Chemical Forums

General Forums => Generic Discussion => Topic started by: Lois on May 20, 2014, 08:05:56 PM

Title: Paradoxes in Chemistry
Post by: Lois on May 20, 2014, 08:05:56 PM

I explore various paradoxes. I am interested in what paradoxes are in chemistry? I have the opportunity to solve paradoxes of using AI.
Title: Re: Paradoxes in Chemistry
Post by: Lois on May 22, 2014, 01:11:22 PM
http://en.wikipedia.org/wiki/Levinthal%27s_paradox

Title: Re: Paradoxes in Chemistry
Post by: curiouscat on May 22, 2014, 01:21:12 PM

 I have the opportunity to solve paradoxes of using AI.


The most intriguing sentence I read this week. Pray elaborate.
Title: Re: Paradoxes in Chemistry
Post by: Borek on May 22, 2014, 02:14:03 PM
http://en.wikipedia.org/wiki/Levinthal%27s_paradox

Straw man. Proteins don't fold by sampling all possible configurations, they fold at the same time they are produced. Finding minimal energy conformation for tripeptide or tetrapeptide is instant, then the protein forms around what was already present. Sure, it is only a simplification, but good enough to show why there is no paradox.
Title: Re: Paradoxes in Chemistry
Post by: curiouscat on May 22, 2014, 04:42:52 PM


Straw man. Proteins don't fold by sampling all possible configurations, they fold at the same time they are produced. Finding minimal energy conformation for tripeptide or tetrapeptide is instant, then the protein forms around what was already present. Sure, it is only a simplification, but good enough to show why there is no paradox.

Interesting argument. But is it always true that the min. energy config for a large protein has each sub-unit (at least each sub unit on the typical build pathway seen in nature) also in a minimal energy config, by itself?

I doubt it.
Title: Re: Paradoxes in Chemistry
Post by: Corribus on May 22, 2014, 05:43:44 PM
I find Levinthal's so-called paradox to be essentially identical to the Junkyard tornado (http://en.wikipedia.org/wiki/Junkyard_tornado) arguments put forth by Creationists as evidence against Natural Selection. I.e., neither one has much merit and both are based on some very bad assumptions about random event sampling.

I hope I didn't just open a can of worms.
Title: Re: Paradoxes in Chemistry
Post by: Borek on May 22, 2014, 06:01:24 PM
Interesting argument. But is it always true that the min. energy config for a large protein has each sub-unit (at least each sub unit on the typical build pathway seen in nature) also in a minimal energy config, by itself?

It doesn't have to. With each added aminoacid peptide is free to reach a new conformation, and the peptide can get locally strained. But each time it doesn't start from nowhere, it starts from the previous conformation, so the number of possible conformations to test in each step is not that large.
Title: Re: Paradoxes in Chemistry
Post by: Borek on May 22, 2014, 06:02:47 PM
I find Levinthal's so-called paradox to be essentially identical to the Junkyard tornado (http://en.wikipedia.org/wiki/Junkyard_tornado) arguments

That was exactly my thought :)
Title: Re: Paradoxes in Chemistry
Post by: Lois on May 22, 2014, 07:36:47 PM
Here's how this paradox decided my AI

duct
mil
hay
seq
fen
oft
Title: Re: Paradoxes in Chemistry
Post by: Borek on May 23, 2014, 02:32:29 AM
This is word salad. Looks like LSD, not AI.
Title: Re: Paradoxes in Chemistry
Post by: curiouscat on May 23, 2014, 05:36:25 AM
This is word salad. Looks like LSD, not AI.

Or, Lois is the AI? What's the chance we've been responding to a script robot?
Title: Re: Paradoxes in Chemistry
Post by: Lois on May 23, 2014, 12:32:42 PM
I find Levinthal's so-called paradox to be essentially identical to the Junkyard tornado (http://en.wikipedia.org/wiki/Junkyard_tornado) arguments

That was exactly my thought :)

Gödel proved that God is

(https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-frc3/t1/p180x540/1797553_10201469285197354_619282146_n.jpg)
Title: Re: Paradoxes in Chemistry
Post by: Borek on May 23, 2014, 12:55:56 PM
People have proven π to equal 3.2.

This won't get anywhere, locked.