life on mars is impossible!! - Page 5

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serge said---> "...Especially when taking into consideration entropy?"
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Entropy is the pulling force that draws energy through the "turbines" that are our living cells. Actually that's only barely an analogy, given the interesting turbine called "F0F1 ATP-Synthase" that rotates in response to protons moving down a thermodynamic gradient across our cell membranes. It's of course more complicated than that but I like to think of life as being a suite of chemical reactions through which photons from the sun pass and which extract energy from the tendency of things to become more "disorded" (which isn't exactly the same thing as the human notion of, for example, a messy room or a meeting in which no decisions can be made). At least energetically and thermodynamically.

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serge said--->"Where everything leads toward chaos instead of organization.. Evolution seems to be nothing compared to the creation of the first living cell."
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I'm not sure what's more complicated; the chemical organization of a cell or the cellular organization of a large mammal. Chemical systems can evolve just as cellular systems can, though. If cells could evolve to mammals, I don't think it's hard to suspect that amino acids and lipids and sugars and nitrogenous bases could evolve into cells.

Regarding the likelihood of life elsewhere: Yeah, we can't give a number, but intuitively we might suspect it's pretty common. Evolution just makes so much sense, once you actually understand it. The earth isn't made out of anything particularly rare and our sun isn't a particularly unusual sun, as far as I understand it.

It's still unbelievably amazing (and almost unbelievable ) that it could lead to the complexity we see around ourselves today. The universe is perhaps programmed to be beautiful and amazing and perhaps even surprising to its own designer (if such a thing even exists).

If you take for example the intuitive biblical notion of "free will" that "god" gave humans so they could "choose good or evil" and liberate it from the trappings of 3000 year old thought processes you might be able to say something like "god made the universe with the 'free will' to self-develop using evolution as one of its tools'"

Flying all over the place here, and probably in a not very clear way, so enough..

Once you introduce God, or one particular set of religious beliefs into the equation, you start to align observation with a preconceived model.

It's dangerous, and faith should be kept separate from rational argument. (Don't be offended by the word rational, I mean deduction from observation).

I'd like to take the debate further on extra-solar-system life. With 25 million solar-system originating meteors impacting the atmosphere against 25 non-solar-system meteors, and taking into account the enormous distances and accurate angles needed, the probability of life transferring from system to system is
infinitesimally low, even compared with the low probability of the same occurring within the Solar System.

Might be a thread for biology.

to reply 82:
I do not know how long spores or freeze dried life can withstand radiation once blasted into space. But suppose our sun has a huge swarm of life infected rocks in orbit and another solar system passes by, capturing a number of this life infected rocks in its orbit. It would only take one surviving spore to properly infect a habital zone.

to reply 80:
Since cells replicate RNA so easily, what is to stop RNA from replicating outside the cell, in a sterile world? Self replcating amino acids could accumulate amino acids to create thier own buffer zone. lenght of peptide is no obstical in the cell, why would it be outside the cell?

You also have to imagine the molten earth cooling off for the first torrential rain. the entire surface would be a steam bath of energy and water (not some isolated puddle). The first water was probably super satureated with everything in that heat. RNA might have been one of the more stable chemical reactions around and found many condusive traits in that heated water.

To respond to the origianl question:
Earth has fossil bacteria in the oldest surviving sediment just after the crust cooled. So it took relatively no time at all for cells to start. It did not take a billion years, it started right off from the first opportunity. 100% chance for life forming. Why would being called mars reduce that chance?

Re Life on Earth - We're talking about 3.5 billion years ago (debatable) for the first life and 4.5 billion years ago for the formation of the solar system including the Earth.

That's a gap of a billion years. That spans the period from the late Precambrian at which time there were still only simple monocellular organisms, until the present day. The first complex organisms appeared in the Cambrian period, about 0.5 Billion years ago.

That's by no means instantaneous!

Karl and Aldeb:
Replies 83 and 82 -- a peer reviewed article of
possible interest:
http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1991Icar...94..250B&db_key=AST&high=390876040f00208

It seems if the standard models of solar system
formation are not wrong, then solar systems are
slopping spit all over the place.

to Aldebaran's reply 84:

The OLDEST sedimentary earth rock known has fossil bacteria. That means, at the first oppo9rtunity (or close to it) for water on the surface of earth, there were already cells present. Cells present! Not amino acids or peptides, full blown bacteria.

That first billion years you mention, the earth was still molten lava so obviously it doesn't count.

Multi-cellular life requires alot of energy and had to wait for a highly oxygenated atmosphere to really take off (hence the cambrian explosion). Aerobic respiration (kreb cycle) is 6x? more efficient than anerobic respiration.

Actually, there was large multi-cellular life before the cambrian and there is a recently named geologic era for this multi-cellular life (eocardian or something?) I think they hovered around the algea and blue green bacteria for oxygen.

The oldest sedimentary rock found possibly does contain traces of bacteria, if you mean the Greenland example, however, there is likely to have been sedimentary rock a long time before that/ We can tell that from derived rocks in the oldest sedimentary examples.

The oldest sedimentary rock is around 3.6 billion years old. The oldest rocks are orthogneisses found in Nigeria, and these are around 4 billion years old. Gneisses are metamorphosed sedimentary or igneous rock, so the original rock must have been older still.

They are all highly metamorphosed, however, and there is no trace of organics in these deposits. All we have are hollow impressions.

The Earth did not take a billion years to cool according to recent studies. Figures of only a hundred million years have been quoted.

[link]

So there is still a gap.

Thanks for posting that article, PB. I've always wondered about the possibility of solar systems coming close to each other.

A current theory (the Death Star or Nemesis theory) is that if a star approaches as close as 10^4 AU, it will set up a disturbance in the Oort cloud that will cause comets to 'drop' in on the inner solar system, increasing the possibility of a major extinction. This is one theory held in respect of the K/T (Cretaceous - Tertiary) boundary, but also for previous extinctions, for example the Permo-Triassic. In the first case we had mass extinction of dinosaurs.

Gray:
Reply 71;
"Hmm, perhaps I don't know what deterministic means. It's been a long time since I studied physics, but I learned that there were certain laws which allowed us to predict the outcomes of certain circumstances. You drop a ball from a tower and you can calculate it's acceleration and terminal velocity. How is a deterministic system different?"

I finally had a moment to respond...
Are you attempting to make a real point?
It has been some time, but was it when
Aristotle was teaching that you last studied
physics? Your assertions have no relevance to
any of the points at hand. If you were
attempting to make a real point, rather than
just dither, please reply.

BTW; "You drop a ball from a tower and you can calculate it's acceleration and terminal velocity"
Wrong on both counts -- you will NEVER
predict an exact acceleration or terminal
velocity in actuality (certainly not in air,
and equally not if you manage to create a
fully evacuated chamber to drop the ball in).

If you don't understand then let's wager:
you setup any conditions you like. Then drop
your ball and predict it's acceleration and
velocity to 20 significant digits, and I'll give you 10 to one odds on a $100,000 bet.

PB,
I told you it has been a long time since I studied physics, maybe even pre-aristotle if you go by the color of my hair. My point was a question really, how do you define deterministic?

Determinism is the philosophical doctrine which claims that every physical event, including human cognition and action, is causally determined by an unbroken chain of prior occurrences. The principal consequences of this doctrine are that free will is an illusion, and that the outcomes of all future events have already been determined. Determinism is associated with the ideas of Materialism and Causality. The long list of philosophers dealing with this issue includes David Hume, Thomas Hobbes, Immanuel Kant, and, more recently, John Searle.

(it is not from me by the way...)

Thanks. I had misunderstood the meaning of the word. Thank-you explaining it to me.

Life would be easier to find, under the trees...

serge: good definition, I would add one word;
from "is causally determined by an unbroken
chain of prior occurrences" to "is causally
determined by an unbroken chain of prior
physical occurrences".

gray, sorry for my harshness. I thought you
sounded like just another debunker using a
misunderstanding of physics to "disprove"
any observation one doesn't like. But you're
just questioning, and that's good.

Which statements ring false?

The probablility that there are other galaxies in the known universe.

Proof there are stars like our sun can be seen on any clear night.

The number of planets forming other solar systems is now up to a count of 112.

The likelihood that water is an abundant element throughout the universe is now known to be very high.

DNA is peculiar to one planet only, on the outer edge of one galaxy only.

Rocks are formed in a different manner, depending on different laws of different parts of the universe.

Gravity is different from place to place.

If there is life, there is only one intelligent form -- us.

Life could not exist three miles below the ocean's surface in complete darkness.

If life could exist far below the ocean's surface it could not be based upon the same building blocks for life, DNA, that we are.

Which statements ring false?

The probablility that there are other galaxies in the known universe.

Proof there are stars like our sun can be seen on any clear night.

The number of planets forming other solar systems is now up to a count of 112.

The likelihood that water is an abundant element throughout the universe is now known to be very high.

DNA is peculiar to one planet only, on the outer edge of one galaxy only.

Rocks are formed in a different manner, depending on different laws of different parts of the universe.

Gravity is different from place to place.

If there is life, there is only one intelligent form -- us.

Life could not exist three miles below the ocean's surface in complete darkness.

If life could exist far below the ocean's surface it could not be based upon the same building blocks for life, DNA, that we are.

Here are three statements that everyone would agree to;

"Life on Mars is possible"

"Life on Mars has not been proven"

"extraordinary claims require extraordinary proof"

Yawn. Your theory is sinking fast Gregory.

Theory? I don't have a theory.

Can NYONE disagree with these thre statements?

BTW, Who is posting without posting a name?

Vote early. vote often!! (not that voting here seems to make any diffrence)

[link]

Theory? I don't have a theory.

Can NYONE disagree with these thre statements?

BTW, Who is posting without posting a name?

Vote early. vote often!! (not that voting here seems to make any diffrence)

[link]