paradox seems to be telling something important about the Universe. If only we knew what it is...
Such a limited view (Score:3, Insightful)
Let us roll back the clock, say, 200 years: A person up to date with the technology of the time would have no knowledge of airplanes, cars etc would make the some silly statement that it would be impossible for a person to ever cross USA in one day. They'd also say that it is very unlikely to find a particular quote in some random book within three months of s
Re:Such a limited view (Score:5, Interesting)
I for one would really like to explore the universe and make contact with alien species. Unfortunately, my just wishing this is the case doesn't make it so.
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Theories are rarely (if ever) "proven to be true" as it's a lot easier to show that something is false rather than absolutely 100% true and correct. Science is more about finding the best model to fit the data than a quest for certainty. Even experiments don't prove theories, they just add to the evidence that a model is the best explanation for a certain phenomenon.