Bacterial life found on Mars!

[Arising_uk]

Thanks IBB, this bit;
"...So even though first radio transmissions have travelled 120 lightyears, intelligent life identical to us would not be able to pick it up that far away."
I sort of get this but part of me wants to say this "If its a 120 lightyears that must be that distance?". Am I are right in understanding that if we assume that other Life may be at the same stage as us and taking our current technology into consideration we may be within the radio 'cone' of a technology at the same level as us? But that we have not the technology to detect the signals?
a_uk

[i blame blame]

Thanks IBB, this bit;
"...So even though first radio transmissions have travelled 120 lightyears, intelligent life identical to us would not be able to pick it up that far away."
I sort of get this but part of me wants to say this "If its a 120 lightyears that must be that distance?". Am I are right in understanding that if we assume that other Life may be at the same stage as us and taking our current technology into consideration we may be within the radio 'cone' of a technology at the same level as us? But that we have not the technology to detect the signals?
a_uk

That's right. The challenge is to develop technology to detect faint signals and technology to generate powerful ones.

[Arising_uk]

That's right. The challenge is to develop technology to detect faint signals and technology to generate powerful ones.

LOL My thought was that the challenge is to develop technology to detect faint signals and the technology to mask powerful ones. Then "maybe this explains the quietness?" LOL
a_uk

[i blame blame]

That's right. The challenge is to develop technology to detect faint signals and technology to generate powerful ones.

LOL My thought was that the challenge is to develop technology to detect faint signals and the technology to mask powerful ones. Then "maybe this explains the quietness?" LOL
a_uk

Yes this could be the "great filter". So far, we have detected one planet on which live developed, namely our own, but no planet that can generate signals powerful enough to be detected by us.

[Arising_uk]

I'm still not sure why we should assume these 'great filters' based upon the non-evidence from SETI. I'm also not sure that the assumption that Life could just be starting out everywhere, or at least in some 'band' of Life 'environment', doesn't counter the whole argument. But I'm dead sure I'm confused by the last paragraph? What is he hinting at?
a_uk

[Richard Baron]

I'm still not sure why we should assume these 'great filters' based upon the non-evidence from SETI.

I think it is not so much the non-evidence from SETI as what we would have to conclude from that non-evidence plus a visit (or signals) from an advanced civilization. If it is easy for life to arise and get that advanced, then we should get lots of visits. If we get very few, then:

1. it is very hard for life to get going in the first place; or
2. life tends to get knocked on the head by a filter early on; or
3. life tends to get knocked on the head by a filter at some advanced stage.

1. and 2. would not worry us: we have got past those stages. Bostrom is concerned at the idea of 3., because trouble for us could be just around the corner. No visits or signals would make it easy to think that 1. or 2. is the problem. A few visits or signals might be thought to rule out 1. and 2., leaving us with 3.

Two ways of attacking Bostrom's argument are then:

(a) there could be all sorts of things which could go wrong, at different stages, and many of them could be unrelated to our state of progress. The argument does rely heavily on the idea that there is one big problem, and I am not even sure that the probabilities would work if you discarded that assumption;

(b) he does not convincingly dismiss the fourth possibility, that the Universe is a very big place and with or without von Neumann probes, it will take a long time to run into people with whom it is worth conversing.

I'm also not sure that the assumption that Life could just be starting out everywhere, or at least in some 'band' of Life 'environment', doesn't counter the whole argument.

It would counter the argument, but the response would be that you should not make that assumption because the Universe has been running for a very long time, so it is implausible to think that the conditions for the growth of life have only existed for the past (say) 4 billion years, so it is unlikely that life everywhere is only just getting to our sort of level. (We also cannot assume that evolution would take as long everywhere as it has taken here.)

But I'm dead sure I'm confused by the last paragraph? What is he hinting at?

I think he means that there is lots to think about in this sort of area, that it is worth making the effort to think clearly and that we should not allow our thinking to be distorted by the popular mood (in this case the fact that many people, not having read H G Wells, would love to meet Martians).

[Arising_uk]

Thanks for the thoughts Richard,
Okay barring some of my assumptions.

Two ways of attacking Bostrom's argument are then:
(a) there could be all sorts of things which could go wrong, at different stages, and many of them could be unrelated to our state of progress. The argument does rely heavily on the idea that there is one big problem, and I am not even sure that the probabilities would work if you discarded that assumption;
(b) he does not convincingly dismiss the fourth possibility, that the Universe is a very big place and with or without von Neumann probes, it will take a long time to run into people with whom it is worth conversing.

(a) means what? That 2. might not be ignorable even now? If so I'd agree but think that this depends upon what we are considering Life to be? I.e. extinction events for species might still be occuring?(but probably miss the point here).
(b) Or the possiblilty that the probes have been and gone and we are just waiting for Culture and Technology to catch up.

...It would counter the argument, but the response would be that you should not make that assumption because the Universe has been running for a very long time, so it is implausible to think that the conditions for the growth of life have only existed for the past (say) 4 billion years, so it is unlikely that life everywhere is only just getting to our sort of level. (We also cannot assume that evolution would take as long everywhere as it has taken here.)

Its a good point. But it can also be considered implausible that conscious Life is the purpose of Evolution and time has no factor apart from being a good guess as to how long it does take. So Life as the process that has led to conscious life has taken what? 100s of Millions of years. Given the Universe is 4 billion years old, is it ureasonable to assume that the conditions are now ripe all over but limited to certain ranges? Plus if it is a one-way calculation, i.e. its 'running' a non-reversable computation then we can assume that this is now the time conscious Life is kicking-off in the Universe?

I think he means that there is lots to think about in this sort of area, that it is worth making the effort to think clearly and that we should not allow our thinking to be distorted by the popular mood (in this case the fact that many people, not having read H G Wells, would love to meet Martians).

See, this is why I asked, as my loony head had the Head of Faculities at blah hinting that his paper was a dis-information piece aimed at producing data for computerised social meta-models based upon the idea of meme-mapping social behaviour(whoops!)
a_uk

[Richard Baron]

Two ways of attacking Bostrom's argument are then:
(a) there could be all sorts of things which could go wrong, at different stages, and many of them could be unrelated to our state of progress. The argument does rely heavily on the idea that there is one big problem, and I am not even sure that the probabilities would work if you discarded that assumption;
(b) he does not convincingly dismiss the fourth possibility, that the Universe is a very big place and with or without von Neumann probes, it will take a long time to run into people with whom it is worth conversing.

(a) means what? That 2. might not be ignorable even now? If so I'd agree but think that this depends upon what we are considering Life to be? I.e. extinction events for species might still be occuring?(but probably miss the point here).
(b) Or the possiblilty that the probes have been and gone and we are just waiting for Culture and Technology to catch up.

Yes, if (a), then 2. is not ignorable even now. If there is no reason to think that the dangers all lurk at or before a given point in the evolution of a species, there is no point at which the species can breathe a sigh of relief.

(b). Yes, they might have been and gone. Erich von Däniken thought so. But even though he is not to be taken seriously, one should allow for the possibility when considering Nick Bostrom's argument. What they would have had to do in order for us to be aware of visits, is to have turned up not just "by now" but to have turned up at some time in the fairly short period during which we have had reliable means of recording events for posterity. They would also have had to turn up in a part of the world inhabited by people who were in the habit of making such records. Alternatively, they could have turned up at any time, with or without meeting people, and left some obvious litter. But perhaps they are tidy folks.

On the available time for life to evolve, I think that the Universe is about 14 billion years old. You do of course need time for a range of elements to form, and for planets to form and cool down. I don't know how long we have had since potentially life-bearing planets first formed and got cool enough. I think that the earth has been around for about 4.5 billion years and that life of some sort started within the first billion.

[Arch_Anarchist]

I think we are looking for evidence of past bacterial life on Mars because it may indicate that some quite complex organisms, if not anywhere near as evolved as mammals, once existed on mars and this would be very interesting.

[Psychonaut]

I think the main purpose is that it would conclusively prove that life could occur outside of Earth.

Such a conclusive proof of this principle is something I could not care much less about.

People used to think that heaven was tangibly above the clouds. My mother was lodging in a cottage in rural Cumbria when the moon landings came on the television. The landlady got a confused look on her face and pondered how far one had to go to reach heaven.

[mark black]

Babble,

I cannot understand someone who wouldn't care if it were conclusively shown that life occurs outside earth's environment. It expands our knowledge of the universe and raises all kinds of fundamental questions - and it wouldn't interest you? Bizzare! What's more interesting though is that you would take the time and make the effort to venture that opinion. If you don't care, why would you do so? There are many threads on this forum discussing issues that don't interest me - and so I don't comment on them. Why do you?

mb.

[Psychonaut]

The reason why I couldn't care about a proof so conclusive is because it does not require such a conclusive proof, and it would tell us little about the fundamental nature of our Universe.

Apart from dispelling the already unfounded principle that God created life solely on this planet, it would change nothing.

What might enhance our knowledge is if we found life forms based on some other fundamental principle, which we could find on another planet or upon our own.

I have at least a passing interest in everything, at least in the reasons why I would not be interested in it, what interests me is, why would you care ?

[mark black]

I'd find it interesting becuase proof of life elsewhere would bear upon our conception of self. I agree that it is almost certian that life occurs elsewhere in the universe, but it is not known. There's a major difference between speculation on an evolutionary theme and knowledge that evolution is universal.

Finding life elsewhere would strengthen the case considerably for a non-miraculous explanation of life on earth, speaking against the religious fantasies that so enthrall man in his ignorance - and divide men in thier mock-certainty.

By emphasizing the likely fact that it is only because conditions were right for our existence that we exist, this in turn might encourage respect for the environment - the need for sustainable use of resources to secure continued existence.

Perhaps without the safety net of a God, waiting to jump in and save the day when our understandable follies and failures cause our extinction, man might act to save himself. For even deviod of magical interpretation, it is a wondrous miracle that we exist - and a great folly that we should act in such a manner as to put that at risk.