B Will we ever communicate with extraterrestial life in a reasonable time frame?

[Davephaelon]

Avi Loeb is a little bit out there.

Admittedly that is the public perception. But I like his boldness, tempered by a disciplined scientific approach. In many ways he reminds me of another astronomer - Dr. J. Allen Hynek - who served as the scientific consultant for Project Blue Book, on a subject unfortunately associated with the loony fringe. Dr. Hynek ultimately became very critical of that Air Force project. I wrote to him in the early 70's and was thrilled to receive a letter in response (just wish I could find it!). Another scientist, back in those days, that I greatly admired was Dr. James E. McDonald: "a senior physicist at the Institute for Atmospheric Physics and a professor of meteorology at the University of Arizona in Tuscon" (Wiki page). He favored the extraterrestrial hypothesis.

I remember how discouraged I was back about 1966 when I looked into the incredible difficulties of humanity ever traveling to other solar systems. But when Miguel Alcubierre came up with his warp drive concept in the 90's it seemed like the prospect for humanity traveling to the stars in reasonable time periods was perhaps not entirely impossible. But that fizzled with more rigorous analysis by other scientists - Pfenning, Ford, Broeck, if memory serves.

 

[sophiecentaur]

Is our species, as a species, so filled with hubris as to reject the possibility we could learn from a very different intelligent species? There is no useless knowledge other than the knowledge you don't possess. They possess knowledge we don't and vice versa. Why throw away the chance?

Throw away what chance? You talk as if this sort of project would take up no resources. It's a bit like "you've got to be in it to win it", which is the way Lottery tickets are sold. And we actually know the probability involved in a lottery.( I am totally shocked, btw, at the total amount of money spent in the UK by the national lottery.) You are suggesting a massive outlay with an infinitessimally smaller chance of 'winning'. Who pays???

Avi Loeb of Harvard even speculated that Oumuamua might have been an artificial craft from another civilization

Speculations like that don't impress me. It's along the lines of biblical and koranic statements but with a lot less 'authority' and it shows a huge indication of lack of discipline, imo. That sort of message is blatantly seeking publicity for the article and his book sales and supplies nothing to the real argument.

Remember Eric Von Daniken? He had me fooled when I was 14. He got me believeing that my Physics Master was from Venus!!!!!

 

[Davephaelon]

Speculations like that don't impress me. It's along the lines of biblical and koranic statements but with a lot less 'authority' and it shows a huge indication of lack of discipline, imo. That sort of message is blatantly seeking publicity for the article and his book sales and supplies nothing to the real argument.

Actually, his speculation is based on empirical data. For example the last paragraph on page 2 of the link to his pdf above states:

"These were just the initial anomalies that made `Oumuamua different from all the comets and asteroids that we had seen before in the Solar system. As it tumbled every eight hours(see Figure 4), the brightness of sunlight reflected from it changed by a factor of ten. This meant that it has an extreme shape, which at the ~90% confidence level was disk-like (Mashchenko, 2019). The Spitzer Space Telescope did not detect any carbon-based molecules or dust around `Oumuamua, setting a tight limit on ordinary cometary activity (Trilling et al., 2018). The lack of heat, detectable in the infrared, placed an upper limit of about 200 meters on its size, the scale of a football field. But most remarkably, `Oumuamua exhibited an excess push away from the Sun which would have required it to lose ~10% of its mass if it was caused by the rocket effect from normal cometary evaporation (Micheli et al., 2018). An extensive evaporation of this magnitude was absolutely ruled out by the Spitzer telescope data; moreover, the repulsive force declined smoothly with distance from the Sun, showing no change in spin or sudden kicks as routinely observed from localized jets on the surface of comets (Rafikov, 2018). Finally, there was no apparent cut-off in the push at the distance beyond which evaporation of water ice by the heating of sunlight is expected to stop (see Figure 5)."

His paper is well worth a read. Among many other things he points out that there were similarities between the dynamical behavior of Oumuamua and 2020 SO, a remnant of a NASA spacecraft launched in 1966. This is brought up in the abstract: "`Oumuamua’s anomalies suggest that it might have been a thin craft - with a large area per unit mass - pushed by the reflection of sunlight; sharing qualities with the thin artifact 2020 SO - launched by NASA in 1966 and discovered by Pan STARRS in 2020 to exhibit a push away from the Sun with no cometary tail". He also points out significant problems with various proposed natural origins for Oumuamua.

 

[ShadowKraz]

Throw away what chance? You talk as if this sort of project would take up no resources. It's a bit like "you've got to be in it to win it", which is the way Lottery tickets are sold. And we actually know the probability involved in a lottery.( I am totally shocked, btw, at the total amount of money spent in the UK by the national lottery.) You are suggesting a massive outlay with an infinitessimally smaller chance of 'winning'. Who pays???

That sort of reasoning argues against spending ANY money/resources on ANY scientific research. And don't misrepresent me hoping I'll cave and give you a win; I am NOT suggesting a massive outlay with an infinitesimally smaller chance of winning simply because I'm not making a thin air assumption that the outlay MUST be massive or that there is an infinitesimally smaller chance of winning. You have exactly zero to back up your assumptions. What I have is the fact that spending on science has ALWAYS paid off; even if it took a long time or produced negative results, it has always paid off. I repeat, the only useless knowledge is the knowledge you don't have.

 

[pinball1970]

That sort of reasoning argues against spending ANY money/resources on ANY scientific research. And don't misrepresent me hoping I'll cave and give you a win; I am NOT suggesting a massive outlay with an infinitesimally smaller chance of winning simply because I'm not making a thin air assumption that the outlay MUST be massive or that there is an infinitesimally smaller chance of winning. You have exactly zero to back up your assumptions. What I have is the fact that spending on science has ALWAYS paid off; even if it took a long time or produced negative results, it has always paid off. I repeat, the only useless knowledge is the knowledge you don't have.

There is SETI, satellites, ground and orbit telescopes. Ok, only SETI to my knowledge is "looking" specifically but all the other kit could pick up something. Webb for instance cost 10 billion and interesting planets is on the hit list.

 

[sophiecentaur]

I am NOT suggesting a massive outlay

Your average mission costs $1B which may or may not seem massive. What sort of project would you be thinking of? JWST was about $10B. That would correspond to very good value for money because the data it produces is much more than a yes / no answer. However, JWST doesn't look for low entropy signals. It has its feet firmly on the ground (in a manner of speaking) and the returns on investment have been increasing on a daily basis.

You have exactly zero to back up your assumptions.

I have evidence that, so far we have received no signals. You have no evidence of signals - just faith that they are going to arrive some day.

In terms of value for money, how much of your income would you be prepared, personally, to spend on an as-yet unspecified project? Would that amount (scaled up) be representative of other peoples' contributions (taxes) who have basically been paying for Entertainment and the esoteric enjoyment of seeing rich tourists burn up millions of their dollars?

 

[gmax137]

That sort of reasoning argues against spending ANY money/resources on ANY scientific research.

I don't see it that way.

We have finite resources, hence we need to prioritize our choices.

 

[sophiecentaur]

That sort of reasoning argues against spending ANY money/resources on ANY scientific research. And don't misrepresent me hoping I'll cave and give you a win; I am NOT suggesting a massive outlay with an infinitesimally smaller chance of winning simply because I'm not making a thin air assumption that the outlay MUST be massive or that there is an infinitesimally smaller chance of winning. You have exactly zero to back up your assumptions. What I have is the fact that spending on science has ALWAYS paid off; even if it took a long time or produced negative results, it has always paid off. I repeat, the only useless knowledge is the knowledge you don't have.

Look up “straw man” as a form of argument.

 

[ShadowKraz]

Look up “straw man” as a form of argument.

Tit for tat, I suppose.

 

[ShadowKraz]

Your average mission costs $1B which may or may not seem massive. What sort of project would you be thinking of? JWST was about $10B. That would correspond to very good value for money because the data it produces is much more than a yes / no answer. However, JWST doesn't look for low entropy signals. It has its feet firmly on the ground (in a manner of speaking) and the returns on investment have been increasing on a daily basis.

I have evidence that, so far we have received no signals. You have no evidence of signals - just faith that they are going to arrive some day.

In terms of value for money, how much of your income would you be prepared, personally, to spend on an as-yet unspecified project? Would that amount (scaled up) be representative of other peoples' contributions (taxes) who have basically been paying for Entertainment and the esoteric enjoyment of seeing rich tourists burn up millions of their dollars?

Again, you are misrepresenting my thoughts with your unfounded assumptions. I do not have faith that they are going to arrive some day. None. I do hope that we will receive indication of life elsewhere in this galaxy but I'm not so stupid as to think it MUST exist. As I will not engage with you on this again, you can make another unfounded assumption; you won.

 

[DennisN]

Remember Eric Von Daniken? He had me fooled when I was 14.

Even though it's really painful (truly, ) to write this I have to admit that I got fooled by Däniken too when I was young.

We do silly things when we're young. Some start to smoke, some drink, some start to steal.
My shame is having read Däniken.

There, I've said it.
Ah, I feel so much better now.

You youngsters, listen to wisdom from an older man:
Don't drink, smoke or steal. And stay away from Däniken.

 

[DennisN]

Avi Loeb is a little bit out there.

Further out than Oumuamua?

 

[pinball1970]

That sort of reasoning argues against spending ANY money/resources on ANY scientific research. And don't misrepresent me hoping I'll cave and give you a win; I am NOT suggesting a massive outlay with an infinitesimally smaller chance of winning simply because I'm not making a thin air assumption that the outlay MUST be massive or that there is an infinitesimally smaller chance of winning. You have exactly zero to back up your assumptions. What I have is the fact that spending on science has ALWAYS paid off; even if it took a long time or produced negative results, it has always paid off. I repeat, the only useless knowledge is the knowledge you don't have.

I did not mention Kepler Launched 2009.

That was looking for earth type planets and star systems. https://www.nasa.gov/news-release/n...rs-first-earth-size-planet-in-habitable-zone/

It is now decommissioned.

JWST has already been mentioned that is collecting data right now on exoplanets as part of its mission. Launched 2021

SETI already mentioned (first funded in the 1970s by NASA according to wiki) and I would check out the https://en.wikipedia.org/wiki/Breakthrough_Listen 2016

Recently there was an interview with a youtuber and the Director of astronomy, regarding the habitable worlds Observatory https://cor.gsfc.nasa.gov/studies/habitable-worlds/hwo.php

Interview here

 

[sophiecentaur]

I did not mention Kepler Launched 2009.

That was looking for earth type planets and star systems.

IS this thread discussing the quest for life forms or the quest for advanced civilisations? I would not be surprised if some life forms were discovered within a decade or so but that is many orders of magnitude from chatty little green men.

 

[sbrothy]

Even though it's really painful (truly, ) to write this I have to admit that I got fooled by Däniken too when I was young.

We do silly things when we're young. Some start to smoke, some drink, some start to steal.
My shame is having read Däniken.

There, I've said it.
Ah, I feel so much better now.

You youngsters, listen to wisdom from an older man:
Don't drink, smoke or steal. And stay away from Däniken.

What's even worse is that I like a few programs on History Channel ("Forged in Fire" for instance) but suddenly up comes this "Ancient Astronauts" series which actually gives the man screentime!!

"Ancient astronaut theoriticians say Yes!"

NO! Just no! Get out of of my TV! :P


And if you really want wisdom:

Stay away from relationships, upbringing (includes pets) and drug-related debts. No matter how good your intentions are they are fights you can't win and should stay away from.

Noone wants advise on how to bring up your own child for instance.

EDIT: I'm tempted sometimes though. I've seen several examples of people learning their children to run in traffic(!). In my opinion, if you need to run in traffic something already went wrong. You need to make eyecontact and be predictable to other people. But per my own "words of wisdom" above I just keep it inside.

 

[MotherMayhem]

Granted that life exists somewhere. Just by stating that are 200 billion stars in the Milky Way galaxy tends to make us believe that intelligent life is close by.

We need to set a limit of 100 years to send and receive one answer. This necessary requirement will greatly reduce the possibility of any contact.
How many planets similar to Earth are within 50 light years?
What are the energy requirements to send that message?
What is the lowest signal we can reliably detect?

Many star systems contain two and three stars. Will planets in such systems have stable orbits to allow life billions of years to evolve?
Even if we find planets that can harbor life today, what was the history of such planets? We do not know.

Ohhhh, I'm sooooo sooorrrry I didn't get back to you in what YOU call a "reasonable time frame".. but I had alien stuff to do!
Wow... just...wow...
I'm gone for 5 years and you go and talk about me to all your friends on the internet!

You are so not getting the Milky way I picked up on my way back now.

 

[sbrothy]

If we have time enough (I'm talking geological time here) E-sail might be an alternative. Though I'm not even sure the we, or indeed the Milky Way, is still here when something returns.

 

[ohwilleke]

Well, when you looked it up on Wikipedia, you would have discovered there are 130 K, G and F type stars within 50 light years. You also, when you looked it up on Wikipedia, learned that estimates from Kepler are that 1.4-2.7% of such stars have planets in their habitable zones. That's 2-3, one of which is the sun.

So, there are 1 or 2 candidate stars. To have a civilization, this requires that the star not only has planets in the habitable zone, but that these planets are habitable. The sun has, arguably four: Venus, the Earth, the Moon, and Mars. Only one is habitable.

The rest is speculation, but I point out:

• For half of earth's history, there were no eukaryotes
• For 75% of eukaryote history, there were no multicelluar organisms
• For 99.5% of multicelluar life history, there were no people (genus homo)
• For 99.5% of human (genus homo again) existence, there was no civilization.
• For 99% of civilization, radios did not exist.

Give all that, 1 or 2 candidate stars does not seem like a lot.

The argument that there are only four candidates in the solar system, a priori (we've probed enough to rule out advanced civilizations on many them by now) seems low.

Carl Sagan, when pressed to consider the question of where in the solar system it was possible to support some kind of life in a glossy illustrated book I recall reading as a kid (I can't recall the title), came up with about a dozen. There could be blimp-like creatures in the atmospheres of Jupiter or Saturn, there could be life below a frozen ocean on Titan. There could be life on Neptune or Pluto, or on several other moons in the solar system. And so on. NASA thinks so too.

Movies and TV tend to imagine each different world as having only one ecosystem, but life only needs one tiny microenvironment to emerge, and that can happen in one little ecosystem corner on a world that is predominantly uninhabitable.

Now, one factor is that SETI has made a concerted effort to look for possible communications from other life forms in space for decades and not found anything. This puts a ceiling on the strength of a signal that could be receiving unless we receive this alien civilization's very first transmission in our direction. Most conceivable civilizations within 50 light-years of Earth that could send us a message would have done so already and been discovered, if the signal was strong enough for SETI to hear.

But if we did discover an alien civilization, right now would be a pretty plausible time to do so, because the power of our "telescopes" (broadly defined) has improved dramatically in the last decade or two. So, we can now detect all sorts of signals from space that we were previously deaf to. If some alien civilization is regularly transmitting signals in our direction, then we are likely to discover any too weak to hear before the latest wave of "telescopes" but within our power to detect now, any time now. Major new discoveries from new telescope technologies tend to be front loaded.

Also, because it doesn't seem to have been mentioned yet, the primary way for scientists (lots of them) to structure the question asked in this thread is through analysis of Drake's Equation. There are, for example, sixty pre-prints at arXiv that discuss this equation.

 

[MotherMayhem]

If we have time enough (I'm talking geological time here) E-sail might be an alternative. Though I'm not even sure the we, or indeed the Milky Way, is still here when something returns.

My Milky Way had BETTER be here when I get back!
If anyone eats it while I've popped out, I'm getting out the lazer beams so help me!

 

[DennisN]

NO! Just no! Get out of of my TV! :P

What's even worse is that I like a few programs on History Channel ("Forged in Fire" for instance) but suddenly up comes this "Ancient Astronauts" series which actually gives the man screentime!!

"Ancient astronaut theoriticians say Yes!"

The funny thing is that I understand (at least I think I do ) why the ancient astronauts/ancient aliens belief system is popular among some people. It is an incredibly thrilling and compelling story. And numerous science fiction stories have used it (e.g. Sphere, Stargate, Prometheus and Indiana Jones and the Kingdom of the Crystal Skull).

 

[Jaime Rudas]

Humans are too primitive

Regarding whom are humans too primitive?

 

[sbrothy]

The funny thing is that I understand (at least I think I do ) why the ancient astronauts/ancient aliens belief system is popular among some people. It is an incredibly thrilling and compelling story. And numerous science fiction stories have used it (e.g. Sphere, Stargate, Prometheus and Indiana Jones and the Kingdom of the Crystal Skull).

Yeah, But as someone metioned (@sophiecentaur ?), Däniken is something you read when you're 16 and spiritually searching until you look out into the cosmos and realize there's no need to come up with crazy stories. Reality is plenty crazy as it is. :)

 

[sbrothy]

My Milky Way had BETTER be here when I get back!
If anyone eats it while I've popped out, I'm getting out the lazer beams so help me!

I'm gonna quick-draw my Nicoll-Dyson beam.

 

[Hyku]

Regarding whom are humans too primitive?

six-eight million years ago, we shared a common ancestor with the chimpanzee and the bonobo. To this day, we share 98.8% of our DNA with the chimp.*

Chimpanzees wage war, and they are sadists. **

The myriad 20th century atrocities are common knowledge. Three common causal factors were - a disillusioned desperate population - the emergence of a leader - and the population being bombarded by propaganda that targeted emotion - not intellect. I argue that the populations subsequently behaved like chimps.

* https://www.amnh.org/exhibitions/pe...ding-our-past/dna-comparing-humans-and-chimps

** https://duckduckgo.com/?q=chimpanzee+warlike+sadists&t=ffab&ia=web

 

[Jaime Rudas]

six-eight million years ago, we shared a common ancestor with the chimpanzee and the bonobo. To this day, we share 98.8% of our DNA with the chimp.*

Chimpanzees wage war, and they are sadists. **

The myriad 20th century atrocities are common knowledge. Three common causal factors were - a disillusioned desperate population - the emergence of a leader - and the population being bombarded by propaganda that targeted emotion - not intellect. I argue that the populations subsequently behaved like chimps.

* https://www.amnh.org/exhibitions/pe...ding-our-past/dna-comparing-humans-and-chimps

** https://duckduckgo.com/?q=chimpanzee+warlike+sadists&t=ffab&ia=web

Nice set of non sequiturs

 

[Hyku]

Nice set of non sequiturs

What you meant to say was - that was a nice set of non sequiturs.
So you wrapped an ad hominen fallacy in a cloak of grammatically flawed sarcasm.

Please explain the flaws in "The myriad 20th century atrocities are common knowledge. Three common causal factors were - a disillusioned desperate population - the emergence of a leader - and the population being bombarded by propaganda that targeted emotion - not intellect. I argue that the populations subsequently behaved like chimps."

Did you read the 2 cited sources?

 

[Jaime Rudas]

What you meant to say was - that was a nice set of non sequiturs.

What I meant to say is that correlation does not imply causation. In other words, I cannot find a causal relationship between the following statements:

Humans are too primitive.

We share 98.8% of our DNA with the chimp.

Chimpanzees wage war, and they are sadists.

The myriad 20th century atrocities are common knowledge.

The population is disillusioned and desperate.

A leader emerged.

The population is being bombarded by propaganda that targeted emotion - not intellect.

The population behaves like chimps.

 

[pinball1970]

IS this thread discussing the quest for life forms or the quest for advanced civilisations? I would not be surprised if some life forms were discovered within a decade or so but that is many orders of magnitude from chatty little green men.

Fair enough, I was just pointing out active research past and present for ET life and planets they could be on.

 

[Sheik Yerbuti]

I think a missing factor in the discussion about contacting ET is the question of how long we will be homo sapiens. The 100,000 light years that are our galaxy is roughly the same as the age of homo sapiens sapiens. Assuming that in the distant future time will be no barrier to communication (yeah- big assumption), they could be us. Especially since we try to contact other civilizations, our first contact could be ourselves from 10,000 years in the future trying to contact other civilizations. Or time can't be conquered. I find it interesting to consider, though.

 

[MotherMayhem]

I'm gonna quick-draw my Nicoll-Dyson beam.

You could try, Earth Man...