How Are Physics and Chemistry Interconnected in Modern Science?

[theallknower]

I like physics very much,and I'm shore I would enjoy chemistry as well(actualy I never understood why chemistry is not a subdivision of physics,like thermodynamics,or magnetism and electricity)
but I can't learn a thing via school chemestry...they require that I think of atoms as they were thought of in 1900's...full,undevided balls,ignoring a lot of things...I'm absolutley shore those quarcs do something...or further on,I'm shore those preons and haplons do something...so where should I start?
thanks in advance

 

[turbo]

You should get a chemistry text from the last 10 years or so, that takes quantum effects into account and does not characterize electron shells as "orbits". Chemistry seems like a "hard" science because it is well-understood, but the physical properties underlying chemical effects can be a bit slippery when you get to the sub-atomic level.

 

[Borek]

I'm absolutley shore those quarcs do something...

Quarks don't do anything that'll give measurable effects in the realm of chemical reactions.

Hard to tell anything about the rest of your message not knowing what level of physics do you know and what level of chemistry you are taught, but in many cases simplifications (like treating atoms as balls) are justified - they help to concentrate on what is really happening, without adding tons of confusing information about things that don't matter at given energy/matter amount scale.

 

[gravenewworld]

Much of the QM & thermo that you learn as a chemistry student is nothing more than good background knowledge, that's about it unless you are going to specialize in something like theoretical chemistry.


95% of chemists don't care about quarks, gluons, etc. We'll leave all the theory to the physicists.


When I'm busy making an organic product, I don't care about wave equations, molecular orbital theory, or much of the thermodynamics of the reaction. All I care about is the most efficient synthetic route possible, how to purify my product, and how to identify it via NMR and mass spec.


Chemistry and Physics, albeit related, are different sciences.

 

[Renge Ishyo]

It's like Borek and gravenew said, chemists simply have a different focus. Almost the entire subject (sans nuclear chemistry) can be understood by just considering electron movement between atoms. You might be surprised to learn that none of those nuclear particles are necessary to understand chemistry...almost every chemical reaction is a consequence of electromagnetism (the nuclear forces don't "reach out" far enough to influence the behavior of a valence electron to any appreciable degree). Hence, chemists simplify the nucleus. They ignore a lot of details not because they are "unsophisticated," but because the information doesn't matter in the issue at hand. The same things are done in physics just in different ways. For example, in thermodynamics the system is described in detail (say a box filled with gas attached to a piston), but the surroundings are ignored. Aren't there things in the surroundings? Sure, but are they necessary to understand the principles under study? An ecologist would focus largely on what energy requirements surround an organism, but they would probably ignore the actual energy processing mechanisms within the organism (so the biochemists system is the ecologists surroundings and vice versa!).

All subjects work this way, and as far as making gross simplifications physics is BY FAR the most guilty science (what's the joke...To a physicist a chicken is a uniform sphere of mass "m").

 

[epenguin]

Just an epigram but I once heard it said a physicist is happy to succeed in explaining the similarities between water and liquid argon, a chemist happy to succeed in explaining the differences.

 

[theallknower]

I see...well,I don't quite agree with the way chemistry is working...they just do something,and if that worked once,it will allwais work...In my opinion,you should take every detail in consideration...if you want to make a tough armor,for example,you should think about it and know exactley what to do it...not combine every posibility and use the best result...that's what I think of chemestry,allthow I'm quite shore I'm rong(I know I'm confusing you right now,sorry)
I don't think of chemistry as gastronomy(put in that,that and that,and voala: you get a good soup)or at least not the 3'rd milenium cheestry...there must be more fun then that:)
this is me...I want to find THE elemental particle,figure out it's proprietes,and from that predict the universe exactley how it is(violating the principle of incertenty) I don't like to take a group of entities(like an atom,like a rock,like sferical chikens:) ) and clasify it with uniform proprieties.
some time ago,a physicist from cern,that works at the LHC came to my country,and talked about diversed,interesting things...his name is Burkhard Schmidt(he may be on physics forums to,I don't know:) )and said something like this:physics can tell us how things work,but not why they do so!
that is a problem for me as a guy tring to become an elementary particle physicist,and that must be the problem I don't "get" chemistry that well.

 

[gravenewworld]

I see...well,I don't quite agree with the way chemistry is working...they just do something,and if that worked once,it will allwais work...In my opinion,you should take every detail in consideration...if you want to make a tough armor,for example,you should think about it and know exactley what to do it...not combine every posibility and use the best result...that's what I think of chemestry,allthow I'm quite shore I'm rong(I know I'm confusing you right now,sorry)
I don't think of chemistry as gastronomy(put in that,that and that,and voala: you get a good soup)or at least not the 3'rd milenium cheestry...there must be more fun then that:)
this is me...I want to find THE elemental particle,figure out it's proprietes,and from that predict the universe exactley how it is(violating the principle of incertenty) I don't like to take a group of entities(like an atom,like a rock,like sferical chikens:) ) and clasify it with uniform proprieties.
some time ago,a physicist from cern,that works at the LHC came to my country,and talked about diversed,interesting things...his name is Burkhard Schmidt(he may be on physics forums to,I don't know:) )and said something like this:physics can tell us how things work,but not why they do so!
that is a problem for me as a guy tring to become an elementary particle physicist,and that must be the problem I don't "get" chemistry that well.

Sounds like you would absolutely LOVE to be a process chemist. Those people pay attention to the details to the EXTREME.

 

[Renge Ishyo]

theallknower, if you think chemists are just mixing chemicals together without predicting any theoretical consequences or results then you really don't have a clear view at this point of how the ideas in chemical knowledge interconnect. Maybe in the days before such knowledge was available then yes, chemists (or alchemists if you prefer because we really are going back to before the 1600's here) were just mixing things together and seeing what happens or what mixtures made the best "armor" or whatnot, but in todays world chemists don't have a death wish (or the money) to operate in such a fashion. Instead they must develop an intuition about how elements behave, how they react in certain situations, and what properties they can expected to have after they form bonds, etc. and all of this is built from numbers, data, and theories of chemical structure. I am amazed sometimes that an organic chemist armed with only generalities about the behavior of chemical bonds can accurately predict the favored product of a complex organic synthesis by rearranging extremely simple symbols with a few dots around them and nothing else.

If the problem is that chemists can't predict "exactly in detail" what would happen that is only true because it is true of the physics that the chemist ultimately uses. Quantum mechanics is indeterminate in nature and both the physicist and the chemist must speak in terms of statistical averages. This is still a better approach than random guessing. I don't know how far you have gone with your physics so you may not know this is a fundamental limitiation of both chemical and physical knowledge yet (the belief that physics can predict exactly what will happen is a classical belief...left behind by necessity about 100 years ago).

 

[theallknower]

theallknower, if you think chemists are just mixing chemicals together without predicting any theoretical consequences or results then you really don't have a clear view at this point of how the ideas in chemical knowledge interconnect.
Instead they must develop an intuition about how elements behave, how they react in certain situations, and what properties they can expected to have after they form bonds, etc. and all of this is built from numbers, data, and theories of chemical structure.
I am amazed sometimes that an organic chemist armed with only generalities about the behavior of chemical bonds can accurately predict the favored product of a complex organic synthesis by rearranging extremely simple symbols with a few dots around them and nothing else.

If the problem is that chemists can't predict "exactly in detail" what would happen that is only true because it is true of the physics that the chemist ultimately uses.

oh,yes...you may be referring to Werner Heisenberg's uncertenty principle,that sais that you can't predict a particle's position and velocity exactley in the same time,and the more you acurate one,the more inacurate the other it will be...another thing is Richard Feynman's sugestion that a particle has multiple histories,thus the probability of a partcle having the traiectory I've chosen is very small...
there are lot of limitations,yes,but I like to go to the limit...
and no,I don't have a clear view...I am very confused(and very surprised,like you) of the way chemists work...might be couse I have 1 hour of chemestry/week at school,so my teacher can't get into detail...so far,that intuition that you refer to is very ilogical(for me...to a profesionist it must have logics)
the reason why I want to start learning chemistry to,is that all things folow the laws of the universe,and geting a grip of this misterious chemistry might help me at physics a lot

 

[Renge Ishyo]

Chemistry is built on top of physics. It is more like physics will give you an idea of how chemistry works and not necessarily vice versa. What you get with chemistry is not a tool to help you understand physics at some deeper level, but rather an "expansion pack" that goes beyond what happens in the general situations in physics to apply the concepts to more specific situations where specific atoms are interacting. The limitation of physics is that it is narrow in scope and neglects many of the peculiarities that one system may have in comparison to another. It does so in order to look for the generalities that each system shares. Chemistry on the other hand begins the laborious process of describing how the chemical composition of one system distinguishes that system from another (as in epenguin's statement which is right on). Which is deeper? It simply depends on what question you are asking. But a chemists intuition is not illogical, it is based on conclusions derived from experiment just like physics.

 

[kingdomof]

oh,yes...you may be referring to Werner Heisenberg's uncertenty principle,that sais that you can't predict a particle's position and velocity exactley in the same time,and the more you acurate one,the more inacurate the other it will be...another thing is Richard Feynman's sugestion that a particle has multiple histories,thus the probability of a partcle having the traiectory I've chosen is very small...
there are lot of limitations,yes,but I like to go to the limit...
and no,I don't have a clear view...I am very confused(and very surprised,like you) of the way chemists work...might be couse I have 1 hour of chemestry/week at school,so my teacher can't get into detail...so far,that intuition that you refer to is very ilogical(for me...to a profesionist it must have logics)
the reason why I want to start learning chemistry to,is that all things folow the laws of the universe,and geting a grip of this misterious chemistry might help me at physics a lot

To begin with, Chemistry requires theory, hence it is a science. If chemistry did not require a rigorous theoretical background, there would be not be such a massive background of information to teach (furthermore, if you think Chemistry does not require any sort of Physics, and is just a blind science, I suggest you look at the computational fields of it) . Furthermore, what you seem to not be grasping is a philosophical argument that has been challenging humanity for an extremely long amount of time: the subjective versus the objective. What you must realize before progressing in your studies in science is not simply the theory behind a generalized phenomenon, but why it is described as a generalized phenomenon and not truth that simply must be.

However, the thing which I believe is clouding your judgment here, as to how to work in science or what your interests are is the fact that you are not exposed to a diverse group of researchers, beyond what is popular (the mysterious super theory physics about something called a quantum!). There is more to science than just what is portrayed in the mainstream media or in textbooks. Research is the real war front; this is where you find yourself and your interests. Your are not too focused on the answer in research and you are more focused on the methodology and acquisition of data; not this lofty ******** vision of science based of some theory dude sitting in a dark room all day crunching numbers, only to be greated like a God in MIT by students and faculty alike. That is not what science is really like.

Also, for the love of whatever divine being, do not assert a science is fake because it makes assumptions. Especially when you like theoretical stuff, and you're talking about a science as empirical as chemistry. Keep in mind, quantification applies to simple systems, whereas complex systems cannot be modeled so much, such as the human body. Quantification into a theoretical number does not equate truth.

 

[gravenewworld]

If I remember by Pchem correctly, the Schrödinger equation can only be solved for the hydrogen atom and hydrogen like atoms. It is basically impossible to fully describe complex chemical reactions that have a mind boggling amount of different variables. So just because we can not theoretically describe a system fully does this somehow prevent us from doing chemistry with an atom like carbon? Certainly not, organic chemistry is a huge field of science.

Chemistry is an experimental science first, a theoretical one 2nd. Chemical theory is based upon what is observed in the lab.




When I hand my molecule over to a biologist to test in vivo, do you think that biologist cares about how that molecule was made? Nope. The only thing the biologist cares about is in what tissues is that molecule found, how long it takes to be secreted, how it is metabolized, etc. Does this somehow make biology not a science now because the biologist doesn't care or have a rigorous understanding of how that molecule was made?

Same thing with chemistry. Do most chemists really care or even need a rigorous theoretical understanding of how two atoms bond, their wave equations, etc to do chemistry? No.


Theory does not translate into praticality. I can't tell you how many reactions I have tried that were supposed to theoretically work, but ended up creating nothing more than a mess.

 

[Renge Ishyo]

If I remember by Pchem correctly, the Schrödinger equation can only be solved for the hydrogen atom and hydrogen like atoms. It is basically impossible to fully describe complex chemical reactions that have a mind boggling amount of different variables.

If you are solving the wave function by hand that is likely the case for most of us. This approach isn't needed for chemistry anyways, most energy level diagrams for complex molecules or atoms can be generated directly from spectroscopic data and using normalized wave functions together with group theory to generate the diagram. I guess some people may say "well, that's a work around that merely gets the same result as you would get if you built up the knowledge from some pure equation." My response to that is "welcome to science."

 

[epenguin]

Although there is more to be said and I could say more about the theory we are leaving out something important if we talk only about the theory. There are also the insights, knowledge and perspective that come from the laboratory. This is more true of chemistry than other sciences because you do not really see any chemistry outside the laboratory, whereas you do see physics and biology at some level, an idea I expressed in https://www.physicsforums.com/showthread.php?t=270483 .

I am guessing you are still at school. I think all the chemists here will back me up when I say there is no substitute for a good school course in chemistry with laboratory demonstrations and experience if you can get it. To say it briefly you need experience of substances not just formulae. That is University cannot fully make up for not getting it at school, there is not the time or organisation for it except for maybe specialist chemists . I have seen e,.g. medical students who have had little or poor school chemistry really struggle with chemistry and biochemistry - and hate them. Like e.g. they had no way than painful learning off by heart to know whether the order of atoms in the universal molecules nucleoside triphosphates is C-P-O-P C-P-O C-P-P-O P-O-C-O-P C-O-P-O-P or other permutations. They have never opened a bottle of acetic anhydride and have no feeling for what an anhydride is or many other examples.

Chemistry is certainly a necessary condition for learning biology or medicine etc and will do no harm at all for engineering, so it is unwise to close your options off for a premature vision of science.

 

[theallknower]

I am guessing you are still at school. I think all the chemists here will back me up when I say there is no substitute for a good school course in chemistry with laboratory demonstrations and experience if you can get it.

yes,I am in school,and I also agree to what you say...but,I'm on an intensive programing class...first I was triled about it,but I've dropt programing when I saw the beauty of physics...still,I didn't transfered...I'll at least make an extra hour of physics and get rid of 7 hours of programing...but that means I'll lose my physics teacher,witch I find the best,and I'm staing just for that,allthow I hate everyone else in there,form the guard that makes me freze outside couse I'm late,or forgot my ****** student card identification to the principles that makes us wear this sily uniforms that look like very bad pijamas...I only make 1 hour of chemestry,and from the 7'th grade,since I study chemistry till now(11'th grade) I've never seen the school laboratory...so I guess that explanes it...

 

[theallknower]

either way,I see the key-word for chemistry is "practical" and it isn't worth to consider all those details,and chemistry works even if you look at the atom as an undevided ball,at least at my level...
thanks a lot for posting...seems I've gatherd a lot of posts here:) any further comments are very welcomed

 

[kingdomof]

yes,I am in school,and I also agree to what you say...but,I'm on an intensive programing class...first I was triled about it,but I've dropt programing when I saw the beauty of physics...still,I didn't transfered...I'll at least make an extra hour of physics and get rid of 7 hours of programing...but that means I'll lose my physics teacher,witch I find the best,and I'm staing just for that,allthow I hate everyone else in there,form the guard that makes me freze outside couse I'm late,or forgot my ****** student card identification to the principles that makes us wear this sily uniforms that look like very bad pijamas...I only make 1 hour of chemestry,and from the 7'th grade,since I study chemistry till now(11'th grade) I've never seen the school laboratory...so I guess that explanes it...

What country are you from? I'd love to give you some advice, but that advice is sort of location dependent.

 

[kingdomof]

either way,I see the key-word for chemistry is "practical" and it isn't worth to consider all those details,and chemistry works even if you look at the atom as an undevided ball,at least at my level...
thanks a lot for posting...seems I've gatherd a lot of posts here:) any further comments are very welcomed

The key word for science, in general, is practical. The most simple answer is probably the correct one. When thinking about fluid dynamics, one does not consider quarks, and so on. I'm sure particle physicists do not consider many things (as to what, it's beyond my scope of knowledge, as I'm mainly a Biology person).

The best way to learn science is to look at how the science was done. Theory work distorts the vision of how science is founded. Theory and computation comes in after an observation is made. All calculations are not true values, and even those units which are described by the values are subjective, yet standardized.

I also suggest you attempt to download some real textbooks on some elementary calculus based Physics and Math. I also suggest you attempt to do the same for Chemistry and Biology. I cannot directly tell you how to get them, as it's sort of taboo to speak about. I'm sure its very easy to torrent from the many sites, however.

 

[epenguin]

Yes I had meant to say nothing is stopping you reading around, reading a book. Textbooks if you can manage them, but not necessarily textbooks though. There are plenty of non-textbooks or not-quite-textbooks or popular books about physics, I don't know of any about chemistry with what interests you in. (I make mental maps of the one I would write but I am stuck on the hydrogen atom right now! )

I am sorry you too are stuck, in what sounds like a concentration camp with guards and parading in the cold in silly pyjamas - is it in some remote Russian province that has not kept up with the times? It is an improvement these places now have internet at least.

 

[Gokul43201]

I like physics very much,and I'm shore I would enjoy chemistry as well(actualy I never understood why chemistry is not a subdivision of physics,like thermodynamics,or magnetism and electricity)
but I can't learn a thing via school chemestry...they require that I think of atoms as they were thought of in 1900's...full,undevided balls,ignoring a lot of things...I'm absolutley shore those quarcs do something...or further on,I'm shore those preons and haplons do something...so where should I start?
thanks in advance

Quarks do nothing for a chemical reaction. Haplons and/or preons do not exist (not according to the Standard Model, at least).

The place where you should start is a regular high school chemistry course (along with the regular high school math and physics courses). Since you admit you know very little about chemistry, you must agree that you are in no position to be objecting the the content of the course matter just yet.

Actually, even before that, you could start by paying some attention to how the word 'chemistry' is spelled!

 

[Renge Ishyo]

I am sorry you too are stuck, in what sounds like a concentration camp with guards and parading in the cold in silly pyjamas - is it in some remote Russian province that has not kept up with the times? It is an improvement these places now have internet at least.

That description sort of reminds me of a community college that I went to for a brief period of time. Fortunately, I didn't attend a chemistry course there.

 

[theallknower]

What country are you from? I'd love to give you some advice, but that advice is sort of location dependent.

thanks:) I'm from bucharest(romania) (in europe,with opening to the black sea,if it helps:) )

 

[theallknower]

I am sorry you too are stuck, in what sounds like a concentration camp with guards and parading in the cold in silly pyjamas - is it in some remote Russian province that has not kept up with the times? It is an improvement these places now have internet at least.

in romania,lol...in 1989 we shoot our "lider" and turned to democracy(from comunism) but it dosn't actualy make any diference,lol
@ the internet...I don't know...our principles are "deleting" informatics classes bit by bit,replacing them with SAM clases(a sort of high school for those who didn't got the exams...witch is quite hard to fail...you must be real stupid not to know how many minutes does 3 quarers of an hour have)learning stuff like how to be a waiter...still,they keep building state of the art informatics laboratories...(of course,they are never enough...we make practice programing on the board,in a dusty chamber while others learn biology in our labs:) )
oh,I forgot to mention about all those cameras(they are everywere...hallways,entrance,clases,courtyard...even in bathroms)
also,everyday a truk comes and deployes "special forces" guards,like on a violent football match...
so we are not quite low-tech,but all that tech is on mad hands:)

I remembered someone else's opinion...it was somethinh like "but where do you learn?in bagdad?"
but you're right...russian prison is closer to the truth:)

 

[Renge Ishyo]

Even jokes aren't safe on PF I suppose...

Well then, just trust me, chemistry is a fascinating subject if you get a chance to give it a real look at some point. A biologist armed with physics and chemistry would have the tools to make many exciting discoveries as we are going through a biological information revolution here at the moment. You can even show this post to the security guards if they need to be encouraged to let you pursue it (I know how much they love the idea of "revolution" over there in the east!).