Thursday, January 03, 2008

Why biology is harder than physics

 
Rosie Redfield says [Why biology is harder than physics].
Beginning university students in the sciences usually consider biology to be much easier than physics or chemistry. From their experience in high school, physics has math and formulae that must be understood to be applied correctly, but the study of biology relies mainly on memorization. But in reality biology is much more complex than the physical sciences, and understanding it requires more, not less, brain work.
Read the rest over at RRTeaching. Rosie makes a point that I've also tried to make, but she does a better job.

Rosie is a Professor at the second best (in my opinion) university in Canada.

For another perspective, check out the views of a physics-trained graduate student (Philip Johnson) who works here at the best university in Canada [Biology is harder than physics?]. After expressing some skepticism, Philip closes with ...
I hope someone in the social sciences gets wind of this and belittles biologists. Sociology is obviously more complex than biology, so it clearly requires more brainpower to be a social scientist than a biologist, right?
Uh, no Philip. Sociology is the study of the behavior of one particular biological species (Homo sapiens). It's a teeny, tiny subset of biology.


29 comments:

  1. I'm actually only a PhD student! Ahh, to be a post-doc already...

    I don't think of sociology as a subset of biology, in the same way that I don't think of biology as a subset of physics. To each their own.

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  2. One can also say that biology is a subset of physics. Everything down to its core is physics. I guess it depends on how you try to understand and explain things. Of course you can explain things happening in biology using the laws of physics; however, that explanation will be tremendously long and complicated. Therefore, biochemistry etc. is developed.

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    1. It seems to be that simple, but physics really can't do much to explain the phenomenon of consciousness, and consciousness and human observation are now being seen as a fundamental influences in our understanding of not just the universe, but reality. It takes us just as close to metaphysical questions as fundamental physics does. To look at the whole thing from a bottom-up, linear viewpoint is fallacy, and with that conclusion, philosophy seems to be the only 'fundamental' way of studying the universe, by deciding HOW we ask these questions, not which field we categorise them into.

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  3. I can't say much about bio, since the last time I took it was Grade 10, but my sense is that bio and chemistry are very similar in that they are incredibly complex subjects that depend to a large extent on memorization. In my own experience, I found chemistry incredibly frustrating- if you can't remember something you're screwed, whereas in most of the 'harder'** sciences like math and physics, if you forget something you can usually derive it from the things you remember. Granted, my PhD was in computer science and I'd imagine that grad-school physics also involves a lot of memorizing...

    ** By 'harder' I mean the opposite of 'softer', but that's purely my subjective opinion.

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  4. > I don't think of sociology as a subset of biology...

    That seems right to me, given that sociology is about human behavior, which is clearly of a different order than marsupial behavior.

    No biology textbooks cover group psychology, and I think the latter much more complex--may it be said that the depth of understanding of sociology is shallow indeed compared to the depth of understanding in biology.

    So I would say the difficult subject to study at this point would be biology, not sociology, by far.

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  5. First of all, only a biologist would make such a silly claim as "biology is much more complex than the physical sciences", and secondly, all the really difficult problems in biology are currently being addressed by biophysicists. :)

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  6. I would predict that some of the most significant 'breakthroughs' in modern biology are often the result of great work in other fields such as physics and chemistry. Like Jane said.
    I also agree that if you specialize in biology you are aware of all the complex problems in the field. If you specialize in physics you are aware of all the complex problems in physics. So it would be ignorant to claim one is 'harder' than the other unless you have, say a PhD in both fields.

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    1. You misunderstand what it is to be a biologist, biology is a collective field of relevant theories and principles to be picked from and applied to different problems we encounter in the study of life. Every biologist is a 'biophysicist', or a 'biochemist' - why not 'biohistorians' and 'biomathematicians'? Because a biologist is all of those - and to answer big questions about ecology and the biosphere, standing alone, physics and chemistry can't even come close.

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  7. Jane says,

    First of all, only a biologist would make such a silly claim as "biology is much more complex than the physical sciences", ...

    I'm not "just" a biologist. I'm a biologist—biochemist, actually—with a daughter who has a Ph.D. in physics.

    Helping her pass her graduate level physics courses was about as hard as falling off a log. :-)

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  8. rob says,

    I would predict that some of the most significant 'breakthroughs' in modern biology are often the result of great work in other fields such as physics and chemistry.

    I await your "predictions."

    But even assuming your prediction is correct (it isn't) doesn't it prove my case? We have to await discoveries in the simple fields like physics and chemistry before we can apply them to the complex field of biology. It's just like school. You have learn about arithmetic in third grade before you can understand calculus.

    I also agree that if you specialize in biology you are aware of all the complex problems in the field. If you specialize in physics you are aware of all the complex problems in physics. So it would be ignorant to claim one is 'harder' than the other unless you have, say a PhD in both fields.

    I think you missed the point. Biology is intrinsically harder because it's so messy. For every rule in biology there are multiple exceptions. Do you know of any exceptions to general relativity?

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  9. Do you know of any exceptions to general relativity?

    Yes. A little-known theory called quantum mechanics.

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  10. Philip, thanks for reading my post before commenting on it.

    Robert, you're restating precisely the misconception my post was hoping to change. Badly taught high school biology does involve a lot of memorization, but the science of biology does not.

    Jane, biophysicists are addressing the subset of biology's problems that they find attractive. That's because they've discovered how thrilling and complex biological problems can be, not because only physicists are smart enough to tackle them.

    Rob, how much biology background do you base your prediction on?

    Larry, thanks for getting this discussion going.

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  11. Anyone familiar with the complexity of designing ecological experiments can appreciate what Larry and Rosie are saying.

    Dave Wisker

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  12. Rosie, on how much physical science background do you base your assertion that your field is harder? I am currently a PhD candidate in biochemistry, and perhaps this is why we disagree a bit about the biological sciences being ‘harder’ than the more physical sciences.
    From my perspective I was thinking more about the frontiers of biology vs physical science research and in that case I think that we can agree the problems in each are equally daunting. Extremely intelligent people are working in all these fields and pushed current research into areas which are all ‘hard’.
    From a teaching perspective perhaps you are correct, biology may be more difficult to teach. I don’t know I have never taught any physical sciences. Although I would still argue that, other than memorization in biology, most of the concepts are simple in comparison to physics for example. Maybe this is my biased opinion because of my educational background.
    Sure biological systems are inherently messy, and full of exceptions, but sit down and try to understand some string theory or something. I don’t and until you do I think it is difficult to argue that one is ‘harder’ than the other. I am again arguing from a more ‘frontiers of research’ perspective, which maybe is not your point.
    I did agree with much of your article, in that teaching biology at a university level should involve more concepts and a deeper understanding of biology.

    I would predict that some of the most significant 'breakthroughs' in modern biology are often the result of great work in other fields such as physics and chemistry.

    Prediction was a bad choice of words. Perhaps I am being misunderstood because I find it difficult to believe that you really disagree with that statement. This ‘prediction’ is really just a reflection on biological research of the past. The structure of DNA was determined using x-ray crystallography. Your post about the ‘breakthrough of the year’ as determined by Science magazine was largely a result of work in physics and chemistry developing sequencing methods. Microarray technology and the microscope also come to mind. This is just off the top of my head.

    We have to await discoveries in the simple fields like physics and chemistry before we can apply them to the complex field of biology.

    Your statement without the terms ‘simple’ and ‘complex’ that are part of your argument makes just as much sense, so it doesn’t validate your argument, I don’t think. You have, however, managed to convince me that my prediction doesn’t have anything to do with which field is harder. I just had to agree with Jane’s comment as it seems the big revolutions in biological research follow from the application of tools developed in other fields.

    Awesome blog BTW.

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  13. Rob, I didn't really mean that advanced research in biology is harder than similarly advanced research in physics. The post was on my teaching blog (I mainly post at RRResearch), and I wanted to shake up students' misconception that introductory university biology would be less intellectually challenging than introductory physics.

    And your prediction has so many qualifiers ("some...breakthroughs...are often the result of great work in other fields such as...") that I can hardly disagree with it.

    I sailed through first year physics many years ago, and then sat in on it three years a row in the course of a collaborative teaching project. And your biology background?

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  14. And your prediction has so many qualifiers ("some...breakthroughs...are often the result of great work in other fields such as...") that I can hardly disagree with it.

    But isn't your statement that "biology is harder than physics" so bereft of qualifiers that it's impossible to agree with? Of course your qualifiers come later, "I didn't really mean that advanced research in biology is harder than similarly advanced research in physics"; "[The post's] primary goal is to counter their foolish expectation that they success in biology depends mainly on memorization." (from biocurious.com) This leads one to believe that the headline was chosen for attention rather than accuracy.

    I agree with your notion that it's foolish to expect success in biology is dependent on memorization, and I certainly agree with the approach of teaching understanding over recitation. That's true with any discipline - you'd be foolish to expect success in physics simply by memorizing equations (and there are plenty of people who believe that physics is just equation memorization) instead of understanding underlying concepts. How people approach learning/teaching a subject seems to me to be a different issue than which is intrinsically/objectively harder.

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  15. But even assuming your prediction is correct (it isn't) doesn't it prove my case? We have to await discoveries in the simple fields like physics and chemistry before we can apply them to the complex field of biology. It's just like school. You have learn about arithmetic in third grade before you can understand calculus.



    There is general agreement among most biologists today that Schrödinger, like O. T. Avery, belonged to that small circle of scientists whose primary research was not in genetics, but who nevertheless had a decided impact in initiating the development of molecular genetics. There are, however, profound differences between Avery and Schrödinger. Avery conducted biochemical experiments, showing that DNA is the genetic material. Schrödinger was a theoretical physicist who happened to write an influential book on biology.


    http://www.genetics.org/cgi/content/full/153/3/1071

    I don't really know about Avery, but I was aware that Schroedinger had written a piece which influenced biology, positively (he predicted important aspects regarding the genetic material of life, IIRC). If one believes the blurb I copied, it looks as though Avery went even further, although he was not a physicist, rather a physician and bacteriologist.


    I think you missed the point. Biology is intrinsically harder because it's so messy. For every rule in biology there are multiple exceptions. Do you know of any exceptions to general relativity.


    "Harder" is so subjective, unless we define what we mean by it. Yes, biology is "harder" if we mean by "harder" that it is more difficult to understand in full, but I believe that it is really not as hard as physics if one is discussing how hard and difficult certain concepts and mathematical models may be.

    One presumably could do some important work as an amateur biologist (at least at the level of description and perhaps classification), then, while amateur physicists are very unlikely to be able to make important observations.

    Nevertheless, I rather suspect that biology can be about as hard as one's abilities allow, which is the same for physics. There doesn't seem to be much excuse for comparing one favorably or unfavorably to the other, only to evaluate individual abilities and the value of models.

    The notion that biology is a "soft science" and physics a "hard science" probably has some historical basis (biology was soft in Paley's day, when Newtonian mechanics was hard and predictive), yet I wonder if another reason is that most "physics materials" are hard (or sometimes gaseous, but dealt with in a hard and abstract manner), and "biological materials" tend to be squishy. I know that such associations make no sense. They often occur regardless of the "sense" that they make.

    Glen Davidson

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  16. I just stumble upon this blog by mistake through Google. I can't help but to briefly chime in as a Physics PhD student. Without really defining what is "harder", this discussion cannot be very rigours nor can it be quantify. From which is really the core difference between physics and biology. In general, physics require the kind of mathematical rigors in theory and the detailed understanding of the systematics in experiment that make it "harder" than biology. My biologist friend agree that physics is a more rigorous field.

    While there are no denying that biology is an interesting and complex field (thus the "sexiness" of biophysics in recent years), many biophysicists will point to their more mathematical training in physics, the tendency to want to better quantify things than the traditional biologists, as an advantage working in biology [at least this is what I hear from a talk given by Nobel Physics laureate, Steven Chu, who has shifted to doing more biophysics work in recent years].

    So my point is that physicists are generally better trained at applying the scientific method, etc. than the biologists; so at the educational stage, I would claim that physics is harder. Now as for the actual field, I would argue that pure physics require the kind of abstraction and creativity that exceeds anything in biology.

    Before I go, I should make a stronger statement specifically about designing experiments (particularly since I'm an experimentalist), in one sense, you can possibly say that physics experiments are cleaner/more controllable than what biology can possibly be and thus can be more rigorous. Then the "biology is harder than physics" can be used as an excuse why biology experiments are sometimes hokier than physics experimients (and don't get me started on the social sciences "experiments"...just b/c statistics are used doesn't mean it is really scientific).

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  17. Rosie asks Rob:

    Rob, how much biology background do you base your prediction on?

    and

    And your biology background?


    Interesting that there was no response.

    As an aside, on Rosie's blog and on Philip's Fred Ross mentions that he does not think biology is "complex" as per the working definition of 'complex' that he apparently prefers.

    However, 'complex' as a term is NOT under the sole purview of physicists and their kin, and under any basic definition, viology most certainly is 'complex.'

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  18. I didn't respond to the query as to my biology background because I said that I'm a biochemistry PhD student in my first post.
    I have a masters in biochemistry and am working on a PhD dealing mostly with virology.
    Although this isn't straight up biology I think that this is a reasonable amount of biology background to be able to make the comments that I did. We have a blog that deals with biology at
    http://www.bayblab.blogspot.com

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  19. However, 'complex' as a term is NOT under the sole purview of physicists and their kin

    Shall we apply that argument to the word 'theory'? Of course we don't because we know we're talking about a scientific theory. It doesn't seem unreasonable to expect an article dealing with physics to use physics terminology.

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  20. This is an interesting discussion that I've been having with a number of people in my department. Since everyone's background is continually attacked, I'll state mine. I have a BS in Computer Science and Electrical Engineering (Device physics) and have been a practicing engineer for about 10 years. I have since gone back to school to get a PhD in Neuroscience. Neuroscience is, in many ways, just at the cusp of physics and biology; there are people attacking it from all angles. Many mathematicians and computer scientists what to understand how information is processed (this and neuro-electrophys is where I am) and others want to understand the genetic basis of disease and development (more biologists) just to name a few. I have training from both sides and there is no way anyone can state that biology is more difficult (or harder I think it was stated) than physics! While it is true the overall system is more complex, this doesn't mean that our study has progressed to the point where this complexity is even close to being addressed. All of the biology-is-harder arguments seem to operate under the assumption that we have exhausted all the physics we know, and are now applying it to biology. That somehow our STUDY (not actual biology) is built upon all the foundations of physics. This couldn't be further from the truth! We have just scratched the surface on this melding of the 2 disciplines. From my experience, most biologists have little understanding of the methods and complexity of physics and many don't care to learn them. In fact, anything expressed mathematically makes most of them run for the hills! The conceptual level at which the CURRENT STUDY of biology operates is far below that of physics. It is more of the order of cascades of events (one thing effect another and another and here's our finding). This has its place as the biological systems under study are extremely complex; we need to make a number of observations before we can apply hard math models to them. It is absolutely necessary to operate at this conceptual level right now because we don't know enough to move it to a more fundamental, physical level (physics went through this as well; it wasn't until people like Newton started making fundamental modeling breakthroughs that we now have such a robust field). At the moment, biology-types seem to be content with showing that some mechanism exists or different from another. This is not satisfying to a physicist; it takes a different attitude to put the information together into a cohesive big picture and try to answer why something is the way it is. As we are now doing (I'm happy to be involved in this!), the same techniques are being applied to biological models. There is a long way to go, but I do believe that one day high-energy particle physics will meet biology and information processing theory. I can't predict when this will be, but it will certainly take more of a physicists' approach than the simplified, elucidation-of-mechanisms approach that most biologists currently apply.

    Personally, (and here is where I'll let my biases in) I don't think that biologists can't learn these techniques, but they do seem resistant to it. I think statements like the one made at the beginning of this blog merely reinforce this unimodal thinking and keep people from exploring other ways of thought. I don't think they are dumb inherently, but its more of attitude thing. All this being said, I think any hard-core physicist would be bored doing pure biology (what ever that means...) as it is practiced today.

    That is all.

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  21. I can only comment on the undergraduate level having completed a triple major in Biology, Mathematics, and Physics with a minor in Chemistry. I would have to say Biology is the easiest, followed by Chemistry, then Mathematics, and finally Physics. If you want to discuss this further feel free to email me at malachad@yahoo.com .

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  22. Why does it matter? Look at their outcomes. The most important breakthroughs to me, are in medicine. I don't give a crap about physics or chemistry. If I have cancer, is a physicist going to help me?

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  23. @nervegenetics

    Apparently medical imaging has nothing to do with physics...lmao

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  24. @ nerve genetics:

    I would say that physics will help you if you have cancer, in two ways: diagnostic and treatment. That is, nearly all the imaging technologies (MRI, x-ray, CT, PET) in a hospital are both created and periodically maintained by physicists. Finally, radiation therapy, particularly with computational modeling of new devices, is one of the most effective treatments to treat cancer.

    @ general population

    The study of physics is not simple. It is beautiful because it takes seeming complexity and via elegant insight produces highly predictive models. Biology is on a lower level of abstraction than physics. It is in this sense that it is more "complex"---it needs more descriptive content to cover it's area at this point and time in history, and thus why exceptions are the norm. It does not yet have the kinds of predictive power than physics does. I hope in the future it does.

    @ Larry
    You must be very gifted to find physics graduate exams easy, especially for it not being your field. While your claim might be particularly true, generally I think it is not. That is, I couldn't imagine the vast majority of non-physicist scientists even remotely coming close to passing a graduate physics exam. My same skepticism is shared in the converse. That is, If a physicist claimed he could easily pass molecular biology or biochemistry graduate exams without serious training, I'd laugh and chalk it up to arrogance. The knowledge bases of the fields are just plain different. As a side note, I do think a physicists's quantitative training has advantages for easily picking up other fields that significantly depend on mathematics. I'm sure there are comparable skills that are more likely developed by those studying biology, etc.

    Thank you for stimulating some thoughtful discussion.

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  25. I'm a Biology undergraduate at the moment and I'm moving into Medicinal Chemistry just because I feel I will enjoy that course more. I'm quite disappointed a biochemist would talk like this... surely it doesn't matter what you major in as long as you love doing it? I never knew it was a competition, but maybe that's just me.

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  26. @nervegenetics
    Yes - the health physicist, the biophysicist and the nuclear physicists and chemists who developed...
    1. the nuclear medicines in the first place and run the reactors and cyclotrons that make these medicines in order to treat you, and
    2. the imaging machines and techniques used to diagnose you in the first place!

    That was in all, a rather ignorant comment.

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  27. Wouldn't everything derive from physics? I mean it's actually even called the theory of everything...

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