life out there?

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Discussion

jmorgan

36,010 posts

283 months

Tuesday 21st July 2015
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Eric Mc said:
jmorgan said:
We cannot go toe to toe with a lion obviously,
You haven't taken into account the attributes of the PH powerfully built company director.
Yeah well nuts

There was a camera crew recording lions in Africa, the sound guy started to put on a pair of running shoes. The cameraman said "you can't out run a lion!"

The sound man said "nope, but I can out run you"

Eric Mc

121,782 posts

264 months

Tuesday 21st July 2015
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I bet he was a PHer smile

jmorgan

36,010 posts

283 months

Tuesday 21st July 2015
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Nah, he would have started a thread first asking for the best running shoes to out run a lion.

Eric Mc

121,782 posts

264 months

Tuesday 21st July 2015
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And what watch to wear in case they had to do an autopsy on the lion and he wouldn't want to be embarrassed by its stomach contents.

Prof Prolapse

16,160 posts

189 months

Tuesday 21st July 2015
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Eric Mc said:
Explain why it's not just better quality guessing then.

Don't forget that probability theory was a key tool used in determining the probable behaviour of markets in the world of international banking and debt management - and look what happened there.

That to me shows that just throwing lots of fancy formulae at a problem does not always mean you are going to come up with a better or more accurate answer.
You're making the claim, the onus is on you to put up the explanation. Contextually "probability" has an entirely different definition to what you describe, so you explain why it's wrong and it's just "intelligent guessing"?

The term is a debasement of the scientific process, which has little or anything to do with banking and economics. Similarly the use of formulas does not necessarily infer the scientific method. Using Pythagoras, or working out the wattage on an electrical appliance, does not make you a scientist.

In its simplest terms "probability", lets us measure how likely to be true something is. Scientists do not deal in certainties so it is a measure of the trust we allow our selves to place on something, based on transparent evidence which can be challenged at any time. For example our confidence that the sun will rise tomorrow is a function of probability based on extremely sound evidence and reasoning. It is not simply improved guesswork, it is the result of hundreds of years of accrued knowledge and constant self doubt and testing.

Back to the case in point, the probability of life starting has been estimated based on masses of data and experimentation. I've done these myself, it's fascinating and can be measured. It's not random chance that leads us to conclude that life, although special, is not particularly rare or difficult to produce. It is inevitable given the appropriate conditions. You can see this for yourself.

As for planets that potentially harbour life, I'm sure you realise that the systems for find these are quite new but pretty robust, and in the last few years they have found that planets that could harbour life are not particularly rare, even through our narrow little view.

We then scale up the exercise. The universe is mind boggling huge, if you think you can envision it's scale you're wrong. Probably by factor over a hundred fold. The short of it is we have enough monkeys, we have enough typewriters, and we're not looking for the works of Shakespeare. They just need to mash the keypad with their feet.

MartG

20,622 posts

203 months

Tuesday 21st July 2015
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Prof Prolapse said:
Eric Mc said:
Explain why it's not just better quality guessing then.

Don't forget that probability theory was a key tool used in determining the probable behaviour of markets in the world of international banking and debt management - and look what happened there.

That to me shows that just throwing lots of fancy formulae at a problem does not always mean you are going to come up with a better or more accurate answer.
You're making the claim, the onus is on you to put up the explanation. Contextually "probability" has an entirely different definition to what you describe, so you explain why it's wrong and it's just "intelligent guessing"?

The term is a debasement of the scientific process, which has little or anything to do with banking and economics. Similarly the use of formulas does not necessarily infer the scientific method. Using Pythagoras, or working out the wattage on an electrical appliance, does not make you a scientist.

In its simplest terms "probability", lets us measure how likely to be true something is. Scientists do not deal in certainties so it is a measure of the trust we allow our selves to place on something, based on transparent evidence which can be challenged at any time. For example our confidence that the sun will rise tomorrow is a function of probability based on extremely sound evidence and reasoning. It is not simply improved guesswork, it is the result of hundreds of years of accrued knowledge and constant self doubt and testing.

Back to the case in point, the probability of life starting has been estimated based on masses of data and experimentation. I've done these myself, it's fascinating and can be measured. It's not random chance that leads us to conclude that life, although special, is not particularly rare or difficult to produce. It is inevitable given the appropriate conditions. You can see this for yourself.

As for planets that potentially harbour life, I'm sure you realise that the systems for find these are quite new but pretty robust, and in the last few years they have found that planets that could harbour life are not particularly rare, even through our narrow little view.

We then scale up the exercise. The universe is mind boggling huge, if you think you can envision it's scale you're wrong. Probably by factor over a hundred fold. The short of it is we have enough monkeys, we have enough typewriters, and we're not looking for the works of Shakespeare. They just need to mash the keypad with their feet.
As far as the Drake Equation is concerned, at least half the term in it have to be pure guesses as we have absolutely no data to use for them. This means the result from it could be anywhere between 0 and 1 for the probability of finding life depending on the guesses you make

Prof Prolapse

16,160 posts

189 months

Tuesday 21st July 2015
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MartG said:
As far as the Drake Equation is concerned, at least half the term in it have to be pure guesses as we have absolutely no data to use for them. This means the result from it could be anywhere between 0 and 1 for the probability of finding life depending on the guesses you make
I'm not sure if this is just annotation or you're trying to counter what I said?

I'm struggle to see how the "Drake" equation is relevant. It's about finding talking aliens in the milky way galaxy. It also tries to make estimates in a way I'm not even suggesting we try.

I'm instead talking about finding life in an area over a billion times the size based on what we know. That is that there's nothing special about life on Earth.

Eric Mc

121,782 posts

264 months

Tuesday 21st July 2015
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Just throwing clever maths at something does not make a particular outcome more or less likely. Indeed, throwing clever maths at something can actually fool people into thinking they are coming to some sort of meaningful and relevant conclusion. In those circumstances, it can be very dangerous because it instills confidence in a predicted outcome in which they have no right to be confident in.

It doesn't really matter when you are talking about the possibility or probability of life in the universe. It matters a lot when it throws whole economies into a tailspin.

Prof Prolapse

16,160 posts

189 months

Tuesday 21st July 2015
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Eric Mc said:
Just throwing clever maths at something does not make a particular outcome more or less likely. Indeed, throwing clever maths at something can actually fool people into thinking they are coming to some sort of meaningful and relevant conclusion. In those circumstances, it can be very dangerous because it instills confidence in a predicted outcome in which they have no right to be confident in.

It doesn't really matter when you are talking about the possibility or probability of life in the universe. It matters a lot when it throws whole economies into a tailspin.
I have no idea what you're referring to. This isn't complex maths, this is basic predictions based on the scale of something. I wasn't being facetious earlier, it really is like the whole monkeys and typewriters thing.

If you want to dismiss it based solely on the strength of maths which are not being employed it is your choice however.

RobM77

35,349 posts

233 months

Tuesday 21st July 2015
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jmorgan said:
That is the thing with evolution, at least evolution on this planet. Does the same arms race happen elsewhere? I say arms race, when watching documentaries on dinosaurs, they liken evolution to an arms race. I develop teeth to get at the meat, the meat develops bony plates, I develop claws to deal with plates, the meat developed horns to up the ante.
Richard Dawkins wrote a piece on that in a book that I have called "Things we Believe but Cannot Prove", which is full of short pieces by leading scientists. He said that he thinks it's extremely likely that Natural Selection, as described by Darwin, applies everywhere that there's life, but he of course cannot prove that.

In answer to the original question, yes, I think it's very likely indeed that there's other life out there. The problem is that we only have a sample of one to go on and we don't know what form life will take elsewhere so it's hard to make predictions.

The chances of finding life is a different question entirely. I think that if there's life within the Solar System, on a comet or in a subterranean lake on a moon etc, we will probably find it at some point, if looking after our planet doesn't divert money and attention away from space exploration, which is sadly quite likely. Finding life outside the Solar System is another matter entirely.

Of course, for us (SETI etc) to find a signal, the lifeform that sent it must evolve to the point where it can put one out (if we assume evolution occurs! Another assumption..). If you look at the history of the earth for example (our only example!), it's around 4.5 Billion years old and it's taken until the last few decades for us to get to the point where we can reliably listen and send signals beyond the planet. A related question is how long sufficiently intelligent life lasts for before it would go extinct, i.e. blow themselves up due to wars started by the sorts of superstitions intelligent life can be susceptible to, or ruin the planet they live on - think of what happened on Easter Island as an analogy, etc. I'm inclined to think that intelligent life might exist on earth for a blink of an eye - and I don't mean 'exist up until now', I mean exist at all - the planet may be barren in no time at all (i.e. 100k-200k years from now, which is nothing at all if you add it onto the time since life started).

Incidentally, it's often quoted (usually by religious people) that Earth exists in the middle of a "Goldilocks zone" where water exists as a liquid etc, but in actual fact that's not true - we're on the edge of such a zone. We also orbit a star that's inherently unstable as it progresses through its lifecycle. These and other factors mean that Earth really isn't a great candidate for life - this was discussed in depth by many contributors in a recent issue of Scientific American, most of whom worked on the search for "earth-like planets", which is mis-named, because earth is not ideally what they think of when they think of somewhere suitable for life. So, on that note, yes, I think it's very likely that there's life out there. I'm not so sure we'll ever see evidence of it, although I wouldn't be hugely surprised if we ever find something on a doorstep; perhaps on a comet, a moon of Saturn or similar.

Eric Mc

121,782 posts

264 months

Tuesday 21st July 2015
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Just because the universe is massively huge and enormous does not suddenly make it more likely to harbour life. Honestly, it doesn't.

And it certainly doesn't make it easier for us to predict whether it harbours life precisely because we have very little genuine knowledge as to how life begins. We don't even know how life began on earth.

If we ever learn the precise way non-living chemicals and molecules become living, reproducing and (perhaps) thinking entities THEN we'll have a better understanding of whether it is likely to have happened elsewhere.

MartG

20,622 posts

203 months

Tuesday 21st July 2015
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Current theories on the origin of complex life indicate that it may be extremely rare even where simple life exists - essentially tied up in how eukaryotic cells first came into being

MartG

20,622 posts

203 months

Tuesday 21st July 2015
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The presence of free oxygen in an atmosphere doesn't necessarily mean the presence of complex lifeforms such as plants - most of Earth's oxygen originally came from prokaryotic cyanobacteria

Prof Prolapse

16,160 posts

189 months

Tuesday 21st July 2015
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Eric Mc said:
Just because the universe is massively huge and enormous does not suddenly make it more likely to harbour life. Honestly, it doesn't.

And it certainly doesn't make it easier for us to predict whether it harbours life precisely because we have very little genuine knowledge as to how life begins. We don't even know how life began on earth.

If we ever learn the precise way non-living chemicals and molecules become living, reproducing and (perhaps) thinking entities THEN we'll have a better understanding of whether it is likely to have happened elsewhere.
We're going in circles Eric. I can only assume you either don't understand the argument as you make no reponse to it that can be sensibly debated.

As a biologist, YOU may not know the way life evolved. But WE have a good idea, good enough we can make hypotheses and draw conclusions based on trying to disprove them. YOU do not have the grounding in the field to speak on OUR behalf.






Moonhawk

10,730 posts

218 months

Tuesday 21st July 2015
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ash73 said:
I'm not sure I understand your reasoning. If you accept life is basically chemistry, and the elements and physical laws are the same everywhere, then a vast universe means lots of opportunities for those things mix in the right quantities; whereas a small universe might mean only one opportunity?

And the current thinking is the universe is literally infinite.
And if it is infinite (with an infinite number of stars and planets) - the probability of life occurring elsewhere is exactly 1.

MartG

20,622 posts

203 months

Tuesday 21st July 2015
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We still only have a single example of a planet which has life - and there is no way to extrapolate from a sample of one to get a figure for the likelihood of other planets having life. We can guess, but that is all

guffhoover

536 posts

185 months

Tuesday 21st July 2015
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Life in this universe and intelligent life in this universe are, i think, hugely different propositions.

This universe is 91 billion light years in diameter (for simplicity lets imagine our universe as a sphere), our earth is 4.6 billion years old and the Kepler space program has to date estimates that there are 11 billion planets in Goldilocks zones around a sun-like star.

This sounds pretty good for life, at a single cell level.

For us to exist on earth we needed great luck with associated tiny probabilities; those single cell life forms which knocked around on our planet for the first few billions years of our planets life integrated with each other and started the cambrian explosion from which life evolved, during that evolution there were a potent mix of environmental stimuli in the great rift valley of Africa that required an order of primates to start the evolution of homo sapiens. The start of intelligent life, 4.4 billions years after our rock settled in its time-space dimple around our star.

As unthinkable as it seems this stuff happened. A bit like winning the lottery; the odds are stacked against you but somebody wins don't they? And how many microbiable lottery players are out there right now? I'd wager, lot's, but none of them sitting round a fire looking up at the stars or tapping madly away at their keyboard analysing radiation signatures from space.

As unsettling as it is, across the 91 billion light years of our universe it's just us. You and me and our loved ones last less than a nano in it's contextual time.

So keep happy, do something you love, don't waste it, you won't come back as a cat or see pearly gates. You are the luckiest organisms in the universe you have a nano of the universe's time to live......so live.

https://en.wikipedia.org/wiki/Drake_equation

TwigtheWonderkid

43,248 posts

149 months

Tuesday 21st July 2015
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Moonhawk said:
even if a significant portion of them harboured intelligent life, the chances of us overlapping in time (taking into account light travel time) from a technological perspective so as to make them detectable to us, us detectable to them, or both - are fairly remote.
This is the big problem. Even if there is intelligent life, the chances of their tiny window of existence overlapping with our tiny window of existence in a universe 13.7 billion years young (we are not even a trillionth of the way thru the expected life of the universe by all accounts) is so vanishingly small as to be rendered a virtual impossibility.

mudflaps

317 posts

105 months

Tuesday 21st July 2015
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ash73 said:
That's the observable universe, the universe as a whole is thought to be infinite.
I believe the bit outside of our observable bubble meant to be as good as meaningless to us as we'll never know or be able to tell what's happening there.

jmorgan

36,010 posts

283 months

Tuesday 21st July 2015
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TwigtheWonderkid said:
Moonhawk said:
even if a significant portion of them harboured intelligent life, the chances of us overlapping in time (taking into account light travel time) from a technological perspective so as to make them detectable to us, us detectable to them, or both - are fairly remote.
This is the big problem. Even if there is intelligent life, the chances of their tiny window of existence overlapping with our tiny window of existence in a universe 13.7 billion years young (we are not even a trillionth of the way thru the expected life of the universe by all accounts) is so vanishingly small as to be rendered a virtual impossibility.
Time is often forgotten, we are here now, they may have been there then but no more. Or still a puddle of ooze waiting to kick off. If we ever find evidence, it will be out of date as to their existing status.