Monday, November 19, 2007

Engineering Is Scientific

Engineering is scientific in that it compares results to theory and adjusts accordingly. However, in engineering it is not always the theory that gets adjusted.

I was having a discussion with Gerald Browning at Climate Audit about engineering vs science. Two related but very different disciplines. Which brought up this polemic (thankfully short) from me.

In engineering it only has to work. The theory need not be correct. It just needs to bring you in the vicinity of a solution.

Second, a feed back system properly designed will cover up a lot of misunderstanding. I know the valve will be highly non-linear. Its components (O-Rings [pdf]) will have serious hysteresis and material creep problems. The gas flows will be probabilistic (see comments). You servo the system to the desired results and it doesn’t matter. Which is why some of the companion articles deal with feedback and control. Instrumentation. Detectors.There is also a bit about having sufficiently large tanks inserted in the system at convenient places in order to reduce rates of change possible. It is ALL about scale. Try doubling the size of the oceans to slow down the dT/dt (rate of change of temperature with time) for a given energy input. An exercise best left to the reader.

A very bad way to do basic science. A good way to do engineering. The fact that this is engineering in service of basic science is even better.

Of course if your system response is exponential to change and your feedback loop is longer than the system response time you are farklempt. Nuclear reactors would be uncontrollable for this reason if it wasn’t for the approximately 1% delayed neutrons. Even then there is a narrow range of reactivity where the delayed’s help. Get above that range and the reactor self controls - i.e. melts down.

Let me add that what usually happens in these cases is that if you can get a lash-up to work and it has high utility a lot of people get assigned to understanding and improving on the original design and correcting the bad theories.

Read some of Tesla's work. Brilliant in general, but he had some serious and glaring mis-understandings - according to what we know now. The thing is his mis-understandings lead him to dead ends. OTOH he made things work. Like radio controlled boat models in the very late 1800s. An amazing accomplishment for its time.

Now it is good to have so many people studying climate. What is unfortunate is that our minuscule understanding has given rise to orthodoxy that pretends to more understanding than it actually has. This is easy to hide because the time scales are so long and the system itself is chaotic with strange attractors (You want to know the most likely weather for tomorrow? Same as today). Even when the time scales are short (electricity) understanding is some times decades in coming. The real crime in all this is not this prediction or that prediction. It is confidence intervals that do not match the quality of the data and its analysis.

One must take this as a common human failing because we see it in all fields. Predicting the future gains one prestige. Tarot reader or climate scientist. Doesn't matter.

Cross Posted at Classical Values

12 comments:

Nomism said...

Predicting the future gains one prestige. Tarot reader or climate scientist. Doesn't matter.

Does this comment apply to people who claim that full scale, net power producing Bussardigan Fusion Reactors are possible in 3-5 years with $200M in funding?

M. Simon said...

The proof will be in the pudding.

I actually expect a lot more than $200 million will get spent.

In any case like Climate Science you will have to wait until WB-7 experiments are done and then if they are successful a further 3 to 5 years.

nomism said...

Whatever. What will you spend your time on when WB-7 fails to perform as anticipated? Or will you and your fellow Bussardigans never accept a negative result? I hope you have a big garage to continue the development.

LarryD said...

A Bussardigan Fusion Reactor. Singular. The purpose of WB-7 is to explore the parameters and fine-tune the design for reactor number one. Which, like IETR, will be a custom rig. Unlike IETR, it will be a prototype power reactor.

Then some experience will need to be gained actually operating the reactor, and a manufacturing design will need to be engineered. Then factories can be built or modified and mass production can begin.

LarryD said...

OK, I got the numbering wrong.

WB-6 worked, nomism. It produced fusion, validating the theory and design.

WB-7 is to reproduce WB-6's results, to demonstrate to others.

WB-8 is to work out a full scale design.

I rarely make bets, but I'm willing to put up $100. What odds do you want? And we have to agree exactly what constitutes success or failure of WB-7. Which should be apparent some time next year.

Nomism said...

How do you know it worked Larryd? I've got some great swampland for sale -- a Google Talk complete with slides will be forthcoming. For WB-6, you have only the feeblest anecdotal evidence to point to in the form of a Google talk and and a conference paper submitted in absentia. There was no formal publication, no paper presented at an APS plasma physics conference, no peer review, no nothing. Just a rush to Google to plead for money. That's a classic hallmark of pseudo and pathological science. And you Bussardigans have eaten it all up -- complete with massive overconfidence, self-absorbed backslapping, and grandiose speculation about how it will revolutionize the world. If you really believe in Polywell go donate your $100 to EMC2 Corp -- they have a "donations" link on their page. Go for it. Become a card carrying Bussardigan!

LarryD said...

They don't need my contribution nomism, they have a Navy contract, for which finding is again available. Dr. Bussard's research was interrupted by the Navy's Energy Program being cut for 2006. He manages to fix the last big engineering hurdle and get three successful tests run before WB-6 shorted out. But the analysis of the data had to wait until December. Now that they've been funded again, they can build WB-7 and demonstrate that it works. And publish the papers that you want.

And now that you have shown that you aren't willing to put your money where your mouth is, how about you just wait until WB-7 is built and running before you comment any further. It's the only way you can be sure of not eating crow. Or do you think it's physically impossible for Dr. Bussard to have been right?

It shouldn't take but about six more months.

nomism said...

Larryd -- you are the one who is going to eat crow on this. You're the one violently bragging about IEC and it's unverified claims. Let me know when you demonstrate a Q value beyond 0.0001 - in fact, one of Farnsworth's original fusors still holds the record for neutron output you ignorant moron. Try getting to that level first.

I've got a better idea about your sophmoric bet: How about you give me half the money right now, I'll take you out back and kick you in the nuts, and we'll call it day? Why the hell would I place a bet with some dumbshit I don't even know? Six months from now you will be telling me the same thing -- "just wait and see! In six more months...". Blah, blah, blah. You are obviously completely ignorant of how science works and nothing more than a pseudoscientist hack. Go play with some batteries and a light bulb in your garage you hack.

LarryD said...

"Violently bragging"?

Well, I guess I struck a nerve somewhere.

I'm no nuclear physicist, but I have a decent science background, enough to understand Bussard's work on the conceptual level. His work makes sense, conceptually, violates no laws of physics, and he believed that WB-6 had produced enough fusion (three times) to prove his concept workable. Not that there isn't a lot of work to be done before the first power reactor goes on line, but all the remaining work is just standard engineering.

WB-7 should be operational in six months, then we'll find out who would have won the bet. Except that nomism never started to discuss terms. Hmm, Q beyond 0.0001 - I'll look that up, it might be a valid measure. Bussard's letter claimed that WB-6 "produced DD fusions at a rate over 100,000x times higher than the data of Farnsworth-Hirsch in the 1960's for same drive conditions." That's what WB-7 needs to reproduce.

OK. in fusion research, Q is the fusion energy gain factor, where 1 is the break even point. Normally defined as the ratio of output to the energy needed to sustain the plasma. Since a Bussard reactor doen't use thermal heating, the definition would have to be tweaked a bit, but the concept can be retained.

nomism said...

Larryd,

The Q value does not need to be redefined for an IEC fusion reactor. The people who do IEC fusion research use the same definition: fusion yield as a ratio to input power. See the following peer-reviewed publication for a good take on IEC's current state and the potential applicability of POPS -- Periodically Oscillating Plasma Sphere:

"Experimental Observation of a Periodically Oscillating Plasma Sphere in a Gridded Inertial Electrostatic Confinement Device", J. Park, R.A. Nebel, and S. Stange, Physical Review Letters, 95, 015003 (2005).

These authors provide a much more balanced and realistic view of IEC fusion as a neutron source for explosive detection, medical isotope generation, and potential future power generation.

linearthinker said...

nomism said...
...How about you give me half the money right now, I'll take you out back and kick you in the nuts, and we'll call it day? Why the hell would I place a bet with some dumbshit I don't even know?

Last time I heard a rant like this, the playground monitor took the kid by the ear and marched him into the principal's office. It was later rumored that his own nuts were smaller than the marbles in his pocket, but that's another story.

nomism said...

Linear you must be getting low on your Viagra? Just ask Msimon -- he'd be happy to set you up with some low price, top quality "medicinal" equivalent...puff, puff, puff you rec druggies!