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Reciprocating Bill



Posts: 4238
Joined: Oct. 2006

(Permalink) Posted: Feb. 10 2009,06:33   

Quote (RFJE @ Feb. 10 2009,06:01)
My purpose is not to be proud. You people lynched me. I was only showing you that the research is there for all to see, AND there are credentialed people in science that do not share your worldview or theory.

I don't have any doubt that there are people on this thread far more credentialed than me--far more educated in science. But I am not illiterate, and I can write, think and communicate.

My points are elementary. A second grader is quite qualified to answer the equation 2+2=4. I did not come here claiming to have solved the secrets of blackholes. It is not required that I have a PHD in biochemistry to see the problems your theory has. It only takes common sense to see some impasses.

You want to talk about humility, now you are entering into my arena of study and practice. Knowledge puffs up, but godly love edifies. Since I have been on this site I have seen nothing but arrogance and elitism. A vaunting of self and knowledge. Knowledge and wisdom are not the same. I think some of you are so full of knowledge you have no room for wisdom.

Bzzzzt.

Your play of the "humility" and "wisdom" cards is contradicted by the nauseating, presumptive arrogance of your posts. You do in fact possess a second grade education in these matters - worse, really, in that you have immersed yourself in the rotting fish-heads of creationist disinformation - yet from this stance of willful ignorance actually imagine that you are detecting and articulating problems missed, indeed hidden, by an entire community of tens of thousands of working scientists. Puffed up? You're a fucking blowfish.

If this typical of the edification supplied by godly love, please take it elsewhere. Asshole.

--------------
Myth: Something that never was true, and always will be.

"The truth will set you free. But not until it is finished with you."
- David Foster Wallace

"Here’s a clue. Snarky banalities are not a substitute for saying something intelligent. Write that down."
- Barry Arrington

  
Reciprocating Bill



Posts: 4238
Joined: Oct. 2006

(Permalink) Posted: Feb. 10 2009,06:37   

Page turn bug so soon?

--------------
Myth: Something that never was true, and always will be.

"The truth will set you free. But not until it is finished with you."
- David Foster Wallace

"Here’s a clue. Snarky banalities are not a substitute for saying something intelligent. Write that down."
- Barry Arrington

  
Schroedinger's Dog



Posts: 1691
Joined: Jan. 2009

(Permalink) Posted: Feb. 10 2009,07:07   

Oh, don't worry RB, I don't think this one will give up so easily!

I mean, He's got a chemist, and actual chemist (thanks Louis, I learned a lot), to spell it out to him, but still he comes back.

But at least, what he lacks in knowledge, he has made up for so far by engaging the "issue" in a so non-FTK way. Give him those 2 remaining strikes before we can all agree that he is a fully commited IDot.

--------------
"Hail is made out of water? Are you really that stupid?" Joe G

"I have a better suggestion, Kris. How about a game of hide and go fuck yourself instead." Louis

"The reason people use a crucifix against vampires is that vampires are allergic to bullshit" Richard Pryor

   
Spottedwind



Posts: 83
Joined: Aug. 2008

(Permalink) Posted: Feb. 10 2009,07:09   

Great post Louis. Though I have to say that the stand out part for me was:

 
Quote (Louis @ Feb. 09 2009,16:47)

Also, I have added a few links to Wikipedia etc for your edification. These are simple articles with very simple information in them. I suggest them as a beginning point for your investigation, not as "proof".


Now, I'm not a big Wikipedia fan, but what I like is that you stress that it is the beginning of learning, not the end. It's not a matter of 'Here, Wikipedia says this, so it is' but a 'teach thyself' offer; which to me is even better.  I'm pretty sure the offer is lost on RFJE but such is life.

  
Louis



Posts: 6436
Joined: Jan. 2006

(Permalink) Posted: Feb. 10 2009,07:32   

Quote (Schroedinger's Dog @ Feb. 10 2009,13:07)
Oh, don't worry RB, I don't think this one will give up so easily!

I mean, He's got a chemist, and actual chemist (thanks Louis, I learned a lot), to spell it out to him, but still he comes back.

But at least, what he lacks in knowledge, he has made up for so far by engaging the "issue" in a so non-FTK way. Give him those 2 remaining strikes before we can all agree that he is a fully commited IDot.

But I skipped over the really beautiful detail (one reason the technical post on bonding I want to do for Lou is taking me so long is because I am NOT skipping the detail. I want to do a good job. Sorry Lou).

If the guy is struggling at the differences between amino acid, amide/peptide bond, dipeptide/short chain polypeptide, and long chain polypeptide/protein or primary structure vs tertiary structure then what the hell is the point of discussing real mechanistic detail with him?* Bond strengths, rate constants, quantum mechanics and delocalisation, all of these and more illuminate the topic of abiogenesis wonderfully. It's vastly more detailed and complex than a few words from a numpty like me.

I know I bang on about it, but if anyone takes the time to understand the Soai reaction's kinetics it is truly fascinating. If anyone has read Godel, Escher, Bach by Douglas Hofstadter (or any of his other stuff about strange loops etc) then it will be immediately obvious how relevant it is. The detail really is fun, it's not just for chemistry geeks like me.

Louis

*The occasional chemdraw scheme isn't too much of an imposition, but excessive equation editor bores the absolute arse off of me, the effort is only worth it for special cases!

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Bye.

  
Doc Bill



Posts: 1005
Joined: April 2007

(Permalink) Posted: Feb. 10 2009,07:37   

Mayberry RFD,

You are right and I am wrong.

You are not illiterate.  My mistake.  Wrong word.

You are ignorant, however.

Also, I gave you a D out of charity.  Back in the day when I was teaching, if you had turned in on a test what you wrote, I would have failed you.

So, I'm taking back the D and giving you an F.

But, I'm not done yet!

Should you return, please explain the importance of "common sense" in science.  Start with the Observable Fact that the Sun rises in the east, sets in the west and the Earth observably does not move much less rotate at a rate of 1000 miles per hour.  Then, using common sense, describe or prove a heliocentric system of sun and planets, and that the Earth moves and rotates.

Thank you for playing Common Sense 101.

p.s.  There will be a quiz on Monday.

  
Louis



Posts: 6436
Joined: Jan. 2006

(Permalink) Posted: Feb. 10 2009,07:46   

Quote (Spottedwind @ Feb. 10 2009,13:09)
Great post Louis. Though I have to say that the stand out part for me was:

Quote (Louis @ Feb. 09 2009,16:47)

Also, I have added a few links to Wikipedia etc for your edification. These are simple articles with very simple information in them. I suggest them as a beginning point for your investigation, not as "proof".


Now, I'm not a big Wikipedia fan, but what I like is that you stress that it is the beginning of learning, not the end. It's not a matter of 'Here, Wikipedia says this, so it is' but a 'teach thyself' offer; which to me is even better. I'm pretty sure the offer is lost on RFJE but such is life.

The point is lost on the RFJEs/Denials/FTKs/etc of this world.

It's always the thing that annoys me with creationists/denialists of any species: claim humility on their part, claim arrogance on the part of scientists, claim persecution by an elite and then spout off about a topic they clearly know nothing about or make egregious errors and refuse to correct them. It's not like it's restricted to the "foot soldiers" either, the Hams and Dembskis of the creationist world do this too.

I don't go to bible websites and tell them the bible proves Jesus was a llama and then claim persecution when they (quite rightly) excoriate me. In fact I don't go to bible websites at all! They just have to learn that their ignorance is not as good as anyone else's knowledge.

Well, they just have to learn!

Louis

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Bye.

  
J-Dog



Posts: 4361
Joined: Dec. 2006

(Permalink) Posted: Feb. 10 2009,07:53   

Hip Hip Hurray and Huzzah to everyone on this thread - I think it proves the InterTubes do work...

I nominate this entire thread for teh coveted Thread Of The Week Award , (which I just invented) and would like it submitted to the Noble and Pullitzer Committees and of course the Smithsonian and British Museums, and for Schrodingers Dog, La Cit des Sciences et de l'Industrie.

Congratulations to you all.

added in edit:  And send it to AIG - "Arguments Not To Use Cuz You'll Look Teh Stoopids."

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Come on Tough Guy, do the little dance of ID impotence you do so well. - Louis to Joe G 2/10

Gullibility is not a virtue - Quidam on Dembski's belief in the Bible Code Faith Healers & ID 7/08

UD is an Unnatural Douchemagnet. - richardthughes 7/11

  
Schroedinger's Dog



Posts: 1691
Joined: Jan. 2009

(Permalink) Posted: Feb. 10 2009,08:20   

Quote (Louis @ Feb. 10 2009,07:32)
Quote (Schroedinger's Dog @ Feb. 10 2009,13:07)
Oh, don't worry RB, I don't think this one will give up so easily!

I mean, He's got a chemist, and actual chemist (thanks Louis, I learned a lot), to spell it out to him, but still he comes back.

But at least, what he lacks in knowledge, he has made up for so far by engaging the "issue" in a so non-FTK way. Give him those 2 remaining strikes before we can all agree that he is a fully commited IDot.

But I skipped over the really beautiful detail (one reason the technical post on bonding I want to do for Lou is taking me so long is because I am NOT skipping the detail. I want to do a good job. Sorry Lou).

If the guy is struggling at the differences between amino acid, amide/peptide bond, dipeptide/short chain polypeptide, and long chain polypeptide/protein or primary structure vs tertiary structure then what the hell is the point of discussing real mechanistic detail with him?* Bond strengths, rate constants, quantum mechanics and delocalisation, all of these and more illuminate the topic of abiogenesis wonderfully. It's vastly more detailed and complex than a few words from a numpty like me.

I know I bang on about it, but if anyone takes the time to understand the Soai reaction's kinetics it is truly fascinating. If anyone has read Godel, Escher, Bach by Douglas Hofstadter (or any of his other stuff about strange loops etc) then it will be immediately obvious how relevant it is. The detail really is fun, it's not just for chemistry geeks like me.

Louis

*The occasional chemdraw scheme isn't too much of an imposition, but excessive equation editor bores the absolute arse off of me, the effort is only worth it for special cases!

Louis, I trully admire your commitment.

I only wish MY teachers were so good at their job.

RFJE should be gratefull for that. I am but a humble entertainer, going "down" in the Blipey class (Blipey, nothing diminishing there, I was merely pointing out the fact that non-scientists can be quite smart and informed), But even I, so simple and basicaly unbiased, can see where the evidence points, and the way it points is nowhere near what RFJE thinks/says/extrapolates...

Taking out the blindfolds would be a nice start, RFJE...

--------------
"Hail is made out of water? Are you really that stupid?" Joe G

"I have a better suggestion, Kris. How about a game of hide and go fuck yourself instead." Louis

"The reason people use a crucifix against vampires is that vampires are allergic to bullshit" Richard Pryor

   
Dr.GH



Posts: 1954
Joined: May 2002

(Permalink) Posted: Feb. 10 2009,08:33   

Quote (RFJE @ Feb. 09 2009,19:41)
The other point is left handed amino acids--only produced in organisms. Miller's random (with intelligent help) experiment produced left handed and mirror imaged AA which can not produce organic protein.[I]

Do I get an A for effort guys?

Before this new one runs away;

Regarding chirality (which creationists like to pontificate about without the slightest idea of what it means), there is actually no problem at all.

L-amino acids are not the only form of AAs used.

Pasteur discovered that most amino acids came in two forms which can be identified by how they refract light. We label theses L- (for levo or left) and D- (for dextro, or right). The interesting thing is that life on Earth uses the L form of amino acids, and hardly ever uses the D- form. A solution of just one form is called "chiral" and a mix of forms about 50/50 is called racimic. The kinds (L or D) are called enantomers.

The nucleic acid bases are also found in L- and D- forms, only in this case life on Earth only uses the D- form.

Creationists like to present this as a profound mystery that is supposed to "prove" that they are correct. I want to mention a neat instance where both left and right amino acids are used in a living thing. It seems at first to be very rare, but it does happen. Next time a creationist claims to be an "expert" and that amino acid chirility "proves" something supernatural, you can gob-smack-em. I have found that even many biologists will bet an "adult beverage" that all proteins are exclusive L- amino acids. The protein is called Gramicidin A and it has 8 L-amino acids, 6 D-amino acids, and one glycine which is an amino acid that is neither L- or D- in its structure. Gramicidin A links to itself and forms a transmenbrane pore. An important feature of these short racemic peptides is that they always form a helix.

Before we go forward another couple of basic chemical facts need to be added to the discussion. First, L- amino acids will randomly convert to D- amino acids over time, and D- forms will convert to L- forms. This is called "racimization" because eventually you will end up with equal amounts of L- and D- amino acids. The rate that this occurs at varies with the amino acid, and its surroundings. The fastest conversion happens to amino acid molecules all by themselves in hot water. Under cold, dry conditions when the amino acids are attached to one another, or better yet, if they are also attached to a mineral, racimization can be very slow. Very, very slow.

This means that if there is even a tiny advantage one way or the other, the favored form will become the dominant form. The advantage comes from a surprising direction: outer space.

Cronin, J. R. & Pizzarello, S., 1999. Amino acid enantomer excesses in meteorites: Origin and significance. Advances in Space Research 23(2): 293-299.

Service, RF, 1999. Does life's handedness come from within? Science 286: 1282-1283.

Antonio Chrysostomou, T. M. Gledhill,1 Fransois Mnard, J. H. Hough, Motohide Tamura and Jeremy Bailey 2000 "Polarimetry of young stellar objects -III. Circular polarimetry of OMC-1" Monthly Notices of the Royal Astronomical Society Volume 312 Issue 1 Page 103 - February

Michael H. Engel and Bartholomew Nagy, 1982 "Distribution and Enantiomeric Composition of Amino Acids in the Murchison Meteorite", Nature , 296, April 29, , p. 838.

Jeremy Bailey, Antonio Chrysostomou, J. H. Hough, T. M. Gledhill, Alan McCall, Stuart Clark, Franois Mnard, and Motohide Tamura 1998 Circular Polarization in Star- Formation Regions: Implications for Biomolecular Homochirality Science 1998 July 31; 281: 672-674. (in Reports)

Chyba, Christopher F. 1997 Origins of life: A left-handed Solar System? Nature 389, 234- 235 (18 Sep 1997)

Engel, M. H., S. A. Macko 1997 Isotopic evidence for extraterrestrial non- racemic amino acids in the Murchison meteorite. Nature 389, 265 - 268 (18 Sep) Letters to Nature

That should do for that. The next question is can the advantage of L- amino acids be conserved in the formation of more complex molecules called "peptides?" Yep.

Schmidt, J. G., Nielsen, P. E. & Orgel, L. E. 1997 Enantiomeric cross- inhibition in the synthesis of oligonucleotides on a nonchiral template. J. Am. Chem. Soc. 119, 1494-1495

Saghatelion A, Yokobayashi Y, Soltani K, Ghadiri MR, 2001"A chiroselective peptide replicator", Nature 409: 797-51, Feb

Singleton, D A,& Vo, L K, 2002 "Enantioselective Synthsis without Discrete Optically Active Additives" J. Am. Chem. Soc. 124, 10010-10011

Yao Shao, Ghosh I, Zutshi R, Chmielewski J. 1998 Selective amplification by auto- and cross-catalysis in a replicating peptide system. Nature. Dec 3;396(6710):447-50.

And there seems to be other L- selection advantages as well. For example:

Hazen, R.M., T.R. Filley, and G.A. Goodfriend. 2001. Selective adsorption of L- and D-amino acids on calcite: Implications for biochemical homochirality. Proceedings of the National Academy of Sciences 98(May 8):5487.

So chirility doesn't seem to be a big problem. This is far different from the way creationists present this. They cite a few out of date reports and then falsely claim that chiral life is impossible by natural means.

There are larger arguments for a racemic origin of life.

Edward Trifonov (2004) confirmed two ideas, that the earliest amino acids were those easiest to form abiotically, that codons and aa's organized contemporaneously to form short ogliomers (what he didn't cite was the notion that oligomers can form spontaneously, are "selected" merely by being stable, and that RNAs (or Lacanzo and Miller's PNAs) imprint and replicate "successful" short peptides.) Trifonov wrote, "The amino-acid chronology itself is a quintessence of natural simplicity and opportunism: use first those amino acids that are available. When done with all codons, take from those amino acids that have too many."

The fact is that there are a growing list of short proteins with D- aa's, (most of the ones I know of are bacterial membrane components but there are also examples from yeasts to humans). Add to this, most bacteria have evolved enzymes that convert L-aa's to D-aa's for the same Miller/prebiotic amino acids. Again even we humans have enzymes to use D-aa's.

ETA: I forgot to include two citations:

Lazcano, Antonio, Stanley L. Miller
1996 The Origin and Early Evolution of Life: Prebiotic Chemistry, the Pre-RNA World, and Time Cell vol 85:793-798


Trifonov, Edward N.
2004 "The Triplet Code From First Principles" Journal of Biomolecular Structure & Dynamics, ISSN 0739-1102 Volume 22, Issue Number 1, (2004)




Edited by Lou FCD on Feb. 10 2009,13:23

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"Science is the horse that pulls the cart of philosophy."

L. Susskind, 2004 "SMOLIN VS. SUSSKIND: THE ANTHROPIC PRINCIPLE"

   
Richard Simons



Posts: 425
Joined: Oct. 2006

(Permalink) Posted: Feb. 10 2009,08:35   

Quote (RFJE @ Feb. 10 2009,05:01)
My purpose is not to be proud. You people lynched me.

The reaction you got is the normal reaction to be expected when a complete know-nothing comes blasting in, convinced that they have all the answers and that the scientists are completely ignorant on the subject they have spent decades studying.
Quote
I was only showing you that the research is there for all to see, AND there are credentialed people in science that do not share your worldview or theory.

Do you seriously think that we are not aware of these people that those on the creation/ID side believe to be credentialed and therefore correct? And you accuse us of arrogance!
Quote

My points are elementary.

So why did you assume that no-one has considered them?
Quote
It is not required that I have a PHD in biochemistry to see the problems your theory has.

Interestingly, even people with PhDs have failed to find problems in the theory of evolution. In fact, the better a person is informed on the topic, the less likely they are to have problems with it.
Quote
You want to talk about humility, now you are entering into my arena of study and practice.

I recall you've said you've been a missionary. In my opinion, nobody is as arrogant as a missionary. Imagine, that of the thousands of religions around, you have found the one true one and are sufficiently convinced that you have the urge to convert all others. What could possibly be more arrogant?

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All sweeping statements are wrong.

  
Kristine



Posts: 3037
Joined: Sep. 2006

(Permalink) Posted: Feb. 10 2009,08:52   

His purpose was to be a martyr, which he has accomplished.

You have to have a little bitty bit of experience with the "Darwinists," just like the totally canned "missionary experience." It's street cred - then you can go back to tell your grandchildren all about how you battled the forces of evil.

(Yes, I saw the missionary experience, not in Africa, in Jamaica. What a waste, compared to what my organization was doing - but we actually had to consult with the Jamaican people we were working with as equals! The missionaries sat in a circle and talked about God and hauled rocks around; we connected a computer network so that the kids at York Castle High could teleconference with the kids at St. Paul Academy. )

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Which came first: the shimmy, or the hip?

AtBC Poet Laureate

"I happen to think that this prerequisite criterion of empirical evidence is itself not empirical." - Clive

"Damn you. This means a trip to the library. Again." -- fnxtr

  
Louis



Posts: 6436
Joined: Jan. 2006

(Permalink) Posted: Feb. 10 2009,08:53   

Quote (J-Dog @ Feb. 10 2009,13:53)
Hip Hip Hurray and Huzzah to everyone on this thread - I think it proves the InterTubes do work...

I nominate this entire thread for teh coveted Thread Of The Week Award , (which I just invented) and would like it submitted to the Noble and Pullitzer Committees and of course the Smithsonian and British Museums, and for Schrodingers Dog, La Cit des Sciences et de l'Industrie.

Congratulations to you all.

added in edit: And send it to AIG - "Arguments Not To Use Cuz You'll Look Teh Stoopids."

Thread of the week? Does it last for a whole hour?

Louis

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Bye.

  
J-Dog



Posts: 4361
Joined: Dec. 2006

(Permalink) Posted: Feb. 10 2009,09:29   

Quote (Louis @ Feb. 10 2009,08:53)
Quote (J-Dog @ Feb. 10 2009,13:53)
Hip Hip Hurray and Huzzah to everyone on this thread - I think it proves the InterTubes do work...

I nominate this entire thread for teh coveted Thread Of The Week Award , (which I just invented) and would like it submitted to the Noble and Pullitzer Committees and of course the Smithsonian and British Museums, and for Schrodingers Dog, La Cit des Sciences et de l'Industrie.

Congratulations to you all.

added in edit: And send it to AIG - "Arguments Not To Use Cuz You'll Look Teh Stoopids."

Thread of the week? Does it last for a whole hour?

Louis

No - For the entire year, IMO. This thread will be hard to top.
As a matter of fact, the next time I run into my former state Senator, I will ask him to put this in ALL the text books as an example of How To Do It Right. I think Barack will agree.

You have obviously confused the Post Of The Week with the Much More Prestigious Thread Of The Week...

edited for sp

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Come on Tough Guy, do the little dance of ID impotence you do so well. - Louis to Joe G 2/10

Gullibility is not a virtue - Quidam on Dembski's belief in the Bible Code Faith Healers & ID 7/08

UD is an Unnatural Douchemagnet. - richardthughes 7/11

  
Louis



Posts: 6436
Joined: Jan. 2006

(Permalink) Posted: Feb. 10 2009,09:46   

Quote (J-Dog @ Feb. 10 2009,15:29)
Quote (Louis @ Feb. 10 2009,08:53)
 
Quote (J-Dog @ Feb. 10 2009,13:53)
Hip Hip Hurray and Huzzah to everyone on this thread - I think it proves the InterTubes do work...

I nominate this entire thread for teh coveted Thread Of The Week Award , (which I just invented) and would like it submitted to the Noble and Pullitzer Committees and of course the Smithsonian and British Museums, and for Schrodingers Dog, La Cit des Sciences et de l'Industrie.

Congratulations to you all.

added in edit: And send it to AIG - "Arguments Not To Use Cuz You'll Look Teh Stoopids."

Thread of the week? Does it last for a whole hour?

Louis

No - For the entire year, IMO. This thread will be hard to top.
As a matter of fact, the next time I run into my former state Senator, I will ask him to put this in ALL the text books as an example of How To Do It Right. I think Barack will agree.

You have obviously confused the Post Of The Week with the Much More Prestigious Thread Of The Week...

edited for sp

But surely in AtBC-world more prestige = less time. So the prestigious POTW can last for hours, maybe even days, and as TOTW is even more prestigious it should possibly last for minutes. Just think POTY could last for picoseconds...

;-)

Louis

P.S. I think the POTUS has more important issues on his hands than POTW. Like being funky for one (sorry, I've been reading Sinfest again).

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Bye.

  
noncarborundum



Posts: 320
Joined: Jan. 2009

(Permalink) Posted: Feb. 10 2009,10:30   

Quote (Richard Simons @ Feb. 10 2009,08:35)
 
Quote (RFJE @ Feb. 10 2009,05:01)
You want to talk about humility, now you are entering into my arena of study and practice.

I recall you've said you've been a missionary. In my opinion, nobody is as arrogant as a missionary. Imagine, that of the thousands of religions around, you have found the one true one and are sufficiently convinced that you have the urge to convert all others. What could possibly be more arrogant?

Ah, but you misconstrue his point. His area of expertise is not the practice of humility, it's the regurgitation of aphorisms about humility.
 
Quote
Knowledge puffs up, but godly love edifies.

See?

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"The . . . um . . . okay, I was genetically selected for blue eyes. I know there are brown eyes, because I've observed them, but I can't do it. Okay? So . . . um . . . coz that's real genetic selection, not the nonsense Giberson and the others are talking about." - DO'L

  
Lou FCD



Posts: 5377
Joined: Jan. 2006

(Permalink) Posted: Feb. 10 2009,12:26   

Quote (Louis @ Feb. 09 2009,16:47)
**LENGTH AND SLIGHT CHEMISTRY WARNING**

Dear RFJE,

As Ive said already Hello and Welcome, I hope you have a productive and enjoyable time here at AtBC. Im always amused when people come in espousing well refuted canards, erroneous nonsense, and generally being unpleasant. Especially when they then complain that they are somehow persecuted by the less than pleasant replies such behaviour engenders.

I am, however, for the moment going to ignore all that nonsense and focus on the chemical claims you make. Im also going to ignore the philosophical and biological errors you make re: origin of life/naturalism/evolution. Others can deal with those if they like. What Im going to do is make a break down of your chemical claims to make sure I have them correct:

 
Quote
Observable Chemistry Fact #1

Presence of water is a problem: Some amino acids break down in water by the process called hydrolysis. It actually breaks the bonds of the amino acids preventing them from forming the chains that build proteins. Stanley Miller, who attempted to create life in a test tube in the early 1950's, knew this, and isolated the products in order to avoid this destructive reaction.


a) Amino acids do not simply break down in aqueous solution at any appreciable rate at room temperature (and in the absence of other reagents), nor indeed do dipeptides or polypeptides. You can in fact buy aqueous solutions of most amino acids. The hydrolysis of the amide bond is comparatively difficult to achieve, normally requiring more forcing conditions (strong acid or base, or powerful nucleophiles etc). I think what you are trying to get at is that formation of the peptide/amide bond, which since it is a condensation reaction (i.e. the formation of an amide results in the elimination of a small molecule like water), is hindered by the presence of water. Below I have drawn a simple amino acid and a simple dipeptide (no solution structure is implied) to illustrate the difference for you.



Unfortunately, you are clearly unaware of very basic methods in chemical synthesis. Even though these are not claimed to be the precise routes taken during abiogenesis, they clearly demonstrate that water is not necessarily a hurdle to amide synthesis. Take for example the Schotten
-Baumann conditions for peptide synthesis. This is where a biphasic mixture of solvents, one of which is water and the other a water immiscible organic solvent, are used. The simplistic treatment of the various methods of peptide synthesis as equilibrium processes, and hence trivially subject to Le Chatelier's principle, misses many of the other thermodynamic and kinetic factors and is, in this case at least, erroneous.

Solid phase methods of peptide synthesis or use of activating agents like various carbodiimides etc can also be performed in the presence of water. Water isnt the problem you think it is. Not only that, aqueous phase syntheses of simple poly/dipeptides are not the only methods proposed for the origins of these sorts of molecules.

b) The Miller-Urey experiment included water as part of the design. The last bit of your claim is mistaken.

 
Quote
Observable Chemistry Fact #2

Presence of Oxygen: Stanley Miller purposely left out oxygen in his experiment. Why? Because he knew that oxygen would be corrosive and tend to destroy the organic compounds for life.

Some scientists have suggested that the early earth's atmosphere did not contain oxygen, but then the atmosphere would have had no ozone layer to sheild the compounds from the ultraviolet rays of the sun---a catch 22 for evolutionists. ALso, is there any evidence for a non-oxygen atmosphere?


a) Oxygen was purposely left out if the Miller-Urey because the best evidence at the time strongly suggested that the early atmosphere had no oxygen in it. Oxygen is a pollutant produced by organisms. What Miller and Urey were trying to do was see if simple molecules like amino acids etc could be produced by conditions similar to those proposed on the early earth. Many other experiments of this type have been performed, testing various hypothetical early earth scenarios.

b) Lack of stratospheric ozone is not a problem because UV radiation is not only destructive. It is also positively useful. Many complex molecules exist in space (in conditions of vastly greater UV radiation), not only that but UV can promote certain reactions. For example the formose reaction is positively aided by UV radiation.

c) Evidence for the early atmosphere being free of oxygen is found in the composition of rocks dated back to the Siderian period of the Precambrian.

Quote
ANOTHER SIGNIFIGANT PROBLEM

Amino acids in living things

1. There are 2000 types amino acids, of which are only 20 are found in living things. We're talking mathematics working against it now.


a) There are vastly more than 2000 possible amino acid types, another basic chemical misunderstanding on your part. The fact that 22 proteinogenic amino acids (plus a few non-proteinogenic ones) are commonly found in modern organisms, is not a mathematical problem for evolutionary biology or abiogenesis. This is no more a problem than the fact that my route to the pub commonly involves me walking via the park rather than via Uzbekistan. Firstly, like my route to the pub, many of the amino acids found in modern organisms are relatively simple (i.e. the R group side chain is not 16 Buckminster-fullerenes linked into a Borromean ring system, its a methyl or tolyl group etc). If I were to take a pack of a billion cards and deal 22, that specific 22 card hand is no more or less improbable than any other 22 card hand. There may be reasons the 22 proteinogenic amino acids are the ones we find in modern organisms (thermodynamic stability, specific reactivity etc) but these are very complex and dependant on the chemical environment of the time.

Quote
2. THE BIGGEST PROBLEM--All amino acids come in left and right handed forms called "enantiomers." Living things have only the left handed amino acids. When Stanley Miller attempted life in a test tube, he produced only a racemic mixture of right and left handed amino acids that is detrimental to life.


a) There are a myriad of perfectly natural ways for homochirality to arise. Not least is autocatalysis (an example, again not specifically related to abiogenesis, but very indicative is my favourite the Soai reaction). Many other ways like crystal templating and chiral transmission etc. Not only that but once homochiral self-replicating systems like those actually proposed for abiogenesis exist then maintenance of homochirality is evolutionarily more favourable.

b) Again, Miller and Urey were not trying to create life in a test tube, they were trying to discover if simple molecules that are the building blocks of life could be produced by the conditions proposed for the early earth at the time. They could, and were. Miller and Urey did what they were trying to do.

In conclusion, might I suggest that, instead of posting well refuted common misunderstandings of science on message boards, your missionary zeal inspired thirst for knowledge, if it actually exists, would be better served by some time in the library. As I recommended to Daniel Smith, there is a very good book on the current state of abiogenesis research by Pierre Luigi Luisi called The Emergence of Life. I also recommend a couple of basic chemistry courses BEFORE you tackle that book.

Also, I have added a few links to Wikipedia etc for your edification. These are simple articles with very simple information in them. I suggest them as a beginning point for your investigation, not as "proof". As you claim to be a well read layman, it would behove you familiarise yourself with the very basic elements of the science you claim is in error because it contradicts your religious faith. A quick search of the internet, a medium you clearly have access to, would have disabused you of the fallacious claims you make re: abiogenesis.

Thanks

Louis

ETA: Several edits for formatting etc. More may be needed. Also, RFJE, I have a lot of experience dealing with creationists and I operate a "three strikes" policy. Demonstrate a modicum of intellectual honesty and engagement and I'll happily spend my valuable time explaining things and debating.


 
Quote (Dr.GH @ Feb. 10 2009,09:33)
Quote (RFJE @ Feb. 09 2009,19:41)
The other point is left handed amino acids--only produced in organisms. Miller's random (with intelligent help) experiment produced left handed and mirror imaged AA which can not produce organic protein.[I]

Do I get an A for effort guys?

Before this new one runs away;

Regarding chirality (which creationists like to pontificate about without the slightest idea of what it means), there is actually no problem at all.

L-amino acids are not the only form of AAs used.

Pasteur discovered that most amino acids came in two forms which can be identified by how they refract light. We label theses L- (for levo or left) and D- (for dextro, or right). The interesting thing is that life on Earth uses the L form of amino acids, and hardly ever uses the D- form. A solution of just one form is called "chiral" and a mix of forms about 50/50 is called racimic. The kinds (L or D) are called enantomers.

The nucleic acid bases are also found in L- and D- forms, only in this case life on Earth only uses the D- form.

Creationists like to present this as a profound mystery that is supposed to "prove" that they are correct. I want to mention a neat instance where both left and right amino acids are used in a living thing. It seems at first to be very rare, but it does happen. Next time a creationist claims to be an "expert" and that amino acid chirility "proves" something supernatural, you can gob-smack-em. I have found that even many biologists will bet an "adult beverage" that all proteins are exclusive L- amino acids. The protein is called Gramicidin A and it has 8 L-amino acids, 6 D-amino acids, and one glycine which is an amino acid that is neither L- or D- in its structure. Gramicidin A links to itself and forms a transmenbrane pore. An important feature of these short racemic peptides is that they always form a helix.

Before we go forward another couple of basic chemical facts need to be added to the discussion. First, L- amino acids will randomly convert to D- amino acids over time, and D- forms will convert to L- forms. This is called "racimization" because eventually you will end up with equal amounts of L- and D- amino acids. The rate that this occurs at varies with the amino acid, and its surroundings. The fastest conversion happens to amino acid molecules all by themselves in hot water. Under cold, dry conditions when the amino acids are attached to one another, or better yet, if they are also attached to a mineral, racimization can be very slow. Very, very slow.

This means that if there is even a tiny advantage one way or the other, the favored form will become the dominant form. The advantage comes from a surprising direction: outer space.

Cronin, J. R. & Pizzarello, S., 1999. Amino acid enantomer excesses in meteorites: Origin and significance. Advances in Space Research 23(2): 293-299.

Service, RF, 1999. Does life's handedness come from within? Science 286: 1282-1283.

Antonio Chrysostomou, T. M. Gledhill,1 Fransois Mnard, J. H. Hough, Motohide Tamura and Jeremy Bailey 2000 "Polarimetry of young stellar objects -III. Circular polarimetry of OMC-1" Monthly Notices of the Royal Astronomical Society Volume 312 Issue 1 Page 103 - February

Michael H. Engel and Bartholomew Nagy, 1982 "Distribution and Enantiomeric Composition of Amino Acids in the Murchison Meteorite", Nature , 296, April 29, , p. 838.

Jeremy Bailey, Antonio Chrysostomou, J. H. Hough, T. M. Gledhill, Alan McCall, Stuart Clark, Franois Mnard, and Motohide Tamura 1998 Circular Polarization in Star- Formation Regions: Implications for Biomolecular Homochirality Science 1998 July 31; 281: 672-674. (in Reports)

Chyba, Christopher F. 1997 Origins of life: A left-handed Solar System? Nature 389, 234- 235 (18 Sep 1997)

Engel, M. H., S. A. Macko 1997 Isotopic evidence for extraterrestrial non- racemic amino acids in the Murchison meteorite. Nature 389, 265 - 268 (18 Sep) Letters to Nature

That should do for that. The next question is can the advantage of L- amino acids be conserved in the formation of more complex molecules called "peptides?" Yep.

Schmidt, J. G., Nielsen, P. E. & Orgel, L. E. 1997 Enantiomeric cross- inhibition in the synthesis of oligonucleotides on a nonchiral template. J. Am. Chem. Soc. 119, 1494-1495

Saghatelion A, Yokobayashi Y, Soltani K, Ghadiri MR, 2001"A chiroselective peptide replicator", Nature 409: 797-51, Feb

Singleton, D A,& Vo, L K, 2002 "Enantioselective Synthsis without Discrete Optically Active Additives" J. Am. Chem. Soc. 124, 10010-10011

Yao Shao, Ghosh I, Zutshi R, Chmielewski J. 1998 Selective amplification by auto- and cross-catalysis in a replicating peptide system. Nature. Dec 3;396(6710):447-50.

And there seems to be other L- selection advantages as well. For example:

Hazen, R.M., T.R. Filley, and G.A. Goodfriend. 2001. Selective adsorption of L- and D-amino acids on calcite: Implications for biochemical homochirality. Proceedings of the National Academy of Sciences 98(May 8):5487.

So chirility doesn't seem to be a big problem. This is far different from the way creationists present this. They cite a few out of date reports and then falsely claim that chiral life is impossible by natural means.

There are larger arguments for a racemic origin of life.

Edward Trifonov (2004) confirmed two ideas, that the earliest amino acids were those easiest to form abiotically, that codons and aa's organized contemporaneously to form short ogliomers (what he didn't cite was the notion that oligomers can form spontaneously, are "selected" merely by being stable, and that RNAs (or Lacanzo and Miller's PNAs) imprint and replicate "successful" short peptides.) Trifonov wrote, "The amino-acid chronology itself is a quintessence of natural simplicity and opportunism: use first those amino acids that are available. When done with all codons, take from those amino acids that have too many."

The fact is that there are a growing list of short proteins with D- aa's, (most of the ones I know of are bacterial membrane components but there are also examples from yeasts to humans). Add to this, most bacteria have evolved enzymes that convert L-aa's to D-aa's for the same Miller/prebiotic amino acids. Again even we humans have enzymes to use D-aa's.

ETA: I forgot to include two citations:

Lazcano, Antonio, Stanley L. Miller
1996 The Origin and Early Evolution of Life: Prebiotic Chemistry, the Pre-RNA World, and Time Cell vol 85:793-798


Trifonov, Edward N.
2004 "The Triplet Code From First Principles" Journal of Biomolecular Structure & Dynamics, ISSN 0739-1102 Volume 22, Issue Number 1, (2004)



I am hereby unilaterally awarding dual PotWs.

Excellent and informative, not to mention just plain cool science.

--------------
Lou FCD is still in school, so we should only count him as a baby biologist. -carlsonjok -deprecated
I think I might love you. Don't tell Deadman -Wolfhound

Work-friendly photography
NSFW photography

   
Louis



Posts: 6436
Joined: Jan. 2006

(Permalink) Posted: Feb. 10 2009,12:37   

Quote (Lou FCD @ Feb. 10 2009,18:26)
[SNIP]

I am hereby unilaterally awarding dual PotWs.

Excellent and informative, not to mention just plain cool science.

POTW? How long for? I want at least an hour!

;-)

Louis

--------------
Bye.

  
ppb



Posts: 325
Joined: Dec. 2006

(Permalink) Posted: Feb. 10 2009,13:08   

Quote (RFJE @ Feb. 10 2009,06:01)

You want to talk about humility, now you are entering into my arena of study and practice.

You know someone has true humility when they have to point it out to you. :D

Louis, I love reading your posts. You clearly know what you are talking about, and you seem to really enjoy teaching others. You have the patience of a saint.

--------------
"[A scientific theory] describes Nature as absurd from the point of view of common sense. And it agrees fully with experiment. So I hope you can accept Nature as She is - absurd."
- Richard P. Feynman

  
J-Dog



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(Permalink) Posted: Feb. 10 2009,13:25   

Quote (ppb @ Feb. 10 2009,13:08)
 
Quote (RFJE @ Feb. 10 2009,06:01)

You want to talk about humility, now you are entering into my arena of study and practice.

You know someone has true humility when they have to point it out to you. :D

Louis, I love reading your posts. You clearly know what you are talking about, and you seem to really enjoy teaching others. You have the patience of a saint.

A saint? Louis? Well, he could look like this Saint, I guess..




For those that couldn't place it, this is actually Marcelino Ravery. Or maybe Louis at last weeks staff meeting...
he is British donchaknow, and they do take things a bit more seriously than we do here in the states.

--------------
Come on Tough Guy, do the little dance of ID impotence you do so well. - Louis to Joe G 2/10

Gullibility is not a virtue - Quidam on Dembski's belief in the Bible Code Faith Healers & ID 7/08

UD is an Unnatural Douchemagnet. - richardthughes 7/11

  
Louis



Posts: 6436
Joined: Jan. 2006

(Permalink) Posted: Feb. 10 2009,13:33   

Quote (ppb @ Feb. 10 2009,19:08)
Quote (RFJE @ Feb. 10 2009,06:01)

You want to talk about humility, now you are entering into my arena of study and practice.

You know someone has true humility when they have to point it out to you. :D

Louis, I love reading your posts. You clearly know what you are talking about, and you seem to really enjoy teaching others. You have the patience of a saint.

BWAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHAHAHAHAHAHAHA!

Sorry, I appreciate the compliment but I am a horribly impatient and intolerant person. I've just mentioned your comment to my wife, she is sending over a trained psychologist and counsellor. Taking that level of hallucinogenic drugs is not good for you.

Thanks though.

;)

Louis

ETA: Of my many great qualities I think my humility is probably my best one. ;)

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Bye.

  
JLT



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Joined: Jan. 2008

(Permalink) Posted: Feb. 10 2009,13:36   

Quote

b) Lack of stratospheric ozone is not a problem because UV radiation is not only destructive. It is also positively useful. Many complex molecules exist in space (in conditions of vastly greater UV radiation), not only that but UV can promote certain reactions. For example the formose reaction is positively aided by UV radiation.


Isn't UV also absorped by water?
I always thought that the shorter the wavelenght, the more water the light can pass through before it's filtered out. I tried to find out how deep that is for UV light and I found this list (German) with absorption coefficents for different wavelenght and the layer thickness* after which the intensity is reduced to 1/1000 of the original:

Lambda(nm) k(1/m) x(0,001)(m)
=======================================
200 ca. 7 1
250 ca. 1 7
300 ca. 0,2 35
350 ca. 0,2 35
400 ca. 0,06 110
450 ca. 0,02 350
500 ca. 0,025 280
550 ca. 0,05 140
600 ca. 0,2 35
650 ca. 0,32 22
700 ca. 0,65 11
750 ca. 2,6 2,7
800 ca. 2,0 3,5
1000 37 0,19

So, the shorter the wavelength, the deeper the light can reach seems to be true only for the visible light. According to this list UV light can't reach as deep as e.g. blue light.

Does anyone know whether that is true?
Unfortunately, the author of that list states that he found several vastly different absorption coefficents for UV light in the literature and he would provide only a "best guess".


* This isn't exactly a topic I discuss on a daily basis, so I'm not sure whether I use the correct terms. I hope it's still clear what I mean....

--------------
"Random mutations, if they are truly random, will affect, and potentially damage, any aspect of the organism, [...]
Thus, a realistic [computer] simulation [of evolution] would allow the program, OS, and hardware to be affected in a random fashion." GilDodgen, Frilly shirt owner

  
Louis



Posts: 6436
Joined: Jan. 2006

(Permalink) Posted: Feb. 10 2009,13:36   

Quote (J-Dog @ Feb. 10 2009,19:25)
Quote (ppb @ Feb. 10 2009,13:08)
Quote (RFJE @ Feb. 10 2009,06:01)

You want to talk about humility, now you are entering into my arena of study and practice.

You know someone has true humility when they have to point it out to you. :D

Louis, I love reading your posts. You clearly know what you are talking about, and you seem to really enjoy teaching others. You have the patience of a saint.

A saint? Louis? Well, he could look like this Saint, I guess..




For those that couldn't place it, this is actually Marcelino Ravery. Or maybe Louis at last weeks staff meeting...
he is British donchaknow, and they do take things a bit more seriously than we do here in the states.

Ok, I'll cough to wearing the funny dress, but a crucifix? Come ON! Even I wouldn't go that far.

Louis

--------------
Bye.

  
Louis



Posts: 6436
Joined: Jan. 2006

(Permalink) Posted: Feb. 10 2009,13:48   

Oh and before I forget, I just want to commend Gary (Dr GH) for his post, I didn't even think of explaining to RFJE that there are organisms with "unnatural" amino acids in them. This is why a multidisciplinary approach is a great thing. The consilience of data from disparate fields is one thing creationists can't get their heads around.

Cheers

Louis

--------------
Bye.

  
Louis



Posts: 6436
Joined: Jan. 2006

(Permalink) Posted: Feb. 10 2009,13:57   

Quote (JLT @ Feb. 10 2009,19:36)
Quote

b) Lack of stratospheric ozone is not a problem because UV radiation is not only destructive. It is also positively useful. Many complex molecules exist in space (in conditions of vastly greater UV radiation), not only that but UV can promote certain reactions. For example the formose reaction is positively aided by UV radiation.


Isn't UV also absorped by water?
I always thought that the shorter the wavelenght, the more water the light can pass through before it's filtered out. I tried to find out how deep that is for UV light and I found this list (German) with absorption coefficents for different wavelenght and the layer thickness* after which the intensity is reduced to 1/1000 of the original:

Lambda(nm) k(1/m) x(0,001)(m)
=======================================
200 ca. 7 1
250 ca. 1 7
300 ca. 0,2 35
350 ca. 0,2 35
400 ca. 0,06 110
450 ca. 0,02 350
500 ca. 0,025 280
550 ca. 0,05 140
600 ca. 0,2 35
650 ca. 0,32 22
700 ca. 0,65 11
750 ca. 2,6 2,7
800 ca. 2,0 3,5
1000 37 0,19

So, the shorter the wavelength, the deeper the light can reach seems to be true only for the visible light. According to this list UV light can't reach as deep as e.g. blue light.

Does anyone know whether that is true?
Unfortunately, the author of that list states that he found several vastly different absorption coefficents for UV light in the literature and he would provide only a "best guess".


* This isn't exactly a topic I discuss on a daily basis, so I'm not sure whether I use the correct terms. I hope it's still clear what I mean....

Yes water does absorb UV to some extent.

As for how deep different wavelengths of EM radiation can penetrate into bodies of water, I honestly don't know off the top of my head. I'm also not sure about the correlation between wavelength and depth of penetration. A couple of things spring to mind though:

a) Gamma rays, X rays, cosmic radiation etc pass through water. They have very short wavelengths compared to blue light for example.

b) Different materials have different absorption spectra, so there isn't necessarily a linear relationship between wavelength and depth of penetration.

I could be wrong however, I'll nip off and have a read!

Louis

--------------
Bye.

  
khan



Posts: 1479
Joined: May 2007

(Permalink) Posted: Feb. 10 2009,14:05   

Quote (Louis @ Feb. 10 2009,14:57)
Quote (JLT @ Feb. 10 2009,19:36)


Isn't UV also absorped by water?
I always thought that the shorter the wavelenght, the more water the light can pass through before it's filtered out. I tried to find out how deep that is for UV light and I found this list (German) with absorption coefficents for different wavelenght and the layer thickness* after which the intensity is reduced to 1/1000 of the original:


Yes water does absorb UV to some extent.

As for how deep different wavelengths of EM radiation can penetrate into bodies of water, I honestly don't know off the top of my head. I'm also not sure about the correlation between wavelength and depth of penetration. A couple of things spring to mind though:

a) Gamma rays, X rays, cosmic radiation etc pass through water. They have very short wavelengths compared to blue light for example.

b) Different materials have different absorption spectra, so there isn't necessarily a linear relationship between wavelength and depth of penetration.

I could be wrong however, I'll nip off and have a read!

Louis

Admit you don't know?

Look it up?

You'll never be a good IDiot.

--------------
"It's as if all those words, in their hurry to escape from the loony, have fallen over each other, forming scrambled heaps of meaninglessness." -damitall

That's so fucking stupid it merits a wing in the museum of stupid. -midwifetoad

  
Texas Teach



Posts: 1014
Joined: April 2007

(Permalink) Posted: Feb. 10 2009,14:12   

Quote (Louis @ Feb. 09 2009,15:47)
Firstly, like my route to the pub, many of the amino acids found in modern organisms are relatively simple (i.e. the R group side chain is not 16 Buckminster-fullerenes linked into a Borromean ring system, its a methyl or tolyl group etc).

This image made my morning.  Thanks, Louis.

--------------
"Creationists think everything Genesis says is true. I don't even think Phil Collins is a good drummer." --J. Carr

  
JohnW



Posts: 2226
Joined: Aug. 2006

(Permalink) Posted: Feb. 10 2009,14:18   

Quote (Texas Teach @ Feb. 10 2009,12:12)
Quote (Louis @ Feb. 09 2009,15:47)
Firstly, like my route to the pub, many of the amino acids found in modern organisms are relatively simple (i.e. the R group side chain is not 16 Buckminster-fullerenes linked into a Borromean ring system, its a methyl or tolyl group etc).

This image made my morning. Thanks, Louis.

The mystery lies in his route back from the pub.

--------------
Math is just a language of reality. Its a waste of time to know it.
- Robert Byers

  
J-Dog



Posts: 4361
Joined: Dec. 2006

(Permalink) Posted: Feb. 10 2009,14:37   

Quote (Louis @ Feb. 10 2009,13:36)



For those that couldn't place it, this is actually Marcelino Ravery. Or maybe Louis at last weeks staff meeting...
he is British donchaknow, and they do take things a bit more seriously than we do here in the states.[/quote]

Ok, I'll cough to wearing the funny dress, but a crucifix? Come ON! Even I wouldn't go that far.

Louis

Louis - What???  You don't like it????

Oh!  I see - you thought it was "just a toy" crucifix...

Nope - This is an actual built-to-scale model!* - (The C-0909 model) It is for use with LOLCatz**, leprechauns and fairies that cross the line and offend you.

* Yeah, you DO need a slightly larger model for IDists.

** For some reason, I could not find a LOL Cat on a crucifix! :(

--------------
Come on Tough Guy, do the little dance of ID impotence you do so well. - Louis to Joe G 2/10

Gullibility is not a virtue - Quidam on Dembski's belief in the Bible Code Faith Healers & ID 7/08

UD is an Unnatural Douchemagnet. - richardthughes 7/11

  
JLT



Posts: 740
Joined: Jan. 2008

(Permalink) Posted: Feb. 10 2009,16:38   

Quote (Louis @ Feb. 10 2009,19:57)
Quote (JLT @ Feb. 10 2009,19:36)

Isn't UV also absorped by water?
[snip]
So, the shorter the wavelength, the deeper the light can reach seems to be true only for the visible light. According to this list UV light can't reach as deep as e.g. blue light.

Does anyone know whether that is true?
Unfortunately, the author of that list states that he found several vastly different absorption coefficents for UV light in the literature and he would provide only a "best guess".

Yes water does absorb UV to some extent.

As for how deep different wavelengths of EM radiation can penetrate into bodies of water, I honestly don't know off the top of my head. I'm also not sure about the correlation between wavelength and depth of penetration. A couple of things spring to mind though:

a) Gamma rays, X rays, cosmic radiation etc pass through water. They have very short wavelengths compared to blue light for example.

b) Different materials have different absorption spectra, so there isn't necessarily a linear relationship between wavelength and depth of penetration.

I could be wrong however, I'll nip off and have a read!

Louis

Thank you!
Re. a) That fits with what I'd thought before I found this list.

Re. b) That's obviously true (otherwise we wouldn't see different colours), but it didn't occur to me that it applies to water, too. Thanks for reminding me.

I've read a bit more myself and found out that I've forgotten A LOT since I had physics classes during my study.... I'm sure that we learned about the Beer-Lambert law and I seem to remember that we used an experimental setting like this

to calculate concentrations but most of it I eradicated quite successfully from my memory...

--------------
"Random mutations, if they are truly random, will affect, and potentially damage, any aspect of the organism, [...]
Thus, a realistic [computer] simulation [of evolution] would allow the program, OS, and hardware to be affected in a random fashion." GilDodgen, Frilly shirt owner

  
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