https://www.space.com/seti-extraterrestrial-search-human-biases-can-cloud-research.html
One thing I see, even if there are aliens just like us and transmit signals like we do, there would be an end to such signals because no civilization can live forever. Even STARS die.
So it could be say a million years ago a civilization say 10,000 light years away starts out like we do with primitive transmitters and then develop more sophisticated equipment like we have done with multi megawatt transmitters and such, so a million years ago they start sending out their waves but say they last 100,000 years and go extinct and were transmitting all that time. Well that means they stop transmitting 900,000 years ago and since we are 10,000 light years away, even if they are 100,000 light years away, which is about as far away as they can be and still be in our galaxy, using those numbers, the wavefront passes by Earth 800,000 years ago when we are just a stone tool making set of tribes.
So we would never hear them, ships passing in the night.
That is BESIDES the philosophical issues brought up in this piece.
@ogb
What they THINK doesn't matter. What matters if there is an actual unambiguous detect. Personally I don't think they will see signs of aliens in the next 100 years. By that time, assuming we still HAVE a scientific civilization 100 years from now, they may have giant radio telescopes on the backside of the moon or out a billion miles away from the sun with kilometer plus sized dishes that can detect a cell phone from 100 light years away. If we have THAT maybe....
@sonhouse saidThis 'window of opportunity' has always been discussed as only one of the problems searching for ET. The tech window for some species could be quite short, and that's only if they don't blow themselves to oblivion once they discover element 92.
https://www.space.com/seti-extraterrestrial-search-human-biases-can-cloud-research.html
One thing I see, even if there are aliens just like us and transmit signals like we do, there would be an end to such signals because no civilization can live forever. Even STARS die.
So it could be say a million years ago a civilization say 10,000 light years away starts out like we ...[text shortened]... em, ships passing in the night.
That is BESIDES the philosophical issues brought up in this piece.
@Suzianne
Indeed. And there is the possibility intelligent tech life is so rare we get one only per galaxy. Not my estimate but there it is.
Even with one per galaxy, there are almost a trillion galaxies but it would mean without faster than light travel we would be forever out of reach, even the closest galaxy, the Magi Clouds are 175,000 light years away and Andromeda, couple of million LY out. And those are just the closest ones.
Or say we get TWO per galaxy. Us and someone maybe 100,000 ly away, pretty much same scenario.
I wonder about life in general, for instance, if life is found on Mars or Europa for instance, just bacteria, whatever.
So would that life form look like our DNA, like double helix and the like?
If it is, it would suggest life formed at least in our solar system from some common cause, a gas cloud with the right stuff of prebiotic molecules to lead to our kind of life or if it was something totally different, just to throw out some BS, suppose their DNA was a square twisted shape with four sides and totally different molecules, THAT would suggest life is everywhere conditions are halfway decent for life, any planet in the goldilocks zone and such which even if such conditions occur at a rate of one in a thousand, out of the many billions of stars in our galaxy would lead one to assume millions of planets with life.
I really am looking forward to manned missions to Mars to see if they find any life and what does their version of DNA look like.
It might be possible to find life on Europa by the water clouds squirting off the planet, a mission just a flyby through those clouds and return to Earth could find some kind of life forms, bacteria maybe, whatever, just floating in the cloud of water and such streaming off Europa.
@sonhouse saidLife in another solar system is probably many hundreds of light years away at least. My grandchildren (if my kids have their own kids) would be dead before radio waves ever reached intelligent life that mastered technology like man.
https://www.space.com/seti-extraterrestrial-search-human-biases-can-cloud-research.html
One thing I see, even if there are aliens just like us and transmit signals like we do, there would be an end to such signals because no civilization can live forever. Even STARS die.
So it could be say a million years ago a civilization say 10,000 light years away starts out like we ...[text shortened]... em, ships passing in the night.
That is BESIDES the philosophical issues brought up in this piece.
SETI is a project that would only benefit future generations. We will unlikely ever live long enough to get a signal back. Even if there was a freak occurrence of life evolving in a solar system nearby, what are the odds of that life being intelligent enough to master radio technology?
SETI makes for neat science fiction movies, but the reality is extremely boring. Even if an advanced alien civilization exists how do we know they would be listening? If they sent a signal we have no idea how long they would send it. What if Tesla received a signal from another solar system like he once claimed? Almost nobody believed him. Maybe our SETI signal would result in some genius alien being thrown into an insane asylum. We don't know what they would be like if they exist.
SETI is flawed if anyone has high expectations of it. Don't get your hopes up. You will be long dead before anything could possibly come from it.
@Metal-Brain
The point is just finding unequivocal signs of alien life would be a game changer philosophically to Earthlings. It would say we are not alone, even if we know for a fact we could never respond to those aliens because we may know they are a thousand light years away, so that would not happen in anyone's lifetimes.
That doesn't matter.
For instance, the presence of the moon was a motivation to THINK about going there for the past thousand years and eventually led to us going there. That is the motivation for SETI. Not that we would automatically be able to say HI.
@lemondrop
And they may use communications technology based on say, gravity waves and we are at the point in that regard as we were 120 years ago in regards to radio waves. Radio detectors in 1900 were very primitive, requiring a very large received signal to show detection.
We are in the same boat as far as gravitational radiation goes. The energy given off by say two colliding black holes that goes into GR, is as much as our star produces in its lifetime converted to gravitational radiation.
So we are somewhat in the same boat as we were 120 odd years ago with regards to radio waves and with similar restraints as to wavelengths also. Back then they considered 1 megahertz like we do microwaves, 1 meg was microwave to them and we have a similar problem with GR, we are working on ways to detect gravitational radiation in wave bands out of reach of present instruments like LIGO and the like.
@sonhouse saidso we may yet get to say hello
@lemondrop
And they may use communications technology based on say, gravity waves and we are at the point in that regard as we were 120 years ago in regards to radio waves. Radio detectors in 1900 were very primitive, requiring a very large received signal to show detection.
We are in the same boat as far as gravitational radiation goes. The energy given off by say two col ...[text shortened]... ct gravitational radiation in wave bands out of reach of present instruments like LIGO and the like.
@lemondrop
Even if they are on a planet in the Alpha centauri system I say HI, 4 1/3 years later they get HI, and they answer, 9 2/3 years later I get HOWDY back.
So suppose it is on a planet going round a star 400 light years away.
I say Hi, 400 years later they get my HI, send me HOWDY, which I get 800 years after I said HI. Not exactly conducive to a philosophical discussion, eh.
There are so many variables, it is pure speculation that any intelligent exo-life-form would even try to communicate. Imagine an opaque-cloud-covered planet like Venus, or a water-world; intelligent life could develop there and never get beyond its own atmosphere or ocean, never see the sky, never even suppose that there might be anything above their own atmosphere or ocean to communicate with.
@moonbus saidDon't get too excited. We could simply be a half-baked offshoot of an older, wiser human race that lives somewhere out there.
There are so many variables, it is pure speculation that any intelligent exo-life-form would even try to communicate. Imagine an opaque-cloud-covered planet like Venus, or a water-world; intelligent life could develop there and never get beyond its own atmosphere or ocean, never see the sky, never even suppose that there might be anything above their own atmosphere or ocean to communicate with.
@bunnyknight
There is no reason to think that intelligent life on other planets must have opposable thumbs and use electricity, just because we do.
@lemondrop
Gravity waves still are stuck propagating at c. So same problem as radio or light.