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Old 04-21-2003, 12:44 PM   #11
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Originally posted by yguy
OK, but SOME organism did. How come we can't throw some raw materials together and duplicate what happened in the beginning?
Because we don't know the exact starting condition. There are way too many variables.
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Old 04-21-2003, 01:14 PM   #12
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Originally posted by yguy
[B]Perhaps you could be so kind as to take issue with what I actually said, since I said precisely what I meant - nothing more, nothing less.
I DID.

Quantum mechanics IS just that--entirely probabilistic. What value you will get when you run an experiment once--entirely probabilistic. To test your wave function, you have to build hundreds of identical ones and test them all, and plot the distribution.

And on the small scale, EVERYTHING obeys quantum mechanics.

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Allow me to test your thinking, if you will.

If a pebble is dropped from atop a building on Earth, the distance d that it falls in time t, neglecting air resistance, is governed by the equation:

d = 1/2 gt^2, where g is Earth's gravitational constant.

True or false?
False--gravity is not constant. We approximate it as such, but it isn't really. The force of gravity is given as:

F=GmM/r^2, where G is the universal gravitational constant, m is the smaller mass, M is the larger, and r is the distance between them.

Further, the actual distance fallen is in dispute on a fine scale. There exists a certain amount of uncertainty in the posistion (and the time, and the energy change, and the momentum) of the object. THis effect is small most visible objects, but still exists.

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The correct answer is "false". Why?
Since it's only an approximation....
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Hint: the validity of the equation is irrelevant.
Hint: you're wrong.
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Old 04-21-2003, 01:17 PM   #13
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Quote:
Originally posted by yguy
OK, but SOME organism did. How come we can't throw some raw materials together and duplicate what happened in the beginning?
What raw materials? What conditions? This includes concentration of numerous chemicals, the atmospheric makeup and pressure, influx of every form of solar radiation, energy from exothermic reactions and volcanic activity...

You nail those conditions, I'm sure you can get a result.
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Really? I thought the earth was only 4 1/2 billion years old. That would be cutting things a bit close, wouldn't it?
Isn't life only 2.5 billion years old? The earth is 4.5--so you have approximately 2 billion right there.
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Old 04-21-2003, 01:26 PM   #14
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Originally posted by Jesus Tap-Dancin' Christ
I DID.
You did no such thing.

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Quantum mechanics IS just that--entirely probabilistic. What value you will get when you run an experiment once--entirely probabilistic. To test your wave function, you have to build hundreds of identical ones and test them all, and plot the distribution.

And on the small scale, EVERYTHING obeys quantum mechanics.
Fine, but that has nothing to do with what I said.

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Since it's only an approximation....
As I said, the correctness of the equation to the nth degree is not the issue. Modify it so as to provide absolute theoretical accuracy, and the answer is still false.
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Old 04-21-2003, 01:28 PM   #15
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Quote:
Originally posted by yguy
OK, but SOME organism did. How come we can't throw some raw materials together and duplicate what happened in the beginning?
Because we don't know the precise conditions that existed when life first arose. But there are scientists testing various potential scenarios.

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Really? I thought the earth was only 4 1/2 billion years old. That would be cutting things a bit close, wouldn't it?
For whom? It isn't as if there was some pre-amoeba watching the clock saying, "Oops, not time to evolve yet."
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Old 04-21-2003, 01:34 PM   #16
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Originally posted by Jesus Tap-Dancin' Christ
What raw materials?
If it were me, I'd break down the simplest known single celled organism down the the molecular level, "reshuffle the deck", and go from there.

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What conditions? This includes concentration of numerous chemicals, the atmospheric makeup and pressure, influx of every form of solar radiation, energy from exothermic reactions and volcanic activity...
What does the raw material know about volcanic activity? All it "experiences" is heat, pressure, etc. Why can't we sythesize these conditions?

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You nail those conditions, I'm sure you can get a result.
I'm not the one positing the validity of abiogenesis, pal.

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Isn't life only 2.5 billion years old? The earth is 4.5--so you have approximately 2 billion right there.
So, from the time the "process" started, it took 2 billion years for the first cells to form...and only 500 million for everything else to evolve?
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Old 04-21-2003, 01:36 PM   #17
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Originally posted by DrLao
Because we don't know the precise conditions that existed when life first arose. But there are scientists testing various potential scenarios.
Got any links?
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Old 04-21-2003, 01:47 PM   #18
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So, from the time the "process" started, it took 2 billion years for the first cells to form...and only 500 million for everything else to evolve?

Actually, I think the current theory is that life has been around for about 3.5 billion years. First prokaryotic single celled organisms, then about 1.5b years ago eukaryotic single-celled organisms, then somewhere between 1.5b-600m years ago, multicellular organisms developed.
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Old 04-21-2003, 02:06 PM   #19
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So, from the time the "process" started, it took 2 billion years for the first cells to form...and only 500 million for everything else to evolve?
Depending on who you ask - the fossil record is pretty rough back then - the first life is from about 3.5 billion years ago, and the first multicellular life from about 0.7 billion. Eukaryotes, like amoebas and us, started out sometime in the middle of those dates, but were single-celled for a long time.

As to "the first cell," here's an interesting tidbit from the present:
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In aquatic systems, the concept of the 'microbial loop' is invoked to describe the conversion of dissolved organic matter to particulate organic matter by bacteria. This process mediates the transfer of energy and matter from dissolved organic matter to higher trophic levels, and therefore controls (together with primary production) the productivity of aquatic systems. Here we report experiments on laboratory incubations of sterile filtered river water in which we find that up to 25% of the dissolved organic carbon (DOC) aggregates abiotically to particles of diameter 0.4–0.8 micrometres, at rates similar to bacterial growth. Diffusion drives aggregation of low- to high-molecular-mass DOC and further to larger micelle-like microparticles. The chemical composition of these microparticles suggests their potential use as food by planktonic bacterivores. This pathway is apparent from differences in the stable carbon isotope compositions of picoplankton and the microparticles. A large fraction of dissolved organic matter might therefore be channelled through microparticles directly to higher trophic levels—bypassing the microbial loop—suggesting that current concepts of carbon conversion in aquatic systems require revision.
From Nature 422, 150 - 154 (2003).
Hmmm, bacterium-size and -shape particles spontaneously self-assembling from the stuff that floats around in rivers....
I'm well aware that this "stuff" is detritus from living organisms, but it sure looks like another puzzle piece falling into place to me.
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Old 04-21-2003, 02:16 PM   #20
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Quote:
Originally posted by Monkeybot
I've heard, and I am by no means an expert, that the first "life" was not necessarily a cell but a self-replicating strand of RNA. So the complexity factor goes down a notch.
even simpler, the first "life" could have been a self replicating peptide. there are several such peptides that we know about.
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