Scientists Find an ‘Earth Twin,’ or Perhaps a Cousin
nytimes.com
nytimes.com
Which means that if there is life on Kepler 186f, it could be billions of years ahead of us. Would that have been a long enough time scale for an intelligent species to emerge, civilize, and develop a way to traverse the 500 light years between us and them? Or did the dim light (less UV ~ less mutation) and lower availability of heavy elements (less iron) in the star system hemper the evolution of life and/or civilization?
Will there ever be an answer to questions like this, perhaps in a thousand years, a million years, or even a billion years?
The universe will be dead in 10 billion years tho ;)
Not so. There's no basis for this claim. The universe will continue to expand, and will eventually become much colder and darker than it is now, but there's no mechanism that ends the universe in our current models.
More here: http://arachnoid.com/dark_energy
As for the universe, see various conjectures at https://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe
https://upload.wikimedia.org/wikipedia/commons/d/dc/Friedman...
I am not sure if it is logical to argue that since red dwarfs can live a long time that any particular red dwarf is older than the sun. It is like arguing that since bristlecone pine can live for thousands of years that a particular individual tree you chance across is thousands of years old - it could be a young sapling.
I do agree that the low metallicity supports it being old, but there are young stars with lower metal levels. Really we just don't know at this stage, but it is an exciting discovery.
Considering we don't know anything besides Earth, we may not be even in a position to recognize life (let alone intelligent life), since we have such a biased definition of it.
Just as until the microscope invention a whole universe of lifeforms was unknown, we could be looking at things at the wrong space/time scale and missing the obvious. I find this more exciting than the possibility of ever finding carbon-based, spaceship-building creatures.
Also would it be possible start broadcasting radio waves or maybe some kind of laser towards this planet incase there's something there that can respond to us a thousand years from now?
There are limits to the angular separation a telescope can detect. Even the very largest telescopes on Earth (or more often: arrays of several telescopes, effectively creating multi-thousand-kilometer baselines) can resolve the disks of even the largest stars. It turns out that Betelguese is roughly the same distance as Kepler 186f -- 643 light years (plus or minus 146), and its disk can be resolved, even to the point of detecting surface features. But Betleguese is roughly 1000 times the radius of our Sun, and 4x wider than Earth's own orbit: "If Betelgeuse were at the center of the Solar System, its surface would extend past the asteroid belt, possibly to the orbit of Jupiter and beyond, wholly engulfing Mercury, Venus, Earth and Mars." (Wikipedia)
http://en.wikipedia.org/wiki/Betelgeuse
http://www.space.com/7771-spots-sun-revealed-giant-star.html
For planets, we're limited to detecting brightness fluctuations in the parent star (how Kepler detects planets), and possibly spectral absorption lines.
That last would be hugely exciting, as it allows knowledge of the composition of the atmosphere of a planet. And there's one molecule whose presence would be an almost absolute certain tell-tale of life: oxygen.
Ordinarily, free oxygen reacts with other substances in its presence to create oxides. Only if new oxygen is being released will an atmosphere be high in oxygen. So a planet with an oxygen-rich atmosphere should almost certainly have light.
As for beaming radio signals, the challenge is in creating signals which would be strong enough to detect at 500 light years' distance. Signal strength for most broadcast sources would be undetectable even at the nearest star, 100x closer:
http://zidbits.com/2011/07/how-far-have-radio-signals-travel...
Just to clarify: In radio-bands we can easily achieve sub-mas angular resolution using VLBI (the mentioned multi-thousand-kilometer baselines) or large arrays (ALMA, VLA, etc.)
In the optical/NIR bands your baselines are typically limited to a few hundred meters, where you can go down to mas, but it's much more difficult than in the radio bands. And direct imaging of the disks of the largest stars is possible in the optical/NIR.
Crazy to think that we may have awoken on this planet after an unfathomable amount of time and not appreciate how rare we are.
Does our situation get more or less beautiful if we discover no one else is out there?
That said, it won't change anything knowing there's no one else out there. Actually it would be a little bit frustrating because it would mean that there's nothing more to discover... Biologists might feel limited on this planet alone.
[1] http://en.wikipedia.org/wiki/Universe#Size.2C_age.2C_content...
But, we can never know that there's no one else out there, right? We can only discover that there is.
Still, perhaps every moment is rare in some way but we have the advantage of having a way to express that.
At 1.1x, it's possibly livable for humans, making it more interesting; 1.7x is probably too rough without some new technology or adaptations.
Scientists have noted that the atmosphere of Relpek 681f would have to be very thin in order for it to maintain cool enough temperatures, but it's well known that plant life would probably have an easier time dealing with it's solar radiation output..."
At these distances, our radio spectrum would be difficult to discern from random galactical noise - even if the radio waves had enough time to cross the distance. And in fact, so far it looks like the more advanced we get the less telling our radio signature becomes. There are no large-scale constructs or artifacts visible that hint at any technological activity in the solar system.
Looking at how crowded the solar system is, an onlooker might well assume it's too unstable for life to have developed. The Earth might be seen as too small to support life, its atmosphere too thin to shield against radiation and also too thin to allow for a comfortable temperature interval in which liquid water exists. Due to the difficulties of aerodynamic flight under these circumstances, they can safely assume there will be no winged lifeforms on Earth.
They might also think that any plant life on Earth would be extremely sparse and desolate - yet the abundance of oxygen hints at a world dominated by microbial life. The orbital and rotational instability of the planet leads to wild temperature variations which will likely prevent the rise of higher life forms.
The presence of several semi-unstable interplanetary debris fields suggests asteroid impacts will be frequent, and likely to extinguish life on any of the planets. The relative proximity and high mass of the Earth's moon (or shall we say: sister planet) makes it likely that the planet will be subject to tidal disturbances and might imply a history of extreme geological instability.
Water covers a large part of the Earth's surface, but generally is only present in the form of very shallow oceans tainted with poisonous chloride salts in high concentrations. It's unclear if unchlorinated water exists on the surface and in any case it's doubtful that there's enough water to form a stable cycle able to support any but the most primitive extremophiles.
But what if Earth is that planet? Obviously it can support intelligent life, but while there's lots of ways it could be harsher, there's also lots of ways it could be friendlier. For instance, it would be nice if this ice age that we're in the middle of wasn't happening. (Incidentally, you can add that to your list of reasons why Earth can't possibly support advanced life... it's spent an awful lot of time nearly entirely frosted over lately. http://xkcd.com/1225/ )
I did think of that, read the comment again - it's the one about the extreme temperature variations which prevent higher life forms from arising :)
But yeah, harsher environments leading to harsher species feels instinctively right, though on the other hand what's considered a strength on one world will be a weakness on many others. On Earth, most life is coupled pretty tightly to the local conditions and that's why so many species die off whenever some minute changes occur.
Luckily, there are more resilient generalists around as well, like us. And if technology-producing intelligence is a generalist trait, we could assume life on other worlds to be similar in that regard. Intellectual generalism seems to require, or at least strongly favor, a departure from innate mental dispositions in favor a cultural imprinting. So that leaves some measure of hope that, whatever an intelligent species' origins, traits such as being warlike might not be inescapable.
Anyway, it's unlikely there are Klingon-style people out there who can just come here and perform much better in our own environment than us, the natives. At least not without massive technological help, which kind of nullifies the importance of biological strength.
Ah, sorry.
As for actual contact... many earth civilizations would rise and fall before a spaceship going at even 2% of the speed of light could reach such a planet.
Perhaps every habitable planet develops life but only our plant has developed intelligent life. Perhaps only our planet among all the planet in the universe has life. Perhaps every planet develops civilization life and all such civilizations destroy themselves within about 10,000 years, leaving only hunter-killer robots.
In any case, interstellar space is so vast we couldn't practically other civilizations even if they turned out to be quite common in other solar systems.
On Earth, high tech civilization appeared relatively shortly after humans evolved. Agriculture was independently invented half a dozen times in different places, and cities and civilization at least twice in the new and old world. We were also moving in the direction of science and technology even before we discovered coal power so the "other planets don't have fossil fuels" doesn't seem like a great candidate either.
Edit: I agree we do know that human brings on earth are likely to invent agriculture.
But I show add there is even a view with no "Great Filter" at all. That is the claim that life on the Earth has developed with a steady, linear increase in log-complexity whose zero-point is fairly close to the big-bang. And thus the human species developing now is developing about as early as it could have, as quickly as it could have and so there's no surprise that no civilizations earlier than us elsewhere exist even if we plausibly expect these civilization to be appearing now.
Punctured equilibrium is a good theory to explain particular species diversity and morphology. It may or may explain increases in complexity as such and there may or may not be a tendency for the various jumps to even each other out over time.
I'm arguing I know such a theory is true, just that things are so complex that no theory is definitive.
Or that there are no aliens, raising concerns that most civilizations inevitably destroy themselves.
Or that there are, but they haven't made contact because they don't care about us. If they don't care they might wipe us out because they want our resources, or see us as a potential threat.
Space travel is more speculative but it seems theoretically possible to reach a significant fraction of c even with 20th century technology. Even today's spacecraft could reach other solar systems in a few thousand years, which is reasonable on a geological timescale. If probes are self-replicating, or the mother civilization simply sends a lot of them, they could cover the entire galaxy in a few million years at most.
A radio signal would need to be extremely powerful to travel 500 light years without degrading (not to mention that even the senders may not be able to decode it after 1000 years :-)), and sending spacecraft to navigate 500 light years hoping it will perform all maneuvers correctly and not get hit by something in order to reach a planet without being able to send any useful information back seems naive and pointless.
If there's any space faring civilization out there, they're probably content with their own star system and maybe the ones closest to it - there are so many planets and asteroids to mine for resources (plus recycling would be a big thing) they could last for hundreds of millions of years...
Interstellar distances do prevent a lot of practical expansion, but it'd be nice to say hello to your neighbors, and start making preparations for when your star dies, or the even longer term heat death of the universe.