What exoplanet might reply us back?

[alfa015 (Alberto)]

So.. we have sent radio messages to Gliese 273 b and the Gliese 581 system, where planet 'g' hasn't been confirmed yet but it is potentially habitable.

Which of these exoplanets, if any, do you think might reply us back?

Put in other words, which of these exoplanets do you think it might have intelligent life?

I recently made a video about this topic, just in case someone wants to check it out: http://www.youtube.com/watch?v=egEco...x313_nrZtX4W8M

[doppler (Rick)]

Maybe none?
https://qz.com/1314111/we-may-have-a...-the-universe/

[bojan]

I deeply disagree with approach and way of thinking in that article, it's just rambling without any value in it.

We can't possibly draw conclusions about what we don't know...and those guys are doing just that.
Let's not forget, intelligence can manifest itself in many ways and we have examples here on earth (primates, dolphins, cetaceans.. even craws are quite intelligent), and technological civilizations are not the only necessary outcome of the evolution of life, even if intelligence is (which I doubt - it took 3.5 or more billions of years for homo sapiens to appear, we are here - how long - 100ky only?).
Also, difficulties related to interstellar communications and/or travel are enormous.. perhaps detrimental both physically and financially (maybe they also have liberal/trumpesque governments as well)

I say, lets just wait and see what happens... and let's keep looking.

[LewisM]

I relate this all back to String Theory.

How long is a piece of string is your answer.

[rally]

Paper here
https://arxiv.org/pdf/1806.02404.pdf

They treat the Fermi Paradox as a range of uncertainties rather than as point values

Their Conclusion :

When we update this prior in light of the Fermi observation, we find a substantial probability that we are alone in our galaxy, and perhaps
even in our observable universe (53%–99.6% and 39%–85% respectively).
’Where are they?’— probably extremely far away, and quite possibly beyond the cosmological horizon and forever unreachable.

Shame about that I was hoping for ET

[Wavytone]

What i don't understand is the blind assumption that its a good idea to rather noisily advertise our presence.

[Sato (Dom)]

Anyone returning calls from 'Earth' will be universally recognised as the new suckers for a 'You have inherited $5000000 from your Ugandan 2nd cousin, please send a deposit...' email .

[gaa_ian (Ian)]

Originally Posted by bojan

I deeply disagree with approach and way of thinking in that article, it's just rambling without any value in it.

We can't possibly draw conclusions about what we don't know...and those guys are doing just that.
Let's not forget, intelligence can manifest itself in many ways and we have examples here on earth (primates, dolphins, cetaceans.. even craws are quite intelligent), and technological civilizations are not the only necessary outcome of the evolution of life, even if intelligence is (which I doubt - it took 3.5 or more billions of years for homo sapiens to appear, we are here - how long - 100ky only?).
Also, difficulties related to interstellar communications and/or travel are enormous.. perhaps detrimental both physically and financially (maybe they also have liberal/trumpesque governments as well)

I say, lets just wait and see what happens... and let's keep looking.

Yep, totally agree. Also the window for communication with our radio is a very narrow one as we move away from broadcast communications ourselves after 100 odd years of radio.

Scotty: Captain, getting some interference on subspace band.
Captain: Remember the Prime Directive Scotty, no interference with primitive cultures.

[Atmos (Colin)]

I did a fairly in depth review of the Femi Paradox a few years back. The point of the Drake Equation is not only for intelligent species but for intelligent species with the technology to be able to communicate further out than their own little globe, or it not communicate as such, make enough noise for others to be able to detect them. A year or two ago I listened to a lecture in at Swinburne that discussed the distance of radio transmissions through space. What I got out of that was that our general radio pollution through the universe, although it has been happening since the 50's, becomes so weak and buried in noise that after about a lightyear it isn't even detectable. Even with purpose built powerful directed radio transmitters, we're still only limited to a few light years and even at that distance it would just be a very weak noise source.

As to the Drake Equation itself, it is pretty much a moot point. The first half of the equation has a scientific base that, through some research, can be calculated to defined values such as ~1.3% of stars within a defined region (not too close and not too far from the galactic centre) in our epoch have potentially habitable rocky planets [I think that was the value anyway, been a few years since I wrote it].
The second half of the equation however is just pure conjecture. For instance, there have been approx 100 billion species on Earth in the last few billion years so from that stand point you can say that there is a 1/100E9 chance of intelligent life forming (if you believe we are indeed intelligent life ). But that is not what the Drake Equation is asking for as you can either take the stance that the value is 0 in that intelligent life forming was a complete fluke of nature and that the 1/100,000,000,000 is a conservative estimate and that it is in reality so close to zero that we are the only intelligent life in the universe. OR you can say the value is 1 and take the stance that anywhere life can live, intelligent life is inevitable given enough time.

So, depending on your personal belief, just one of the values can range between virtually 0 and virtually 1. What is the chance of life forming at all? Somewhere between "impossible" to "it WILL happen if the conditions are right".

[clive milne]

This all presupposes that you are not actually in the Matrix .... or simply a brain in a beaker being stimulated by a mad scientist in order to make you hallucinate an approximation of the real world.

Equally valid conjectures..

~2c

[geolindon (Lindon)]

g day,

quantifying planets per stars ratio has taken us one step further along Drakes equation.
i believe the next intelligent/logical contribution to the solution of Drakes equation will come from the discovery of fossils or bugs on Mars and bugs at Europa and later at Enceladus, along with the detection of signs of life on nearby exoplanets.
proven negatives of the same are also an advance.

regards, L

[xelasnave]

We are on the old problem of working out if there is life out there which is great but before we can go to far we need to find something outside Earth evidencing life..Mars, the various Moons a pinch of suggestion in a comet. .. and we will move a little further with our speculation but not far.
Logic well not logic but a wild unsupported belief tells me there must be life everywhere but the reality is there is no evidence of life such that we have any useful plugins for the Drake equation or any other that seek to introduce "odds".
I think the answer to will probably be one of inference from a future understanding of the chemical process of life.
I personally believe, which means nothing really, that life is an inevitable result of a chemical process ...
If life is mere chemical reaction it will be everywhere ...
It seems too arogant to entertain a proposition that we are it.
However the vastness of just our little part of the galaxy indeed the universe means that even powerful signaling systems may be well below adequate or productive.
Nevertheless someone hopefully will find a way to make my sceptism old hat.
We dont know what we dont know is perhaps our greatest hope...
I hope someone from elsewhere can visit and tell us we are not alone and not eat us.
Alex

[rally]

Colin,

That is pretty much the approach the authors of the linked paper took.

Treat all parameters of the Drake equation as a range using known uncertainties and some of their own.

Rally

Originally Posted by Atmos

I did a fairly in depth review of the Femi Paradox a few years back. The point of the Drake Equation is not only for intelligent species but for intelligent species with the technology to be able to communicate further out than their own little globe, or it not communicate as such, make enough noise for others to be able to detect them. A year or two ago I listened to a lecture in at Swinburne that discussed the distance of radio transmissions through space. What I got out of that was that our general radio pollution through the universe, although it has been happening since the 50's, becomes so weak and buried in noise that after about a lightyear it isn't even detectable. Even with purpose built powerful directed radio transmitters, we're still only limited to a few light years and even at that distance it would just be a very weak noise source.

As to the Drake Equation itself, it is pretty much a moot point. The first half of the equation has a scientific base that, through some research, can be calculated to defined values such as ~1.3% of stars within a defined region (not too close and not too far from the galactic centre) in our epoch have potentially habitable rocky planets [I think that was the value anyway, been a few years since I wrote it].
The second half of the equation however is just pure conjecture. For instance, there have been approx 100 billion species on Earth in the last few billion years so from that stand point you can say that there is a 1/100E9 chance of intelligent life forming (if you believe we are indeed intelligent life ). But that is not what the Drake Equation is asking for as you can either take the stance that the value is 0 in that intelligent life forming was a complete fluke of nature and that the 1/100,000,000,000 is a conservative estimate and that it is in reality so close to zero that we are the only intelligent life in the universe. OR you can say the value is 1 and take the stance that anywhere life can live, intelligent life is inevitable given enough time.

So, depending on your personal belief, just one of the values can range between virtually 0 and virtually 1. What is the chance of life forming at all? Somewhere between "impossible" to "it WILL happen if the conditions are right".

[Atmos (Colin)]

What I wrote was far less technical, no graphs

Fermi Paradox I wrote in 2014

Pretty much came to the same conclusion. If you believe that life is enivitable given enough time then the universe will be teeming with life. If you don’t believe that, then we’re alone.

Pick a number, any number

[alfa015 (Alberto)]

Originally Posted by Atmos

What I wrote was far less technical, no graphs

Fermi Paradox I wrote in 2014

Pretty much came to the same conclusion. If you believe that life is enivitable given enough time then the universe will be teeming with life. If you don’t believe that, then we’re alone.

Pick a number, any number

thanks for the link!

[geolindon (Lindon)]

https://www.skyandtelescope.com/astr...ough-for-life/

"Now a closer analysis of the spectrometers' data reveals that the organic brew inside Enceladus must contain organic "parent molecules" much more massive and complex than realized. This discovery, published last week in Nature, bolsters scientists' hopes that life is present there and in other locations of the solar system. But stronger evidence is needed to make the case."

regards ,L

[doug mc]

The only thing we know about life is that it comes from life. All other statements are theoretical concepts. Perhaps science one day will be able to tell us how it started, but so far the rules of observable, testable and repeatable have come up short.

[julianh72 (Julian)]

Originally Posted by Atmos

If you believe that life is enivitable given enough time then the universe will be teeming with life. If you don’t believe that, then we’re alone.

Pick a number, any number

The biggest range of assumed values in the Drake equation tend to relate to fl (the fraction of planets that could support life that actually develop life at some point). At present, we know of only one planet where life has developed out of thousands of known worlds, and the pessimists are inclined to think that fl approaches zero.

If we actually discover evidence for some form of life (current or past) elsewhere in our Solar System (Mars, Europa, Enceladus, etc), or elsewhere in the universe (e.g. bio-signatures in the atmosphere of an exo-planet), then that will tend to push estimates for fl to something much closer to 1 (don't forget - even 1 in 1,000 is MUCH bigger than some of the pessimistic estimates), and the inevitable conclusion would be that life is teeming throughout the universe.

As for intelligent, communicating life - well, again, in the absence of any signals, the pessimists are inclined to think that the probability of technologically advanced life is approximately zero. However, we would need just one signal from "out there" to promote estimates for fi (the fraction of planets with life that actually go on to develop intelligent life) and fc (the fraction of civilizations that develop a technology that releases detectable signs of their existence into space) to values much higher than the pessimistic estimates, and just one such signal would lead to the inevitable conclusion that the universe is teeming with technologically advanced lifeforms.

[Atmos (Colin)]

The original equation back in the 60’s presumed that the Earth has life and Mars doesn’t, therefore 50% of life supporting planets have life. Outside of this, until we discover anything else out there we’re alone in the vast and cold, lonely usiverse

[Shiraz (Ray)]

Who might reply? - almost certainly nobody.

There are maybe only a few thousand planets that are close enough that their inhabitants could reply (at light speed) in anyone's lifetime. The odds that any of these supports technology-literate life comparable to ours - at this exact time - are surely almost zero, given the single example that we are aware of.

we might one day find a one-way transmission from someone else ("we are here"), but conversations are exceedingly unlikely.