On November 06 2013 04:05 white_horse wrote: And if humans attain the technology to travel in space, why the hell should we go around looking for others? It's like native americans in the 1500s traveling across the atlantic to let europeans know that they are available to be invaded.
come on, thats crazy. thats like if we went out of our way to destroy some microbes on an ant hill in africa.
On September 13 2011 05:39 zimz wrote: i always knew there were thousand if not millions of planets like earth out there like over 10 years ago. i thought it was quite close minded for many people to assume earth is exceptionally rare and maybe the only one etc.
I feel people are close minded when it comes to other life. By that I mean people who think other life has to necessarily have the same living conditions as us when for all we know they have to live opposite (we'll never know at least not in our life time).
Why do people always think aliens are some rampaging zerg-like creatures? Why aren' t they kind and nice or both? and why all the generalization
iirc There' s something like bilions of different planets and milions of solar systems. So matematically there probably are different kinds. TIme to start thinking that maybe a lot of things have always been happening but we where never (or only in the long past) aware of them. Modern humans are not in touch with theor soul enough
On November 05 2013 20:07 ThePhan2m wrote: This is all just fantasy and dreaming. We can all hope for life out there, even if there is there is no where near any technology that can get us there for the next imaginable future. There are enough stuff to do on this planet! Lets focus on fixing it rather than spend time, money and energy on something that is out of reach. My two cents
That bolded part is what we're spending on it right now. With that attitude we'll all still be sitting in our gravity well when the next killer asteroid enters the earths atmosphere, which could happen at any time.
Not to mention that sooner or later this planet is going to die.
It's not like we are going to wake up one day and have the technology to travel trillions of light years to new places. One has to take tiny steps and that is why every bit of science is important and will take us closer to finding new planets and maybe one day for humans to travel there instead of getting extinct.
From that Wiki: The NASA research team has postulated that their findings could reduce the energy requirements for a macroscopic spaceship moving at ten times the speed of light from the mass–energy equivalent of the planet Jupiter to that of the Voyager 1 spacecraft (~700 kg)[9] or less.[10] By harnessing the physics of cosmic inflation, future spaceships crafted to satisfy the laws of these mathematical equations may actually be able to get somewhere unthinkably fast—and without adverse effects.[11] Also, Physicist and EarthTech CEO Harold E. Puthoff explained that contrary to widespread belief even the highly blue-shifted light seen on board such a spaceship would not fry its crew, being bathed in strong UV light and X-rays. It would however be dangerous to anyone seeing it fly by closely.[1]
As I understand it, we are finding more and more habitable planets which means *if* we manage to figure out a way to reach them we will be sorted but we may not figure out how to do that in time.
Is there any possibility of finding potentially habitable planets that our closer to Earth than those we have already discovered, or are we simply finding more and more further afield?
On November 07 2013 03:55 pebble444 wrote: Why do people always think aliens are some rampaging zerg-like creatures? Why aren' t they kind and nice or both? and why all the generalization
iirc There' s something like bilions of different planets and milions of solar systems. So matematically there probably are different kinds. TIme to start thinking that maybe a lot of things have always been happening but we where never (or only in the long past) aware of them. Modern humans are not in touch with theor soul enough
why is it always the position of the egghead set that aliens would always be benign?
On November 07 2013 08:53 Reason wrote: As I understand it, we are finding more and more habitable planets which means *if* we manage to figure out a way to reach them we will be sorted but we may not figure out how to do that in time.
Is there any possibility of finding potentially habitable planets that our closer to Earth than those we have already discovered, or are we simply finding more and more further afield?
I would assume that the closest stars have been observed the most, so there's probably not much closer.
On November 06 2013 04:05 white_horse wrote: And if humans attain the technology to travel in space, why the hell should we go around looking for others? It's like native americans in the 1500s traveling across the atlantic to let europeans know that they are available to be invaded.
come on, thats crazy. thats like if we went out of our way to destroy some microbes on an ant hill in africa.
Any civilization that can accelerate stuff to a useful % of the speed of light for space travel can accelerate rocks fast enough to wipe out civilizations without the receiver being able to detect it. The only way to defend against that would be to preemptively wipe out other civilizations if they don't seem friendly or even before they find you if you are sufficiently paranoid.
Atleast that's what some of the cynical hard SF authors like to think about.
People arguing about why we haven't seen extraterrestrial life, watch this.
Very likely that it is impossible for a civilization to advance far enough before is dies out, likely drives it's own kind to extinction, or the 100-1500 million years that a planet is habitable by life is not enough for evolution or technology to reach far enough that such extreme space exploration would be possible. The other option is, that it may be possible to actually leave a galaxy because special things happen, just like when you leave the solar system, there is a lot more danger, maybe the Milky Way provides such a barrier as well.
So realistically, there are many possible reasons as to why another civilization will never find Earth.
On November 07 2013 08:53 Reason wrote: As I understand it, we are finding more and more habitable planets which means *if* we manage to figure out a way to reach them we will be sorted but we may not figure out how to do that in time.
Is there any possibility of finding potentially habitable planets that our closer to Earth than those we have already discovered, or are we simply finding more and more further afield?
There's a possibility but it requires different techniques. Most habitable planets have been found using the Kepler space telescope. Kepler looks at a large number of stars at the same time to see if their brightness dips. If these dips are happening periodically they are interpreted as a planet passing in front of the star causing a partial eclipse.
It turns out that stars don't have to be particularly close for this technique to work. All you need is the star to be reasonably 'quiet' (i.e don't change its brightness very much on its own), a field of the sky with many stars, and some luck. You need luck because the orbit of the planet has to be almost exactly aligned to your field of view, else the planet won't pass in front of the star from your point of view.
Kepler's field of view contains about 150,000 stars but as far as I know none of them are nearby. I think this could be deliberate a sun like star 10lys away would be much brighter than the typical Kepler star and could mess up the detectors.
On November 07 2013 08:53 Reason wrote: As I understand it, we are finding more and more habitable planets which means *if* we manage to figure out a way to reach them we will be sorted but we may not figure out how to do that in time.
Is there any possibility of finding potentially habitable planets that our closer to Earth than those we have already discovered, or are we simply finding more and more further afield?
I would assume that the closest stars have been observed the most, so there's probably not much closer.
There was actually a study published this week on the relative frequency of Earth-like planets around Sun like stars. It's based on Kepler data but done by people who don't work for the Kepler mission.
"What this means is, when you look up at the thousands of stars in the night sky, the nearest Sun-like star with an Earth-size planet in its habitable zone is probably only 12 light years away and can be seen with the naked eye," said co-author Erik Petigura, from the University of California, Berkeley.
How do we find these planets? The transit method used by Kepler can't work. You'd need a full sky survey and even then you'd only catch the planets whose orbits are exactly aligned. There are techniques that look for dopler shifts in the star's spectrum as planets pull it back and forth. But the signals are tiny for Earth-sized planets on 1 year orbits and potentially swamped by stellar activity. Plus it requires over a hundred observations over a few years on large telescopes.
For the transit method you only need to take a picture of the field of view and you get the brightness of 150,000 objects to a few parts per million. There are no similar instruments for spectroscopy. It used to be that even if you wanted to take the spectrum of two objects that were quite close on the sky you'd need to take two different pictures. There are some instruments that can take multiple spectra now, but none that would take thousands of spectra allowing for the kind of results Kepler produced.
Bottom line is there's no technique that guarantees finding a planet as long as it's there. The transit method relies on luck, the RV method doesn't scale and direct imaging only finds extremely large planets. We can speculate on how common these planets are based on the Kepler data, and indeed they seem to be quite common.
On November 06 2013 04:05 white_horse wrote: And if humans attain the technology to travel in space, why the hell should we go around looking for others? It's like native americans in the 1500s traveling across the atlantic to let europeans know that they are available to be invaded.
come on, thats crazy. thats like if we went out of our way to destroy some microbes on an ant hill in africa.
Any civilization that can accelerate stuff to a useful % of the speed of light for space travel can accelerate rocks fast enough to wipe out civilizations without the receiver being able to detect it. The only way to defend against that would be to preemptively wipe out other civilizations if they don't seem friendly or even before they find you if you are sufficiently paranoid.
Atleast that's what some of the cynical hard SF authors like to think about.
Technically you don't a planet when you're advanced far enough. And destroying the home planet of a civilization that already has significant assets in deep space can lead to nasty consequences.
If there's any civilization that does this kind of thing they are cutting it awfully close with humanity.
Stars are quite far away from us. I think the nearest star will still take us around 10.000-100.000 years to travel towards using current technology. Obviously that's too long for generation ships and the like.
On November 09 2013 22:03 Taekwon wrote: Welp. It looks like Kepler's new data shows that there are billions of Earthlike planets.
And by this you mean that scientist have made new estimations
Kepler has recearched over 150 000 starts, and identified over 3 000 possible planets. Scientists have made their conclusions from that data, and that information is collected from inside our galaxy only.
These calculations are based on the assumption that life can only be sustained on a rock based planet that can contain liquid water, and is orbiting a sun like star.
People arguing about why we haven't seen extraterrestrial life, watch this.
Very likely that it is impossible for a civilization to advance far enough before is dies out, likely drives it's own kind to extinction, or the 100-1500 million years that a planet is habitable by life is not enough for evolution or technology to reach far enough that such extreme space exploration would be possible. The other option is, that it may be possible to actually leave a galaxy because special things happen, just like when you leave the solar system, there is a lot more danger, maybe the Milky Way provides such a barrier as well.
So realistically, there are many possible reasons as to why another civilization will never find Earth.
This is a pretty popular theory. Another is that we may the be the most technologically advanced race which is why we've never seen other life forms because they're not even close to our technology.
Another thing is that when aliens view our planet, they may only see dinosaurs due to how far away we may be from them, similar to how we see stars, but some of those stars may have already disappeared (not COMPLETELY, but I don't know the scientific term I'm looking for). Also, this:
On September 13 2011 05:39 zimz wrote: i always knew there were thousand if not millions of planets like earth out there like over 10 years ago. i thought it was quite close minded for many people to assume earth is exceptionally rare and maybe the only one etc.
I feel people are close minded when it comes to other life. By that I mean people who think other life has to necessarily have the same living conditions as us when for all we know they have to live opposite (we'll never know at least not in our life time).
Alien life may not be visiting us because Earth doesn't have the resources they need to survive. Much like ourselves, why would we try to explore a planet where we don't see any valuable resources?
On November 06 2013 04:05 white_horse wrote: And if humans attain the technology to travel in space, why the hell should we go around looking for others? It's like native americans in the 1500s traveling across the atlantic to let europeans know that they are available to be invaded.
come on, thats crazy. thats like if we went out of our way to destroy some microbes on an ant hill in africa.
Don't we do that, though? People see bugs on the ground, and their instinct is to kill them. They're not really harmful, but people kind of go out of their way to kill that which seems to minuscule. If we reveal ourselves to other species, it's not out of the realm of possibility that they may not see us as we see other people - they may see us as bugs.
While we're on the topic of Xenobiology, everyone should read Ender's Game and it's sequels because it deals a lot with the philosophical concepts of meeting new species. The first book talks about one species, but the sequels (not the shadow series) talk about several other species that interact with the universe in different ways. Not saying it's the goto manual for alien relationships because our manual will be our experience - But I think he does a great job of showing our attitudes of other life, and how we as humans may treat them when the time comes.
On November 09 2013 22:03 Taekwon wrote: Welp. It looks like Kepler's new data shows that there are billions of Earthlike planets.
And by this you mean that scientist have made new estimations
Kepler has recearched over 150 000 starts, and identified over 3 000 possible planets. Scientists have made their conclusions from that data, and that information is collected from inside our galaxy only.
These calculations are based on the assumption that life can only be sustained on a rock based planet that can contain liquid water, and is orbiting a sun like star.
The best way to read this is as an estimate on the proportion of of K and G type stars having planets that are similar in size, composition and stellar irradiation to Earth. Whether these are sufficient or even necessary for life to start is unkown and that's not what these papers are about.
Even though the result is based on a relatively small number of planet candidates there's little reason to believe that it isn't true in the rest of the Universe. When stars form there's a disk of material left over circling the young star called the circumstellar disk. From first principles it seems to be easy for planets to form in this disk, so in that sense the high proportion of Earth-sized rocky planets on Earth-like orbits is not a surprise at all. Indeed, it would have been harder to explain a complete lack of Earth-sized planets.
EPT
