Reductionism: Physics-Chemistry-Biology [Archive]

Ziggurat

31st January 2007, 02:13 PM

Can you prove that the Schrödinger equation is solvable for all systems?

Poorly framed question. Do you mean analytically solvable? Do you mean numerically solvable? Do you mean does a solution exist? Your question is ambiguous.

Better question: Can the Schrödinger equation describe the time evolution of any input wave function? The answer is, yes.

There are no known phenomena in chemistry or biology which do not operate according to the laws of physics. In an abstract sense, these sciences can indeed be reduced to physics. But as a practical matter, they are well served by treating them as different sciences. With chemistry, the distinction isn't always even clear to begin with (quantum chemistry, for example, pretty much IS physics), but it's generally the case with biology. Secondly, there are a lot of systems (including even systems within physics) where we either aren't interested in trying to solve problems from first principles or where (because of the complexity of the system) we cannot do so for practical reasons. Many such systems are ammenable to treatment with emmergent principles (such as natural selection in biology) much more easily than with first principles (good luck trying to construct the quantum mechanical wave function of a fruit fly). But that doesn't mean that the first principles aren't still operative, and don't underly the emmergent principles. So yes, all chemistry is physics, but that statement doesn't mean much on a practical level.

TheChadd

31st January 2007, 07:07 PM

Poorly framed question. Do you mean analytically solvable? Do you mean numerically solvable? Do you mean does a solution exist? Your question is ambiguous.

Better question: Can the Schrödinger equation describe the time evolution of any input wave function? The answer is, yes.

There are no known phenomena in chemistry or biology which do not operate according to the laws of physics. In an abstract sense, these sciences can indeed be reduced to physics. But as a practical matter, they are well served by treating them as different sciences. With chemistry, the distinction isn't always even clear to begin with (quantum chemistry, for example, pretty much IS physics), but it's generally the case with biology. Secondly, there are a lot of systems (including even systems within physics) where we either aren't interested in trying to solve problems from first principles or where (because of the complexity of the system) we cannot do so for practical reasons. Many such systems are ammenable to treatment with emmergent principles (such as natural selection in biology) much more easily than with first principles (good luck trying to construct the quantum mechanical wave function of a fruit fly). But that doesn't mean that the first principles aren't still operative, and don't underly the emmergent principles. So yes, all chemistry is physics, but that statement doesn't mean much on a practical level.

Yep and this is what I've been taught/agree with. I don't think many accept 'greedy reductionism' as Dennet called it.

Slimething

31st January 2007, 07:21 PM

Slimething: See above - this also applies very much to geology, and the other natural (as in nature study) sciences.

You'll get no argument from me there, fishbob. However, if one is going to get down to the very rudiments of "why everything is", mathematics trumps physics. So, let's hear it for the mathematicians. But that isn't even recognized as a science.

Frankly, this topic is what I characterize as scientific bar-talk. It's as relevant and important as who was the best actor ever, the best athlete ever, the best sports team ever, etc. Issues like this are never resolved to anyone's satisfaction but I sure like to drink beer while I'm listening!

So, let's hear it for Nature, yes? That's what we're all studying, no matter what we call it or how humble anyone else considers our passtime.

balrog666

31st January 2007, 07:24 PM

Hey guys,

Well I'm having this argument with a close friend of mine who's about to begin her 2nd year of undergraduate science. The argument is essentially about the most basic form of reductionism: I explained that physics 'comes' from mathematics, chemistry comes from physics and biology comes from chemistry.

She's someone who loves chemistry and seemed angry at the suggestion that it is reducible down to physics... I gave some examples of the way chemistry is working off the foundation of physics but they didn't seem to satisfy. I'm wonder if anyone could offer up a simple way to show her exactly what I mean - Or if there really is strong argument out there about whether chemistry is reducible to physics (I'm doubting it).

Thanks.

I disagree. Physics is not reducible to mathematics in spite of the essential nature of mathematics within physics . Ditto for chemistry/physics, the reduction is practically meaningless.

cyborg

31st January 2007, 08:01 PM

Mathematics cannot TELL us anything about our world. It cannot be a science.

TheChadd

31st January 2007, 09:28 PM

But everything you do in physics would be meaningless without the mathematic principles.

Ditto for chemistry/physics, the reduction is practically meaningless.

The idea isn't to say if you know physics you understand chemistry, but to point out that (as was said earlier in this thread): I like to say that math is to physics what letters are to words. Words are to a sentence what physics is to chemistry and a sentence is to a paragraph as chemistry is to biology. Understanding grammar does not mean you will be able to grasp literature, but it is a foundational component. Grammar being essential to literature does not mean it is “better”, they are two different beasts in many ways.

Slimething

31st January 2007, 11:35 PM

Mathematics cannot TELL us anything about our world. It cannot be a science.

I agree with you but there are several instances where anti-intuitive discoveries have been made by following mathematics alone, devoid of human observation. The most famous example is the Theory of Special Relativity.

Like I wrote earlier, I'm not going to participate in what begat what science. That's a fool's game. When I was in college, I had some nebbish physics major taunt me that chemistry was all physics so I wrote down two chemicals and told him to calculate the product of the reaction, if there was any. That worked pretty well.

We're all after the same thing, which is to understand nature and, if you're good at it, you won't limit yourself to the classical definitions of the basic sciences. Use any tool that you find useful and the names be damned.

cyborg

1st February 2007, 05:22 AM

I agree with you but there are several instances where anti-intuitive discoveries have been made by following mathematics alone, devoid of human observation.

This is only possible when the maths relates to the real world and the math can only relate to the real world by engaging in physics.

Being able to predict unanticipated phenomena and then seek them out is one of the primary reasons maths is useful but it cannot be said the discovery is complete until the prediction is confirmed - you may be wrong after all.

DeviousB

1st February 2007, 06:27 AM

There are no known phenomena in chemistry or biology which do not operate according to the laws of physics.

I would argue that natural selection operates according to the rules of statistics.

geni

1st February 2007, 07:28 AM

What do you mean by solvable? An analytic solution isn't even possible for helium. Even Newtonian gravitation can't be solved for the solar system, but that never seemed to be a reason to think it was wrong.

I never said it was wrong. However if you are going to describe chemisty through physics you are going to need to be able to solve the Schrödinger equation for systems or more than 1 electron. Unless you can prove it is posible to do (you don't have to do it just need to prove it is posible) this you can't prove it is posible to derive all chemistry from physics.

I'd expect that approximations to the Schrödinger equation would allow you to derive any chemical principles,

You need kinetics and relativity as well at a mininium.

although it might be practically impossible for large enough systems, like trying to predict enzyme activity. I suppose if you must satisfy the philosophy of science types it might be better to say "in principle any theory of chemistry or biology can be derived from the theories of physics".

First you need to show that it is in thoery posible to solve the Schrödinger equations for multi election systems.

pgwenthold

1st February 2007, 08:23 AM

IFirst you need to show that it is in thoery posible to solve the Schrödinger equations for multi election systems.

To what level of accuracy?

That is the question at hand. No, the SE cannot be solved analytically for any multi-electron system. However, with numerical approaches you can come more or less as close as you want to the solution.

No, it's not sophisticated, but the reaction H + H2 is pretty well known based on QM calculations, at least the chemistry of it. Sure, there are plenty of people who are still studying it, but they are focusing on the details of the physics.

Heck, even state-of-the-art dynamics calculations (especially those that are QM based) are not all that far off the mark for complex reactions. For example, the gas phase SN2 reaction is extremely well-described computationally. Similarly, very good success has been achieved with unimolecular reactions. Reaction rates and branching ratios can be calculated.

The limiting factor is the complexity. You have to know enough to include all the relevant coordinates, and for large systems, it's tough to know which of the 3N-6 should be important. In principle, you could just include them all, but that is a resource limitation.

Yes, there is a long way in order to do the calculation on any type of system. However, that is mainly in resources. Right now, we know what we need to do in order to do it, it is just way beyond our capabilities.

The SE can be solved to within "chemical accuracy," which is the accuracy level of typical chemistry measurement. It's not easy to get there (especially with larger systems), but you can if you put enough effort into it.

Ziggurat

1st February 2007, 09:34 AM

I would argue that natural selection operates according to the rules of statistics.

Yes, but that's an emergent property. Statistics doesn't describe mechanisms, it describes the logic of what you can conclude from incomplete or imperfect information. Which is why it pops up in so many places. The mechanisms themselves are still physical mechanisms, describable (at least in principle) by physics.

Ziggurat

1st February 2007, 09:38 AM

You need kinetics

You aren't under the mistaken impression that the Schrödinger equation cannot handle kinetics, are you?

And yes, the Schrödinger equation can be solved numerically for arbitrary numbers of particles (if you've got the computational power).

DeviousB

1st February 2007, 10:51 AM

Yes, but that's an emergent property. Statistics doesn't describe mechanisms, it describes the logic of what you can conclude from incomplete or imperfect information. Which is why it pops up in so many places. The mechanisms themselves are still physical mechanisms, describable (at least in principle) by physics.

Unless you are arguing for strong determinism, there is no way to get from the physical properties of an organism to an example of evolutionary complexity like an eye.

The eye is selected for by the processes of natural selection, not physics. The physics of the eye may be what confer efficiency on it but they do not result in the progressive refinement (or not) of the eye.

Physics may explain how the eye works, it cannot explain why we have them.

Ziggurat

1st February 2007, 02:30 PM

Unless you are arguing for strong determinism, there is no way to get from the physical properties of an organism to an example of evolutionary complexity like an eye.

Well, I'm not sure what you mean by "strong determinism".

The eye is selected for by the processes of natural selection, not physics.

Natural selection is an emergent property. That doesn't mean it's not still rooted in physics. The organization of hexagonal convection cells in heated liquids is another example of an emergent property of a complex system. There's no simple way to show that such self-organization is what will result using, for example, the Schroedinger equation, but it's all still just physics. The more complex the system, the harder it is to trace emergent properties back to their physical origin (and often times, the less useful such an exercise is anyways). We label things as being something other than physics when we either can't trace the link (because of the complexity) or don't care to, not because the link doesn't exist.

DanishDynamite

1st February 2007, 02:47 PM

And yes, the Schrödinger equation can be solved numerically for arbitrary numbers of particles (if you've got the computational power).
Is this correct, even theoretically? How powerful a computer would you need to solve the Schrödinger equation for every particle within 6,000 miles of the Earth's center? Or within 20 AUs of the center? Given that we can't solve the Schrödinger equation for a cup of pond water, I feel your view is even theoretically wrong, unless you posit close to infinite time to solve it in.

pgwenthold

1st February 2007, 02:57 PM

Is this correct, even theoretically? How powerful a computer would you need to solve the Schrödinger equation for every particle within 6,000 miles of the Earth's center? Or within 20 AUs of the center? Given that we can't solve the Schrödinger equation for a cup of pond water, I feel your view is even theoretically wrong, unless you posit close to infinite time to solve it in.

There is no such thing as "close to infinite." Every thing else is finite, and is an infinite amount of time short of infinite.

Yes, it can be calculated in a finite amount of time. I just hope there isn't a power outage.

DanishDynamite

1st February 2007, 03:54 PM

There is no such thing as "close to infinite." Every thing else is finite, and is an infinite amount of time short of infinite.
I know. I think my meaning is clear. Perhaps I should have put "within the expected life of the Universe assuming a closed Universe".
Yes, it can be calculated in a finite amount of time. I just hope there isn't a power outage.
Yes, but if the expected time to claculate is greater than the expected lifetime of the Universe, can it be said to be even theoretically correct?

Ziggurat

1st February 2007, 04:54 PM

Is this correct, even theoretically?

Depends what you mean by theoretically possible. But there are no barriers other than limited computational power.

How powerful a computer would you need to solve the Schrödinger equation for every particle within 6,000 miles of the Earth's center?

Many, many, many orders of magnitude larger than we can envision ever building. The difficulty is that the numerber of calculations needed to solve this numerically scales exponentially with the number of particles you're trying to calculate for. So it doesn't take a system anywhere near this large to become impossible to calculate from a practical perspective. But that exponential scaling problem isn't even unique to quantum mechanics computations - you get the exact same problem trying to calculate Newtonian gravitational interactions of all the stars within a galaxy, for example.

DanishDynamite

1st February 2007, 05:09 PM

Depends what you mean by theoretically possible. But there are no barriers other than limited computational power.
And time. Don't forget time. And if the maximum theoretical time remaining for this Universe is limited....is something that takes longer theoretically possible?
Many, many, many orders of magnitude larger than we can envision ever building. The difficulty is that the numerber of calculations needed to solve this numerically scales exponentially with the number of particles you're trying to calculate for. So it doesn't take a system anywhere near this large to become impossible to calculate from a practical perspective. But that exponential scaling problem isn't even unique to quantum mechanics computations - you get the exact same problem trying to calculate Newtonian gravitational interactions of all the stars within a galaxy, for example.
Exactly. The devision of chemistry and physics will last for quite a while, perhaps forever (read: until the end of the Universe)

Ziggurat

1st February 2007, 05:28 PM

And time. Don't forget time. And if the maximum theoretical time remaining for this Universe is limited....is something that takes longer theoretically possible?

Doesn't really matter for my argument. What I'm claiming is that physics equations describe all chemical reactions. In that sense, all chemistry is physics. Whether or not WE can solve a particular set of equations is a different question from whether or not they provide an accurate description of the mechanics involved. It's not possible to solve 3-body Newtonian gravity problems analytically, and before the advent of computers not even numerically, but it was quite clear that the equations involved were still an accurate description of the mechanics. And the only limits to computational power are practical limits. It may indeed be the case that the lifetime of the universe limits computational power, but that too is only a practical (though insurmountable) limit, because there's nothing fundamental about the age of the universe.

Exactly. The devision of chemistry and physics will last for quite a while, perhaps forever (read: until the end of the Universe)

I never said otherwise. In fact, let me quote myself from my first post: "So yes, all chemistry is physics, but that statement doesn't mean much on a practical level."

DanishDynamite

1st February 2007, 05:49 PM

Doesn't really matter for my argument. What I'm claiming is that physics equations describe all chemical reactions. In that sense, all chemistry is physics. Whether or not WE can solve a particular set of equations is a different question from whether or not they provide an accurate description of the mechanics involved. It's not possible to solve 3-body Newtonian gravity problems analytically, and before the advent of computers not even numerically, but it was quite clear that the equations involved were still an accurate description of the mechanics. And the only limits to computational power are practical limits. It may indeed be the case that the lifetime of the universe limits computational power, but that too is only a practical (though insurmountable) limit, because there's nothing fundamental about the age of the universe.

I never said otherwise. In fact, let me quote myself from my first post: "So yes, all chemistry is physics, but that statement doesn't mean much on a practical level."
I agree. I just thought that the question I posed ("If the maximum theoretical time remaining for this Universe is limited....is something that takes longer theoretically possible? ") was kind of interesting. Wanted to give it a bit more play. :)

pgwenthold

1st February 2007, 07:27 PM

I know. I think my meaning is clear. Perhaps I should have put "within the expected life of the Universe assuming a closed Universe".

Why are you assuming that? I thought that at last best interpretation, the universe is essentially balanced, or perhaps even open.

Yes, but if the expected time to claculate is greater than the expected lifetime of the Universe, can it be said to be even theoretically correct?

Note that we are talking about current methodology and equipment.

There is no reason to think that computing power and methodology won't improve substantially in time, as well, such that with appropriate computing resources (say, put every processor we have right now and run them parallel) there would not be a foreseeable time limit to the answer (albeit it could be billions of years, but hey, still within a universal time constraint)

geni

1st February 2007, 08:19 PM

You aren't under the mistaken impression that the Schrödinger equation cannot handle kinetics, are you?

Stikes me as being a rather overcomplex way of trying to model the differences between H2O and D2O

And yes, the Schrödinger equation can be solved numerically for arbitrary numbers of particles (if you've got the computational power).

Those are only approximations. To be able to reduce chemistry to physics you would need to be able to show that it is posible for an analytic solution to exist for all systems that appear in chemsitry.

Throw in structures that do anoying things such as haveing both quantum and mocro properties and at the present time phyics is still working on chemistry.

Schneibster

1st February 2007, 11:00 PM

First of all you should note that winning isn't always about being right. I suggest you consider which is more important to you before you continue this line of conversation.

I will, however, give you some food for thought.
Hey guys,

Well I'm having this argument with a close friend of mine who's about to begin her 2nd year of undergraduate science. The argument is essentially about the most basic form of reductionism: I explained that physics 'comes' from mathematics, chemistry comes from physics and biology comes from chemistry. I'd argue that physics doesn't come from math, rather more the other way 'round. However, physics does come from observation of the behavior of the world around us; and math describes that behavior.

She's someone who loves chemistry and seemed angry at the suggestion that it is reducible down to physics... I gave some examples of the way chemistry is working off the foundation of physics but they didn't seem to satisfy. I'm wonder if anyone could offer up a simple way to show her exactly what I mean - Or if there really is strong argument out there about whether chemistry is reducible to physics (I'm doubting it).

Thanks.The fact of the matter is that chemistry is about the combination of atoms into molecules, and the behavior of atoms whether in or out of molecules is described by physics. So you are indeed correct. I caution you again, however, that you may find that being right isn't as important as winning. ;)

Schneibster

1st February 2007, 11:02 PM

Those are only approximations. To be able to reduce chemistry to physics you would need to be able to show that it is posible for an analytic solution to exist for all systems that appear in chemsitry.Basically, then, you think that chemistry isn't about atoms?

Whatever you're smoking, I need some. 'Cause man, you are HIGH.

TheChadd

1st February 2007, 11:08 PM

First of all you should note that winning isn't always about being right. I suggest you consider which is more important to you before you continue this line of conversation.

I was already there shortly after making this post :)

geni

2nd February 2007, 06:19 AM

Basically, then, you think that chemistry isn't about atoms?

Whatever you're smoking, I need some. 'Cause man, you are HIGH.

Interesting strawman you've got there although there are bits of chemistry that don't worry about atoms they are not areas I deal with.

pgwenthold

2nd February 2007, 07:34 AM

Those are only approximations. To be able to reduce chemistry to physics you would need to be able to show that it is posible for an analytic solution to exist for all systems that appear in chemsitry..

No, you only need to show that it is possible to obtain a solution that is to the level of "chemical accuracy," i.e. the level of accuracy that can be obtained in the empirical science of chemistry.

You are requiring physics to provide exact solutions in a field that is wrought with uncertainty? Why should physics have to provide an exact (analytical) value for anything when chemistry doesn't have to?

If I carry out a measurement that has an uncertainty of 10%, but if I know I can calculate the same value to within 5%, then the calculation is better than the experiment.

Ziggurat

2nd February 2007, 08:22 AM

Stikes me as being a rather overcomplex way of trying to model the differences between H2O and D2O

I never claimed that an explicit wave function for a system was the best way of modeling it from a practical standpoint. Of course it often isn't, and I thought I made that rather clear. How one SHOULD solve a problem is usually only a subset of how one COULD solve it.

Those are only approximations.

So what? They are approximations with potentially arbitrary precision.

To be able to reduce chemistry to physics you would need to be able to show that it is posible for an analytic solution to exist for all systems that appear in chemsitry.

Nonsense. Analytic solutions don't exist for Newtonian gravitational interaction of 3 masses, and yet nobody points to that lack as an indication that physics isn't what describes gravity.

Schneibster

3rd February 2007, 06:56 PM

Interesting strawman you've got there although there are bits of chemistry that don't worry about atoms they are not areas I deal with.Well, if you're dealing with atoms, you're dealing with physics, because that's the science that describes atoms. Chemistry certainly doesn't, at least not in terms of their internal structure; to chemistry, the internal structure of an atom is moot, all you have to know is how atoms combine with one another to form compounds.

I'd like to know precisely what "bits" or "areas" of chemistry you believe don't "worry about" atoms, considering that chemistry is all about how atoms combine with one another to form compounds.

I'd also like to know why, if you're talking about such things, you think that what I said represents a straw man; I responded to what you said, not what you thought you said. Perhaps you should review your posts a bit more carefully before hitting the submit button.

Schneibster

3rd February 2007, 06:57 PM

I was already there shortly after making this post :)I hope that's good news. ;)

JamesM

3rd February 2007, 07:16 PM

chemistry is all about how atoms combine with one another to form compounds.

That describes organic and inorganic chemistry reasonably (admittedly, organic chemistry is what most non-chemists think of as chemistry); it's not a good description of physical or analytical chemistry.

To my mind, chemists are more concerned with the behaviour of electrons, albeit normally only the least well-bound electrons. That often involves controlling their behaviour at the level of abstraction that covers a handful to hundreds or thousands of atoms at a time.

Schneibster

3rd February 2007, 07:26 PM

That describes organic and inorganic chemistry reasonably (admittedly, organic chemistry is what most non-chemists think of as chemistry); it's not a good description of physical or analytical chemistry. "Physical chemistry." I rest my case. ;)

To my mind, chemists are more concerned with the behaviour of electrons, albeit normally only the least well-bound electrons. That often involves controlling their behaviour at the level of abstraction that covers a handful to hundreds or thousands of atoms at a time.Well, first, "electrons without physics" looks like an oxymoron to me; and second, I don't think the level of abstraction matters much, really. Bear in mind that we are finding more and more out about both chaos math and about scaling laws that affect mass behavior, such as the fluctuation theorem (which has modified our understanding of the 2LOT substantially). If we can't describe the activities of hundreds or even millions of atoms today, the time is not far off either for brute force (have you seen the articles recently about the new resist strategy that Intel or someone came up with?) or elegant (like the FT) descriptions of such things.

And the argument here is, "can the principles of the science of chemistry be reduced to the actions of physics?" And I still contend that the answer is, "yes." That is not, to my mind, any indictment of chemistry either as a science, or as a discipline; that it can be so reduced does not necessarily mean that the goals of physicists and those of chemists can be equated one to another, since chemists are interested more in "what" than "why," whereas the interests of physicists are just about the opposite of that, and I see the answers to neither "what" nor "why" as more important one than the other. I suspect that the contrapositive of that last is the reason that the OP's lady friend was less than pleased with the assertion; perhaps that analysis will help with that.

Mercutio

3rd February 2007, 07:51 PM

To me, the wonderful thing about this silly argument is what happens when the various different levels of abstraction agree.

Lemme 'splain.

I'll start one level of abstraction beyond Biology, actually--Psychology. For most (but, sadly, not all) psychologists, Psychology is a biological science. (For the rest, it must simply be magic.) These psychologists get bent out of shape by biologists claiming that psychology is just biology; these biologists resent the chemists, who are pissed off at physicists, who resent mathemeticians, who are just angry that they can't find dates.

Anyway, at a conference a couple of years ago, a neurobiologist reported on a nerve pathway in honeybees that was moderated by octopamine. His description of the function of this pathway made me think (although it appears he was unaware of the connection) of the Rescorla-Wagner model of classical conditioning. The RW model is a mathematical model that most behaviorists recognize does a fabulous job of predicting classical conditioning phenomena. No behaviorist would ever say "therefore, there is a mechanism that does this"--that would be circular--but it was quite refreshing to hear this guy describing a system, independently discovered, that fits the model exactly. Of course, octopamine would be perfectly describable by a biochemist, and the description would be accepted by any physicist, and so on down the line. It simply worked.

Contrast this with any number of psychological concepts that have been circularly inferred, rather than described from observation. Take the Id, Ego, and Superego: haven't the psychobiologists had enough time to locate these? Don't the biochemists have an understanding? Um...no. They ain't there. Of course, there is no evidence for them in psychology either, other than the behavior they allegedly cause. Purely circular.

Anyway, it doesn't mean the R-W model is right. It just means that this particular evidence does not kick it's feet out from under it. Whereas Freud...or Chomsky's "Language Acquisition Device", or any number of other crap psychology theories...

I love the way sciences mesh.

Jeff Corey

3rd February 2007, 10:00 PM

Me too. We have biopsychologists who confer with the behaviorists on how to measure things like "reinforcement".
Skinner was not a reductionist, in the sense that we have as our task discovering functional relationships at the level of behavior. Sure, in the ideal world, we will discover how reinforcement works at the biological level, but now we try to do what we know best.

lenny

4th February 2007, 12:48 PM

Lemme 'splain.
I'll start one level of abstraction beyond Biology, actually--Psychology. For most (but, sadly, not all) psychologists, Psychology is a biological science. (For the rest, it must simply be magic.) These psychologists get bent out of shape by biologists claiming that psychology is just biology; these biologists resent the chemists, who are pissed off at physicists, who resent mathemeticians, who are just angry that they can't find dates.

it is called physics envy.

(and it stops at physicists, who do not resent mathematicians, although they might sometimes wish the real world was as platonic as many mathematicians believe it is!)

Schneibster

4th February 2007, 04:05 PM

Heh, I remember reading some popular physics writer saying that when budding physicists get to college and start learning math, the physics professors all go, "Don't pay any attention to the mathematicians, they're off on a power trip, they'll melt your brain, we'll teach you all the math you need to know."

Slimething

4th February 2007, 10:05 PM

"Physical chemistry." I rest my case. ;)

Rest is somewhere else. You're wrong. Physical chemistry encompasses more than quantum mechanics. It also includes thermodynamics, electrochemistry, and the like. If you want to believe in a Theory of Everything that allows physicists to model everything that chemists do, will do or know, you are entitled but it doesn't exist yet and probably never will. I'm an analytical chemist, I know QM and more than how to make molecules come together.

And the argument here is, "can the principles of the science of chemistry be reduced to the actions of physics?" And I still contend that the answer is, "yes."

And, you'd be wrong. :jaw-dropp Five minutes in a chemistry lab tripping over your tongue would be enough to convince you of that.

That is not, to my mind, any indictment of chemistry either as a science, or as a discipline; that it can be so reduced does not necessarily mean that the goals of physicists and those of chemists can be equated one to another...

There, I highlighted your strawman for you. If it can be so reduced, do it. I'd love to stay and watch but I gotta go unquestioningly figure out why a molecule fragments in my mass spectrometer in certain pattern.

DeviousB

5th February 2007, 04:30 AM

Natural selection is an emergent property. That doesn't mean it's not still rooted in physics. The organization of hexagonal convection cells in heated liquids is another example of an emergent property of a complex system. There's no simple way to show that such self-organization is what will result using, for example, the Schroedinger equation, but it's all still just physics. The more complex the system, the harder it is to trace emergent properties back to their physical origin (and often times, the less useful such an exercise is anyways). We label things as being something other than physics when we either can't trace the link (because of the complexity) or don't care to, not because the link doesn't exist.

No-one (in biology) is arguing that biological creatures do not follow the principles of physics and chemistry. And if you want to say NS is 'emergent', fine. But it is strongly emergent; it is not directly explainable by the mechanisms of the underlying system. Ergo, does not reduce.

A mutation with a frequency f in a population of animals P results in a 1% improvement in vision, but also a 2% increase in the metabolic cost of the eye. How might physics tell us about how we might expect f to change over time? Or chemistry?

Chemistry can be reduced to physics because the systems of chemistry are specific cases of the systems of physics, chemistry is a special type of physical interaction. Similarly, biochemistry is a special type of chemistry. Developmental biology is a special type of biochemistry. And so on.

But NS doesn't fit so neatly in this little tree. You don't explain the features of NS with the systems of biochemistry, chemistry, physics, etc. You use NS to explain the complexity in particular examples of these systems that they can't explain.

Beisdes, I thought the so called 'laws of physics' were just a result of natural selection (http://www.amazon.com/Life-Cosmos-Lee-Smolin/dp/0195126645) in the first place? Surely then, physics is the emergent process?
;)

Roboramma

5th February 2007, 05:58 AM

Rest is somewhere else. You're wrong. Physical chemistry encompasses more than quantum mechanics. It also includes thermodynamics, electrochemistry, and the like. If you want to believe in a Theory of Everything that allows physicists to model everything that chemists do, will do or know, you are entitled but it doesn't exist yet and probably never will. I'm an analytical chemist, I know QM and more than how to make molecules come together.
He didn't say anything about modelling everything chemists do. He said that the complex interactions that chemistry describes are just the interactions of atoms, and the way that atoms interact is described by physics.

When two atoms interact, their interaction will happen in a way that physics can describe. When more than two atoms interact they must necessarily be following the same rules.

Maybe there is some part of chemistry that isn't based on the interactions of (many) atoms - if so please be specific about what it is, because I'm having a hard time imagining it.

Slimething

5th February 2007, 06:47 AM

He didn't say anything about modelling everything chemists do. He said that the complex interactions that chemistry describes are just the interactions of atoms, and the way that atoms interact is described by physics.

And I wrote that physics has yet to advance to that stage. Now, you return with the presumptive statement that interactions between atoms can be described by physics. That is not so. I challenged him and now I challenge you to illustrate one chemical reaction, describe the products (odor, color, melting/boiling points, etc.) Choose any reaction you want. I'll wait. Let me know when you're done.

When two atoms interact, their interaction will happen in a way that physics can describe. When more than two atoms interact they must necessarily be following the same rules.

What you are describing is chemistry, not physics. Please attend to challenge above.

Maybe there is some part of chemistry that isn't based on the interactions of (many) atoms - if so please be specific about what it is, because I'm having a hard time imagining it.

Well, I left a big, big hint in the post you replied to. There are many. In analytical chemistry, we exploit the characteristics of a compound or class of compounds to define its composition or its concentration. Physical chemists (if you believe that the word "physical" in a title necessarily involves physics, you should go back to physical education) elucidate the nature of the electronic state in atoms and molecules. Formulation chemists study the properties of mixtures, as do metallurgists.

An earlier post made the excellent point that non-chemists see chemistry as all organic synthesis. That is a level of over-simplification that I find extraordinary in an educated individual. It's tantamount to my believing that physicists only study the motion of boxes on inclined planes.

Roboramma

5th February 2007, 07:45 AM

And I wrote that physics has yet to advance to that stage. Now, you return with the presumptive statement that interactions between atoms can be described by physics. That is not so. Okay, point taken. I phrased things poorly. What I am trying to say is that all the forces involved are known. At least the important ones.
From this we can conclude that if we could analyse these forces well enough we could model the interactions. Niether I nor anyone else is saying that we actually can do so, just that the forces involved are known.

If you aren't suggesting that there is some other force at play, then I don't see how chemistry isn't reducible to physics. Will any particle be affected by any other in a way that contradicts known physics?
Or are you suggesting that this is some other force involved.
This is a serious question, I don't know that much about either chemistry or physics and am hoping to have my own errors shown to me.

I challenged him and now I challenge you to illustrate one chemical reaction, describe the products (odor, color, melting/boiling points, etc.) Choose any reaction you want. I'll wait. Let me know when you're done. As I said I phrased things poorly. My bad. But I make no claim to be able to do that, or that anyone can. Obviously we are very very far from that.

What you are describing is chemistry, not physics. Please attend to challenge above. Point taken.

Well, I left a big, big hint in the post you replied to. There are many. In analytical chemistry, we exploit the characteristics of a compound or class of compounds to define its composition or its concentration. Are you suggesting that the characterists of a compound don't depend on the characterists of the atoms that it's made of and the way that those atoms interact, or that the way that those atoms interact is not itself dependent upon physics?
If physics doesn't describe the chemically relevent characteristics of atoms (I think it does, but whatever) are they not dependent upon the characteristics of the particles that make up those atoms and the way that they interact?

Physical chemists (if you believe that the word "physical" in a title necessarily involves physics, you should go back to physical education) Thanks for the advice. I don't.
elucidate the nature of the electronic state in atoms and molecules. Formulation chemists study the properties of mixtures, as do metallurgists. Again, see what I said above.

An earlier post made the excellent point that non-chemists see chemistry as all organic synthesis. That is a level of over-simplification that I find extraordinary in an educated individual. It's tantamount to my believing that physicists only study the motion of boxes on inclined planes.
Well, as I don't pretend to be an educated person, just one who's trying to understand, I won't pretend to even know what you mean by organic synthesis.

I'm very happy for you to explain things to me to the point that I say, "Oh! I get it now, there is something going on in chemistry that isn't just the interactions of particles." I'm arguing for the case that I think is true simply because that seems like the best way to get you to explain yours.

Ziggurat

5th February 2007, 07:47 AM

No-one (in biology) is arguing that biological creatures do not follow the principles of physics and chemistry. And if you want to say NS is 'emergent', fine. But it is strongly emergent; it is not directly explainable by the mechanisms of the underlying system. Ergo, does not reduce.

We cannot reduce it now (and might not ever). But we also have limited intelligence to figure these things out. Our particular limitations don't mean that it is impossible to reduce. It's just like irreducible complexity in biology: without proof that something is irreducible, the inability to reduce it should not be taken as a sign of anything more profound than our own inadequacy.

DeviousB

5th February 2007, 08:42 AM

We cannot reduce it now (and might not ever). But we also have limited intelligence to figure these things out. Our particular limitations don't mean that it is impossible to reduce. It's just like irreducible complexity in biology: without proof that something is irreducible, the inability to reduce it should not be taken as a sign of anything more profound than our own inadequacy.

In otherwords you have no proof that NS can be reduced, and introduce a strawman as justification. Natural selection isn't an 'irreducibly complex' bit of physics, it isn't physics.

What element of physics is essential to the operation of NS? How do we then create computer models with no physics in them at all and still have them evolve through NS?

Can you demonstrate any link between NS and physics other than they can both apply to physical objects?

Ziggurat

5th February 2007, 11:55 AM

In otherwords you have no proof that NS can be reduced,

Proof? No, there can be no proof that it's reducible unless you actually reduce it. Rather, I have reason to believe it is reducible and NO reason to think it isn't. More below.

and introduce a strawman as justification.

It's not a strawman unless I attribute the position to you. I did not.

Natural selection isn't an 'irreducibly complex' bit of physics, it isn't physics.

This is turning into a semantic debate about what it means to "reduce" something from biology to physics, which is really not very interesting. More below.

What element of physics is essential to the operation of NS? How do we then create computer models with no physics in them at all and still have them evolve through NS?

How good a model is depends upon what you demand of that model. That you can throw away details from the model and still have it work doesn't mean those details aren't critical to the real-world operation of the system. For example, your natural selection model probably doesn't take into account details like sperm motility, womb pH levels, etc. even though those are all biological factors which the real-world phenomenon most certainly depends upon. Why? Because the model works even without that level of detail, because the demands on the model are very limited. A model which included those details wouldn't be worse, it would probably be better, but the added complexity probably does not produce enough improvement to justify the extra effort. The fact that something can be reduced does not mean from a practical standpoint that it should be. As a general rule, one should use the simplest model that is accurate enough, not the most accurate model available.

If you could model the entire physics of an ecosystem (something we cannot do and quite possibly never will be able to do for purely practical reasons), I expect we would indeed find that it behaves according to natural selection, WITHOUT putting natural selection into the model explicitly. That is what it means to be an emmergent property, and if a property is emmergent, then it is at least in principle reducible. If it is NOT reducible, then that means that no matter how complex we make our physical simulation, it would not match reality. And that cannot happen unless there is some process going on which does NOT obey physics as we understand it, but actually violates it. While that might be possible (I can't prove that natural selection is reducible, and we cannot construct such massively complex models to test them against reality), there is no evidence that any such processes actually occur (ie, there's no reason to think it isn't reducible).

Slimething

5th February 2007, 06:36 PM

Okay, point taken. I phrased things poorly. What I am trying to say is that all the forces involved are known. At least the important ones.
From this we can conclude that if we could analyse these forces well enough we could model the interactions. Niether I nor anyone else is saying that we actually can do so, just that the forces involved are known.

Roboramma, I apologize for the tone of my response. It was generally unfriendly and I was more peeved at shneibster than anything else. I can only conclude the man has not the faintest idea of what chemistry involves or he would not have written something so ignorant. I believed you were parroting him.

Let's get to it. All the major forces known, yes. All the forces known, no. Even then, we can say the same about the more popular sports as the gaming world has gotten sophisticated enough that the leading software includes player's tendencies and individual athletic skills. So, why not just model the games? Because, as human foibles, there are also certain aspects of chemistry that it would take too long to include in a model or are not yet known. Hell, if we could model to that degree, it would be a cinch to program cancer cell receptors and design the magic bullet to obliterate these cells.

If you aren't suggesting that there is some other force at play, then I don't see how chemistry isn't reducible to physics. Will any particle be affected by any other in a way that contradicts known physics?
Or are you suggesting that this is some other force involved.
This is a serious question, I don't know that much about either chemistry or physics and am hoping to have my own errors shown to me.

And it's a very good question. Philosophically, it's easy to say that, as all materials are made of atoms and physics can characterize a simple atom, that every science which studies materials made of atoms must be reducible to physics. Theoretically, I would agree that, if physics were capable of defining higher complexities, that it would rule all the known scientific universe. But, it can't. Don't get me wrong, I love physics and am spellbound what has been achieved but it can't yet, nor every will, replace chemistry let alone biology which is even more complex. I believe that Godel's Theorem probably comes into play here. Yes, there must be forces at play that neither physics nor chemistry know yet.

Are you suggesting that the characterists of a compound don't depend on the characterists of the atoms that it's made of and the way that those atoms interact, or that the way that those atoms interact is not itself dependent upon physics?

I'll declare it outright. Yes, there are characteristics of compounds that do not depend on the interaction of the atoms it consists of. That's not surprising to someone who knows chemistry. Not all characteristics can be deduced from the components therein. One of the major aspects that physics can't address is toxicity. Ordinary table salt comprises two deadly elements but it's relatively non-toxic to us. Odor cannot be modeled from atomic interaction. Strangely, the color of conjugated organic molecules can be modeled but that's more from empiricism than theory.

If physics doesn't describe the chemically relevent characteristics of atoms (I think it does, but whatever) are they not dependent upon the characteristics of the particles that make up those atoms and the way that they interact?

I think it's fairly established that chemically relevant characteristics are not wholly predictable from current physical knowledge. Why? Dunno. Maybe you'll find out.

Well, as I don't pretend to be an educated person, just one who's trying to understand, I won't pretend to even know what you mean by organic synthesis.

You are an educated person. It was I acting like a boor. Organic synthesis is the preparation of more complex organic molecules from simpler organic or inorganic molecules. Those are the guys in the white coats with all the fancy glassware. These are the guys who can make pharmaceuticals from basic building blocks. They are quite talented and, no, they cannot be replaced by a computer program. Admittedly, a lot of the theory behind what is done there has been successfully modeled but billions are still spent "playing the game".

So, there's my point. Be well. :)

pgwenthold

6th February 2007, 07:31 AM

I'll declare it outright. Yes, there are characteristics of compounds that do not depend on the interaction of the atoms it consists of. That's not surprising to someone who knows chemistry.

I guess I am the exception, then. yes, I know chemistry.

Not all characteristics can be deduced from the components therein. One of the major aspects that physics can't address is toxicity. Ordinary table salt comprises two deadly elements but it's relatively non-toxic to us.

Actually, someone who knows chemistry will know that table salt is not made of atomic elements, but is made of ions.

Their are huge differences between elemental sodium and sodium ion, and they originate in and are reflected in the physics.

Odor cannot be modeled from atomic interaction.

What? Odor is all about molecular shape and intermolecular interactions!

Strangely, the color of conjugated organic molecules can be modeled but that's more from empiricism than theory.

Only to the extent that the concept of "color" is empirical. To the extent that color results from the absorption of light, it is completely calculable! In fact, that is one thing that is done pretty well nowadays (although it requires adequate dynamic correlation in the excited state). Not quite as accurate as structures and vibrational absorption frequencies, but still pretty good. In fact, many people use "color" calculations to help identify transient species.

Slimething

6th February 2007, 07:50 AM

I guess I am the exception, then. yes, I know chemistry.

OK, pg, explain stereochemical phenomena in light of strictly intramolecular interaction between atoms.

Actually, someone who knows chemistry will know that table salt is not made of atomic elements, but is made of ions.

You're just quibbling here. How am I going to give you vial of sodium ion? What you are saying is that elemental sodium and elemental chlorine will NOT form table salt on combination?

Their are huge differences between elemental sodium and sodium ion, and they originate in and are reflected in the physics.

Please do go on about the physics of elemental sodium and ionic sodium, pg. This will be fascinating. Please do explain. Explain why and how they are different using only physics. This will be rather delightful.

What? Odor is all about molecular shape and intermolecular interactions!

Ahem, the point in question is to whether or not physics can account for all chemical phenomena, pg. Even so, can you put up the physics as to why some chemicals smell sweet and some not? Start with carbonyl chloride. That's an easy one that smells like hay. I'll just stand over here so as not to be in your way.

Only to the extent that the concept of "color" is empirical. To the extent that color results from the absorption of light, it is completely calculable!

Thanks, that's what I wrote. But it's only true in some cases, pg. Again, please, do carbonyl chloride. Please calculate its color using only physics.

Cuddles

6th February 2007, 08:16 AM

I think Dawkins discussed this whole thing rather well.

Look at an aeroplane. You can see the whole plane as one thing and study how it flies. You can look at it as made of several large structures like wings and body and see how they interact with each other. You can look at individual components and how they connect, how the engines work and so on. You can look at the materials used to make components and see how they react under different conditions and with each other. You can look at the atoms in the materials and see how they effect their properties. You can look at the particles that make up atoms and see why the atoms behave the way they do. You can look at the fundamental things that make up the particles in atoms and see why it is even possible for atoms to exist. No doubt one day we will be able to go even further than this.

All these are perfectly valid ways of looking at a plane, and they are all reducible to a more fundamental view, but this does not mean that one is the correct way, or that any way is better than any other. A plane is made of atoms, you cannot deny this, but this does not mean that designing an engine based on quantum physics is sensible, practicle and certainly not useful. In the same way, chemistry is entirely made up of physics, because it studies things that are entirely governed by the laws of physics. This does not mean that it is in any way useful to try to derive all of chemiistry through quantum mechanics, but it does mean that it is just plain stupidity to try to claim that it is not based on physics. In the same way, to study the function of the liver you use biology because you simply don't care what individual quarks are doing, even though everything that happens only happens because of them.

And as others have pointed out, maths is completely different. Biology, chemistry and physics are all sciences that focus on different scales. Maths is the language that science speaks.

pgwenthold

6th February 2007, 08:17 AM

Thanks, that's what I wrote. But it's only true in some cases, pg. Again, please, do carbonyl chloride. Please calculate its color using only physics.

Do you think the absorption bands of carbonyl chloride cannot be calculated?

You give me a good computer with code for EOM- or MR-CCSD(T) that I can extrapolate to an infinite basis set, and I'll be able to calculate the long wavelength absorption of carbonyl chloride.

Can it be reduced to physics? Absolutely! Actually, I am surprised that you even bring this up, because it is such a trivial example of where physics _can_ be used to calculate "chemical" properties.

In terms of odor, yes, it is complicated. But it is doable, which is the question (show that the substrate will activate the same receptors as does those in freshly cut hay - that's an issue of structure and intermolecular forces, which are subject to physics principles)

Please do go on about the physics of elemental sodium and ionic sodium, pg. This will be fascinating. Please do explain. Explain why and how they are different using only physics. This will be rather delightful.

Oh, where to start...how about "total angular momentum of the wave function"? Sodium ion S = 0. Sodium atom: S = 1/2

How about "total electronic charge"? Sodium atom = 0, sodium ion = +1

Charge and angular momentum are basic physics concepts.

How about stability? Can physics tell me that Na is more reactive than Na+? Absolutely. Calculate the first and second ionization energies of Na, and they are extremely different (I mean, 40 eV different)

Man, the physics of elemental sodium and sodium ion are so completely different to be laughable.

How am I going to give you vial of sodium ion?

I can give you a beam of it, if you want (you have to be careful when talking to people who might be a mass spectrometrist)

What you are saying is that elemental sodium and elemental chlorine will NOT form table salt on combination?

Of course they will, but then again, butadiene reacts with ethylene to give a substance that is neither butadiene nor ethylene. It has properties that are distinct from its reagents. Similarly, sodium and chlorine react to give a substance that contains neither atomic sodium nor atomic chlorine. Properties change when electrons move. The differences in the properties of Na and Na+ illustrate that clearly.

DeviousB

6th February 2007, 08:19 AM

It's not a strawman unless I attribute the position to you. I did not.

What you actually said is, "It's just like irreducible complexity in biology: without proof that something is irreducible, the inability to reduce it should not be taken as a sign of anything more profound than our own inadequacy."

Sorry, that it is like irreducible complexity in biology is an unproven assertion on your part. Please demonstrate that this is so. Without such proof you have created a proposition that is simpler to refute instead of attacking the original argument. So it is either a strawman argument, if you are implying that your proposition is analagous to mine, or a meaningless digression, if you are not.

How good a model is depends upon what you demand of that model. That you can throw away details from the model and still have it work doesn't mean those details aren't critical to the real-world operation of the system [...]

You are confusing natural selection with the biology of the organism. Nowhere did I say that I was modelling biological organisms and selecting upon them. In fact most computer models of selection do no such thing, Dawkins, for example, had a population of letters evolve into the sentence "METHINKS IT IS LIKE A WEASEL".

Natural selection requires (1) that a population of objects reproduce with a degree of inheritence, (2) that there is also a degree of variation between the parent and child object, and (3) that the variation affects the ability of the object to reproduce. That's it.

Inheritence, variation, fitness.

In biological organisms, the inheritence is provided by DNA, the variation by mutation, the fitness by (for argument's sake) differential survival. These are physical properties of the organism and can be potentially explained as physics (as I have already accepted).

They are, however, just postulates of natural selection (to use John Maynard-Smith's terminology). Other postulates in other systems will serve just as well. Natural selection reduces directly to mathematics, do not pass physics, do not collect 7 extra dimensions.

If you construct a model of the real world accurate enough to demonstrate NS, it will be because you have directly modelled the mathematics from which NS arises.

Slimething

6th February 2007, 08:45 AM

Do you think the absorption bands of carbonyl chloride cannot be calculated?

I know they can. I asked you to do it.

You give me a good computer with code for EOM- or MR-CCSD(T) that I can extrapolate to an infinite basis set, and I'll be able to calculate the long wavelength absorption of carbonyl chloride.

You made the claim, pg. You arrange for your own tools. You are in a skeptic's forum so I'm calling you on your claim.

Can it be reduced to physics? Absolutely! Actually, I am surprised that you even bring this up, because it is such a trivial example of where physics _can_ be used to calculate "chemical" properties.

For it being so trivial, you are not doing very well. All I asked you to do was to back up your claim. You chose the easiest of the various challenges, completely disregarding the stereoisomerism question, and all I see is words. No physics, just words.

In terms of odor, yes, it is complicated. But it is doable, which is the question (show that the substrate will activate the same receptors as does those in freshly cut hay - that's an issue of structure and intermolecular forces, which are subject to physics principles)

All I asked you to do was to back up your claims, not give me a song and dance about how it would be possible if... You cannot do it. Fess up.

NOTE: You may now want to return to what I wrote and read it more carefully. What I wrote was that, if you use facile thinking and philosophically define physics as the science that defines atoms, then anything reduces down to physics. However, physics does not define atoms yet.

Oh, where to start...how about "total angular momentum of the wave function"? Sodium ion S = 0. Sodium atom: S = 1/2

How about "total electronic charge"? Sodium atom = 0, sodium ion = +1

Charge and angular momentum are basic physics concepts.

How about stability? Can physics tell me that Na is more reactive than Na+? Absolutely. Calculate the first and second ionization energies of Na, and they are extremely different (I mean, 40 eV different)

Man, the physics of elemental sodium and sodium ion are so completely different to be laughable.

I'm not laughing. This is getting rather tiresome. I know all this stuff. You told me you could explain the difference between the ion and the element. I see nothing here regarding the types of interactions that either form would have with anything else. You have to do better than this. Again, describe the differences in such relevant things as solubility, color, odor, toxicity, etc of both sodium ion and metallic sodium using only physics. Time's a-wasting.

I can give you a beam of it, if you want (you have to be careful when talking to people who might be a mass spectrometrist)

One of these days, you'll truly get to know just how much I enjoy smart ass answers.

Of course they will, but then again, butadiene reacts with ethylene to give a substance that is neither butadiene nor ethylene. It has properties that are distinct from its reagents. Similarly, sodium and chlorine react to give a substance that contains neither atomic sodium nor atomic chlorine. Properties change when electrons move. The differences in the properties of Na and Na+ illustrate that clearly.

The statement above could have been ripped out of any elementary chemistry book, pg. What happened to the physics you were so loudly proclaiming?

DeviousB

6th February 2007, 08:53 AM

They are, however, just postulates of natural selection (to use John Maynard-Smith's terminology). Other postulates in other systems will serve just as well.

Okay, it looks like I've screwed up that sentence and the edit button has disappeared.

*Note to self: use the goddamn preview!*

DeviousB

6th February 2007, 09:00 AM

And as others have pointed out, maths is completely different. Biology, chemistry and physics are all sciences that focus on different scales. Maths is the language that science speaks.

But it's not invariably the same math.

Ziggurat

6th February 2007, 10:11 AM

You are confusing natural selection with the biology of the organism. Nowhere did I say that I was modelling biological organisms and selecting upon them. In fact most computer models of selection do no such thing, Dawkins, for example, had a population of letters evolve into the sentence "METHINKS IT IS LIKE A WEASEL".

If you're not selecting biological organisms, then it isn't biology. It may provide insight into biology, but that is NOT the same thing. Yes, natural selection for letters forming a sentence doesn't depend upon physics. Same with the rules of sudoku. But neither of them is biology, or even a physical science.

Natural selection requires (1) that a population of objects reproduce with a degree of inheritence, (2) that there is also a degree of variation between the parent and child object, and (3) that the variation affects the ability of the object to reproduce. That's it.

Inheritence, variation, fitness.

And if you don't account for how those values arrise for a biological population, but merely assign them, then you are brushing the actual mechanics under the rug. That may work as a practical matter, but the fact that you don't NEED to reduce the system doesn't mean it cannot be reduced.

In biological organisms, the inheritence is provided by DNA, the variation by mutation, the fitness by (for argument's sake) differential survival. These are physical properties of the organism and can be potentially explained as physics (as I have already accepted).

They are, however, just postulates of natural selection (to use John Maynard-Smith's terminology). Other postulates in other systems will serve just as well. Natural selection reduces directly to mathematics, do not pass physics, do not collect 7 extra dimensions.

As I said, this is turning into a debate about what it means to be reducible. The model itself IS NOT REALITY. That you can make a successful model independent of physical details does not mean that the phenomenon is not reducible.

It is only irreducible if it is not possible, even in principle, to model the system based only upon the physical details. Slimething gets that. He understands that there must be some NEW physical process, which we do not currently know about or which CANNOT be modeled (even in principle), in order for complex systems to be irreducible. He thinks there are such processes, I think there are not, and there's no way to prove it either way. But the logic of that requirement is quite clear. The only way to maintain the concept of irreducibility outside of that is to do what you have essentially done: include non-physical sciences. Which is, well, kind of pointless.

DeviousB

6th February 2007, 10:42 AM

There are no known phenomena in chemistry or biology which do not operate according to the laws of physics.

Natural Selection is certainly a phenomenon of biology, it is also non-physical (as I pointed out in my original post and you disputed).

The only way to maintain the concept of irreducibility outside of that is to do what you have essentially done: include non-physical sciences. Which is, well, kind of pointless.

So in essence you are saying that only physical phenomena are reducible to physics. Which, if it is not an actual 'bait-and-switch', is hardly a profound observation.

Ziggurat

6th February 2007, 10:55 AM

So in essence you are saying that only physical phenomena are reducible to physics.

Well, yes. That's what I thought this thread was about: physical phenomena.

DeviousB

6th February 2007, 11:05 AM

Well, yes. That's what I thought this thread was about: physical phenomena.

My mistake, I thought the topic included Biology and Chemistry.

Ziggurat

6th February 2007, 11:10 AM

My mistake, I thought the topic included Biology and Chemistry.

You don't think biology and chemistry are studies of physical phenomena? If not, then perhaps you have a different definition of the term than I do.

Earthborn

6th February 2007, 11:36 AM

I explained that physics 'comes' from mathematics, chemistry comes from physics and biology comes from chemistry.I think it is fair to say that biology is reducible to chemistry, chemistry is reducible to particle physics. That is to say, you can study these things at a smaller and smaller scale and you'll pass every all those sciences. But that of course ignores the fact that at larger scales emergent proporties arise that justify making it into different sciences. It will be very difficult to express a lion's hunting behaviour in purely chemical terms.

Physics encompasses all things, but chemistry is only reducible to a specific subset of physics: particle physics. The movements of the planets need not be considered.

The claim that physics comes from mathematics is silly, IMHO. Physicists use mathematics as a tool, but I don't think there is anyone of them who claims that physics is a subset of mathematics or that the laws of physics are somehow reducible to pure mathematical abstractions. They use mathematics for as far as it has real world applications, but mathematicians don't necessarily concern themselves with the real world (at least in their work).

Ziggurat

6th February 2007, 11:46 AM

DeviousB

6th February 2007, 11:51 AM

[Nevermind]
:rolleyes:

Yllanes

6th February 2007, 12:02 PM

Perhaps an example can shed some light.

Consider nuclear physics. Atomic nuclei are made of nucleons (protons and neutrons), which themselves are made of quarks. We want to study the interaction between nucleons and instantly find that it is a very difficult problem. The force is not central, it depends on spin, isobaric spin, velocity, etc. We know this from experimental facts about two-nucleon systems. The problem is so difficult that we attemp a phenomenological explanation. We set some conditions

The interaction potential must be Poincaré invariant (remain the same after translations, rotations, etc.)
Invariant under parity transformations.
Invariant under time reversal.
Which we must reconcile with some empirical facts

The interaction depends on spin.
It also depends on isospin.
The force is not central
The force depends on velocity.
Charge symmetric and even charge independent (at least as a first approximation).
Repulsive at very short distances.
And we try to write an interaction potential, such as

\[V = V_1(r) + V_2(r)\ \vec\sigma_1\cdot\vec\sigma_2 + V_2(r)\ \vec \tau_1\cdot\vec \tau_2 + V_3 (r) (\vec\sigma_1\cdot\vec\sigma_2) (\vec \tau_1\cdot\vec \tau_2) + V_4(r) \vec L\cdot\vec S+ \ldots\]

With this potential we can study the interaction between nucleons (it typically has as much as 14 or 18 terms). We have not explicitly used the fact that the nucleons are made of quarks, or the SM description of the strong force. In this example of a very simple system (one proton and a neutron), we can use those facts to get some idea of the shape of the several V(r) terms, studying some equations from quantum field theory. For example, modelling the interaction with the exchange of a pion (a particle consisting of a quark and an antiquark with zero spin), we can arrive at a tensorial term that describes the interactions at 'long' distances pretty well ('long' is ~1.5·10-15 m).

For an iron, oxygen, or any other nucleus with more than two nucleons such a fundamental description is completely impossible. We have to use several semiempirical models, mean field approximations, etc. We certainly can't solve the Schrödinger equation for the system of protons and nucleons, much less use QFT to describe what all the quarks are doing. Yet nobody, I think, denies that the strong and EM interactions of the SM are ultimately what determines the dynamics of the system.

If we couldn't solve the Schödinger equation for a single atomic nucleus, we obviously can't do it for a chemical reaction or a whole ecosystem. To study those things we have to start somewhere else. But even if we have to start somewhere else in any human description of the system, the fundamental forces studied by physics are, practically by definition, all that's happening underneath.

Of course, should we eventually achieve an unified theory of the 4 interactions (the Theory of Everything...) we would not get any closer to explaining natural selection or how to make a good cheese. Some people think this fact makes the previous explanation meaningless and claim that because of it, physics cannot explain chemistry or biology, etc. My opinion is that physics can, by definition, explain them. But the problem is certainly beyond the reach of our human theories of physics. At which point the discussion turns into a semantic question and I couldn't care less.

DeviousB

6th February 2007, 12:08 PM

The claim that physics comes from mathematics is silly, IMHO. Physicists use mathematics as a tool, but I don't think there is anyone of them who claims that physics is a subset of mathematics or that the laws of physics are somehow reducible to pure mathematical abstractions. They use mathematics for as far as it has real world applications, but mathematicians don't necessarily concern themselves with the real world (at least in their work).

Um, just a minute...

If it is NOT reducible, then that means that no matter how complex we make our physical simulation, it would not match reality. And that cannot happen unless there is some process going on which does NOT obey physics as we understand it, but actually violates it. While that might be possible (I can't prove that natural selection is reducible, and we cannot construct such massively complex models to test them against reality), there is no evidence that any such processes actually occur (ie, there's no reason to think it isn't reducible).

Surely, if similarly, if no part of physics does NOT obey the rules of mathematics or actually violates them, then physics is reducible to maths under your own definition?

DeviousB

6th February 2007, 12:16 PM

I can't see it myself.

Physics is a tool frequently used by biologists, big deal. But Ziggurat seems to be arguing some sort of ontological reductionism I can't fathom.

As a (former) biologist, I used all sorts of math tools my physicist girlfriend had never heard of, and vice versa. Methodologically, biology can't reduce to physics because some of the theories and concepts of biology are mathematically distinct from the mathematical basis of physics.

Biological concepts such as Evolutionarily Stable Strategies, etc. which form an essential part of our understanding of large swathes of biology are based on game theory. To my knowledge no part of physics is. Physics can no more model an ESS than it can model chess.

Ziggurat

6th February 2007, 12:23 PM

Surely, if similarly, if no part of physics does NOT obey the rules of mathematics or actually violates them, then physics is reducible to maths under your own definition?

No, it is not, because as I already stated math cannot distinguish WHICH self-consistent theories actually conform to reality. It's quite easy to come up with theories which do not, yet remain mathematically self-consistent. Mathematical self-consistency is believed to be a necessary requirement of any good physical theory, but it is most certainly NOT sufficient. There's only one way to determine which self-consistent model(s) correspond to reality: actual experimentation. And once you start doing actual experiments, you're no longer doing math, but science.

Yllanes

6th February 2007, 12:32 PM

Surely, if similarly, if no part of physics does NOT obey the rules of mathematics or actually violates them, then physics is reducible to maths under your own definition?

Think of it this way: In mathematics we have several axioms, with which we build analysis, algebra, etc.

In physics, at the most fundamental level, you can start QFT by taking all of mathematics as given and adding several extra axioms that are not contained within mathematics. For example:

Microcausality.
Asymptotic completeness.
Eigenvalues of P lying on the closure of the future light cone.If you drop or change any of these axioms, you can make theories that are perfectly consistent form a mathematical point of view. If we drop the last one, we can have tachyons, particles going faster than light. It is possible to construct a QFT for free tachyons that works mathematically. But they are unphysical. From a different point of view: the elementary particles are irreducible representations of the Poincaré group. If we classify all the mathematically possible representations we find that some of them have imaginary mass or continuous spin. Mathematics by itself can say nothing of whether they exist or not. Experiments, observations are the only way of showing that they are unphysical.

On a different scenario. The mathematics of differential geometry describes gravitation. But we also need Einstein's equations, to show which is the precise relation between energy and geometry. Other equations are mathematically sound. Even starting from Einstein's equations, mathematics cannot tell the whole story. Assuming isotropy and homogeneity mathematics shows that there are only three possible shapes for the universe and that it can recollapse, be static or expand indefinitely. Physics is what determines which one of those possibilities is the real one, etc.

But in principle, a sufficiently sophisticated set of axioms for the fundamental theories of physics would describe anything at whatever scale. It will never be realised by humans, but there is no jump between physics and chemistry of the same nature as the one between mathematics and physics.

Schneibster

6th February 2007, 01:17 PM

Just so we're all on the same page here, I own a book called Electronic Structure and the Properties of Solids, "The Physics of the Chemical Bond." ISBN 0-486-66021-4, by Walter A. Harrison.

I think stating that we cannot derive the physical properties of substances from the physics of their atomic structures is basically disproven by the mere existence of this book. I'll point out that it is a textbook in the physical chemistry curriculum, which also tends to shoot down the assertion that physical chemistry isn't based on physics.

In case there are questions about what characteristics this is capable of predicting, it turns out that this book shows how spectra, hardness, melting point, elasticity, piezoelectricity, surface roughness, and specific heat can be derived from the electronic structure of the atoms that make up a solid. The author hints that we are near to being able to describe many other characteristics of materials, and near to being able to describe the characteristics of liquids as well. The second edition is copyright 1989- eighteen years ago. I suspect that a great deal has been found out since then.

So tell me again that chemistry isn't based on physics.

Slimething

6th February 2007, 08:20 PM

So tell me again that chemistry isn't based on physics.

OK. Chemistry is not based on physics. Your move.

Just so we're all on the same page here, I own a book called Electronic Structure and the Properties of Solids, "The Physics of the Chemical Bond." ISBN 0-486-66021-4, by Walter A. Harrison.

I think stating that we cannot derive the physical properties of substances from the physics of their atomic structures is basically disproven by the mere existence of this book.

Just like the existence of a Bermuda Triangle is confirmed by vonDanniken's (sp?) repertoire. But, let's presupposed that Harrison wrote a book about the physics of the chemical bond. Does that imply that there is more to a chemical bond than physics? Otherwise, the title would be "The Chemical Bond", no?

I'll point out that it is a textbook in the physical chemistry curriculum, which also tends to shoot down the assertion that physical chemistry isn't based on physics.

Un, no. It's called physical chemistry because the subject deals with the behavior of particles. It's not called physical chemistry because physicists were just too busy to teach the subject. Physical education and physical plants also have nothing to do with physics.

In case there are questions about what characteristics this is capable of predicting, it turns out that this book shows how spectra, hardness, melting point, elasticity, piezoelectricity, surface roughness, and specific heat can be derived from the electronic structure of the atoms that make up a solid.

Wow, hey, that's a lot of stuff! Does he give examples of is he merely postulating? I've seen and used the models that predict polarity, some types of spectra, and the like but I have not seen any so far that go anywhere near this far. Care to post a successfully modeled melting point from the book? Surface roughness would be a neat thing also as one can make most materials smooth or rough so I can't see that that characteristic could be predicted from the chemical bonding.

I've done a search to try and find a scientific review of the book but was unsuccessful. I did find quite a few articles that cited the book as a source but none of them had anything to do with modeling the physical characteristics of complex substances from the known physics of the bonding. But, hey, schneib, if the book makes those claims and they're true, you sure got a bargain for $17! That kinda stuff would normally cost thousands and earn the author a Nobel. No kiddin!

I suspect that a great deal has been found out since then.

You've seen my challenges to pgwethold. Why don't you do them?

Schneibster

6th February 2007, 09:26 PM

Just like the existence of a Bermuda Triangle is confirmed by vonDanniken's (sp?) repertoire. That you compare anything by that idiot with a textbook says everything about you that I care to know: you are no friend of the truth.

Schneibster

6th February 2007, 10:15 PM

Just so we don't have to listen to any more of this horsepucky.
But, let's presupposed that Harrison wrote a book about the physics of the chemical bond. He didn't. You can tell that from the title.

Does that imply that there is more to a chemical bond than physics? What "more" do you suppose there would be? Little fairies that hold the little atomies together? Perhaps you think there's micro-glue holding them together. Or maybe you think von Daniken is doing it.

Otherwise, the title would be "The Chemical Bond", no?Maybe if it was a book about chemical bonds. Which, given the title, it obviously isn't.

Un, no. It's called physical chemistry because the subject deals with the behavior of particles. Whaaaaaaaaat? Are you actually this dumb, or is this some sort of joke?

It's not called physical chemistry because physicists were just too busy to teach the subject. I don't even know what this means, and I'm growing more and more certain you don't either.

Physical education and physical plants also have nothing to do with physics.And this is relevant because...?

Wow, hey, that's a lot of stuff! Does he give examples of is he merely postulating? Why don't you read it and find out. It's a textbook. You might be able to learn something, if you can put down the bong long enough.

I've seen and used the models that predict polarity, some types of spectra, and the like but I have not seen any so far that go anywhere near this far. That would be because you had an acid trip and THOUGHT you were a real chemist?

Care to post a successfully modeled melting point from the book? How about a whole table of them? It's the appendix, and it's called the Solid State Table of the Elements.

Surface roughness would be a neat thing also as one can make most materials smooth or rough so I can't see that that characteristic could be predicted from the chemical bonding.You don't know very much about solid-state physics, do you? Of course, you don't know very much about chemistry, either, so I guess that's no surprise.

I've done a search to try and find a scientific review of the book but was unsuccessful. It's on the physics 601/602 book list (http://www.physics.rutgers.edu/~dhv/602/books.html) at Rutgers. You might also want to have a look at the course materials for the Methods of Electronic Structure Theory in Materials Science (http://www.mrl.ucsb.edu/~nicola/etheory.html) class at the Materials Research Laboratory at the University of California, Santa Barbara, and the citations in some pretty recent papers in Physical Review Letters and so forth. Then there's Purdue University's course Nanomaterials Chemistry and Engineering, Chem 697M, which also has it on the book list (http://cobweb.ecn.purdue.edu/~che697m/syllabus.htm). Overall, in the first two pages of hits from google, I found eight college courses and five citations in the peer-reviewed literature.

Either you're really lousy at using google, or you're high on gasoline. Or perhaps, as I originally suggested, you're no friend of the truth.

I did find quite a few articles that cited the book as a source but none of them had anything to do with modeling the physical characteristics of complex substances from the known physics of the bonding. What "known physics of the bonding?" Having a little trouble with the whole reading comprehension thing there, sport? Looks that way. Because whatever you're talkin about, it has pretty much zip to do with this conversation.

But, hey, schneib, if the book makes those claims and they're true, you sure got a bargain for $17! That kinda stuff would normally cost thousands and earn the author a Nobel. No kiddin!Listen, put the bong down and pay attention. You're talking about a book that's being used in current curriculum university physics and chemistry classes, get it?

You've seen my challenges to pgwethold. Why don't you do them?No, actually I hadn't- I don't generally pay you much attention, the kind of crap you posted here is pretty much of the same type as most of the drivel you post, and I don't bother reading it much. It's not really worthwhile, and to top it all off, you'll do ANYTHING, including lie, to "prove you're right." It doesn't prove anything but that you're stupid enough to think that no one will catch you at it.

Slimething

6th February 2007, 11:33 PM

That you compare anything by that idiot with a textbook says everything about you that I care to know: you are no friend of the truth.

I wasn't comparing them, mr. brilliant. I was skewering your illogic: a published book = scientific fact. New one on me.

Supposed I sent you a science textbook from the Middle Ages? Would the stuff in there be fact?

BTW shneib, you put me on your ignore list, remember? Why am I so blessed with your wisdom again? I can find paranoiacs in the alleyways so there really was no need.

Slimething

7th February 2007, 12:08 AM

I know I'm corresponding with someone who's compromised but some of these "comebacks" are so delicious, I couldn't resist.

What "more" do you suppose there would be? Little fairies that hold the little atomies together? Perhaps you think there's micro-glue holding them together. Or maybe you think von Daniken is doing it.

Perhaps you should read that book you bought. Science is a very precise language. Pay attention to detail. Also, answer my questions and I'll answer yours. I don't give out free educations.

Maybe if it was a book about chemical bonds. Which, given the title, it obviously isn't.

Given the title of the book, it most certainly is about chemical bonds. Do you read much?

I don't even know what this means, and I'm growing more and more certain you don't either.

Apparently, there's much that fits in the category of "shneib doesn't know what this means". BTW, I wrote it. Of course, I know what it means. Maybe you should read it more slowly or have someone read it to you.

And this is relevant because...?

Because you seem to make the idiotic assumption that anything with the word "physical' in it is related directly to physics. You need a physician.

Why don't you read it and find out. It's a textbook. You might be able to learn something, if you can put down the bong long enough.

You're the one making the claim, boyo. I don't have to do anything. I've already done it. Chemistry is my field as sophistry is yours. I know what I'm talking about. I earn my money in chemistry. You?

That would be because you had an acid trip and THOUGHT you were a real chemist?

LOL! If I'm not, I do a damned good impersonation!

BTW, do you think that this type of response will somehow fool other readers into ignoring the fact that you're not backing up any of your claims? This is a skeptical forum. Most of the people here are not fools, schneib. You may be able to yell down people at school but it doesn't work here.

How about a whole table of them? It's the appendix, and it's called the Solid State Table of the Elements.

So, this brilliant author who claims to be able to predict all these characteristics from the scant data we have on molecular bonds does not work out any examples in the text? Either you got gypped or you did not understand what he wrote. My money is on that the values in the appendix are empirically derived.

You don't know very much about solid-state physics, do you? Of course, you don't know very much about chemistry, either, so I guess that's no surprise.

I'm a chemist. I don't know much about solid-state physics. That's not what this thread is about, anyway. Let me remind you. You made the broad claim that chemistry is derived from physics. You also made the special claim that, given what physics knows about the nature of atoms and bonding, that physics could predict a wide variety of physical characteristics of compounds. So, what of it? Where's the evidence?

Don't put yourself down, shneib. Anyone reading this thread will recognize that I know a heck of a lot more about chemistry than you do. So, if you want to tell me I don't know much, it's obvious you know even less. In any case, you're right. I don't know nearly as much about chemistry as I want to know. You seem to know now all you ever will about the subject.

It's on the physics 601/602 book list (http://www.physics.rutgers.edu/~dhv/602/books.html) at Rutgers. You might also want to have a look at the course materials for the Methods of Electronic Structure Theory in Materials Science (http://www.mrl.ucsb.edu/~nicola/etheory.html) class at the Materials Research Laboratory at the University of California, Santa Barbara, and the citations in some pretty recent papers in Physical Review Letters and so forth. Then there's Purdue University's course Nanomaterials Chemistry and Engineering, Chem 697M, which also has it on the book list (http://cobweb.ecn.purdue.edu/~che697m/syllabus.htm). Overall, in the first two pages of hits from google, I found eight college courses and five citations in the peer-reviewed literature.

Good. That means it's probably a good book. Don't you wish you could read with comprehension?

What "known physics of the bonding?" Having a little trouble with the whole reading comprehension thing there, sport? Looks that way. Because whatever you're talkin about, it has pretty much zip to do with this conversation.

You're right. Leave the last "the" out and the sentence gains the elegance that would befit a stalwart scholar like you. Now, why don't you address the point instead of giving me a bunch of hoo-ha that only demonstrates your immaturity?

Listen, put the bong down and pay attention. You're talking about a book that's being used in current curriculum university physics and chemistry classes, get it?

No disrespect meant to the book, schneib. My point was that you misunderstood what the author wrote. I don't believe the author wrote what you claim he wrote. I'm being kind: I could presume that you are lying.

No, actually I hadn't- I don't generally pay you much attention, the kind of crap you posted here is pretty much of the same type as most of the drivel you post, and I don't bother reading it much. It's not really worthwhile, and to top it all off, you'll do ANYTHING, including lie, to "prove you're right." It doesn't prove anything but that you're stupid enough to think that no one will catch you at it.

Oh, dear, there's that accusation again. I had a fundie imbecile in a different thread also call me a liar but he refused all calls to point out the lie. Such is the way of idiots. You're not an idiot, are you, shneib? If you're going to call me a liar, the least you could do is to quote my lie. Then, I could get in on the fun, too.

Really, scheib, the one who's more likely lying is you. You won't answer any of my points but I will point out to you that you claimed to have put me on your ignore list way back when. I'm flattered that you're reading anything I write but that still doesn't hide the inconsistency.

Like I told you before, schneib, you need to get medical attention for your anger problem. It's not normal for you to get so damned hepped up on this discussion that you would resort to insults and slander instead of posting evidence that proves me wrong. Now, put me back on your ignore list. Ignore is something you seem to be very good at.

Schneibster

7th February 2007, 12:17 AM

I wasn't comparing them, mr. brilliant. I was skewering your illogic: a published book = scientific fact. New one on me.I bet. Books seem in general to be a "new one on you."

Supposed I sent you a science textbook from the Middle Ages? Would the stuff in there be fact?"Science textbook from the Middle Ages?" What on Earth are you talking about? First, I'm pretty sure they didn't have textbooks in the Middle Ages. Second, I'm pretty sure they didn't even have Science in the Middle Ages. So basically, what you've just said is completely meaningless- which is no particular change from anything else you've said so far.

BTW shneib, you put me on your ignore list, remember? Why am I so blessed with your wisdom again? I can find paranoiacs in the alleyways so there really was no need.Someone decided you might actually be saying something worthwhile, and I wanted to help them overcome their delusion.

Schneibster

7th February 2007, 02:00 AM

I know I'm corresponding with someone who's compromised but some of these "comebacks" are so delicious, I couldn't resist.You probably should have. I'm about to make you look like even more of an idiot than you already do- which, by the way, is a pretty difficult task. But I'm up for it. :D

Perhaps you should read that book you bought. Science is a very precise language. Pay attention to detail. Also, answer my questions and I'll answer yours. I don't give out free educations.Ask some that have something to do with reality and I'll think about it. So far, none of them have.

Given the title of the book, it most certainly is about chemical bonds. Do you read much?Hmm. Let's check this out.

Electronic? Nope. No bonds there.
How about Structure? Nope. Not a bond in sight.
Hmmm, "and the?" Nope. Still no bonds.
OK, how about "Properties?" Nope. Bonds seem remarkably thin on the ground here.
What about "of?" Nope. STILL no bonds to be found.
Here comes the last one: "Solids." Nope. And that's all she wrote.

Overall, I'd say you had a brain fart. I see nothing in the title that has anything to do with bonds.

Apparently, there's much that fits in the category of "shneib doesn't know what this means". BTW, I wrote it. Of course, I know what it means. Maybe you should read it more slowly or have someone read it to you.Oh, well, do tell us.

Oops. Guess you forgot. Never mind, take another hit, big guy.

Because you seem to make the idiotic assumption that anything with the word "physical' in it is related directly to physics. You need a physician.Hmmm, well, I know how we can take care of this: we'll consult a dictionary! Uh oh, look out, that's another of those "book" things you have so much trouble with. But at least everybody else will know what's going on. Let's try that, shall we?

Let's see what Wikipedia has to say about Physical chemistry: "Physical chemistry is the application of physics to macroscopic, microscopic, atomic and particulate phenomena in chemical systems[1]within the field of chemistry traditionally using the principles, practices and concepts of thermodynamics, quantum chemistry, statistical mechanics and kinetics."

Oops. I think I see "application of physics" in there. Well, maybe Wikipedia is wrong. Let's try another one. How about the Biochemistry Division of Northwestern University's definition of physical chemistry? (http://www.biochem.northwestern.edu/holmgren/Glossary/Definitions/Def-P/physical_chemistry.html) "'The physics of chemistry' A branch of chemistry which is interested in things such as, how much pressure would have to be placed on a solid to convert it to a liquid."

Oooooh. That's gotta hurt. You want some ice to put on it?

Maybe we can dig you out of this hole. What's the American Heritage dictionary say? No help there: "Scientific analysis of the properties and behavior of chemical systems primarily by physical theory and technique, as, for example, the thermodynamic analysis of macroscopic chemical phenomena." Physical theory. Yep, that'd be physics. Not to mention thermodynamics. Of course, with that little problem you have, you probably think thermodynamics is a branch of, I dunno, music theory or something, but hey, that's OK, just take another hit and it'll all be fine.

Maybe McGraw Hill will be better? Not a chance. "The branch of chemistry that deals with the interpretation of chemical phenomena and properties in terms of the underlying physical processes, and with the development of techniques for their investigation. The term chemical physics is often employed to denote a branch of physical chemistry where the emphasis is on the interpretation and analysis of the physical properties of individual molecules and bulk systems, instead of their reactions. Theoretical chemistry is another major branch, where the emphasis is on the calculation of the properties of molecules and systems, and which used the techniques of quantum mechanics and statistical thermodynamics. It is convenient to regard physical chemistry as dealing with three aspects of matter: its equilibrium properties, structure, and ability to change."

Oooh, quantum mechanics. Dude, you're sunk. That's REAL physics.

You're the one making the claim, boyo. I don't have to do anything. I've already done it. No, all you've done is make a bunch of claims that have turned out not to be true. Every one of them so far that has been verifiable has plain, flat failed. On the other hand, every one I've made so far has turned out to be solid. I suppose you're going to claim that Rutgers and Northwestern and Purdue and UCSB's Mat Lab have no idea what they're talking about.

If you want to know my opinion, I think you're playing Ludwig Plutonium and doing a very bad job of it.

Chemistry is my field as sophistry is yours. I know what I'm talking about. I earn my money in chemistry. You? Basically, this appears to be nothing but a lie. I'm assuming you wash test tubes or something. Maybe you work in the cafeteria at DuPont.

LOL! If I'm not, I do a damned good impersonation!Or perhaps not so good. Looking pretty bad just about now; all I see is claims, no substance behind them.

BTW, do you think that this type of response will somehow fool other readers into ignoring the fact that you're not backing up any of your claims? So, Rutgers University, Northwestern University, UC Santa Barbara's Materials Lab, the McGraw Hill Encyclopedia of Science and Technology, the American Heritage Dictionary of the English Language, and Wikipedia constitute "not backing up my claims?"

Meanwhile, you've got Erik von Daniken.

Like I said, Ludwig Plutonium.

This is a skeptical forum. Congratulations! Not only is this the first thing you've said that actually approached reality, but

:wave1
YOU NOTICED!!!!
:bigclap

Most of the people here are not fools, schneib. No, but you sure are.

You may be able to yell down people at school but it doesn't work here.Wait a minute... this looks like you've slipped and made an assumption about me because it's true about YOU. Oh, my. A college kid who thinks he's ready to play in the bigs.

Don't hang any curveballs, kid... Oh, wait, guess it's a bit late for that.

Son, I been out of school pretty obviously longer than you been ALIVE. I prolly have hairs growing on my butt that are older than you are. So when you rile me up, I tend to make a show out of it- 'cause, see,