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Researchers in fluid mechanics: engineers , Physicists ?

  1. Sep 28, 2013 #1
    Researchers in fluid mechanics: "engineers", "Physicists" ?

    Dear all,

    I was reading the book "Turbulent flows" of S. Pope and I went to his website at Cornell and started to see his work. In case you do not know him, I can tell you that his work is 100% applied mathematics and fluid physics, although he has degrees in engineering only. This situation is very common in areas fluid mechanics where many engineers are doing theoretical and numerical fundamental research.

    I am wondering now if it is right to say that someone with this profile is an engineer only because he has an engineering degree.

    How important do you think that is the degree when you refer to someone as an "engineer", "Physicist" or "applied mathematician"?
  2. jcsd
  3. Sep 28, 2013 #2
    So this seems like a sort of vague question, but I'll try to answer it best I can:

    In some countries, the title "Engineer" has a specific legal definition, and in those countries being called an engineer requires you meet specific requirements (usually a degree), nothing less, nothing more.

    However, in general a lot of countries where the term engineer is not protected (the US for example) tend to have a far wider range of people who call themselves engineers. In some cases, people with a degree only will call themselves engineers. How seriously they hold to this will vary, and likely most people who call themselves engineers with a degree only will concede that they do very little engineering work and are much more theoretically based.

    In the end, it's just a name, and what's more important than what you call yourself is what you claim you can do/are good at.
  4. Sep 29, 2013 #3

    D H

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    Look at his CV. He is a member of the mechanical and aerospace engineering faculty. He does engineering consulting. He was the director of an engineering company. His research is in areas of significant interest to mechanical and aerospace engineers. His book Turbulent Flows is the textbook for many graduate level classes in mechanical and aerospace engineering. He has been on the editorial board for a number of engineering journals. He is, first and foremost, an engineer.

    I suspect you have a misconception of what engineers are, what they do. Mechanical and aerospace engineering is very heavily dosed with physics and mathematics. It is essentially applied classical physics. Similar things same can be said of many other branches of engineering. Engineers don't suddenly get dumb and stop doing/using science and mathematics when they get their engineering degree.
  5. Sep 29, 2013 #4
    Why does this matter?
  6. Sep 29, 2013 #5


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    Would you think less of a person if he called himself a 'quantum mechanic', because, you know, the 'mechanic' part?
  7. Sep 29, 2013 #6
    I suspect you did not get the point of what I am asking.

    I am not saying that engineers are stupid or that they do not use science and mathematics. I am saying that, at least for me, an engineer is someone who is doing engineering (or at least has done it in some point of his life) and in the case of Pope, I would not say that this is the case.

    Looking at his cv, at his papers and at his book, I would say he is an applied mathematician or a physicist, but not an engineer.

    His work may be relevant for engineers, but well, there are a lot of areas in physics and mathematics which are relevant to engineering, but this is not reason for calling them engineering.

    So, my question is: If you studied physics, but you are working in GM doing engineering, it is right to call you physicist, just because you studied this? Is it the degree which you hold what decides what you "are"?

    For me it should be what you actually do what matters and not what a piece of paper says.
  8. Sep 29, 2013 #7

    D H

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    When NASA needs to know, in exquisite detail, what happens to a spacecraft that is reentering the Earth's atmosphere, NASA inevitably turns to a group of specialists who know how to model that behavior. Those specialists are predominantly aerospace engineers, and by a huge, huge proportion. The models they use include models of turbulent flow and computational fluid dynamics models. Who developed those models? People like Pope. They are engineers.

    When NASA needs to know, in exquisite detail, how a rocket works, NASA inevitably turn to a group of specialists who know how to model that behavior. Those specialists are predominantly aerospace and chemical engineers, and by a huge, huge proportion. Who developed those models? People like Pope. They are engineers.

    You have a misconception of what engineering is.
  9. Sep 29, 2013 #8
    I think you are who has a misconception.

    You are talking about people using models in order: "to know, in exquisite detail, what happens to a spacecraft" or "to know, in exquisite detail, how a rocket works". And yes, they are engineers.

    But I am talking about somone doing things like this:


    There is a very big difference between someone "developing math and physics which can be used for simulating rockets" and someone indeed "simulating and developing a rocket".
  10. Sep 29, 2013 #9


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    My undergraduate degree is in mathematics, plus a bunch of graduate courses.

    I have an MS in electrical engineering.

    I have a PhD in Applied Physics.

    I sometimes teach, have done a fair amount of research, but often work as an "applied mathematician", or as an "engineer", and sometimes as a "consulting physicist".

    I suppose the title used depends on what you are doing. I was a visiting scientist with a mechanical engineering research group which specialized in the controlled, repeatable growth of carbon nanotubes and their applications.

    You could tell it was an engineering group because their goals were applications instead of fundamental understanding - though they use the same tools that a physics or chemistry group would use in order to understand what is happening during growth and after: x-ray and optical images, SEM and TEM analysis, Raman spectroscopy, etc.

    In general they were better at building stuff than most physicists!

    But I would not call myself an engineer if I am working outside of my training and expertise; the claim "engineer" means that I know what I am doing when I talk about or design for my area of expertise. Certainly my son and daughter who are mechanical engineers would never mistake me for a mechanical engineer!

    But a professor of engineering, with a PhD in engineering? Sounds like an engineer to me. I'm also quite certain that he knows a lot of physics, but probably not too much quantum mechanics or nuclear physics (unless he is a nuclear engineer).

    But physicists also specialize; I have a friend who is a PhD electrical engineer specializing in optics and lasers - which is also my field. I'm pretty sure that he knows more than I do as I ask him questions from time to time. He only asks me questions about areas of physics that are outside of his realm.

    One may have many valid descriptors; over a career one may do many things.
  11. Sep 29, 2013 #10


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    Really? I've been doing both in parallel for 20 or 30 years, if you replace "rockets" with "some bits of jet engines." (I'm not saying my work is at the same level as Pope's, or course).

    How do you think you know if the mathematical simulations you develop are any use, except by comparing them with the real world? Or shouldn't "mathematicians" be worrying their pretty little heads about trivial details like that?

    FWIW I know that some national cultures take this nit-picking over exact job titles very seriously indeed, but others (thankfully!) don't care. It would be presumptuous to read too much into the member name "Bunsen" though.
  12. Sep 30, 2013 #11


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    If an engineer has a problem to solve, and the physicists and/or mathematicians haven't solved it yet, then the really good engineer figures out a way to solve it. If they simply threw their hands up and waited for a mathematician or physicist to solve it for them we would never get anything done.

    In the realm of "applied classical physics" (fluids, electrodynamics, continuum mechanics, heat transfer, ...) the pure physicists (at least in academia) typically are not working on the problems that the engineering community needs solutions for.

    Likewise for the "applied math" parts of engineering. Sometimes engineers have to produce mathematical proofs to convince themselves that they are doing the right thing, or that the new approach is guaranteed to be better than the old approach, or that the computationally less expensive approach has an error with an acceptable bound, etc. It may be possible that there is a more general proof in the pure math literature that covers the specific result, but the pure math papers are pretty much unreadable to most non-mathematicians. Applied math papers aren't necessarily any better, and often (at least in my field) concentrate on solving problems that are of no practical interest to those of us designing real systems that have to work in the real world.

  13. Oct 2, 2013 #12
    Another facet: A lot of what a Ph.D. level (or post Ph.D. level) engineer does can be very similar to what an experimental physicist at the same level might do. Likewise, there can be a lot of crossover between applied mathematicians and scientists in other fields who are doing heavy simulation work, depending on the research focus.

    This is really evident in some fields like plasma physics where you get people essentially doing similar jobs, having obtain Ph.D.s in Nuclear Engineering, Aerospace Engineering, Engineering Physics, Physics, Astrophysics, Applied Physics, and even sometimes Applied Mathematicians, depending on what school they went to.
  14. Oct 2, 2013 #13

    D H

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    The person in question has degrees in engineering, teaches in an engineering school, ran an engineering company, edits engineering technical journals. What more evidence do you want that he is an engineer?

    No, there is not. The prima facie evidence goes against your misconception of what is and what is not engineering. I don't quite know what you think engineers do do, but it's not just signing some technical diagram of a bridge design.

    The simple answer to "What is X?" (substitute "X" for mathematics, physics, engineering, or practically any other technical discipline) is the rather circular answer "X is the work done by professionals in the field of X." There is no overarching technical oligarchy that can tell Stephan Pope to cease and desist his work on combustion modeling because what he is doing is outside the domain of engineering.
  15. Oct 2, 2013 #14

    D H

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    Rhetorical question: What in the world is an aerospace engineer doing working with plasma physics? I'll give two specific examples; I'm sure there are others.

    1. Ion thrusters. This emerging propulsion technology involves expelling a plasma from a thruster at very high velocity. This very high exhaust velocity means a very high specific impulse. High ISP thrusters are the pot of gold at the end of a rainbow to aerospace engineers. So it's very natural that some aerospace engineers work on them.

    2. Atmospheric reentry. An aircraft creates a pocket of heated air around it. In a supersonic aircraft, that pocket of hot air becomes non-ideal. When something hits the atmosphere at Mach 25, it's no longer just a non-ideal gas. It's a plasma. Aerospace engineers who worry about structural integrity during reentry need to model that plasma. They do not say "This is outside my scope. Time to call in a plasma physicist." Understanding and modeling that plasma that surrounds the reentering vehicle is an essential part of their job.
  16. Oct 2, 2013 #15

    An interesting thing about that specific Aerospace Engineering program is that some of the plasma groups are just doing straight up fusion stuff.
  17. Oct 3, 2013 #16

    You are always talking about applications and people who want to learn physics/mathematics for using it in those applications and yes, these persons are engineer from any point of view.

    But, again, I am not talking about them. I am talking about people developing numerical methods and studying fundamental phenomena. People who have never worked in any technical application.

    Newton invented calculus and yes, calculus can be used for technical applications, but NO, Newton was not an engineer.

    I think it will never stop to surprise me, how much engineers overestimate what they are.
  18. Oct 3, 2013 #17


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    I believe D H has explained that "engineer" is a term applied based on one's formal education and what one does professionally.

    It's not necessarily exclusively the degree, but what one does in addition to one's degree.

    One is expressing a myopic viewpoint that engineers cannot or do not develop the mathematical principles, theory and/or methodology for the applications they use. There are plenty of 'engineers' who develop the mathematical framework (theory) behind applications. This could mean developing the necessary ordinary or partial differential equations, including systems of coupled (often non-linear) partial differential equations, initial values and boundary conditions, for describing a physical system of phenomenon.

    In short, one seems to be generalizing about the population of 'engineers' and then disparaging or denigrating those who practice engineering. Engineering can and does involve elements of applied mathematics and applied physics, including the development of the mathematical theory and physics.

    Someone with a PhD or D.Sc. (Eng.) in engineering can certainly be exposed to physics, mathematical theory and applied math. Pope is such an example.
    Last edited: Oct 3, 2013
  19. Oct 3, 2013 #18

    D H

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    And how do you know that Stephen Pope never worked in any technical application? He directed an engineering company, he does engineering consulting. You are assuming things contrary to the evidence.

    FIrst off, this is a bit of a red herring. The technical world had not yet split into umpteen specializations in Newton's time. Educated people were still expected to be literate in *everything* back then.

    Secondly, in addition to being a physicist, mathematician, chemist, alchemist, and occultist, Newton was also an engineer. He eventually became Master of the Mint. He worked toward improving the efficiency and quality of the mint and toward detecting counterfeits.

    The fields of science, mathematics, and engineering are not mutually exclusive. There are lots of people who contributed massively to more than one of those fields. In addition to Newton, here's a short but by no means exhaustive list of multitalented luminaries:
    • James Watt
    • William Rankine
    • William Thomson, 1st Baron Kelvin
    • Nicolas Carnot
    • Henri Poincaré
    • Claude Shannon
    • Rudolf Kálmán
    • Andrew Viterbi

    This opinion is completely unjustified. It's now rather apparent that you didn't start this thread to discuss Stephen Pope. You wanted us to agree with you that he is not an engineer. How could he be when he is obviously smart, and engineers are obviously stupid?

    Well, they aren't. Thread closed.
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