Extraterrestial life searching

[Arthur Smith]

34 minutes ago, mistermack said:

The problem of only having the Earth to go by, a single datapoint, is adressed by this guy on youtube, and although I'm a non-mathematician, I think he presents it clearly and well from a mathematical angle, and he claims that you can use maths to get to a real probability result about the existence of life, and the existence of intelligent life.    Well, I liked it enough to watch both, so here are the links, in case you might too :  

https://www.youtube.com/watch?v=PqEmYU8Y_rI  and       https://www.youtube.com/watch?v=iLbbpRYRW5Y   

And apologies if someone has already mentioned them. 

 

 

Thanks for providing links. Unfortunately, my internet speed is 0.5Mb currently, I'm promised fibre later in the year (already behind schedule due to Covid) so at the moment  I can't watch Youtube. ETA I managed via hotspot on my cellphone.

Edited January 22, 2022 by Arthur Smith

[Genady]

When we find a promising but sterile world, shouldn't we throw some archaea there with a purpose to spread life?

[Arthur Smith]

13 minutes ago, Genady said:

After 25 minutes he comes to the conclusion, "We don't know." Should I try the second video?

David Kipping (the astronomer in the videos) has published a paper on this:

https://arxiv.org/pdf/1806.08033.pdf

I managed to watch the second video. Having the paper available helps with following the video.

In his concluding remarks, he seems to agree a second data point would be handy. Actually the video was also good for improving my understanding of Bayesian analysis. So thanks, mistermack!

[Genady]

4 minutes ago, Arthur Smith said:

David Kipping (the astronomer in the videos) has published a paper on this:

https://arxiv.org/pdf/1806.08033.pdf

I managed to watch the second video. Having the paper available helps with following the video.

Thanks a lot. For many reasons, not the least of which is APD, I much prefer to read rather than to listen.

[Arthur Smith]

20 minutes ago, Genady said:

When we find a promising but sterile world, shouldn't we throw some archaea there with a purpose to spread life?

Good grief, no! No knowing where we could end up in a billion years or so. ETA In fact that could be us, the seeded archaea (with a sprinkling of bacteria) and our benign overlords watching developments until we are ready to be contacted I jest but Kipping is making his point using a timescale from abiogenesis to intelligence of a couple of billion years. I think the point that some sort of life (leaving stromatolites as evidence) of life starting very soon after water condenses on Earth is an argument for the inevitability of some sort of life arising, given the right environment. That second data point would be quite useful.

Edited January 22, 2022 by Arthur Smith

[mistermack]

32 minutes ago, Genady said:

After 25 minutes he comes to the conclusion, "We don't know." Should I try the second video?

Very much so. First of all, he's given solid reasons, not just intuition for why we can't know. But secondly, the second one is about the chances if INTELLIGENT life being out there. And the results are not just "we don't know", they tell you more than that.

I could have linked just the second one, but I think you need to watch the first one to appreciate the second. 

[Genady]

1 minute ago, mistermack said:

Very much so. First of all, he's given solid reasons, not just intuition for why we can't know. But secondly, the second one is about the chances if INTELLIGENT life being out there. And the results are not just "we don't know", they tell you more than that.

I could have linked just the second one, but I think you need to watch the first one to appreciate the second. 

Ok, thank you. I will, with the help of the paper linked by @Arthur Smith.

[Arthur Smith]

Duplicate

Edited January 22, 2022 by Arthur Smith
Duplicate

[Genady]

6 minutes ago, Arthur Smith said:

Good grief, no! No knowing where we could end up in a billion years or so.

On the other hand, if we all go extinct here on Earth, then 4 billion years of evolution will go down the drain.

[mistermack]

1 minute ago, Genady said:

On the other hand, if we all go extinct here on Earth, then 4 billion years of evolution will go down the drain.

I feel that way now. Every time another species goes extinct. I know extinction is a natural process, but what we are living through and causing is not natural, it's catastrophic. 

[Arthur Smith]

4 minutes ago, Genady said:

On the other hand, if we all go extinct here on Earth, then 4 billion years of evolution will go down the drain.

Well, climate change will be bad enough that humans could become extinct but that will leave the field open for other species to fill the gap and evolve in all sorts of ways we can't predict.

1 minute ago, mistermack said:

I feel that way now. Every time another species goes extinct. I know extinction is a natural process, but what we are living through and causing is not natural, it's catastrophic. 

Ninja'd 

Edited January 22, 2022 by Arthur Smith

[Genady]

3 minutes ago, Arthur Smith said:

Well, climate change will be bad enough that humans could become extinct but that will leave the field open for other species to fill the gap and evolve in all sorts of ways we can't predict.

Sure. But this scenario cancels the other consideration, "No knowing where we could end up in a billion years or so."

[Arthur Smith]

5 minutes ago, Genady said:

Sure. But this scenario cancels the other consideration, "No knowing where we could end up in a billion years or so."

Sure. I was only being serious about the inevitability of climate change and the problems humankind are already facing that will only get worse. I suspect this is getting a little off-topic for the search for extraterrestrial life.

[TheVat]

Good video, very clear, as it takes a hard look at the value that would be f(l) in the Drake equation.  I'm guessing the second video looks at f(i).  I recall reading Ward and Brownlee years ago, which was especially pessimistic on f(i) and complex life generally.  A universe that teems only with microbes will still be a lonely one for sentient creatures.  (Imagine finding a promising spectral signature in the future that indicated photosynthesis on an exoplanet, but we get there and it's barren except for some lakes and seas full of cyanobacteria.  A bit anticlimactic to our anthropocentric viewpoint!) 

 

Oops, sorry, did not notice a second page had formed and lengthened in the past hour.  I was responding to Mac's posted Cool Worlds Lab videos.  This is what happens when I set down an open page on my tablet and go off to do chores.

51 minutes ago, Genady said:

Thanks a lot. For many reasons, not the least of which is APD, I much prefer to read rather than to listen.

Me too.  I also thank @Arthur Smith.  

[Genady]

Well, after all the statistical analysis I came up with my own ballpark estimates, which seem to fit it:

life - one per galaxy

intelligent life - one per cluster of galaxies

advanced technological civilization (like us) - one per universe

Edited January 22, 2022 by Genady

[skydelph]

11 hours ago, Arthur Smith said:

Good grief, no! No knowing where we could end up in a billion years or so. ETA In fact that could be us, the seeded archaea (with a sprinkling of bacteria) and our benign overlords watching developments until we are ready to be contacted I jest but Kipping is making his point using a timescale from abiogenesis to intelligence of a couple of billion years. I think the point that some sort of life (leaving stromatolites as evidence) of life starting very soon after water condenses on Earth is an argument for the inevitability of some sort of life arising, given the right environment. That second data point would be quite useful.

Exactly, we are not searching a place for life arising. Even observation of it is dangerous as up to now every life ecosystem, that we have investigated, suffered from biologists intrusion (due to we have no other approaches).
Search for life has to milestones:
- is it there in any state?

- is it 'on the same page' with us for communication?

[studiot]

19 hours ago, Arthur Smith said:

I missed that as I don't subscribe to OCS. I see it's available on Amazon Prime now. Thanks for the info. I'll give it a go.

 

I don't know where you are in the world, but it is available free on the BBC iplayer.

[Bufofrog]

19 hours ago, mistermack said:

I know extinction is a natural process, but what we are living through and causing is not natural, it's catastrophic. 

Well, the extinctions that man is causing is of course natural.  We just feel bad that our species is the cause to the extinctions, I certainly wish we weren't doing it.

[mistermack]

20 minutes ago, Bufofrog said:

Well, the extinctions that man is causing is of course natural. 

You could argue that everything's natural. I was just using the common distinction that people make between natural, and man-made. As in diamonds, or lakes, or pearls or forests.

Most extinctions are happening because of human land-use, but many others are down to invasive species, again brought in by man. There's just too many humans on the planet, and we have no real interest in species going extinct, unless they look cute.

[dimreepr]

1 hour ago, mistermack said:

You could argue that everything's natural. I was just using the common distinction that people make between natural, and man-made. As in diamonds, or lakes, or pearls or forests.

Indeed, even the man made "supernatural" (god et al) tries to bring us back to earth;

1 hour ago, mistermack said:

Most extinctions are happening because of human land-use, but many others are down to invasive species, again brought in by man. There's just too many humans on the planet, and we have no real interest in species going extinct, unless they look cute.

 most extinctions are happening because life has cornered the market, but the market will recover... 😉

16 hours ago, Genady said:

Well, after all the statistical analysis I came up with my own ballpark estimates, which seem to fit it:

life - one per galaxy

intelligent life - one per cluster of galaxies

advanced technological civilization (like us) - one per universe

I know, I can't be repeated...

Edited January 23, 2022 by dimreepr

[Arthur Smith]

5 hours ago, studiot said:

 

I don't know where you are in the world, but it is available free on the BBC iplayer.

France. Up until recently I could easily access iplayer via VPN but no longer, it's almost impossible now. I was thinking of renewing my Prime account anyway so may do that.

[studiot]

1 hour ago, Arthur Smith said:

France. Up until recently I could easily access iplayer via VPN but no longer, it's almost impossible now. I was thinking of renewing my Prime account anyway so may do that.

Sadly I see that the original Futurscope (near Poitiers) has been replaced with a Disney style theme park.

Don't know if the original musee is still there, it is mentioned in the credits at the beginning of each episode.