A very basic question...

"Marcel Kuijper" wrote:

[snip]
But that's not even that important.
The question is: could life exist outside our own planet?
Scientists say no. I say most likely to a steady yes.

Actually, scientists say "yes". See the Drake equation.

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


--
Sleepalot aa #1385

On Thu, 26 Jan 2006 23:09:38 +0100, in uk.sci.astronomy , "Marcel
Kuijper" wrote:


"Martin Brown" wrote:

A lot of chemistry necessary for life requires liquid solvents.
Chemistry in solids quickly becomes diffusion limited (pretty effects)
look up Liesgangs rings. Despite this a few things do live in rocks.

But doesn't this apply to life as "we know it"?

Yes, but it may be irrelevant. Only certain chemical combinations are
capable of the complexity and flexibility required for 'life'. This
includes the carbon-based set, and potentially a silicon-based set.


If we evolved in a certain way to survive on Earth's gentle surface, don't
you think that other, more toxic, planets harbour different lifeforms that evolved
differently than we did because they have to survive on a more harsh surface?
Isn't that how it works?

Its certainly possible, and if the universe is infinite, its certain
to have happened. However for this to be anything other than
conjecture, we would need to come up with some plausible means for it
to come about. Currently there is no such plausible means.

I'm not a nutjob, but I can't just sit here and
agree that there is no life outside of planet Earth.

I don't think anybody will disagree. What they /will/ say however is
that as yet we have no evidence for any life outside Earth, and hte
only places we could reasonably expect life to evolve are earth-like
planets, of which we have so far detected exactly zero.

Mark McIntyre
--
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it."
--Brian Kernighan

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Marcel Kuijper wrote:
If it were just ordinary humans making these claims I wouldn't think
anything of it, but when scientists start saying stuff like that

I'd like to take a moment here to point out that scientists /are/
ordinary human beings.
What, you think we're all androids, or martians?
Mark McIntyre
--
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it."
--Brian Kernighan

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"Marcel Kuijper" wrote in message
...

snip

As far as I can see, the Drake equation demostrates mathematically that
intelligent life in the universe is highly probable. The galaxies should be
teeming with races of beings more or less advanved as ourselves. The
existence of SETI (search for extraterrestrial intelligence) surely
demonstrates that astronomers and cosmologists believe they're out there and
are spending a good deal of money and effort trying to hear them.

The only negative statements made on a scientific basis are that advanced
species are not likely to have evolved on gas giants like Jupiter or Saturn,
or on super-cold sterile rocks like Pluto. Planets orbiting variable stars
may be blasted with cauterising radiation at intervals preventing the
evolution of even plants. So there are limits to what is probable and what
is even possible, but we are only just beginning to locate extra-solar
planets in quantity so let's see what turns up in the next decade.
---
TeaTime
Even a fish wouldn't get into trouble if it kept its mouth shut.

Carl Sagan made some speculation about how life might evolve on Jupiter
and/or Saturn, and thought that it might grow quite complex - though
probably not intelligent to a mammalian level.

"TeaTime" wrote in message
...

As far as I can see, the Drake equation demonstrates mathematically that
intelligent life in the universe is highly probable. The galaxies should
be
teeming with races of beings more or less advanced as ourselves. The
existence of SETI (search for extraterrestrial intelligence) surely
demonstrates that astronomers and cosmologists believe they're out there
and
are spending a good deal of money and effort trying to hear them.

The only negative statements made on a scientific basis are that advanced
species are not likely to have evolved on gas giants like Jupiter or
Saturn,
or on super-cold sterile rocks like Pluto. Planets orbiting variable
stars
may be blasted with cauterising radiation at intervals preventing the
evolution of even plants. So there are limits to what is probable and
what
is even possible, but we are only just beginning to locate extra-solar
planets in quantity so let's see what turns up in the next decade.
---
TeaTime

"Marcel Kuijper" wrote in message
...
But until we get actual proof of that, it's my belief that scientists
around the globe should stop saying that life outside planet Earth is not
possible due to factors that we humble humans could not possibly endure.

Hi Marcel, I've just finished the OU 'Astrobiology' course and no one is
saying
" ...life outside planet Earth is not possible due to factors that we
humble humans could not possibly endure...".
There's a lot we do not know but there's a lot we can work out too.
Personally I think there are a multitude of wonderful and surprising
"lifeforms" out there, but lets leave Star Trek ideas out of it for the time
being and see what we discover by observation first.
jc

Marcel Kuijper wrote:

"Martin Brown" wrote:

A lot of chemistry necessary for life requires liquid solvents.
Chemistry in solids quickly becomes diffusion limited (pretty effects)
look up Liesgangs rings. Despite this a few things do live in rocks.

But doesn't this apply to life as "we know it"?

As in "based on chemistry" yes. If you can find some life based on
coherent fluxes of neutrino particles or dark matter then good luck to you.

Microbes living deep in oceanic rock was more than a bit unexpected.
http://oceanexplorer.noaa.gov/explor.../microbes.html

If we evolved in a certain way to survive on Earth's gentle surface, don't
you think
that other, more toxic, planets harbour different lifeforms that evolved
differently
than we did because they have to survive on a more harsh surface?
Isn't that how it works?

After a fashion yes. But you still need a source of energy to drive the
system - either from the sun or from vulcanism for instance.

Mercury is deadly to us, but do we know for sure that there isn't anything
living
deep inside the planetcore? Something that got used to whatever gasses there
are on that planet?

Not much of an atmosphere on Mercury. Mars is more challenging. I'd
still be prepared to go 50:50 for life on Mars if we looked hard enough.

I'm a broad-minded individual and teachers have always considered me to be a
pain in the ass. Now so many years later, in my late thirties, my ideas and
theories
are still here and stronger than ever. I'm not a nutjob, but I can't just
sit here and
agree that there is no life outside of planet Earth.

I don't know where you get the idea that anyone is claiming this apart
from a few fundamentalist religious nutcases. The scientific position is
that we have yet to find conclusive evidence of life elsewhere. Although
personally I believe that the methane in the Mars atmosphere may well be
a smoking gun.

If we can't even get a man past the moon, what gives anyone on this planet
the
right to assume that we are alone in this galaxy, universe and beyond and
publish
that into the media for everyone to read?

Don't blame scientists for the failings of the popular press!

Do we have the perfect planet? I seriously doubt that, but it suits us fine.

You might find Barrow & Tiplers book "The Anthropomorphic Cosmological
Principle" an interesting if difficult read for a non-scientist.

That's what people said about "The Orion Mystery" by Bauval & Gilbert.
But in my experience nothing is too difficult to read.
IQ doesn't have anything to do with science. Attitude, however, does.

It discusses some of the more well founded evidence together with
conjectures about what is plausible.

I'm sure my local bookstore can order it for me so I can take a look at it.
Thanks for the tip.

Seriously borrow it by inter library loan or find a secondhand copy much
cheaper.

That isn't quite what they said. To be honest I think life in LN2 or
even liquid methane is pretty unlikely - neither of them are good enough
solvents. Super critical CO2 or NH3 and you might stand a chance. Liquid
water is by far the best solvent for life as we know it.

"Life as we know it"...there it is again!
It's funny how that keeps coming back.
That's my whole point right there and that, together with all sorts of
chemical
abbreviations, is what scientists report to the media and what everyone else
reads in the papers and listens to on the news.

If you can demonstrate some "life as we do not know it" then you are in
line for a Nobel prize. But there are some pretty tight constraints on
how chemical based life can behave based on the relative abundances of
elements in the universe and their chemical properties.

It is just possible that extremely slow chemistry at low temperatures
could produce spectacular results over the lifetime of the universe.

I've heard people say: "These scientists are the kind of people that
publically
back up Darwin and refute God, they've studied this stuff and obviously know
a thing or two about chemical reactions. If they say that there's no life
elsewhere,
then it must be true."

I don't any scientists making this claim. You are fighting a straw man.
What they do say is we have not seen evidence of life elsewhere. People
are at this moment preparing new experiments to look for life on Mars
and Europa. Both thought to be good candidates in our solar system.

Personally I laugh at people like that, the ignorant amongst our species.
I'm looking for just one scientist (astronomer, biologist, chemist,
astronaut,
bio-chemist) that has it in him/her to say: "Ya know, we just don't know for
sure
and we won't know for sure for a very long time to come."

I think you ought to look at the Drake equation then. Many scientists
will haggle about the coefficients but non that I know would ever be so
rash as to say the only life in the universe is on the Earth. Most
professional astronomers believe the exact opposite but we cannot prove it.

http://www.pbs.org/wgbh/nova/origins/drake.html

This isn't a bad introductory resource either:

http://www.resa.net/nasa/xlife_intro.htm

You might get a more complete answer in sci.astro but it could also
attract the lunatic fringe of abducted by aliens tin foil hat types.

I first posted this message in sci.space.news and it got haulted by the
moderator.

It is off topic for there.

Regards,
Martin Brown

"Sleepalot" wrote:

Actually, scientists say "yes". See the Drake equation.

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

An interesting read.


Marcel

"TeaTime" wrote in message
...

As far as I can see, the Drake equation demostrates mathematically that
intelligent life in the universe is highly probable. The galaxies should
be
teeming with races of beings more or less advanved as ourselves. The
existence of SETI (search for extraterrestrial intelligence) surely
demonstrates that astronomers and cosmologists believe they're out there
and
are spending a good deal of money and effort trying to hear them.


It's taken a significant fraction of the age of the universe - about 1/3 -
for life to evolve on this planet to the point where we're able even to
start looking for other life in the galaxy, so it's not beyind the bounds of
probability we may be among the first. While life on other planets will have
evolved to suit the local conditions perfectly, the bigger question is would
we be able to communicate in any meaningful way with it.

"Andy Guthrie" wrote in message
...

It's taken a significant fraction of the age of the universe - about 1/3 -
for life to evolve on this planet to the point where we're able even to
start looking for other life in the galaxy, so it's not beyind the bounds
of
probability we may be among the first. While life on other planets will
have
evolved to suit the local conditions perfectly, the bigger question is
would
we be able to communicate in any meaningful way with it.

That question is credible and depressing, isnt't it? But maybe they could
teach us so much ...