Questions about engineering and turbulence

[Delong]

These are two rather unrelated questions but I am curious.

1. How much does physics rely on engineering? I think it's pretty clear that modern engineering relies pretty heavily on physics. Without it we wouldn't have electicity, chemicals, or even know the amount of force and heat we are using. But how much does physics rely on engineering? It's true that without machines we couldn't run particle tests and colliders and without observatories we couldn't see into space. But are those exceptions? Or are all the advances in modern physics dependent on upcoming technology?

2. Why is turbulence so mysterious? I have read Werner Heisenberg say "When I meet God, I am going to ask him two questions: Why relativity? And why turbulence? I really believe he will have an answer for the first." and Horace Lamb, a mathematician, say "I am an old man now, and when I die and go to heaven there are two matters on which I hope for enlightenment. One is quantum electrodynamics, and the other is the turbulent motion of fluids. And about the former I am rather optimistic."
Is turbulence just one example of how we have a very good understanding of physics concepts but not so much of mathematical physics concepts that explain medium scale occurences like turbulence?

 

[boneh3ad]

1. How much does physics rely on engineering? I think it's pretty clear that modern engineering relies pretty heavily on physics. Without it we wouldn't have electicity, chemicals, or even know the amount of force and heat we are using. But how much does physics rely on engineering? It's true that without machines we couldn't run particle tests and colliders and without observatories we couldn't see into space. But are those exceptions? Or are all the advances in modern physics dependent on upcoming technology?

I think you are asking the wrong question. Engineering is essentially just the application of physics. In essence, new physics are understood and then new products and devices are created based on those discoveries. Then sometimes those new devices help understand more physics. It is a symbiotic relationship of sorts. Many cutting edge physics problems are left waiting on engineering advances and vice versa.

2. Why is turbulence so mysterious? I have read Werner Heisenberg say "When I meet God, I am going to ask him two questions: Why relativity? And why turbulence? I really believe he will have an answer for the first." and Horace Lamb, a mathematician, say "I am an old man now, and when I die and go to heaven there are two matters on which I hope for enlightenment. One is quantum electrodynamics, and the other is the turbulent motion of fluids. And about the former I am rather optimistic."
Is turbulence just one example of how we have a very good understanding of physics concepts but not so much of mathematical physics concepts that explain medium scale occurences like turbulence?

Turbulence is so mysterious because it is highly nonlinear and chaotic. It is almost stochastic in nature... except it isn't as far as we know. To really understand it, we have to understand how laminar fluid flows develop into turbulent fluid flows, and in some respects that is an even more difficult problem. Empirically, we understand turbulence and numerically we understand a some of the individual processes, but putting it all together into a big picture and being able to model it from beginning to steady-state is a very long way off.

 

[Delong]

Ok thanks. I was just curious how much advances in physics depend on advances in technology in comparison to the other way around but I suppose something like that is hard to measure. Perhaps the engineering depends on the physics but not in a direct ways while the physics depends on the engineering in more direct ways.

Interesting information on the turbulence topic.

 

[boneh3ad]

I would say it is a direct dependence though. Think about it: the Hubble telescope was a major feat of engineering that led to many scientific discoveries. However, it never would have been possible without someone learning all the physics behind optics. There are plenty of examples like this.

 

[Cleonis]

But how much does physics rely on engineering?

'Engineering' is a very wide term. Let me use a narrower definition than the usual one, to get a particular focus.Starting with an example from history: in Roman times the engineering was way ahead of the science. For instance, the Romans used concrete. The Pantheon is built with concrete. The Pantheon is still in good shape, so clearly the Roman engeineers were skilled at mixing a good quality concrete.
Also, the roman engineers knew that while the concrete was still setting you had to keep it moist. Concrete that has dried out before it has set is weak.

The only way for the roman engineers to improve and maintain the quality of their concrete was to do a lot of testing. As far as I know no records of how roman engineers worked have made it down the ages, but clearly they must have done a lot of testing.
We can think of this aspect as trial-and-error-engineering. A modern analog is perhaps the field of high temperature superconductors, that started in 1986. In the years after that many research groups used trial-and-error engineering to find superconductivity at ever higher temperatures, as no theory was available to guide the efforts.

 

[Delong]

Thanks for the interesting information about engineering. Yes I can understand how engineering has been around a lot longer than science and will have the closest relevance to people's lives throughout the ages. I also realize how a lot of engineering is improved by better scientific understanding althouth it is not always necessary to get the job done so to speak. I wonder though how physics discoveries depend on engineering however. For example, like String theory I hear right now has no experimental verification partly because we do not have a particle accelerator right now that can form energies as high as what String theory predicts. That's interesting cause we are unable to advance in science not because of any theoretical difficulties or experimental difficulties but simply because of technological difficulties. We need to make advancements in engineering before we make advancements in science. I always thought it was the other way around. How does engineering advance anyway without science? Do engineers simply try to make things more efficient? How can they do so without an understanding of scientific principles? Is there more to engineering itself that an understanding of scientific principles cannot provide?

Just some curiosities. I have always thought of engineering as nothing without science but I'm trying to see if that is really true.