Trillions of Earths

[astroron]

Universe has more stars:question:
Just in from the BBC
http://www.bbc.co.uk/news/science-environment-11888362
I have been saying that there are more stars than they say there is for a long time and now evidence is coming to the fore:P
Let the discussion begin;)

[CraigS]

Thanks Ron;

Interesting isn't it ?

I don't believe this statement is supportable (that's an opinion !… got to slow down on these … I've been giving a few lately ;) :) ):



.. until they've discovered another instance of exo-life, the above quote is merely speculation.

I do like the sounds of this of this one, though (another opinion) ..



Wouldn't it be terrific if all this 'darkness' stuff turned out to be attributable to measurement technology inaccuracies !! :lol: Classic stuff !

… and a good one to finish off with … a 'plug' for the telescope developers .. the best cause of all !! (another opinion):



Good 'down-to-earth' article supporting real-life observational astronomy !
Very interesting.

Cheers & Rgds.

[Robh]

Ron, very interesting.

Some more here ...
http://blogs.discovermagazine.com/80beats/2010/12/01/the-estimated-number-of-stars-in-the-universe-just-tripled/

Regards, Rob

[mswhin63]

It is a very interesting not only for orbiting planets but the potential collapse of Dark Matter theory.

Still mentions in the post nothing has been conclusively proven but it seems highly likely for both.

I would wonder if there might be loads more Red Dwarf star outside the galaxies in great number, not just tied within the galaxy itself. This could suggest the holding together the outer spiral arms instead of Dark Matter.

[CraigS]

Hmm interesting Malcolm;

I've just been reading another astronomy forum (of low repute) and I'm reminded of how easy it is for us humans (myself included, of course), to completely dump an idea and take up another.

Interestingly Science doesn't quite work that way (thank goodness). It would be interesting to see what effects the additional mass might have on the Lambda CDM model. After all, it predicts an absolutely huge amount of dark matter out there.

I think I'm guilty, (to a certain degree), of 'throwing the baby out with the bathwater' on this one. :)

Also interesting is your question about other stars that might be outside the galaxy.
I had the same thought, but then I wondered what does 'outside the galaxy' really mean ??

Cheers & Rgds

[Suzy]

This article really really got me thinking. And a good question that Malcolm posed about Red Dwarfs perhaps holding the galaxy's structure together.

We have to remember though that the use of the word Dark Matter is a description of matter that cannot be seen. It can be anything. Even these Red Dwarfs. Coming from my understanding, I'm on the right track, yes?

What further interests me is, seeing as a Red Dwarf is a very cool star, can it actually harbour life on these exo planets (I'm thinking not)? My understanding is that our current model states that we need a sun the same age and size as our own, with an Earth like planet to be in the same spot.

Furthermore, am I understanding that the finding of these exo planets around Red Dwarfs may contradict the current age of our universe, and basically we might have to go back to the blackboard?! Oh boy! But that's science right, the more answers it gives us, the more questions it attracts. :question:. As Prof. Kaku recently said so well, "we have learned more in the last 50 years than we ever have in the history of human kind". I think it would serve us all very well to keep an open mind to all of the possibilites science is throwing our way regarding our Universe, as there is such an abundance of information being thrown at us these days.

Thanks Ron for posting that article :).

[bartman]

Somewhat recent BBC article that new telescopes have discovered 3 times as many stars than previously thought. More stars, more planets.....

"It found that galaxies older than ours contain 20 times more red dwarf stars than more recent ones.
Red dwarfs are smaller and dimmer than our own Sun; it is only recently that telescopes have been powerful enough to detect them.
According to Yale's Professor Pieter van Dokkum, who led the research, the discovery also increases the estimate for the number of planets in the Universe and therefore greatly increases the likelihood of life existing elsewhere in the cosmos.
"There are possibly trillions of Earths orbiting these stars," he said. "Red dwarfs are typically more than 10 billion years old and so have been around long enough for complex life to evolve on planets around them. It's one reason why people are interested in this type of star."


Apart from the other interesting stuff in that article, I would like to ask....
If our sun is about 4.5 b years old and the stars they are talking about are about twice the age of our star, and 'complex life' has evolved over an extra ~5 b years, then surely we would have heard from them by now?


Wouldn't 5b years be enough time to figure out inter galactic travel? ( through what ever means....)
Sure, there are billions of galaxies and trillions upon trillions of stars out there, but if they have that 5b years on us they would have invented some sort of 'earth like- supporting life- planet radar'?
We are finding hundreds of exoplanets at the moment, and we are just a speck compared to the research "they" have been doing.....for five billion years.....


:question: .....just wondering.....:confused2:

Bartman

http://www.bbc.co.uk/news/science-environment-11888362

[CraigS]

Ok .. so looking at this more closely, the present CDM model mass estimates are:

i) Heavy Elements ~0.03%
ii) Neutrinos: ~0.3%
iii) Stars: ~0.6%
iv) Free Hydrogen and Helium: ~4%
v) Dark Matter: ~25 %
vi) Dark Energy: ~70 %

So, even if the star matter estimate was out by three times (as the article makes out), it makes almost zilch impact on the proportion of dark matter/dark energy.

Cheers

PS: Ok reading more, they're only saying that the observation might effect the amount of dark matter in the elliptical galaxies only. That's Ok .. makes sense.

[jenchris]

Oh they've been here, had a look, and shook their heads - "Maybe another 2000 years, if they survive that long."
As Groucho Marx said, "I don't want to be a member of a club that would accept me."

Let's face it, if they arrived a mere 200 years ago, they'd have been challenged by a guy with a pointed piece of metal and a lacy ruff. Even HG Wells hadn't worked up the steam to produce War of the Worlds.
300 years ago and they'd been hung for being witches' familiars!

They would have had to have landed around 1980 to get an inkling of our potential and seen us with only one or two wars going on.
They would have noticed - 3 Billion people on the bread line, 1 Billion people starving, 1 Billion gorging themselves on the fat of the land and the surplus energy whilst beating off the others.

[bojan]

Yes..
Fermi paradox was always bugging me.
http://en.wikipedia.org/wiki/Fermi_paradox

http://en.wikipedia.org/wiki/Neocatastrophism

[[1ponders]]

merged threads

[astroron]

Thanks Paul:thumbsup:

[Robh]

OK, so now we are discovering there are lots more of these red dwarfs.
But just how many brown dwarfs are out there? Maybe we can pack some more mass into these galaxies.

Regards, Rob

[CraigS]

I haven't had a look at how much dark matter they currently reckon is in one of these ellipticals, but I have a feeling its a big amount.

For example, dwarfs are mostly elliptical. These galaxies are presently believed to be DM dominated, in a big way .. I think about >10:1 DM:matter ratio.

These guys are reporting that ellipticals contain up to 20 times the previously thought number of red dwarfs .. similar orders of magnitude, at least !

I noted from Rob's earlier post that the paper causing all of this, is presently resulting in a lot of controversy amongst the establishment. I guess there'll be a lot of fallout from this study.

Cheers

[bartman]

Bojan,
Thank you for the link to the Fermi Paradox.
Very interesting and informative!
Certainly has made me think more about whether there is or isn't life out there!
Bartman

[CraigS]

Yes Bojan;

Thanks for the 'heads-up' on the Fermi paradox.

The Wiki article seems to cover all of the human perspectives on exo-life that I, (for one), can imagine, or have encountered in my travels.

I guess we all fit into one, or more, of the headings when we're wrangling on this topic.

There are other dimensions to the scale/probability problem as well.

For instance: the DNA information paradigm. What is the probability that the order in DNA, eventuates over time, given that entropy increases over time? Also, what is the probability that the methodical functions of the 'cellular machinery', (necessary for replication etc), could develop in the way that it has ?

If there were an answer to these questions, it would be truly mind blowing when you lay this on top of the Scale of the Universe. The two 'probability scales may actually end up being of similar orders of magnitude, and we might find that it does actually require an almost infinite scale 'laboratory', (ie: universe), for an instance of life to come about !!

I think its difficult for the human brain to cope with these probability scales.

Cheers

[ngcles]

Hi Bartman & All,


This is a very interesting finding but as has already been pointed out, it has only a small impact on calculating in what form the "missing matter/energy" is because so little matter appears to be actually locked-up in stars in our Universe.

But to provide an answer (there could be other answers for much relies on speculation and best-guesses) to your question, it is manifestly improbable that any of these newly discovered stars play host to advanced/intelligent/space-faring races. They are in elliptical galaxies for a start which are extremely harsh environments for advanced life (or indeed any life).

The stars they mention are "old" red-dwarfs. Old stars obviously formed a very long time before the Sun and it is manifestly improbable that there would have been enough metals in the gas from which these stars formed (so early in the history of the Universe) (a) to make any terrestrial-type planets and (b) have the right elements in the right abundances to produce the chemistry essential to life -- let alone advanced life or intelligent life.

Third, Red-dwarf stars are low mass, low luminosity stars with very narrow habitable zones so close to the host star that tidal locking of any terrestrial planet is a virtual certainty. Red dwarf stars are very often flare stars, a type of star that has high magnetic activity unleasing powerful x-ray bursts from sumo-sized solar flares that continue for very long time-scales. These factors (coupled with the others) further reduce the chances to what I'd suggest is a figure so low, that for all intents and purposes, is zero.

We have added a very large number of stars to the inventory, but none of them appear to be sites where advanced life would stand a whelk's chance in a supernova (apologies to Douglas Adams).


Best,

Les D

[jenchris]

+ngcles
most of the 'first cycle' stars are devoid of anything heavier than helium so eliminating the first cycle after the big bang.
Even short cycle second cycle stars are unlikely to produce as they are usually supergiants and go SN quite early in life.
So we need a third cycle star with no close by heavy radiation to keep us in the slime.
Which means you have to be on the outside of the galaxy arms or lucky.
You then need a mass extinction to produce enough storable energy to lay down hydrocarbon fuels for a prospective intelligent species to break through the industrial revolution.
Then you need the civilisation to be smart enough not to nuke itself when it does reach that level (I'm not sure we've gotten away with this yet).
Then they need to crack plus light travel.
All in all, not a good set of odds. Perhaps one in 1,000,000 planets in our galaxy. That means there's thousands and thousands if not millions of planets out there with intelligent life.... all onthe threshhold of interstellar travel.
Hopefully they're not all as greedy and vicious as us.

[bojan]

Among a lot of creationists crap, I found this:
http://www.youtube.com/watch?v=I14KTshLUkg

I remember couple of articles that discuss this issue.. when I find them again, I will post them here...

[bkm2304]

That's a lot of episodes to get through! I'm still laughing at the first series.....

[CraigS]

Don't bother Bojan … forget about it …

Perhaps poorly considered and articulated thoughts on my part … one of the downsides of taking the position of 'exo-life may, or may not exist', is trying to see it from both sides at the same time .. I'm no creationist, also ;) … so I'm not even going to bother trying to support this line.

I'm outta here … going to concentrate on entanglement instead (ie: the other concurrent thread).

:)
Cheers

[Robh]

We deduce that life requires certain conditions e.g. life supporting chemicals and a habitable zone. However, the existence of those chemicals and a habitable zone do not necessarily imply life will originate there.
In reality, we know nothing about the probability of life forming anywhere else in the Universe. We have no confirmed life data from any exo-planet.

Sure there may be 100 billion galaxies, each with 100 billion stars. That's 10^22 stars. So you think that's big!
The smallest known DNA viruses have 32000 base pairs. A single chain of DNA is composed of a sequence of 4 nitrogenous bases. Assuming they all occur in equal amounts i.e. 8000 of each, then the number of possible ordered sequences of a single chain of DNA are 32000!/(8000!)^4. Don't try using your calculator, the value is too large.
32000! ~ 1.07 x 10^130270 and 8000! ~ 5.2 x 10^27752.
32000!/(8000!)^4 ~ 1.5 x 10^19259
That pretty much dwarfs the 10^22 stars in the Universe!!

Before the biologists come looking for blood, I haven't said anything about the probability of the organism forming. However, the chances of life forming may be significantly lower than any estimate we have in mind.

On the other hand, if by fluke an alien neighbour exists and communicates with us, we can at least say we are not unique.

Regards, Rob.

[CraigS]

Thanks for making that statement Rob. (I failed spectacularly !).

But it really is fascinating just comparing the two number scales.

Of this number of possible ordered sequences of a single chain of DNA (ie: huge), one, or some of these, evolved to result in DNA chain(s) we recognise today - here on Earth.
Lots of things must have influenced these chemicals, to result in the arrangements we now see. We still don't really know the magnitudes of the numbers of these influences yet, either.

The probabilities of these influences occurring, (perhaps even in specific time sequences), anywhere, also seems to be mind-blowing.

Fantastic stuff !

I don't know what this means in the context of the current discussion, though.

Somehow the scales must be linked .. and discovering these linkages would be/is awesome. (Some have been discovered but these discoveries seem infinitesimal, compared with what remains to be discovered).

We skim over these thoughts when we read information about the scale of the universe, but the scale of what's going on in our own backyard, is even more mind-blowing !!

Cheers

[bojan]

The link is obvious (to me): Fermi paradox is N x bigger than previously thought (because there are N x more stars.. especially dwarfs).

As far as comparing the number of possible permutations within DNA and number of stars.. In my opinion this is like comparing apples and pears.
Current DNA on Earth is result of evolution (it started with much, much simpler molecules, and has grown by adding information by means of mutations and Darwinian selection, and I feel this growth was not linear with time). The number of stars has grown, but under different rules....

However, I should have started separate thread to discuss this.. but I didn't.. because I don't have much time recently so I tried to sneak in.
My apologies for this intrusion :P
Later when I have more time, I will certainly start again .

[CraigS]

I would love a discussion on/around this topic, Bojan.

Go for it !! You can start it off.

I agree that we're comparing apples and pears but as far as number scales generated by nature, and somehow linked by nature, the numbers themselves can be laid side by side.

The trick is to talk about the right links. Requires a lot of clear thinking, knowledge and discipline.

Great topic.

Good onya .. I'll look forward to that one.

Cheers

[mswhin63]

I was thinking this needs another thread too

[avandonk]

The odds of winning tattslotto are about eight million to one yet it is won every week or most weeks!

Statistics like this are meaningless as most people do not understand statistics.

A glib calculation of the possible arangment of DNA does not add to anything. To then even compare this to the ' known' number of stars is futile.

I am not saying that all speculation should be suppressed. All I am asking is that a reasonable attempt is made to understand the current science.

Every particle that exists in the Universe follows the laws of Physics. The fact we do not totally understand ALL these laws makes no difference to how the Universe behaves.

To just partition the unexplanable to 'gods' is a total cop out. It is just proof of feeble minds looking for simple answers.

It is OUR job to work out how things tick.

Less than a hundred years ago the scientific view was that there was only ONE Galaxy. Quantum Mechanics had just been made mainstream only amongst top scientists.

Yes by all means have a discussion about biology as I happen to know a bit about it. We call it Molecular Biology.

I happen to think that life is inevitable as everywhere we look it is there.

Bert

[CraigS]

Hi Bert;

I was wondering when you'd comment on all this .. :)

I welcome your expertise on these topics !

What do you mean by your last comment ?...

"I happen to think that life is inevitable as everywhere we look it is there."

This would seem to only refer to Earth.

The main discussion is about life elsewhere.

Cheers

[avandonk]

For quite a while life could only exist with sunlight and plants and animals. Look up terrarium.

Then we found ecosystems living at six or more km deep with only H2S as an energy source. These communities of bacteria and valve worms etc are living at the edges of volcanic vents.

This was my tipping point. I realized we knew nothing of what constituted life.

This latest discovery of bacteria with Arsenic rather than Phosphorus was another fact that nailed it further.

We are just groping our way into the Universe with limited knowledge. If there are self contained ecosystems near volcanic vents then life is everywhere there is liquid water.

I just get angry when people try to prove that life is a god given right by setting up a sham probabilty of how impossible it all is.

It is standard fundie claptrap.

Bert

[CraigS]

Ok .. I accept the bit about fundie stuff. I agree. Lets park that one.

You make the statement: "I realized we knew nothing of what constituted life" and then "Phosphorus was another fact that nailed it further."

This would seem to be at odds with the following statement:

"then life is everywhere there is liquid water".

If we don't understand what constitutes life, then how can we say that it will be everywhere where there is liquid water ? Please note that this question is in the context of the topic at hand … ie:

Does this mean that wherever there is liquid water elsewhere in the Universe, we will find life ?

I'm not having a go at you, I'm just intrigued with where you're coming from on the increased possibility of life existing elsewhere (with extra stars/planets and Phosphorous).

Cheers & Rgds.

[avandonk]

Yes craig all life as we know it needs liquid water. I have no proof life is anywhere else but my argument is far more logical than twits calculating impossible odds for life to exist without a creator. They are trying to prove their uniqueness because of a mythical all knowing all present being. This is total nonsense!
In my humble opinion the Universe is teeming with life. Fortunately they are too far away to hurt us.
The latest bacteria that use arsenic rather than phosphorus shows how ubiquitous life is.
One could contemplate a silicon and germanium rich planet with solid state computer like life. But how do they replicate without a fab?

Bert

[CraigS]

fab ?

[avandonk]

A fab in the trade is the multi billion dollar factory that makes computer chips.

Bert

[CraigS]

Ok .. thanks for that.

Thanks for your views, also. The perspective that were are all composed of molecules obeying the laws of nature, resulting in fractal patterned beings, (and organs), would tend to hint that life now, at least, has some kind of descriptive language.

I've been thinking along these lines lately (since you implanted the idea).

Be interesting to kick that idea around for a while, also.

Unfortunately, I have to run … other things to do.

Catch up with you later .. maybe we need to start our own thread and not wait for Bojan.

;):)

Cheers & Rgds

[Robh]

Hi Bert,

Good to have your input. The calculation of the number of possible base sequences in the DNA actually did have a purpose. The number is extraordinarily large and some would conclude (incorrectly) that the chance the virus exists at all is close to zero. In fact, arguments along this line have been used before by some creationists. However, as Craig correctly remarked, in itself the number tells us nothing about the probability that the virus came into existence. It was meant to counter the argument that the sheer number of stars by themselves imply life is inevitable and widespread. Whether there is a billion stars or 10^22 stars, it tells us no nothing about the frequency of life in the Universe. We can calculate figures for planets in habitable zones but you don't have any statistical evidence for the existence of life forms. As I stated earlier, the existence of suitable chemicals and conditions don't necessarily imply that life exists there.

I don't take the view that life is inevitable or not inevitable in the Universe at large. There is just no statistical evidence to support either view. The Earth may be a unique sample of one.

Regards, Rob

[CraigS]

Thanks Rob.
:)



The problem here is that whatever processes which brought DNA/RNA, viruses and cells into existence on Earth (from chemical 'soups'), should also operate somewhere else, within the vast sample space.

This thinking then leads to the opinion that the Universe is teeming with life.

But the permutations and combinations of environmental conditions, necessary to support the processes leading to a viable candidate outcome, may actually turn out to be of more significance and impact on a single successful outcome, than the mere presence of the right compounds (eg: water), and processes, which have operated here on Earth.

We presently pay very little attention to these aspects. Once again, we have little/no empirical evidence underpinning these considerations, outside of the terrarium called Earth.

How big does our observation window on the fractal have to be before we can perceive, (and empirically, verify), self-similarity ?

Cheers

[CraigS]

The thinking in my last post reminds me of the analogy used to describe extra dimensions in M-theory.

The ant on the telephone wire. No problem for the ant to see the spiral pattern of the wire … big problem for a human 50 metres away to see it, though.

The recognition of the pattern of life existing elsewhere also depends on our own perception of the pattern. The ant at 50 metres, would have great difficulty in recognising humans, as life forms.

The point about this perspective is that our perception of what may constitute life has just changed to include phosphorous [EDIT: oops .. should read Arsenic] based DNA/RNA. Just what level of significance does this really have, (empirically), in the scale of permutations of possible DNA/RNA bases ? Does it really have an impact on the frequency of viable outcomes ?

Cheers

[bojan]

You meant arsenic ,of course ;)

[CraigS]

oops .. Edits made to original post ..
… but what are your comments on the line of thinking, Bojan ?
:)
Cheers

[bojan]

Your line of thinking (and Bert's) is more or less the same as mine :thumbsup:
However, to satisfy the scientific processes and procedures (excuse me for this "managerial talk") we have to go on searching for evidence, direct and indirect., of course.

[CraigS]

Hmm… some might say that the search for evidence is to satisfy human curiosity.

Having said this, I do believe that there is an undeclared scientific theory of the existence exo-life. And this is under investigation.

Strange, because formally, a theory is an explanation of an observed phenomenon. But we don't have any observations yet, (outside Earth).

The other interesting aspect to this, is that this approach will never be able to reveal the ultimate 'truth' of of it all, because of the problem of induction, (it only takes one negative example to destroy a theory), and you can't examine all examples of this phenomenon, throughout all time and space.

It'll never be a scientific law, because a law is a phenomenon which has been observed many times, and no contrary examples found, so then it is accepted as a universal phenomenon .. a law.

So why all the talk of scientific process?
:shrug:

Perhaps a straw-man (hypothesis) ?

Amazing how science is warped around beliefs in disguise !

Cheers

[Robh]

Craig, I agree with your assessment here.

When it comes down to it, the extrapolation of the life is here to the life is everywhere hypothesis is somehow based on the cosmological principle. That the chemistry and conditions here are repeated throughout the Universe. But does similarity of chemistry and conditions necessarily produce life?

Just how finely balanced are the conditions that allow life to originate? Are the very beginnings of life, the transition from inanimate to animate, just a fluke of chemical interactions and environmental conditions?

It is interesting that life on Earth is based on a DNA (or RNA) model of 4 chemical bases. This interconnection between living things implies to me a very narrow window of opportunity for the origins of life. Why haven't we also evolved jungles full of creatures based on a very different model altogether? Is this the only model that the Earth could fluke given the set of conditions at the time or was it just the most efficient model? Are we assuming that life elsewhere will also be based on the DNA/RNA model? If so, why does this happen?

I welcome any of the biologists to give their opinions as I've reached my level of incompetence on this issue!

Regards, Rob

[CraigS]

Yes Rob.

Good questions. I'd like to hear from the molecular-biologists on these ones as well.



Evolution-by-natural selection may have taken 'care' of the other models.

As interesting as the possibility of exo-life is, equally interesting is the question of how would terrestrial DNA/RNA survive or adapt, on an exo-planet. We could learn a lot more about our own DNA/RNA and natural selection, if we plonked some on Mars to fend for itself.

But that would be pollution !

Take a look at this one (http://www.physorg.com/news201938033.html).


There ya go .. bacteria doesn't even need oxygen !!

I agree with Bert .. we know almost zip about what our own life needs to survive/develop !

So what does this say about increased/decreased chances of life with increasing numbers of exo-planets discovered ?

Cheers

[mswhin63]

I have to totally agree, all the findings on earth only provide a statistical reference to earth only. With that reference point all we can do is to say is allow life to exisit in more potentially toxic locations but still have not found these potential toxic locations.

We only need to do a single finding on another planet or a moon of a planet to completely change everything. A base number on a single world is not the basis for statisitical calculations for other worlds.

The first point of interest would be to find life on an active planet, maybe Triton which shows a lot of activity etc. Once we have find life on another planet then we have a second point of statisical calculation and then can justifiably make the claims.

This will obviously take a long time although they are developing a rover for one of the moons of Saturn already to pentrate one of the icy moons.

[CraigS]

So, further to my post #41, which tends to imply that the belief in exo-life is just that .. a human idea, (or belief), as opposed to a scientific one, I offer 'Logical Reasoning' as an alternative interpretation:

There are three kinds of logical reasoning: Deduction, Induction and Abduction.

Deduction means determining the conclusion. It is using the rule, and its precondition, to make a conclusion.

Induction means determining the rule. It is learning the rule, after numerous examples of the conclusion, following the precondition.

Abduction means determining the precondition. It is using the conclusion and the rule, to assume that the precondition could explain the conclusion.

Using these techniques, one could easily argue the case for, or against, probable exo-life. These arguments would appear to be reasonable, perfectly logical statements, based on the available evidence.

However, logical arguments can also be made entirely independently from the available empirical evidence (or absence thereof).

Logical, but not scientific !

Errors in logic can be made by using Abductive logic, also.

Interesting.

Cheers
PS: I've seen a few examples of these techniques, lately.

[avandonk]

Something I just remembered reading about some years ago and discussing with my colleagues.

Would you believe bacteria in solid granite deep in the earth! They replicate about once every hundred or thousand years. Their biomass could be greater than what is on the surface!
Is this alien enough for you?

Here
http://nai.nasa.gov/news_stories/news_print.cfm?ID=46

and here
http://aem.asm.org/cgi/content/abstract/76/14/4788

There is far more if you google


Were these bacteria subducted eons ago by tectonic plate movements? Or did they originate there?

I will quote the line all scientists use at the end of any paper 'further work is needed'.

Why all life on earth uses the same template for DNA, RNA and proteins etc. is for one simple reason if you have a different system you cannot exploit other life for food.

Even in the eighteenth century scientists knew that there had to be enzymes that broke down all different forms of organic matter originating from life. Say that flies legs were impervious to breakdown then we would be knee deep or higher in flies legs.

Until a bacteria evolves to break down the plastics we are polluting the earth with, we will end up with plastic everywhere. It is already a major pollutant in the oceans and responsible for countless deaths of sea life.

I do agree we have no proof of any life outside our Earth. Consider though how many exoplanets did we know of twenty years ago, zero?

Opinion or hypotheses count for nothing but at least it opens the mind to look for the evidence.

Titan looks like a good place to start.

Bert

[CraigS]

Hmm ..
Very interesting there, Bert.

Now I know what you meant when you said (about exo-life):
"Fortunately they are too far away to hurt us" !! Food source, eh .. hmm…

I am hesitant to bring it up, but Tom Gold had a theory about bacteria living deep inside the Earth. He wrote a book called "The Deep Hot Biosphere". I think he theorised that the bacteria were living on hydrocarbons which were continually being generated by deep primordial processes, which have continued since the formation of the Earth. Fascinating read. I think it was created at a time to counter the 'peak oil' hypothesis. I had a thread with Carl on this one. I don't think geologists like Gold's theory.

Titan, eh ? Yep .. I threw that one into our answers to the school kids about possible places where life might be able to exist, (Gold's theory actually predicted it … and Titan's environment !). I'm surprised you wouldn't choose Enceladus or Europa, though, (because of the liquid water presence).

Interesting.

Cheers

[avandonk]

"I'm surprised you wouldn't choose Enceladus or Europa, though, (because of the liquid water presence)."

CraigS



Craig you are of course quite correct. I was just pointing out that a look closer to home was possible. I did not have the facts that you put forward in my head as I cannot know everything. What would we make of life if found on all these possibilities? If it has the same template as life on Earth would it prove seeding of life by comets/asteroids? If the template is different it would indicate that life is everywhere there is liquid water.

Remember that 1950's science fiction movie where the aliens had a book called "To Serve Man". Too late did people find out as they were being spaceshipped out that it was a cookbook!

Bert

[CraigS]

Hmmm .. perhaps it might prove what we'd like to prove .. "wherever there is water, there is life" .. but all it really would show is that there's another moon in our solar system, which has life we recognise .. and has water.



would we recognise it as life if the template was different? I guess it depends on just how much different. Who knows ?
:)



Ha !! :lol:
Haven't seen it … but I like the idea !!
:lol::)

Cheers

[jenchris]

Firstly I think it a bit arrogant to even surmise we're the only lifeform with IQ above 10.
A million monkeys typing for a million years will produce the complete works of Shakespeare (along of course with most other books and novels and possibly quite a few good new ones.)

So RNA/DNA would simply happen given a certain set of values in any situation that warranted it.

65 million years ago, the saurian empire was reduced to ashes.
Who is to say that intelligent saurians would not have evolved in the ensuing period - maybe alongside mammalian proto-human - if we had not been subjected to a comet strike (if that was what put paid to the scaly ones.)
I read a book about it once - West of Eden - great concept.
Wherever the chance for life exists, life will exist in whatever form and style that will allow progenation.

"It's life Jim, but not as we know it." Probably the basis of all of our yearning for the stars. We're boldly going and no one will ever stop us.

[CraigS]

Interesting that this thread has generated such opinions.

I'm reminded of one of the few valuable comments on this topic:

Confusion exists between statistics and empirical data. There is no empirical data. Statistics do not reveal truths. Even a probable outcome is not a dead certainty.



And going there is the only way to find out !

Cheers

[avandonk]

I am reminded of simple computer programs that are allowed to evolve by combining the most successful ones. Very quickly we get programs that can mimic life.

It is not a throw of the trillion dice every time! It is then weeding out of the useless numbers after one throw, and throw again with loaded dice.

Our weakness as humans has turned into our ultimate strength. We are born helpless and lacking very few survival skills and depend on our parents and others for initial survival and teaching us these same skills as we get older. It is this long process that has led to our dominance of the planet.
We can evolve quicker than our genes. Our knowledge is stored in books and more lately on line.
I just wish that more people would learn the lessons that are stored in the multitude of these books rather than relying on the scratchings of goat herders in one book that they call holy.

Bert

[Robh]

Hi jenchris,

Good to have your input.
A lot of the arguments run along this line ... that life has to eventuate given enough stars and enough time.
Your statement about the monkeys is going to be hard to assess.
An interesting point and seemingly feasible. But I wonder?
I'll get back to you when I get some numbers.

Regards, Rob

[CraigS]

Dawkins had one of these .. 'Weasel' I think he called it. Neat stuff.

Can't help but think that it had a copious dose of Post #45 in it .. (Deduction, Induction, Adbduction) … otherwise it would probably crash every time !

Still, as far as a model to counter an attack is concerned, I think it did quite admirably.

:)

A Michio Kaku documentary aired recently, in which a computer program was created, which started out with animated stick figures. Their task was to develop into upright walkers, which they eventually did.

Can't help thinking this program also had a big dose of irrefutable logic in there, as well.

:)

Cheers

[Robh]

Hi all,

The statement was made that ...
A million monkeys typing for a million years will produce the complete works of Shakespeare (along of course with most other books and novels and possibly quite a few good new ones.)

To our perception, the statement appears entirely feasible. But is it? I didn't really know.
Being curious, I thought the problem was worthy of some analysis. If nothing else, it would illustrate the complexity of information.

To reduce the labour involved, I decided to just download a text version of one of Shakespeare's plays "As You Like It". It has the famous line that goes "All the world's a stage". I then counted the number of each character a, b, c etc in the text. No, I didn't sit there and count each individual character! You can use find and change, replace a with a, b with b etc. and it tells you how many it's replaced. There was 110 pages, 22959 words and 123539 characters, which also includes things like commas, semi-colons and spaces. I accounted for every character bar 34 of them but didn't waste more time trying to track these few down. Conservatively, I divided out 34! (that's factorial) in the end just to be sure.

If every character were different, there would 123539! different arrangements of all the characters. That's about 1.06 x 10^575387.
However, there are 7109 letter a's, 1359 letter b's, letter 1913 c's etc. So this reduces the number of possible arrangements to
123539!/(7109! x 1359! x 1913! ...).
After some hours of computation (am I crazy), the number of possible random arrangements came to about 6.9 x 10^160016.
As a comparative reference, the number of stars in the observable Universe is estimated at 10^22 and the number of atoms at 10^80.

So, lets get one monkey typing 1 character per second for a year.
That increase our chances to 1 in 2.2 x 10^160009 of ending up with Shakespeare's classic.
If you put a trillion (10^12) monkeys on a planet around every star in the Universe (just play the game) and let them type for a billion years, that increases your chances to one in 2.2 x 10^159966.

Even a computer operating at 10^15 calculations per second won't put much of a dent in this figure.
Result ... pretty much impossible. Gone to rest my brain.

Regards, Rob

[CraigS]

OMG !!! :eyepop:

Such dedication !! Such tenacity !!

Rob for the next Newton Medal Prize !
(the maths equivalent of the Nobel Prize! … sorry Steven .. he pipped you at the post !).

Mind you, Jennifer's statement had me go into recall, as I have read this same 'story' somewhere, sometime, also. I just can't remember where.

Just goes to show how easy it is to make statements and how easily they become embedded in our collective consciousness as 'truisms'.

Good onya Rob.

Cheers
PS: So, the corollary to the assertion was: "So RNA/DNA would simply happen given a certain set of values in any situation that warranted it." Hmmm …. (??)

[Robh]

Craig,

Just came across this. Oh, well!
At least it supports the order of magnitude of my results.

http://en.wikipedia.org/wiki/Infinite_monkey_theorem
Under the heading Probabilities

Regards, Rob

[CraigS]

Ha Ha :lol:

I knew I'd read about it before … 'twas in The Blind Watchmaker by Dawkins!

The Wiki article says:



Just like I said previously, this program involves hard-coded logic to make Dawkins' point.

There are lots of 'ins and outs' behind this truism, it seems. Everyone wants to interpret it to prove something … for and against. The trap seems to be in attempting to use it as 'proof'.

These words still apply: "Statistics do not reveal truths. Even a probable outcome is not a dead certainty". Nor is an improbable outcome, a dead certainty.

It would seem that one cannot use the typing monkeys analogy, to state anything with absolute certainty .. for or against.

Until we find a highly intelligent monkey !

(Perhaps that was Shakespeare :P:) )

Cheers

[ngcles]

Hi All,

Hmmm ... all very interesting and educational. Just to set a few things straight ...

Though I am personally of the opinion that intelligent life in our galaxy is very, very rare (ie as I said in the other thread and probably <10 and tending towards very small one digit numbers) out of its 300 to 400-odd billion stars, yes of course we should be looking earnestly!

A find of any life-form (past or present) on Mars while very interesting is not particularly significant for gauging the likely extent of life elsewhere in the Milky Way. We know that it is quite possible for simple bacteria and archaea to make the journey inside rocks that have been blasted off the surface by meteor/comet impacts. I think I read somewhere that Earth receives a couple of kg of Mars every year -- and it works in reverse. Viable bacteria/archaea inside a suitable rock could survive for many tens or thousands of years to land somewhere else and colonise that place. If we found evidence of simple life on Mars, fact is, it is too easily transferred either way for us to easily conclude it arose on both bodies independently without other evidence.

The case for Jovian or Saturnian moons is substantially different. There is virtually no mechanism to transport life from Earth or Mars there or vice-versa. If evidence were found there, then that certainly raises the probability that simple life is ubiquitous in our galaxy (and therefore the Universe as a whole). Obviously this is both where and why we should look. I support the idea of searching wholeheartedly. If it is there does it affect my philosophical or world-view – no. If it isn’t there does it affect my world-view – no. If it is there does it increase the probability that intelligent life exists elsewhere – I think a little bit, but not by that much.

It almost amounts to a massive leap of faith to conclude that if we find bacteria/archaea within the oceans of Europa, that intelligent life is similarly ubiquitous. Plants and animals need a much, much, much narrower range of stable conditions to even stand a slight chance. The first bacteria/archaea arose here at about 800 million yeas after the formation of Earth -- a quite long time. It may have happened a little earlier than this but there is no evidence of it.

The bacteria/archaea of today are essentially unchanged compared to those found in the fossil record from 3.5 billion years ago. They are extremely simple creatures who are robust, hardy and can survive in a wide-range of environments – high pressure, low pressure, high/low temps, underground, underwater, chemicals etc etc. But in themselves they will never learn to mix concrete or sign complicated insurance forms.

It took nearly another 3 billion years till we reach the point where there was (merely) multi-cellular life and then another 750-odd million years before we turn up. During that time there were/are literally tens if not hundreds of millions of species and varieties that did not develop intelligence. We are the only one that has managed the trick and we should never have succeeded according to the biologists (ask Charley Lineweaver UNSW astro-biologist). If you can, take in one of his talks on astro-biology and you will come to appreciate that if we (humans) suddenly die out we won’t be replaced by super-smart kangaroos, gorillas or dolphins in a hurry, or much more likely, ever.

If the eventual development of an intelligent species given favourable conditions is common or even fait’ du complete if you start just a few viable organisms, why weren’t/ aren’t there more intelligent species on Earth? Apart from we humans, even the most advanced and “intelligent” creatures in both present day in the fossil record show no sign of becoming more “clever” during the very long stages of their existence as a species – ie the smartest kangaroos today do not have more developed brains than those from many millions of years ago.

The dinosaurs were the “master-race” of this Earth for hundreds of millions of years yet none of them managed it either. Why? On the available evidence (ie without invoking wishful-thinking or speculation that “life may be different elsewhere”) the only conclusion you could reach is that intelligence is an exceptionally rare trait among advanced multi-cellular creatures – in fact it is so rare that in 3.8 billion years of our history and 10s or 100s of millions of species only one creature made the grade – and we shouldn’t have! If you don’t call that flukey, then what is?

/cont Pt 2 ...

[ngcles]

cont ...

But that’s just the icing on the cake! Before you even get to that stage, in order to have conditions suitable for frail, intelligent creatures, the evidence (we have a sample of one as the example, and again without speculative or wishful thinking) indicates you probably have to have the right sort of galaxy in the right sort of cluster. Not as common as you might think! The star has to be of at least moderate to solar metallicity (otherwise there isn’t enough material to make substantial terrestrial planets) and within certain limits on mass. Probably no more massive than say F6 to make it long-lived enough or no smaller than about G6 to make the habitable zone around it distant enough to prevent tidal locking of rotation of any terrestrial planet in the habitable zone. The star will also need to be within the galactic habitable zone and have a circular or near circular orbit. It is also preferable that (like our Sun) it orbits roughly in resonance with the spiral pattern of the galaxy.

The terrestrial planet orbiting such an unlikely star will also probably need conditions that include: a large moon (have you considered how unlikely the event that made our Moon was?), a geo-dynamo to maintain a magnetosphere and prevent evaporation of our atmosphere, the right (and stable) obliquity, be moderately fast rotators (too fast and the weather’s too unstable/extreme, too slow and we freeze to death at night), the right balance between continental crust and ocean plus plate-tectonics. Then it has to be in that habitable zone for a looooooong period of time. The other planets in the system will need stable circular orbits (again, very unlikely on the sample we’ve discovered) and we also need a gas-giant(s) at the right place to act as both a policeman and to direct enough comets at the right time our planet needed to obtain a water reservoir.

It is my opinion that the culmination of all these pre-requisites (and conditions) in one place for sufficient length of time is a manifestly unlikely event. But, we do have 400-odd million stars in our galaxy to pick from. Even so, for all these things to intersect and produce a planet that is habitable by frail, intelligent creatures over long periods would have to be seen as an exceptional rarity. But once you’ve got that suitable home, then and only then do all the further improbable (and time consuming) events that ultimately produce and support a frail intelligent species come into play.

Please don’t see my opinion as discounting yours (whatever it may be) they are all opinions because we have a very distinct lack of empirical evidence that bears directly on the question of whether intelligent life is ubiquitous. By comparison, simple life (bacteria/archaea) is likely to be much more common in our Milky Way (because it is both simpler and a lot less picky) but still very much a rarity compared to the number of stars present.

On that basis, again the way I see it, intelligent life is likely to be exceptionally rare and maybe even singular in our galaxy. Agree or disagree with my opinion (that for the last time I point out that I'm not passing-off as “fact”) by all means, but your view like mine is similarly an opinion.

It is an exceptionally interesting topic.



Best,

Les D

[CraigS]

G'Day Les;

Very cool. I thank you for taking the time to present such a considered case.

I've learned a lot from your terrific posts.

I also respect your final opinion of it all, because you presented it as your opinion.

I think this discussion is influencing my views on it all as well, although my focus is more on how to discuss the topic, given the paucity of empirical data, to make any firm statements, one way or the other.

Your posts serve as a good reminder that so far, what we DO know about what it takes for intelligent life to come about and develop, is quite specific (and keeps growing). The frequency of occurrence of these specific conditions in an infinite universe, leads us to the conclusion that life, (intelligent or otherwise), is probable (ie: probability ~ 1). That's not saying much, because we know we exist !

The second instance of it, is clearly the big question. (That's like stating the glaringly obvious, too … I'm trying hard …)

Personally, I think panspermia or necropanspermia are quite likely, (yep that's an opinion), but there have been some interesting discoveries along these lines lately in support of these views. Possibly even more likely, is that our probes may have transported bacteria or viruses, in some state or another, to the planets we've visited. I'm perplexed about what we'd make of an exo-life finding in our own solar system, particularly if we'd already sent probes to the same location. Also, what might we make of it, if we found bacteria on a passing Asteroid or comet ?

Anyway, I've shared about as much as I'm able to in this thread. It mostly amounts to dimensions of thought about the issue .. which is quite intentional.

Cheers & Regards.

[bojan]

Than could be the explanation for Fermi paradox...

[Jason D]

A number is a number. It might not mean much.

There are trillions and trillions of sand grains on earth, what is the likelihood to find two identical sand grains – atom for atom? We can safely assume 0%

If I flip a coin 10 times, what is the likelihood I end up with at least one “heads?” ~99.9%

Jason

[CraigS]

Hi Jason;

Thanks for your comments .. I have some questions (as follows) ..



Humans make meaning out of everything.
We are meaning adding machines !!



Why is it safe to assume this ?



This is a safe prediction because we know a coin has two sides before we start flipping !

Your former statement however, is definitely 'not safe' ! :)

Cheers

[Jason D]

My point of my earlier post is that calculating/estimating probability is highly influenced by the set of assumptions rather than the size of the sample. In my example, I have shown an event with 99.9% probability of occurring with a sample of 10 and another example of an event with ~0% probability of occurring with a sample of trillions and trillions. By the same token, we should not rely on the sample size of planets count to estimate probability of life but rather we need to come up with a good set of assumptions to do so. Unfortunately, coming up with that set of assumptions is highly subjective.

[jenchris]

If we ARE the only intelligent life in our Galaxy, I find that immensely sad.
To be the only few with the wit to look up and wonder, to look up and weep at the indescribable beauty.

Fortunate even more so that we humble few with telescopes can look further than others and see it first hand.
Of all the worlds in all the galaxy we have to pick one 4 light years from the next one. That's a lot less fun than it could be.

However having beat my breast (metaphorically), I now support my claim with further views that make possibilities seem more likely. We don't have a clue as to ANY of the parameters that support life of any sort. Even Gene Roddenberry knew that. Intelligence may be rare or it may be that we're wierd that only humans have it in spades on this planet.

On the subject of a million monkeys.
You do realise of course that the monkeys would get less random over the next few millenia as they begin to understand what they
are typing. This may hinder or help in the accumulation of Shakespeare's works. (And lets face it, there's even a hint that Shakespeare didn't write much of anything - he just took the credit of someone else's work. In which case the million monkeys could do it in about 10 minutes)

Never forget progress.

All those who bought solar panels - who will be regretting it in a year when the new paint-on type come out and cost almost nothing by comparison.

[CraigS]

Hi Jenny;

You don't have to feel sad … you can choose to be sad, or you can choose to be overjoyed at being the first …

We can't change what may be, and we're trying to find out what else there is !

The journey is worth the effort and we may end up being not alone ! We won't know, if we don't look !

The Monkeys Theorem is fascinating. I'm writing a post about it but its very tricky.

Wish me luck.
:)
Cheers

[Robh]

Les,

Thanks for your informed and deliberated viewpoint. I gained a lot out of your extended posts (59 and 60) as they were both informative and interesting.

Regards, Rob

[Robh]

Jenny,

You could have mentioned they were evolving thoughtwise before I did my head in with all those calculations. :lol:
Still it was a fascinating problem and deserved a look in.
As for understanding Shakespeare's works, that could be a problem!

Regards, Rob

[avandonk]

Has anybody considered if there is 'intelligent' life out there they have either died out when their star's life ended or like us they trashed their only home.
We quite cheekily define ourselves to be intelligent or more intelligent than all other life on earth. We are all guilty of using the Earth's resources at a rate that is faster than replenishment. In less than thirty years we will need two Earths just to stay at the then rate of consumption. This is of course impossible. And we think we are intelligent? Our species has only been around for about one million years tops, and just like dumb bacteria are using all the nutrients in the Petri dish as if there is no limit to our growth. When the nutrients run out folks the party is over.

It could be that life appears in the Universe like fireflies that blink only once and then are gone forever. We just may not have any near neighbours that are at our level of development. They are gone long ago or are still at the bacterial stage which seems to be the longest phase in evolution.

Just like Dr Who we have a temporal and spatial dimension to this problem as he had in navigating the Tardis. Where was the Earth relative to 'space time' ten minutes ago let alone centuries ago.

When I look at the Vela SN remnant and the much older Gum Nebula behind it I see our ancestors or at least the same 'stuff' we are made of!

Bert

[CraigS]

Yes Bert;

Interesting.

Humans are part of the nature, and the environment which created us.

I don't see us being separate from it. That rubbish we make perhaps, was always what we were going to do. We might be able to change it ... we might not. What ever the outcome is of this is, it can be factored into what we know supports, (or doesn't support), life. Ie: another variable.

I sometimes wonder about the dinosaur extinction. I find it difficult to accept the meteor impact extinction hypothesis but there again, that's an opinion. One thing's for sure though, they didn't choose pollution as a means to self destruct !

Hang on a minute !! .. Crocodiles are pretty close to what we call dinosaurs, aren't they ? They survived.

Hmm … perhaps we don't know enough about that variable, either (??)

Cheers

[avandonk]

Yes we do crocodiles are not dinosaurs. They are cold blooded and a can go without food for over twelve months. The dinosaurs were warm blooded and needed huge amounts of food. The smaller ones were OK we now call them birds. Our ancestors at that time were similar to shrews. I know this as I was married to a couple of them.

Bert

[jenchris]

Couple !!:eyepop:

Future eating is what humans do best - Easter Island - The Aztecs; they all removed what gave them their ecology -
I think we're likely to do a similar thing when the third world gets hacked with USA taking all the big cherries for itself.

Then we'll have a major disease outbreak or an engineered one.
This may reduce the population or annihilate it.
Think Drax!

Eugenics - eek

[CraigS]

Hmm .. some debate over the years about warm-bloodedness of dinosaurs (http://en.wikipedia.org/wiki/Warm-bloodedness_of_dinosaurs), eh ?

I think I may have met a shrew or too, also.

Cheers

[CraigS]

Hmm .. interestingly, we might be able to make definitive statements about the proportions of 'intelligent species' at certain definitive points in the evolutionary scale.

But why be concerned with 'intelligence' ?

This kind of equates to the T-Rex having big teeth, as his main weapon.

So, intelligence should lead to greater longevity than big gruesome, scary teeth ! And that's in spite its relatively miniscule proportions !

Things aren't looking too good here, Jenny !

There again, aliens might consider our intelligence to be nothing more than a bee sting (perhaps not even that).

Cheers

[avandonk]

I have 'tame' magpies, possums, rainbow lorikeets, crimson rosellas, currawongs etc. I call it tame because they have no fear of me. Apart from bribing them with good food I never attempt to touch them. They are wild animals and should stay that way.

These animals over many years have worked out my movements to the point where if I have been to the butchers in the case of the magpies and currawongs they are waiting for fresh minced steak at the back door. The older magpies come inside and sit on the kitchen table demanding food much to my dogs dismay!

Even these birds have an ability to learn and adapt.

We are not that special.

Bert

[CraigS]

I agree that we're not special .. so neither is intelligence .. just another weapon.

Interesting your story about maggies. We've just had one which built its nest at ground level, in our garden ! We've been watching the young one, the mother and the father, cope with other marauding predators (cats, us) etc.

No matter how many times we walk by the nest, the mother perched above, still sounds out the warning, despite our non-interference with the young one.

They might have some 'intelligence' but they don't seem to relate non-interference, (ie: safety), with passing humans.

Its kind of threat-aversion instinct at odds with a dumb choice of nest location.

Another type of intelligence !!

The numbers just changed again !

Cheers

[ngcles]

Hi Bert & All,



So did they learn this all by themselves? No! In fact unwittingly you (as an intelligent being) have been teaching them -- and it took them "many years" to learn to repeat a simple behavioural pattern.

By the rewards given out, you have unwittingly taught them when to expect a possible reward, how to act if they want a reward or to increase the probability of a reward. If there was no teacher, how long would it have taken them to learn and display that behaviour? Answer: Likely never. How many of these birds have been independently able to teach this information to other birds (that are strangers to you), so that they come along display a pattern of behaviour to provoke a reward. I can confidently predict the answer is none.



Yes of course they do -- but given their limited (and limiting) physiology and quite small brains, they need a teacher to learn this type of behaviour! Otherwise their learning capacity and learning speed is extremely limited.



Yes you are, we are the only "conscious" teachers on the planet! That makes us very special indeed.


Best,

Les D

[avandonk]

You mean Les that all this time they are not my friends?

I am shocked!

Of course you are quite correct. It takes a long time and selective breeding to make a wild animal as domesticated as the dog.


I am still amazed how carefully they scrutinise me from about two feet away. Then happyly eat out of my hand.

bert

[snas]

So, Craig, as you requested, here are my thoughts, as a biologist, on the biology of the Universe. Please note that these are my thoughts are quite obviously not related to any direct observation leading to hypothesis etc, merely my own personal thoughts. Some is based on observation etc.

Reviewing what I have written below, I guess I need to point out that when I refer to "life", I am mostly referring to "animal" like life as compared to plants, algae etc.

The Earth is in the "so called" Goldilocks zone. Goldilocks for life on Earth, but not Goldilocks for life on, say Eridanus. One would imagine that life on Eridanus, if it did exist, may well have trouble in surviving on Earth. Or, maybe not. There may well be life forms in the Universe that could not possibly survive on Earth or survive in a different planet in the same zone as Earth.

I think (would like to believe, but being a very non-religious type, I steer away from the concept of evidence free belief) that life is, more likely than not, common throughout the Universe. But not to the extent of occurring on, say, even 0.001% of planets.

I think that if there is a planet on which conditions are suitable, life will, at some point in that planet's life, arise and evolve. This thought is based, to an extent, on Paul Davies' suggestion that it seems possible that life may have arisen and become extinct a number of times during the "early period of bombardment". If life arose on Earth on more than one occasion, it would therefore appear that life will form if conditions are suitable.

I think that life throughout the Universe (given the existence the same set if Laws of Physics throughout the Universe) is likely to have certain similarities. For example, what is the prime aim of a living organism? Answer; to reproduce more organisms similar to itself. Therefore a reproductive system is required. Asexual reproduction is inherently a poor form of reproduction due to the lack of mixing of genetic information. Life on Earth consisted of simple, single celled organisms with very little variety for a very long time. The lack of genetic variation leads to a reduced ability to adapt to changes in the local environment, and hence reduced survival ability. It was only once sexual reproduction with sharing of genetic information appeared in life on Earth that life was able to firstly improved its survivability and also to develop into far more complex, multicellular life forms. Therefore, while I think that the majority of life in the Universe is likely to be quite simple, I believe that any complex, multicellular and, by extension, any "intelligent" life is likely to use some form of sexual reproduction associated with some sort of genetic information sharing.

Similarly, the complex life form needs a mode of getting from A to B. Getting from A to B therefore requires some sort of rigid body structure such as a bony (on Earth at least) internal skeleton or a chitin (on Earth at least) external skeleton. Then a means of causing the rigid support structure to move (called muscles on Earth) is required. Using muscles requires energy, so a means of capturing, ingesting and metabolising food into useable energy is also required. I'm not saying that these systems must be exactly as they are on Earth, but the basic set of plans requires what I have described above in order to work.

All up, I would not be surprised at all to see that a complex, multicellular life form in another part of the Universe has numerous basic similarities to life on Earth.

Of course, I could be very, very wrong. In fact, if someone was to discover life elsewhere that did prove me very, very wrong, I would be ecstatic.

Regarding Earth; there are some important things that make Earth a suitable place in which life might arise.

The 23 and a bit degree tilt of the Earth's axis is very important for life on Earth as it leads to us having seasons. The resulting change in weather patterns though the course of a year and also the continually changing day lengths in turn leads to the pituitary glands of pretty much every mammal, and quite a few non-mammals, to produce the hormones essential for effective reproduction. If the Earth had zero axial tilt, would reproduction be possible? I imagine, based on the "life will find a way" theory, that, yes, it would. But would reproduction be as efficient as it is here on Earth?

Having the Moon be the mass that it is, the distance from Earth that it is and having the 29 day lunar cycle that it does leads to tides here on here. Tides lead to the existence of an intertidal zone which may very well have played a major part in complex life being able to leave the oceans and colonise the land.

And of course, orbiting the Sun is far better for us than orbiting many other kinds of stars.

Anyway, Craig, you asked for my biologist's view. Here it is. And again, I am very happy to be proven wrong in any of the above thoughts as said proof will mean we have discovered life elsewhere. I just hope that happens in my life time.

Stuart

[CraigS]

Thanks kindly for your comments, Stuart. Somehow this thread didn't seem complete without your views... they are much appreciated.
:)

Very interesting …


Interesting. I'm not a particularly big fan of Paul Davies (and I'm not too familiar with the theory you mention above), but I can see how life could regenerate, if life was never completely eradicated by such events in the first place.
Is the Earth old enough to continually regenerate life from scratch, if these events were total extinction events ? :question:
… (It would seem Paul Davies thinks so). Interesting.


I was reading the other day that one theory is that life arose from viruses.
Modern viruses require the metabolic processes of a host cell, (I think?). But in this theory (I recall), primordial viruses acquired the necessary fundamental 'metabolic' processes via chemical processes, which then evolved into DNA nucleii and cell structures.

Also, I'm reminded that sharks have been known to reproduce asexually through parthenogenesis. Mammals are the only major vertebrate group where asexual reproduction hasn't been observed. (Or has it ??)

A bit further 'out there' is the idea that crystals could be classified as life forms under general classifications of 'life'. (Mind you, I think this may just be a play on words & definitions, perhaps).


Yep all cool .. thanks for taking the time to comment.

Cheers & Rgds

[Suzy]

How about those Ravens though - their very smart :question:. I watched a doco on the study of them once, and it showed them using a busy road to drop big nuts from a set of traffic lights. They waited for the cars to crush them, and then when the red light came up for people to cross, only then would the crows collect the nuts. Also, in a more detailed lab study, it showed how Ravens would break and bend sticks to get food out of boxes. :eyepop:

[renormalised]

Hey Les...."exhibit A"....your avatar....prime example of consciousness on planet Earth :):P

And at this time of year, after a few cold ones under the belt, very few humans could be deemed to have any conscious awareness :):P

I subscribe to the last few lines by Eric Idle in the "Galaxy Song":)

[astroron]

Suzy is correct:)
Ravens also in the wild have learnt to use sticks as a tools without any human intervention what so ever :shrug:
We are not the only creatures on this earth who can learn to use tools
Contrary to what most think
Chimpanzees are another example.

[xelasnave]

I do think it is important to remember that no matter what facts we solicit to support any argument about the prospect of life or indeed intelligent life in other places besides on Earth that we are merely engaged in speculation.

I believe life will be common place but again that is speculation and no matter what logic I present to support such a belief one (myself) must remember that I simply dont know the answer and never will.

As to intelligence being related to tool use I suggest that there are many humans that may not be considered intelligent if such a test is applied ..lets face it primitive man could round up a feed from the bush but these days put someone out of range of a super market and they will die from starvation.

I have no doubt that those considered above most of us probably have never even prepared a meal for themselves let alone caught it or attended to its growth. Could the Queen of England make a sandwich I wonder?

It would be very confronting if it could be established beyond doubt that life only existed on this planet ..consideration along these lines would leave one feeling either very special or merely some kind of accident.

alex:):):)

[CraigS]

I don't think I would feel confronted about this … (does that make me weird or something ?)

Cheers

[xelasnave]

Yes it most certainly does Craig but with extreme emphasis on "or something".

alex:):):)

[CraigS]

That's OK .. I don't mind being 'weird', either !

Why should we get insecure about this ?

We've lived with this unique feeling for thousands of years now .. it feels kind of familiar, to me !!

Cheers

[xelasnave]

It is my belief that to be different is better than to conform to the expectations of the group. Now this approach is not easy and is not necessarily correct but finally one must except the consequences of ones actions etc rather than abdicate responsibility and assign outcomes being due to anothers action rather than ones own....

AND no doubt the experience of thousands of years or at least a feeling of same establishes "something".

You may find this difficult to accept Craig but there are some who openly state that I am weird ..and that hurts because I know I am more normal than anyone:lol::lol::lol:

Back to life elsewhere.
We do not have the info to say how it is out there ... but if it could be proven that we are the only ones I think I would turn catholic:lol::lol::lol:
mmm maybe not even then;)
alex:):):)

[ngcles]

Hi Craig, Alex & All



No I wouldn't be confronted either and nor would I be particularly surprised. But the answer I want, is to this question:

Why do people feel it would be upsetting, confronting, shocking etc etc if we are alone as intelligent life? Why does this make people feel sad?

Why is this such a bad thing (if it were true)? I just cannot grasp as to why it has become such an emotional issue and further, how that emotion sways our assessments of the probabilities. Jen wants to move to Pandora but I say you can just as easily talk to the trees here on Earth (just ask George III ...)

Alex has also re-emphasised what I think is an important point (and I raised it a few times in this thread too). At the moment it comes down to a statistical argument with a substantial number of assumptions and variables. Some of the variables are being narrowed down as time goes on but there are others that are difficult to estimate to within two or three orders of magnitude -- at the moment. It is, at least in part, guesswork until someone from Zeta Reticuli parks their star-cruiser on the White-House lawn.

The short answer is: We don't know. We can guess, we can estimate but we don't know.

My opinion is that intelligent life is extremely rare in the Milky Way and even the Universe, but that is only my opinion. The rest of you are of course perfectly entitled to your own wrong opinions. ;)


Best,

Les D

[CraigS]

Les, I agree with you.
Why does emotion play a role ?… in one phrase … 'The Anthropic Principle' .. Ie: observations of the physical Universe must be compatible with the conscious life that observes it.

This view seems to be the predominant/politically correct basis to view the world/universe around us, (in present day Society0. If you don't see it this way, you're 'weird'.

(I suspect you know this, and you're looking for someone to challenge you on it … I'm not going to be the challenger, however … I'm in your camp !
;) )



Nothing will be proven using statistics or variables in some formula.

Empirical evidence must be found … which justifies the pursuit of it.
(In my opinion).



Opinions are fine … even wrong ones .. so long as we realise they are opinions, I don't have a problem. Its when we lose sight of our opinions that things go off the rails. When opinions become the 'truth' is when wars break out !

Cheers

[avandonk]

Les I have found truly original thought is very rare indeed. As for so called intelligent life I have rarely met it even amongst humans. They act irrationally without any thought driven by base emotion. They are also prone to believe the last half lie they heard that suited their worldview.

I would be the first to ask for evidence for any hypothesis. The fact that no matter where we look we find life on any habitat on our planet leads me to consider life is ubiquitous. Fortunately it is a long way away!

Both alternatives have very deep consequences. If we are alone in the Universe can we afford to keep sh_itt_ing in our nest we all know as spaceship Earth. It should be spaceship Water with dirt bits with a plague of primates living as if there is no tomorrow. We destroy habitats at our own peril as they sustain us.

Ask the Australian Aborigine, the North American Indian, the African, the South East Asian, etc etc ect what happens when a technologically superior mob turn up. They steal your resources and your women!

Hopefully interstellar aliens have a different biology so we cannot be used for food.

We will destroy ourselves before we meet aliens. I am sure that any 'intelligent' aliens have done this long ago and will do it again in the future. We are not talking geological time but star evolution time and hence stellar system time.

Meanwhile I will still make friends with wildlife as you never know when you need their help!

Bert

[CraigS]

I just read this one from Hofstadter's book;



I reckon these are pretty cool distinctions for intelligence.

If one lines up with them, and agrees with Hofstadter, then there would seem to be more hope in the future that Bert cites, (over that which Bert foresees), if we are truly an intelligent species …. as Les asserts !

Cheers

[avandonk]

Ah, Craig is it humanistic policy or practice? I stole this line from Yes Minister.

You are young and have not hardened up yet.

I used to believe this nonsense but now it is dog eat dog.

No he makes a lot of sense.

You have just described the Irish mind!

Bert

[CraigS]

Bert, I may not be as young as you think !!



There have always been mean dogs, Bert !
:)


Maybe due to Irish ancestry ??

Have a beer and some happiness tonight, bert !!
Too much thinking going on here !!
:)

Cheers & Rgds

[avandonk]

We used to have meetings at CSIRO every Friday. When I spoke the much smarter blokes than me would listen. My immediate superior said at my retirement pissup 'Bert could always see through the crap and see a clear path to something that may work!'

I am about 1/16 Irish the rest is Dutch, Spanish, French and a little bit Indonesian and Indian.

My mothers mob was in Indonesia in 1720.

I am afraid that the Irish genes are strong. I want to give them all a shellacking!

My aim has been to point you in the correct direction. This makes your quest of knowledge far quicker.

When you tell me I am a stupid old man my job will be done!

Bert

[CraigS]

'Twill never happen, Bert !

Cheers

[avandonk]

Apparently whole threads can go missing especially when the stupid have proved they are stupid. I am really amazed that these cretins can denigrate CSIRO and the BOM without fear or favour and when I show them how stupid they are they get a bit upset. What a bunch of sooks.

Bert

[snas]

Have just finished reading Death From The Skies by Phil Plait. A good read as long as you're not going to become depressed by all of the many and nasty ways in which we and our Earth will eventually perish.
He makes the point that war always accelerates the advancement of technology. He therefore suggests that a warlike race is more likely to develop superior technology and therefore be more likely to cross interstellar space in search of new planets. However, this race, being warlike, is also more likely to be xenophobic, paranoid, suspicious of life on other planets. He therefore wonders if they may strike out at any planet capable of supporting life before the same happens to themselves. He also points out that since this and several other scenarios that he describes have not happened to us in the last 4.5 billion years, it seems unlikely that it will happen.
Stuart

[CraigS]

There seems little doubt amongst us humans, that fear is a powerful motivator !

I think 'doom' is the ultimate fear, and hence, the ultimate motivator for us all, eh ?

It may never be empirically possible for any physical particle of mass, to travel at the speeds necessary, in order to bridge the awesome distances involved in interplanetary travel. This is likely to upset the 'dreamer' set, (not that I don't include myself in this category, also).

I actually have a bit of a chuckle when I think annihilation by aliens, which hasn't happen to us yet … seems to suggest they can't crack the nut of interplanetary travel .. or perhaps, they're just 'lazy astronomers', also !
Chuckle .. chuckle ...
:)

Cheers

[astroron]

I am surprised that his thread has gone one hundred posts:eyepop:
with some very interesting replies:thumbsup:
Here's to another hundred:rolleyes::lol:

[CraigS]

Or here's to another thread lock !

;):lol:

Happy New Year to you Ron, … Stuart & everyone !!

Cheers

[snas]

[QUOTE]It may never be empirically possible for any physical particle of mass, to travel at the speeds necessary, in order to bridge the awesome distances involved in interplanetary travel. This is likely to upset the 'dreamer' set, (not that I don't include myself in this category, also)./QUOTE]

Craig,

Phil Plait, in the same chapter that I mentioned yesterday, talks of a continual acceleration system like an ion drive which he seems to feel is within our grasp, not necessarily in our lifetime but not far away; the major hurdle being political will. He feels that using something like this can get us to every "habitable" planet within a relatively short space of time. By using a system of small probes dropped from the initial vehicle onto a suitable (mineral content wise) planet, these probes would then mine the metals from the planet and replicate the original spacecraft (See: Replicators on Stargate :)). If it took 100 years from launch of any one probe to launch of offspring probe from the next planet, in 3000 years there are more than 1 billion (2^30) copies of our original probe exploring the Milky Way. Of course, the replicator part of the technology required would seem to be a fair bit further away than building an ion drive system.

Hopefully though, time is on our side. We have only been here for 200 000 years. Dinosaurs hung on for almost 200 000 000 years. So even if we only have a million years left to our reign on Earth, there's plenty of time to work stuff like this out.

I have to quote one of his footnotes from this chapter.
"Despite a zillion blurry photos, obvious fakes and shaky video, there has not been a single, unequivocal piece of evidence that we have been visited by aliens ever. Deal with it.

Stuart

[renormalised]

Nope...I contend that there are trillions of the little (and big) creepy crawlies out there and that we hardly ever see them because who would want to come visit this mob of knuckle draggers anyway!!!! :D :P

[astroron]

:hi: Suzy, some new evidence to support your post:D:D

http://news.bbc.co.uk/earth/hi/earth_news/newsid_9353000/9353588.stm
Crows are p[roving cleverer than we thought:thumbsup:
Cheers

[Nortilus]

To be able to live forever or at least longer than the average human lifespan. Maybe 2000 years old. To see what the human species will achieve and what we will know. To think that when I was 8 years old and watched Beyond 2000 on TV thinking “wow, the year 2000 is going to be amazing filled with robots and flying cars”. 10 years later when the year 2000 came around, the progression of such things, although had advanced, still didn’t live up to my 8 year old minds expectations. The year 4011, which will be 2000 years from now, is maybe where we should be letting our minds wander too. What will we have achieved in this time, and will it live up to our current expectations. They will if we put our minds to it but only if we overcome our shortcomings.

I agree with some of what has been said and disagree with some of what has been said. People have their own opinions and have the right to their own opinions. But ultimately fact is what is right. Can we really class ourselves as intelligent? Do we even have that right? Yes we can build things and send probes into space and ponder the wonders of the universe, but can that really be passed off as intelligence. Maybe some of the things stated in the Fermi paradox are right, would a truly intelligent species that evolved on a planet going around a distant start, that has developed intergalactic / extragalactic travel really want to stop here and say hi, at this point in our own development. I would honestly say no. We are still the only creatures on this planet that kill each other for belief in a higher power. A higher power that in my opinion does not exist. And no, I’m not afraid to openly state that. Religion is one of the key elements holding back our progress to true intelligence. The amount of money spent on war for a god of some description is ridiculous, money that could be well spent advancing our civilisation. Yes, I’m aware that a lot of it may also be for the black stuff under the ground and using a religious war as the cover, but why not put a bit more money into alternative power resources that doesn’t use fossil fuels reducing our need for fossil fuels. Greed is another one of those key elements holding us back.

We as people are still looking up and thinking, are we alone in the universe. Yes we are alone, but only because we haven’t conquered “space travel” yet or we are just still to uninviting to the passersby to drop down and say “hey, we worked that out awhile ago, here’s how”. Yes, there is life out there in the universe, be it single celled or highly advanced space travelers, but we will never know this as fact until we overcome our own problems here and truly become intelligent.

[mswhin63]

I haven't watched this post for quite some time as it diverted a lot from the original post. I am sort of curious without reading all the post how did it get from trillions of dwarf stars to ravens and typical alien lifeforms that follows most post relating to science. :lol::shrug::

[ngcles]

Hi Malcolm & All,



How it happened was that the original mass-media article concluded that because the inventory of stars in the Universe had tripled, so had the number of Earths. Because the number of "Earths" in the Universe had tripled, the chances for life and intelligent life had also tripled -- and everyone got excited that there would be more people out there to shake hands with. This was done in the title of the article remember: " 'Trillions' of Earths orbit red stars in older galaxies". But it's a good headline -- grabs your attention. Only one problem ...

It is erroneous reasoning because the "new stars" are virtually all very low mass, ultra low metallicity Population II red dwarf stars in elliptical galaxies that are manifestly unlikely to have the building blocks to form rocky, terrestrial-type planets required for advanced life, let alone intelligent life.

It is in fact the point I've been pressing all the way through -- assumptions without evidence or with litte evidence other than a statistical argument. There are in fact a lot more things that go toward making an "Earth" than people usually think of.


Best,

Les D

[mswhin63]

No worries, should have seen that, I was more interested in the extra gravitation within the galaxy extra mass etc etc.

[bartman]

Yeah good Question.....

I think the simplist answer to my question ( see post #7 -which was merged with Astroron's) is that even if 'they' have intergalactic space time travel - we are not advanced enough for them to come and say HI:hi:. (many references to Star Trek inserted here...)
Great to see so many theories and responses!
Bartman

[Rob_K]

http://www.nasa.gov/mission_pages/kepler/news/kepler_data_release.html

Cheers -

[bartman]

Why wont/cant Kepler be aimed or concentrated on Stars that are reasonable close to us?

http://www.bbc.co.uk/news/science-environment-12333766

If we find a star that is say within 10 ly from us with a possible candidate for a habitable planet, then we could concentrate on sending them a msg and then in my life time ( 20 years from now) would receive a msg back saying all is good:D see you in a few decades :welcome:( assuming they have lightspeed capable ships and friendly:P).:anaut:
I would be happy to have lived and died knowing we had ' First Contact':ship2:

Bartman

[CraigS]

So you'll be sad to have lived and died, knowing we had no 'First Contact' ? :question:

Cheers

[CraigS]

Of interest to me is:



Supports my suspicion that we are limited in our own understanding, by our own miniscule experience of the Solar System, and the physical processes observed here on Earth.

This still does not support the idea that 'life MUST be out there', however, it does support the concept of: 'infinite diversity through infinite combinations'.

If this ever turns out to become an emerging consensus picture, then the view that a specific occurrence of life emerging, actually requires a universe of the size and dimensions of our observable domain, would seem to become even more credible than it presently is.

Cheers

[bartman]

Craig;

"Supports my suspicion that we are limited in our own understanding, by our own miniscule experience of the Solar System, and the physical processes observed here on Earth."

Doesn't mean we cant fantasize - read 'make ideas' - that might evolve into real 'things/events'.
Look at Jules Verne and Star Trek (Gene Rodenbury). We dont need to necessarily know all the "physical processes" to make things happen just yet.
Jules Verne ( and others) anticipated that we would make it to the moon.

I am not saying emphatically that there is life out there, but the statement;

"This still does not support the idea that 'life MUST be out there', however, it does support the concept of: 'infinite diversity through infinite combinations'."

in my eyes reads that life IS out there......the infinite diversity and combo bit.

"If this ever turns out to become an emerging consensus picture, then the view that a specific occurrence of life emerging, actually requires a universe of the size and dimensions of our observable domain, would seem to become even more credible than it presently is."

Sorry Craig you got me there..... what the shell does that mean?????:confused2:
In plain words - I dont understand what that says.
I'm re-reading it over and over again:D:question:
#####sarcastic joke coming#######
Craig are you a politician?:shrug:

If that was in bad taste Mods please delete but Craig ...No malice is intended.... I just simply thought it was like a pollies response to a question.......

Please Craig, no offence:hi:

yours humbly, Bartman

[ballaratdragons]

OK, some facts has shown that life probably never had a chance at starting in those Red Dwarf zones.

But some may ask, wouldn't your statement still ring true for other situations.

No, probably not.
If another species/lifeform had developed 5b years earlier, then they probably had their existance. And their sun supernovaed, or they all died, before our Sun was even a sparkle in Sirius's eye ;)

In other words, they've probably been and gone before we have been. :thumbsup:

Where do you think our lifeform (mankind, the animals, etc) will be in another 5b years time?
:)

[CraigS]

No worries about fantasizing, Bart ! I'm into dreaming, also.

I'm a big supporter of exploring out there !

Can't see anything wrong with 'havin' a little faith' and making use of that as a basis to explore .. exploring is the only way to find out, after all !!



Ok .. that's cool .. but that's not what it means to me. :)





No not a pollie .. I'm always seeking new ways to compress the thinking behind the concept, which was outlined way back in this humungous thread (I believe). Apologies if the statement was convoluted.

If life was a 'fluke', then there needs to be a huge number of 'attempts' for it to result in life (as well as beings, like us). Those 'attempts', require an enormous sample space, before 'it works'. We see a huge sample space in our observable universe. Maybe this single instance of life, required everything we see around us in our observable universe, in order for it to exist here.

This concept is just as valid as "there must be life out there because of the numbers". Whichever alternative we choose to believe, is purely by choice (and opinion). Statistics and science cannot 'disprove' one or the other concept.

This all changes immediately however, when a single exo-lifeform instance is discovered … but not until that discovery.

Cheers

[bartman]

Bartman

[Barrykgerdes]

Before I wrote this I read the original article so that I would not drift too far off the subject with my hyperthetical views. I have no proof of anything I say here. Just a feeling that I have about the "Life, the Universe and everything"

Trillions of Earths

This needs a little more defining. Yes in the known universe there will be trillions of earths and jupiters and asteroids and suns and so on. The research that we are capable of in our near environment has shown that the formation of "solar systems" is common and there are a few now being discovered that have similarities to our own solar system. Of these there will surely be some that can and probably support life as we know it, but I am sure that we in our present stage of development will never see or communicate with them.

Before we can even progress our learning we need to understand infinity. That of course is not possible but we should at least believe that it is infinite. Once this is grasped the theories that have been put forward about the creation of our local universe can be put into a better perspective. The greatest accepted theory is refered to as the big bang. This is only a theory based on statistical information that satisfies most of the laws of physics as we know them. But it always falls over when we try to give it a boundary because we then need to define what was before. There have probably been an infinite number of big bangs.

I accept that the most likely basis of our universe is a big bang. But what does this represent. A creation from a singularity as is said or the more probable action as I see it of matter collapsing into a giant "black hole" that eventually contains so much matter that its core temperature reaches a point where matter can no longer exist as a solid.

This creates a monstrous explosions that releases the matter to coalesce into all the elements and compounds of the universe as we know it. This explosion also creates the building blocks of life (DNA if you like). These building blocks are of course the most interesting because it is from these that we have evolved.

An interesting side point here would be to calculate the eventual size of this "black hole" by a reverse process of adding the mass of the universe we believe was created by this explosion to find the eventual pressure at the core and then the temperature.

Once the building block is placed in the right environment it is able to replicate itself. The simplest of life form blocks that are the most abundant find this environment relatively quickly, but the more complex blocks take a long time to find the right environment.

We believe that our human blocks are the optimum in complexity but like the unstable atomic elements that we have created are there more complex and or unstable blocks that will in the future creat a super being that is capable of the understanding we now lack? Just like the dinosaurs disappeared when their use by date expired human life as we know it may some day give way to a superior life form.

Barry

[CraigS]

The universe could be thought of as infinite.

Our observable universe on the other hand, has boundaries and objects which could be counted (if we could see/infer everything).

Life's occurrence may be, or may not be, a 'fluke'. There is no evidence one way or the other ... which is why I said: "If life was a 'fluke' …"

Cheers

[mswhin63]

Interesting report - http://www.physorg.com/news/2011-02-herschel-dark-stars.html

There must be so much un-seen heavy matter out in space it is hard to think it is all dark matter.

[CraigS]

Just started a new thread on this one ..

Star formation (http://www.iceinspace.com.au/forum/showthread.php?p=688593#post688593) .

Time to give the ol' "Trillions " thread a well-earned rest, eh ? ;)
:)

Cheers

[mswhin63]

The other thread is based on Star formation, my reason which this thread talks allot about is Dark Matter. Maybe you are right, I will consider opening a new thread later as I have to get to work cleaning things up before starting Uni.

[astroron]

Nooooo,leave it going;):lol:

[CraigS]

… this guy must get paid by the number of posts on his threads …
:)

But how many astron posts are there on this thread ?

Answer: 6
Total Posts: 125
% of astroron posts: 4.8%

Conclusion: I want to see more astroron views on these threads !! .. Please … pretty please ?
:lol::)

Cheers

[snas]

Oh, come on Craig, I has hoping this thread would hit the 200 replies mark.

Stuart :D

[Suzy]

You've finished it?! And I was just about to make a comment on how this surely must be the highest posted/viewed thread in the "Serious Astro Businesss" dept, uhm meant Science Forum.:lol: Can't believe how long this thread ran for.:eyepop: I see I have some reading on this thread to catch up on.

Hello Craig & Carl & Stephen :hi:I haven't visited this section for a while as I have been busy memorising star names :rolleyes:. Why oh why does each star have two names. :rolleyes: My brain was getting too congested learning astro physics at the same time. :confused2:. Looking forward to catching up on some reading here again. Keep up the good work :thumbsup:.

[renormalised]

Most stars have far many more names than just two :)

[Suzy]

Please don't confuse me further ...:confused2: for I am just a weak, struggling, apperture challenged, overly light polluted, beginner. :shrug: ;) :lol:
Are you talking about the numbering system, Carl? I don't need to know that (do I :question:), but you do :P For now I'll stay happy knowing for example that Avior is also called Epsilon Carinae.:D

Sorry Mr Moderators, back on topic.

[renormalised]

Avior = Epsilon Carinae = HR 3307, CD−59°1032, HD 71129, SAO 235932, FK5 315, HIP 41037, GC 11463, CCDM J08225-5931:):P

( And, does it have a planet/s orbiting in the system??....haven't a clue and probably not:) )

[sjastro]

Hi Suzy.:hi:

My name is spelt Steven.
That's OK however as I have been called a lot worse with very different spelling.;)

Back to topic.

Regards

Steven

[Suzy]

I knew that :ashamed: but my typing fingers had other ideas. :screwy::lol:
Apologies Steven and thanks for bringing it to my attention. :) I hate it when I say Suzanne and people say Susan back to me. :screwy:.

Back on topic. :D

[lone77star]

The one problem with red dwarfs is that for a planet to get enough warmth it needs to nuzzle in real close. But that puts the planet at the mercy of the star's gravitational tidal effects, effectively slowing or stopping the planet's rotation relative to its sun.

With one face always to its sun, a planet like Earth would likely develop life only in the twilight zone near the terminator or sunset line. It's doubtful that such planets would yield intelligent life and civilizations.

The one big exception to this would involve twin planets where both worlds force a rotation relative to their sun. They may not get tired of each other's face, and that helps to spread the heat around, making them indeed more Earth-like. Of course, such twin-Earths are likely to be extremely rare -- the right size and the right distance from their parent star.

[Barrykgerdes]

Hi Steven
The spelling of "stephen" as a proper name is often a cause of error. The name has many variations in most languages.

When I was young the standard was that if it was a christian name it was spelled Stephen and if it was used in a surname it was spelled Steven. However as it is used as a proper name always to my knowledge the spelling is entirely at the perogative of the "owner"

So Hi Steven

Barry

PS made it 2000 posts