Saturday, April 22, 2017

Word-thinking, Science Marches, Engineering, and my abs hurt.

🎵 Science! Ooo! What is it good for? Aah! Absolutely everything. 🎵

"If I drop a large ball bearing from a five meter height, how fast will it be going when it hits the ground? Approximately is fine."

This is a trivial Physics question, made simpler by the choice of numbers. Using $g=10$ $m/s^2$ as an approximation and ignoring other forces on the ball bearing (because they're relatively small), the time for the drop is one second ($5 = g/2 \times t^2$; solving yields $t=1$) and in one second the bearing accelerates to $ 1 \times g$, or 10 m/s.

Most people, including those who have had enough Physics in their formal schooling to know the above relationships, can't really answer questions like this. I've speculated that it's a mix of innumeracy (ignorance), acalculia (inability), and numerophobia (attitude).

It's also a reason why so many people believe that being word-thinkers over technical matters is acceptable. It's not. For a technological society to work, technical matters must be dealt in technical terms, and that almost always implies numbers-thinking.

Sadly, one sees the word-thinkers, or at least word-thinking, invading technical domains.



Many words about "science" but not one about scientific matters


There are several "Marches for Science" around the US today. Because there are some political undertones to some of the elements of these marches, a number of people who oppose the political side of those elements has made a lot of pronouncements about science.

(It's almost guaranteed that these people making pronouncements couldn't answer the question above, or do a mass calculation for the stoichiometric combustion of 2,4-dimethylpentane in pure oxygen.)

Politics aside, and that's a big aside, these people who are so concerned about the hijacking of science by political forces make a big deal of how the word "science" means a bunch of things, scientody, scidolatry, scientage, and other made up words, and then keep on harping about how the "dialectic" of this versus the "rhetoric" of that and so on and so forth.

Word-thinkers. Talking about science. The mirth potential is endless.

And as I read these (with my core muscles sore from yesterday's squat workout making belly laughs extremely painful), all that keeps going over in my mind is "can you explain the function of the Golgi apparatus?" or "what's the difference between alpha and beta decay?" Perhaps you wouldn't sound so ridiculous talking about "scientody vs scientage" if you could explain the macroscopic effects of the differences between a body-centered cubic crystal structure and a face-centered cubic crystal structure.

It's just ab-crampingly funny to read comments on how science works and how is should be interpreted by people who think that evolution and vaccines are conspiracies by the ruling elites to keep the sheeple under control, all data and evidence be damned. To read lofty words of advice on research methodologies by people who can't tell a burette from an Erlenmeyer flask.

As one might imagine, many of these word-thinkers about science are creationists, so it's without a drop of self-awareness that they talk about the sheeple "accepting authority" of scientists regarding the nature of reality.

Of course, most people don't simply accept the authority of scientists blindly; most people, at least people who think for a moment, recognize the incredible advances in quality of life brought on by science and technology (and the one that actually makes stuff, engineering).

While creationists accept the authority of, no, not God, they don't get their ideology from God (at least not without a large dose of LSD, Ayahuasca, or Psilocybin 'rooms -- and that's not God talking, that's the brain malfunctioning). They accept the authority of religious leaders, who have proven themselves a lot less than scientists and engineers.

As I said, not a drop of self-awareness.






Don't abracadabra with technical words, please

(This is an adaptation of a post on the EEVBlog forum.)

I pains me to see engineers use words as if they were incantations rather than technical concepts that have precise meanings.*

A little context: there was a discussion of a water-harvester device using a composite, MOF-81; there's a Science News article presenting it here and the actual peer-reviewed Science paper is here.

Some people complained that the paper itself is behind a paywall; I'm a member of the AAAS, so I can see it fine, but there are ways to read it without paying, the simplest one being through the proxy server of a public library. (Many libraries, including college libraries that carry Science online, have open proxies for their patrons and students to access online databases remotely; some of these proxies require no authentication or geographic validation.)

A few commenters in the forum were disparaging the research, using words like "thermodynamics" or "enthalpy of evaporation" without taking a minute to do some calculations. And no, you don't need to read the Science paper or solve the heat equation to avoid wrong statements.

The point of contention is the 3 liters of water per kg of MOF-81 per day. So, how much energy are we talking about and how big a surface to dissipate it?

The enthalpy of evaporation for water is 2.3 MJ/l and because it's so high you can pretty much ignore the energy of temperature change within the gas or liquid phases; only the phase change matters to a first approximation.

3 liters $\times$ 2.3 MJ/l = 6.9 MJ - per day, therefore (divide by 24*3600) 80 W of power.

(At this point most engineers should realize that there's no problem; 80 W from a large-ish metal surface in open ambient air will almost surely be peanuts. A human being radiates about 100-200 W depending on the level of activity, or at least that's the number used for HVAC dimensioning when I was in college, back in the Pliocene.)

How big an area are we talking about? Again, even without reading the paper we can do some basic calculations, assuming planar geometry for the MOF-81 deposition.

If the MOF-81 were as dense as lead, 11.34 kg/l, a thin(ish)-film deposition over the base material, say 1/25 mm, would lead to 2.2 $m^2$ of area, or a square about 1.5 m on the side. To dissipate 80 W. Piece of cake.

But since the MOF-81 is much less dense than lead and is deposited to maximize porosity (that's how the MOF-81 works, it's all physics, no chemistry), it's more like styrofoam, and the area would be around 24 $m^2$, which makes the "enthalpy of evaporation problem" a non-starter. (It was already a non-starter with 80 W in 2.2 $m^2$, but the 24 $m^2$ is closer to reality.)

(The actual geometry of the deposition is more complex, highly non-planar, making use of a copper foam that is infused with the MOF-81 powder, all on a copper substrate, but to know that you'd need the actual paper. Which you can easily read online using a library proxy.)

We are engineers; let's not act like muggles and resort to lobbing words around as if technical terms were incantations. If it's an engineering word, there are probably numbers hiding behind it somewhere. Get those numbers.

You shall know the numbers, and the numbers shall set you free.

 - - - -
 * Of course, not all forum denizens are engineers; trolls make themselves obvious by nitpicking on details that engineers would assume and by responding to math with word-thinking and cherry-picking.

Tuesday, April 18, 2017

In memoriam

In remembrance of income lost to the revenuers, posting will be light during April.

Saturday, April 8, 2017

Early April geekery

😎 Much ado about YouTube monetization: a few pictures

There's a lot of nonsense in my social media feeds about "The End Of You Tube" and other self-serving notions by people who lost monetization of their videos. Here are a few images about that, which I made in my free time and using only public information sources.





😎 Shane Killian again schools Thunderf00t on basics of Engineering




😎 Having some fun with Rstats

Since RStudio is always up on my machines, sometimes I use it for fun. First, not quite chaos, with the logistic map, $x(t+1) = r \, x(t) \, (1- x(t))$, for an $r$ below the critical level:

Then some cellular automata (using package CellularAutomaton):




Monday, March 27, 2017

Creationists attack evolution, hilarity ensues.

On a site that I occasionally peruse there was a post today about evolution. Since the owner of the site is a creationist and so are most of the commenters on that site, I decided to pick some short comments for analysis.

Usually creationists give themselves away by using "evolutionist" instead of "person who understands basic biology"; they also focus all their attention on politics and personalities instead of ideas and evidence, for example using "Darwinism" and "Darwinian evolution" instead of simply saying evolution.

Comments from that site in italic blue, my analysis follows them.


So now the neo-Darwinists are just like Darwin himself, once again they're holding to their theory out of dogmatic bloodymindedness in spite of the overwhelming evidence against it.

As they say on Wikipedia "citation needed." In fact, evolution by random mutation and non-random selection has been validated as a mechanism for speciation, for example with the flu virus; details of the process get increasingly better understood as we learn more from molecular biology, and as with everything in science, the evidence is what matters.

The alleged "overwhelming evidence against it" always ends up being something that has been thoroughly debunked ("how could an eye evolve?"), arguments from ignorance of the basics, cherry-picked or outright made-up data, personal attacks, or a combination of these.


No one understands the first thing about evolution because all of the predictions it makes come out false.

Ditto with "citation needed," and the response to previous quote.


[Responding to] "Surely, if it was intelligently designed by a supernatural entity or an alien, they would not have made such a very sloppy work."

Only someone who has never been in an engineering lab could possibly make such an ignorant statement.

Engineering labs make technology demonstrators and prototypes. Finished products are held to a different standard. (That was my beef with Thunderf00t's criticisms of the Hyperloop.)

If there had been a designer, then that designer would fail all design and product creation courses in existence, what with putting a waste disposal outlet and amusement area in such close proximity. No need to ask about the infinite regression of designers, which is what design arguments for life always end up tangled in.


Simple observation of the complexity of plant and animal life reveals the theory of evolution as one of the most retarded pieces of BS ever believed by human beings.

The ignorance in this comment might have been tolerated up to the 1960s, as explanations of the actual work of replicator dynamics and evolutionary stable strategies (not by that name, which is modern) were too technical for most people to understand. But since the 1970s there have been a slew of simple, easy-to-understand explanations of how the process works, so there's no longer any excuse for even a lightly-educated person to say such nonsense.


Darwinism violates the central limit theorem, one of the most fundamental laws of probability in the universe.

Now here we have a great example of a species called the Pomposus Ignoramus Maximus: someone who picks a concept at random, places that concept in a already-faulty argument, and states the resulting mess as fact.

The central limit theorem (more precisely, each central limit theorem, since there are many, each a generalization of an earlier one) says that under certain regularity conditions, the distribution of the sample mean converges to a Normal distribution with mean equal to the population mean and variance equal to the population variance divided by the sample size.

Note that this is a theorem about generalizing the results of sampling and has nothing to do with biology or evolution. That's the "picks a concept at random" part. Anyone familiar with a central limit theorem would understand that it has nothing to do with evolution, but obviously the commenter doesn't know that.

The "already-faulty argument part" usually goes as follows: because evolution creates what appears to be order, it violates the second law of thermodynamics. This argument is faulty on a number of different levels, the obvious one being that the second law of thermodynamics doesn't apply to open systems that receive energy from outside, and evolution, which depends on reproduction, does receive energy from the environment.

Of course, the first word, "Darwinism," gives the commenter away as an ignoramus, as no one who understands biology refers to evolution this way. "Darwinism" is used to make it appear as if evolution is just a political movement or a personality cult.



There was also a lot of nonsense about the Universe being a computer simulation. I'll let Lubos Motl deal with that.

Sunday, March 26, 2017

Late March geekery and revealed preference


I drew a random sample of 100 pages from the browser history on my personal laptop, and then classified each of the pages into a number of categories. Results were rounded to 5% because such a small sample will necessarily contain a lot of noise; the 5% is essentially a low-pass filter cutting out the high-frequency noise of occasional browsing.

This is a very rough measure of preference, since it doesn't account for time spent on the page, for example, or other measures of interest. But it's a good starting point, and it matches interests outside of online content (books, videos, participation in forums). I classified book-related pages into the most appropriate category, so the two SciFi-related pages in the sample went into STEM, because they were hard-scifi not space opera.

STEM and business (including economics) are my work areas, but on that chart I map only the non-work related perusal. I start the day with a massive RSS-feed reader, about one- half business and one-half science and engineering; of that about two-thirds has no direct use for work. The other categories in the chart are personal interests with typically map to activities in the real, physical world: exercise, food, culture, and the Bay Area and California (events, traffic, weather, local news; I live in the world, after all).

One surprising omission is photography-related content, but that's the problem of 100 observations. I would have sampled 10,000 but then I'd need to classify those 10,000 by hand, so I didn't. I did have some hits from the StyleForum, but most were about food, not clothing or shoes, so they were classified appropriately. The London Lounge, alas, didn't appear in the sample.

Other than business and economics-related news, I don't follow current events, celebrities, gossip, or sports, so it's not an anomaly that they're not represented in the chart. (I get enough relevant news and cultural developments as part of the work-related information stream. Backed up by charts.) Obviously there's no adult or embarrassing content in my browsing  --- because I don't consume that, of course, not because I understand private mode browsing.

With the above distribution in mind, the rest of the post is an illustration of the content making up that revealed preference (and my take on some of it). I avoid commenting on business, management, and economics for work-related reasons, so I'll leave those out.


😎 Thunderf00t shows how Fukushima worrywarts are wrong:


Here's Thunderf00t being uncharitable again! Making these poor people stretch their 2 IQ points together to understand that 2 Becquerel per cubic meter of seawater from Fukushima is not so enormously dangerous when compared to 10,000 Becquerel from our own body radiation (for 100kg person). Or the extremely dangerous bananas.

Pretty interesting explanation about the bio-accumulation of Strontium (because of chemical similarity to Calcium, which is in our bones).


😎 Internet fitness experts, what a joke:


I could be naughty and notice that both of these pull-up experts have narrow shoulders and thin upper arms, which is interesting since the main purpose of pull-ups is to develop broad shoulders and thick upper arms. But I won't be naughty.


😎 Your tax dollars at work (at Fermilab): the weak nuclear force.




📕 I recently read Dan Ariely's "Payoff," an interesting book about motivation. Highly recommended for everyone: it's not about how to motivate employees (though it does serve that purpose), but rather how to understand one's own motivations. By allowing me to see outside of my own behavior, it clarified some issues of work-related happiness I'd been struggling with.


📕 Now reading Joel Mokyr's "A culture of Growth," an analysis of what really drove the success of industrial civilization. Not one to bury the lede, Mokyr states early on that, unlike what economists and historians (and economic historians) tend to think, it was not intellectuals driving the change but rather the pragmatics (what we would call engineers, entrepreneurs, and venture investors).


👍 Some interesting links:

  • What Costco knows about customers. This is the kind of thing I collect in case I start doing executive education (or regular MBA teaching) again. Interesting, and if I wanted to turn it into a discussion piece or an exercise, it would take less than one hour to do so. I browse these for fun (yes, I've idiosyncratic tastes), but there's a bit of a pragmatic background to it.


🎵 Closing music, via Voices of Music:


Saturday, March 25, 2017

Reality vs nonsensical products (part 688 of Aleph-null)

Via Thunderf00t, I found this Waterseer-wannabe, which is about as feasible as the original Waterseer, that is not at all.



Obviously it's very important that the product is 3D-printed, rather than CNC-machined or heat-molded. 3D-printers, like the Internet Of Things, are magical incantations that can get around the laws of Physics. Or so one would think, given how credulous people become at the sound of these incantations.

Alas, as is usual with engineering, ugly numbers murder beautiful illusions:



Since the battery voltage is 12V, a 12kW Peltier effect cooler will require a 1000A current, which is likely to make Li-ion battery a bit... well, just watch what happens:



Engineering rule: when an electronic device starts outgassing, that's generally not a good thing.

Wednesday, March 22, 2017

The power of "equations"

If a picture is worth a thousand words, an equation is worth a thousand pages of text.

This was inspired by a livestream about free trade based on criticism of "original texts." (Basically Ricardo and Schumpeter.) The quotes aren't a diss on the texts themselves, but rather a way to emphasize that this is a type of scholarly pursuit in itself, though not the type used in modern economics, STEM, or pragmatic professional fields like business analytics or medicine.

What's the problem with the argumentation from these original texts? Simply put, the texts are long and convoluted, with many unnecessary diversions and some logical problems in the presentation. The valid arguments in these texts can be condensed in about one page of stated assumptions and two results about specialization.

It's not just that math's an efficient way to communicate, math has precise meaning and an inference process. It brings discipline and clarity to the texts and the inference process isn't open to debate. (Checks and corrections, yes; debate, no.)

Unfortunately, without math, the speaker's argument was essentially a sequence of variations on "Schumpeter points out that this assumption of Ricardo doesn't hold true," without the extra step of determining whether those assumptions are important to the final result or not. (We'll come back to this problem.)

Word-thinking about quantitative fields is generally to be avoided.

That was the inspiration, and this post isn't about free trade or the particular mode of thought of that speaker, but rather about the power of mathematical modeling, which I'm calling "equations" in the title.

Here's a reasonably robust statement: when the price of a commodity goes up, people buy less of that commodity. (Sometimes this is put as "demand goes down," which is incorrect, it's the demand quantity that goes down. Changes in demand are movements of an entire function.)

So, quantity is a decreasing function of price (and first-time readers of economics textbooks get confused because the charts have quantity in the $x$ axis and price in the $y$ axis). This has been known for a long time; what's the problem with that formulation, simplified to "when price rises, quantity falls"?

The problem, of course, is that there are many different types of decreasing function. Here are a few, for example (click for bigger):


Functions 1 to 4 represent four common behaviors of decreasing functions: the linear function has similar changes leading to similar effects; the convex function has decreasing effect of similar change (like most natural decay processes); the concave function has increasing effect of similar change (like the accelerating effect of a bank run on bank reserves); and the s-shaped function shows up in many diffusion processes (and is a commonly used price response function in marketing).

Functions 5 to 8 are variations on the convex function, showing increasing curvature. (Function 2 would fit between 5 and 6.) They're here to make the point that even knowing the general shape isn't enough: one must know the parameters of that shape.

That figure does have 2000 data points, since each function has 250 points plotted. (When talking about math, some people use drawing tools to make their "functions," I prefer to plot them from the mathematical formula; it's a habit of mine, not lying to the audience.) To describe them in text would take a long time (unless the text is a description of mathematical formulation), while they can be written simply as formulas; for example, the convex functions are all exponentials:

$\qquad y = 100 \, \exp(-\kappa \, x) $

with different values of $\kappa$. They are the type of exponential decay found in many processes, for example, where $x$ is time and $y(x) = \alpha \, y(x-1)$ with $y(0)>0$ models a process of decay with discrete-time rate $0 < \alpha < 1$. In case it's not obvious, $\kappa = -\log_{e}(\alpha)$.*

So, what does this have to do with reasoning?

Here we go back to the problem with arguments like "Schumpeter showed that Ricardo's assumption X was wrong." When a model is written out in equations, we have a sequence of steps leading to the result, each step tagged with either a know result, rules of math inference (say "$a \times b = a \times c$ simplifies to $b = c$ unless $a = 0$"), or an assumption of the model. This allows a reader to quickly see where a failed assumption will lead to problems and determine whether the assumption can be replaced with something true (or, as is the case with many of the assumptions made by Ricardo, is unnecessary for the result).

The main power, however, is that mathematical notation forces the speaker to be precise, and inferences from mathematical models can be checked independently of subject matter expertise. A mathematician may not understand any of the economics involved, but will merrily check that a decay process of the kind $y(n)= \alpha \, y(n-1)$ can be described by an equation $y(n) = y(0) \, \exp(-\kappa \, n)$ and determine the relationship between $\kappa$ and $\alpha$.

From those precise models, one can make inferences that take into account details hidden by language. Consider the "price rises, quantity falls" text and compare it with the different decreasing functions in the figure above. The shape of the function, its slope and its curvature have different implications for how price changes affect a market, differences that are lost in the "price rises, quantity falls" formulation.

It bears repeating the first mentioned advantage: that hundreds of pages can be condensed in one page of equations. Once one's mind is used to processing equations, this is a very efficient way to learn new things. Stories about Port wineries in Portugal and textile factories in England may be entertaining, but they aren't necessary to understand specialization (which is what comparative advantage really is).

Math. It's a superpower mostly anyone can acquire. Sadly, most opt not to.


- - - - - Addendum - - - - -

No self-respecting economist would use the Ricardo comparative advantage argument for international trade now, particularly because it's so simple it can be understood by anyone. Most likely they'd use some variation of the magic factory example:

"Let's say a new technology that converts corn into cars is discovered and a factory is built in Iowa that can take ~ $\$20,000$ of corn and convert it into a car that costs $\$30,000$ to make in Michigan. Can we agree that this technology makes the US richer?

Now, move the factory to Long Beach, CA. Maybe there's a little more cost in moving the corn there, but we're still making the US richer, right?

Now, someone goes into the magic factory and discovers that it's really a depot: stores grain until it's sent to China on bulk carriers and receives cars made in China from RoRos during the night. The effect is the same as the magic factory, so it makes the US richer, right?"

There are many cons to this example, but it does make one issue clear: trade is in many respects just like a different technology.


- - - - - Footnote - - - - -

* It's obvious to me, because after decades of playing around with mathematical models, I grok most of these simple things. There are some people who mistake this well-developed and highly available knowledge (from practice) for ultra-high intelligence (rather than regular very high intelligence), a mistake I elaborate upon in this post. 😎