> Undoubtedly, the most exciting kind of alien life would be the intelligent kind
But intelligent non-life would be even more exciting! Note that SETI is the search for ET intelligence, not ET life.
I mean, read this:
> As robotic space probes continue to explore the solar system, visiting planets, moons, and asteroids, they're finding watery environments where microbial life could grab hold
If robots are better than life for exploring the solar system and visiting remote planets, why are we looking for signs of life, instead of signs of robots?
True, but can't we at least try to address the likelihood of that being the case.
For instance, if we were living on a 9 Billion year old planet but we could only find fossils dating back to 2 Billion years ago, we'd surmise that it took life around 7B to get life started on this planet. Under those circumstances, your hypothesis would be stronger than it is under actual conditions (4.5B and 3.5B respectively).
I'm very suspicious of the hypothesis that our earth is just special or rare. It's a clean solution to the Fermi paradox, but there's no way of knowing this. There's no reason to even think that this is more probable than any other answer.
What if earth isn't special, but the time frame when which life flourishes is extremely small on a cosmological scale? This seems to be the most difficult part for me. Everywhere we look, the universe seems to be a fairly violent place. It may just be that life is common, but short lived. So, due to the distances involved, the chances of life existing in two places at once and being able to observe each other is near 0.
From known data, I don't believe your hypothesis is likely to be correct:
1) 13.8 - Age of Universe (Billion years)
2) 4.5 - Age of Earth
3) 3.5 - (minimum) Age of life on Earth
Our ancestors have already been alive here for at least 25% of the duration of the universe. To me, the most fascinating number is the small gap between 2) and 3). Suggesting that life here, at least, was almost inevitable. Whether through panspermia or ab initio, it appears difficult neither for life to get started nor to keep hanging around.
I read last year about a hypothesis that iirc 100,000 years after the big bang, as the entire Universe was cooling, for some duration it was lukewarm in patches all over. Ideal for the first iteration of life and perhaps for an initial panspermia event that seeded all parts of the expanding universe.
I remember seeing a documentary on Netflix that pointed out how rare the earth was. They seemed to have a good grasp on the science. They ran the numbers and probability was not in favor of there being many planets like our own.
Edit: I think it was called 'The Privileged Planet'.
I looked it up, and it's a documentary arguing in favor of "intelligent design" and against evolution:
"Embracing the concept of intelligent design and refuting the theory of evolution, this intriguing video posits that Earth was created not by a series of random events but by a 'creative designer' who knew exactly what he was doing. Several proponents of intelligent design, including philosophers and scientists, share their views about this controversial theory and provide evidence that supports their premise. Actor John Rhys-Davies narrates."
I reckon we'll quite soon have the telescope/spectroscopy stuff needed to determine whether life is abundant or very rare. New exoplanets are found quite often now, and it's only a matter of improving the technology a bit so we can know whether there's a few or very many interesting places out there.
As for meeting any of these, I think it will be a loooong time.
We will. The TESS (Transiting Exoplanet Survey Satellite) and the JWST (James Webb Space Telescope) will be launching in a few years. The two will sort of act as a spotter-sniper pair -- TESS detecting planets and JWST zooming in. Both are far more powerful than their predecessors, Kepler and Hubble.
There is also plans (not yet funded) to use "starshade" occulter to directly observe planets that don't pass in front of the parent star (by blocking the starlight).
My personal estimate is that we'll definitely detect oxygen in a planetary spectrum within the next 10 years. Which will mostly likely mean photosynthesis on the surface.
A better question is probably: When will aliens find us?
"ET is 99% likely to be more than 50 million years in front of us and that’s ample time to completely explore this galaxy. So it’s 99% likely they know we are here."
This doesn't change the fact that it did happened, there are thousands of witnesses, also the governor who was a former pilot admitted that it was "otherworldly".
Even if thousands of people saw something out of this world is not enough of evidence? What is an extraordinary evidence for you?
I hear this extraordinary evidence claim text often and I think that people that say it in fact ask for an official government statement or a live tv streaming of a landing etc but they will never get it because the government will never admit that is not the absolute power unless it's too obvious to deny it and also to avoid population panic.
For a start eye witness reports are not exactly scientific evidence. Humans can be easily mislead. Maybe they were military flares.
> What is an extraordinary evidence for you?
Any alien piece of technology. Forget tech, I am assuming an alien Pencil would be out of this world too.
> Even if thousands of people saw something out of this world is not enough of evidence?
That is my point, thousands saw yet nobody captured it on a good high definition camera. Now everyone has HD cameras yet no sign on UFO's, coincidence?
Even scientist are humans and have eyes, is the same bias, you don't need special equipment/training to see something as big as a football field moving in the sky blocking stars light without making a sound and still think that is a military craft.
Also having thousands confirm the event rules out a hoax, on top of that the former governor who was also a trained pilot could easily identify flares or other military plane. You need to look at all the evidence and details.
To have a piece of alien technology you can only have it if you receive it, you or me will surely not be that special to receive it and if world leaders will have the privilege you might never know.
Also it's enough proof to hover that big craft in mid day over a big city but for whatever reasons they still give us a chance to doubt, I suspect that the reason is to avoid panic as a big percentage of world population is still religious and not ready yet but they still give us a sign that we are not alone.
There are 4 videos shot from the event on youtube that you can watch, also high definition cameras still don't have very good optics to focus on moving objects at high altitude, a better sensor alone will not help much with the video quality especially in the night.
Also these kinds of events are very rare so there too many things, like good camera with good lenses, tripod, being in the right spot, last long enough etc to be in place to get that clear hd video.
Forget the Gov, he made fun of his own people by making a mockery of the situation in the press conference and then years later changed his position. He could have done something when he was in power.
Lets say there really was a a big craft. Maybe it belonged to the Soviets, who built that huge craft in secret. So it was a UFO but that does not mean automatically that it were Aliens.
I saw the 2 videos, those can be faked too. People believed the yeti video was real. People believe in the loch ness monster.
So many people claim that they were abducted by aliens, they talked to the aliens, well then next time just grab a small medical device, hide it somewhere maybe in the mouth and then once you are back on earth have a press conference and show the world.
> big craft in mid day over a big city
The videos I saw were taken at night. Can you please link to a video taken in daytime.
> but they still give us a sign that we are not alone.
They can just say hello using radio, we are listening for decades yet there is radio silence.
If there are aliens out there yes, they most likely didn't just happen to develop a civilisation at the same time as us, and so are likely to have been around a long time. I don't think that means they're likely to have even reached a neighbouring star yet, other than perhaps a flyby probe, let alone colonised the galaxy. Interstellar travel is just too many orders of magnitude too hard to be practical, and even if you manage it all it takes is one GRB and your whole civilization is toast anyway. I suspect that within about a thousand years we'll pretty much top out technologically. Once we know everything these is to know about the physical universe, we'll start hitting the limits of what is possible with the physical elements and forms of energy available in our universe. Then we'll start hitting the limits of what's possible with the actual materials and sources of energy in our solar system, and face some hard choices about what we do with them.
Whether, not when for now. Even if the odds are for it there is absolutely no guarantee we will. It could happen tomorrow, in the next thousand years or not before we manage to exterminate ourselves (or some great filter does it for us).
> Touching down on Mars for the first time was a big deal, sure.
Viking 1 wasn't the first to land on Mars. It landed July 20, 1976. Mars 3 landed in December 2, 1971.
M3 didn't last long, granted, but that's hardly a reason to twist the facts (presumably for the benefit of narration and not because of any sort of anti-Soviet bias, because that would've been just way too ridiculous coming from BBC, wouldn't it).
Basically, what the last several decades has shown is that while they're probably out there, we won't find aliens until we make serious attempts to look, rather than token efforts.
That means funding astronomy an order of magnitude more than we do now, and flat-out demanding that we mitigate risk and reduce R&D cost-share by building ten to a hundred of everything. Presently we spend a decade and a half perfecting a design's technical aspects and securing funding only to build one unit over five years, with a 70% chance of scaling back that unit or stretching out construction by five more years because of insecure funding late in the game. We should instead spend 3 years designing, 2 years building a prototype and iterating, and 5 years building and installing a large number of production-run units, before moving on to the next design.
Nearly every instrument on every large telescope today is 'couture', with at most 2 units in existence. Telescopes designed for mass replication, like the ATA or PAN-STARRS, end up getting their funding cut off for further units as soon as first light is reached on the prototype, because of the perverse incentives and interests associated with astronomical research.
It also means devoting actual resources to SETI, instead of having it be something tenured professors do as a hobby, with nearly zero funding.
And yet, if alien civilizations are using a method of communicating other than radio, it won't matter how much resources and funding we devote to SETI (often assumed to be the same as radio astronomy).
We have to use what we know, but with a serious effort towards discovering communicating civilizations other methods could be explored. I'm sure the people working on gravitational wave detection would love the boost of interest they could receive as part of a search for exotic forms of communication.
This idea could sound controversial probably, but maybe spacial agencies should focus in the more accesible planet by far. Maybe some of this talent, team and resources, could be destinated instead to save the thousands of critically endangered earthlings that are vanishing and can't wait a decade. To burn all the ships to find a new bacteria in mars will be very interesting of course but also a bad choice in terms of huge costs/uncertain real benefits.
Maybe the funds could be spent into how to solve the nuclear residues problem, how to design a catascope to look under yellowstone or inside the etna, how to predict and minimise the next fukushima/three mile island, or how to study sea currents and discover if those yummy school of anchovies from japan will cause you a leukemia in two years.
Seriously from earth we are only likely to find aliens at the same or slightly ahead of our own technology. If one visits us first it might come sooner. If the aliens are far ahead of us we may never even notice them. It's like dumping Newton in a modern corn field and telling him he is surrounded by people communicating. He would have no idea about cell phone, microwave and other transmissions. Take technology from 300 years in the future in an alien today and we might be equally clueless.
Life in all universe runs on aggression and defense, or else they won't evolve. If they are less advanced we will eat them, otherwise they will eat us.
We are right now like amerindians building a lighthouse to contact people in the old world. If we point it to Africa, elephants and tigers won't know how to respond. If we keep building it higher and higher and point it to Europe, spaniards will come and slaughter us all.
Given that our civilization(s) have nearly always behaved that way when colonizing places, why should we assume that aliens are more "enlightened", and will see us as anything better than we've seen "native savages", or (worse) an "infestation"?
I think the Drake equation is worth mentioning here. It estimates the number of civilizations in the Milky Way Galaxy whose electromagnetic emissions are detectable (https://www.authorea.com/11048). Knowing some of the numbers involved, it can be reduced to approximately:
N ~= 2flfefcL
where fl is the fraction of habitable planets hosting life, fe is the fraction of life-bearing planets that develop an intelligent life-form, fc is the fraction of intelligent life-forms that decide to communicate, and L is the length of time a given civilization is transmitting "visible" communications. Taking ourselves as an example, L is already on the order of 100 years. The original estimates for these values were fl = 1, fe = 1, fc = 0.1-0.2, and L = 1000-100,000,000 (http://en.wikipedia.org/wiki/Drake_equation).
It seems like Moore's-law-like trend can get us to telescopes by 2050 that can detect the chemical composition of exo-planets. Significant oxygen would be a sign, as on Earth, of ongoing chemical respiration from life - otherwise O2 would react and decay to other forms without being replenished.
There would still be the possibility that the presence of oxygen was geologic in nature, and if we sampled a billion exo-planets, it's reasonable that some could have an exotic geology to cause this 'false positive'.
The next step might be to look for a pattern in the carbon-cycle connected with orbits: e.g on Earth the North vs. South hemisphere have different amounts of plant life, and we see C02 wobble several ppm in summer vs. winter. Getting accurate readings of exo-planets to the ppm level might take a while for telescope technology to acheive. For these reasons, I'd say 2100 is a good estimate for when we would have the ability to sample 1B exoplanets, and promote at least one to the rank of 'strong possibility of harboring life'.
We know right where a bunch of aliens are: the bottom of the ocean. Incredibly, it's so hard to go there that it's considered a joke to suggest it, whereas with space it seems if it weren't for the problem of the sheer distances involved, we could really do it and just go anywhere.
"Humanity seems to have a bright future, i.e., a non-trivial chance of expanding to fill the universe with lasting life. But the fact that space near us seems dead now tells us that any given piece of dead matter faces an astronomically low chance of begating such a future. There thus exists a great filter between death and expanding lasting life, and humanity faces the ominous question: how far along this filter are we?
"Combining standard stories of biologists, astronomers, physicists, and social scientists would lead us to expect a much smaller filter than we observe. Thus one of these stories must be wrong. To find out who is wrong, and to inform our choices, we should study and reconsider all these areas."
56 comments
[ 3.4 ms ] story [ 70.8 ms ] threadBut intelligent non-life would be even more exciting! Note that SETI is the search for ET intelligence, not ET life.
I mean, read this:
> As robotic space probes continue to explore the solar system, visiting planets, moons, and asteroids, they're finding watery environments where microbial life could grab hold
If robots are better than life for exploring the solar system and visiting remote planets, why are we looking for signs of life, instead of signs of robots?
[0]: http://en.wikipedia.org/wiki/Spin_(novel)
For instance, if we were living on a 9 Billion year old planet but we could only find fossils dating back to 2 Billion years ago, we'd surmise that it took life around 7B to get life started on this planet. Under those circumstances, your hypothesis would be stronger than it is under actual conditions (4.5B and 3.5B respectively).
1) 13.8 - Age of Universe (Billion years)
2) 4.5 - Age of Earth
3) 3.5 - (minimum) Age of life on Earth
Our ancestors have already been alive here for at least 25% of the duration of the universe. To me, the most fascinating number is the small gap between 2) and 3). Suggesting that life here, at least, was almost inevitable. Whether through panspermia or ab initio, it appears difficult neither for life to get started nor to keep hanging around.
I read last year about a hypothesis that iirc 100,000 years after the big bang, as the entire Universe was cooling, for some duration it was lukewarm in patches all over. Ideal for the first iteration of life and perhaps for an initial panspermia event that seeded all parts of the expanding universe.
Edit: I think it was called 'The Privileged Planet'.
"Embracing the concept of intelligent design and refuting the theory of evolution, this intriguing video posits that Earth was created not by a series of random events but by a 'creative designer' who knew exactly what he was doing. Several proponents of intelligent design, including philosophers and scientists, share their views about this controversial theory and provide evidence that supports their premise. Actor John Rhys-Davies narrates."
I'll pass.
As for meeting any of these, I think it will be a loooong time.
There is also plans (not yet funded) to use "starshade" occulter to directly observe planets that don't pass in front of the parent star (by blocking the starlight).
My personal estimate is that we'll definitely detect oxygen in a planetary spectrum within the next 10 years. Which will mostly likely mean photosynthesis on the surface.
"ET is 99% likely to be more than 50 million years in front of us and that’s ample time to completely explore this galaxy. So it’s 99% likely they know we are here."
Source: http://www.bbc.com/earth/story/20150429-will-we-find-aliens
I hear this extraordinary evidence claim text often and I think that people that say it in fact ask for an official government statement or a live tv streaming of a landing etc but they will never get it because the government will never admit that is not the absolute power unless it's too obvious to deny it and also to avoid population panic.
> What is an extraordinary evidence for you?
Any alien piece of technology. Forget tech, I am assuming an alien Pencil would be out of this world too.
> Even if thousands of people saw something out of this world is not enough of evidence?
That is my point, thousands saw yet nobody captured it on a good high definition camera. Now everyone has HD cameras yet no sign on UFO's, coincidence?
Also having thousands confirm the event rules out a hoax, on top of that the former governor who was also a trained pilot could easily identify flares or other military plane. You need to look at all the evidence and details.
To have a piece of alien technology you can only have it if you receive it, you or me will surely not be that special to receive it and if world leaders will have the privilege you might never know.
Also it's enough proof to hover that big craft in mid day over a big city but for whatever reasons they still give us a chance to doubt, I suspect that the reason is to avoid panic as a big percentage of world population is still religious and not ready yet but they still give us a sign that we are not alone.
There are 4 videos shot from the event on youtube that you can watch, also high definition cameras still don't have very good optics to focus on moving objects at high altitude, a better sensor alone will not help much with the video quality especially in the night.
Also these kinds of events are very rare so there too many things, like good camera with good lenses, tripod, being in the right spot, last long enough etc to be in place to get that clear hd video.
Lets say there really was a a big craft. Maybe it belonged to the Soviets, who built that huge craft in secret. So it was a UFO but that does not mean automatically that it were Aliens.
I saw the 2 videos, those can be faked too. People believed the yeti video was real. People believe in the loch ness monster.
So many people claim that they were abducted by aliens, they talked to the aliens, well then next time just grab a small medical device, hide it somewhere maybe in the mouth and then once you are back on earth have a press conference and show the world.
> big craft in mid day over a big city
The videos I saw were taken at night. Can you please link to a video taken in daytime.
> but they still give us a sign that we are not alone.
They can just say hello using radio, we are listening for decades yet there is radio silence.
Viking 1 wasn't the first to land on Mars. It landed July 20, 1976. Mars 3 landed in December 2, 1971.
M3 didn't last long, granted, but that's hardly a reason to twist the facts (presumably for the benefit of narration and not because of any sort of anti-Soviet bias, because that would've been just way too ridiculous coming from BBC, wouldn't it).
That means funding astronomy an order of magnitude more than we do now, and flat-out demanding that we mitigate risk and reduce R&D cost-share by building ten to a hundred of everything. Presently we spend a decade and a half perfecting a design's technical aspects and securing funding only to build one unit over five years, with a 70% chance of scaling back that unit or stretching out construction by five more years because of insecure funding late in the game. We should instead spend 3 years designing, 2 years building a prototype and iterating, and 5 years building and installing a large number of production-run units, before moving on to the next design.
Nearly every instrument on every large telescope today is 'couture', with at most 2 units in existence. Telescopes designed for mass replication, like the ATA or PAN-STARRS, end up getting their funding cut off for further units as soon as first light is reached on the prototype, because of the perverse incentives and interests associated with astronomical research.
It also means devoting actual resources to SETI, instead of having it be something tenured professors do as a hobby, with nearly zero funding.
https://seti.berkeley.edu/opticalseti
Maybe the funds could be spent into how to solve the nuclear residues problem, how to design a catascope to look under yellowstone or inside the etna, how to predict and minimise the next fukushima/three mile island, or how to study sea currents and discover if those yummy school of anchovies from japan will cause you a leukemia in two years.
Just an opinion
Seriously from earth we are only likely to find aliens at the same or slightly ahead of our own technology. If one visits us first it might come sooner. If the aliens are far ahead of us we may never even notice them. It's like dumping Newton in a modern corn field and telling him he is surrounded by people communicating. He would have no idea about cell phone, microwave and other transmissions. Take technology from 300 years in the future in an alien today and we might be equally clueless.
It's like amerindians wanting to find spaniards.
We are right now like amerindians building a lighthouse to contact people in the old world. If we point it to Africa, elephants and tigers won't know how to respond. If we keep building it higher and higher and point it to Europe, spaniards will come and slaughter us all.
N ~= 2flfefcL
where fl is the fraction of habitable planets hosting life, fe is the fraction of life-bearing planets that develop an intelligent life-form, fc is the fraction of intelligent life-forms that decide to communicate, and L is the length of time a given civilization is transmitting "visible" communications. Taking ourselves as an example, L is already on the order of 100 years. The original estimates for these values were fl = 1, fe = 1, fc = 0.1-0.2, and L = 1000-100,000,000 (http://en.wikipedia.org/wiki/Drake_equation).
There would still be the possibility that the presence of oxygen was geologic in nature, and if we sampled a billion exo-planets, it's reasonable that some could have an exotic geology to cause this 'false positive'.
The next step might be to look for a pattern in the carbon-cycle connected with orbits: e.g on Earth the North vs. South hemisphere have different amounts of plant life, and we see C02 wobble several ppm in summer vs. winter. Getting accurate readings of exo-planets to the ppm level might take a while for telescope technology to acheive. For these reasons, I'd say 2100 is a good estimate for when we would have the ability to sample 1B exoplanets, and promote at least one to the rank of 'strong possibility of harboring life'.
"Humanity seems to have a bright future, i.e., a non-trivial chance of expanding to fill the universe with lasting life. But the fact that space near us seems dead now tells us that any given piece of dead matter faces an astronomically low chance of begating such a future. There thus exists a great filter between death and expanding lasting life, and humanity faces the ominous question: how far along this filter are we?
"Combining standard stories of biologists, astronomers, physicists, and social scientists would lead us to expect a much smaller filter than we observe. Thus one of these stories must be wrong. To find out who is wrong, and to inform our choices, we should study and reconsider all these areas."