Sunday, October 23, 2016

Gravity "batteries"

When there's too little demand for electricity, certain grid operators (like the Portuguese one) use excess capacity to pump water from downstream of dams to the dam reservoir. This is a way to store energy for peak demand.

I understand that some mountainous region is studying the possibility of replicating this with a funicular that would operate as the water in the dam. The losses involved in moving the funicular imply low roundtrip efficiency (the ratio of the energy recovered to the energy entered into the "battery"). And, of course, the funicular can't be used for passengers, unless there's some special discount for unpredictable schedules.

At least two people have told me about a start-up (I forget what its name was) that wants to solve the battery problem by using the same approach, only with dedicated masses on vertical tracks.

The tragedy of engineering is the murder of beautiful illusions by ugly numbers.

Let's say this company can use $100\%$ roundtrip-efficient motor/generators, that is, all the electrical energy that is converted into potential energy of the moved mass can be recovered as electrical energy with zero losses in the whole process. (Yes, this is a ridiculously generous assumption, but it won't matter.)

Say this company has a 1000 metric ton mass that can be raised up to 10 meters. It can therefore accumulate 10 megajoule (MJ) or 2.8 kWh. Sounds ok-ish for a battery, except:

1. If that mass is made of lead (density = $11.34$ kg/l), a cheap-ish dense material, its volume is 88.2 cubic meters. That's large for a battery: it's a cube almost 4.5 meters on the side. Remember that this assumes $100\%$ roundtrip efficiency motor/generators.

2. Gasoline has an energy density of 46 MJ/l and jet fuel has an energy density of 42 MJ/l; using a readily available commercial-grade combined-cycle generator with a $37.5\%$ total efficiency, 10 MJ can be generated with $10/(42 \times 0.375) = 0.635$ liters of jet fuel, or less the volume of two cans of Dr.Pepper (33cc cans, that is :-).

Okay, the combined cycle generator takes some space, but so do the motor/generators and the support frame for the 1000 ton mass. And the space for the vertical track, of course.

Numbers. Killing illusions. No wonder so many people avoid them.

- - - -

To make up for the bursted bubble of delusion, here's the feel-good video of this week:

Thursday, October 20, 2016

Much ado about the University of Cape Town video

Here are Thunderf00t and Computer Forever on it:

I can only assume that neither has been in academe for a while (no, Thunderf00t, I mean real academe, with students and administration and academic life; you know, that for which you talked down to Prof. Moriarty -- a curious reversal of the usual academic snobbery). This kind of thing is common enough in academia. And in most cases it's more entertaining than worrisome.

If the original video was of a meeting of the presidents of Caltech, MIT, Princeton, and Stanford, then I'd be worried. But these were kids having a bull session in college. As in something that happens in all colleges at various times.

There are some worrisome trends in the treatment of science, technology, engineering, and math in society. These kids are a distraction, and true to form the professional YouTubers bring attention and light to the distraction, inadvertently (I assume) helping distract from the more serious problems.

Sunday, October 9, 2016

Aging engineers versus experienced engineers

There are growing complaints that Silicon Valley companies discriminate against middle-aged engineers. But it might not be just ageism, it might just be aggregation error.

Engineering comprises mainly two things: a body of knowledge and a problem-solving mindset. To be a good engineer one needs an up-to-date body of knowledge in the relevant field and a facility with different problem-solving approaches used in the field (and possibly outside it as well).

(For the moment let's leave aside the problem-solving mindset; its dynamics are complicated and very situation-dependent: while some engineers acquire and develop problem-solving skills with experience, other fossilize their thinking, for example due to organizational practices.)

As part of what I do is continuing education, I have observed the dynamics of the body of knowledge as engineers' careers progress.

  • The largest group by far (sadly), makes little attempt to keep up-to-date with their field after formal education ends. In conversation, after a corporate training event, a member of this group told me that keeping up-to-date was "very nice in theory, but we don't have the time." All of us would like more time; but this person spent tens of hours per week watching TV. One of those hours per week spent updating their skill set would mean 52 hours per year, which would be more than enough (most of the participants in that event had fewer than 20h/year of training or study, and self-paced learning can be much more effective than group events.)
  • Most of the remaining engineers realized their technical obsolescence would become a problem and were retooling themselves for a management job. The main problem with this attitude is that there will always be fewer management jobs than engineers who plan to go into management. Secondarily, firms have both partially replaced management jobs with consultancy engagements and started prioritizing management-trained applicants over engineers.
  • A few engineers fell into a third category: those who keep up-to-date either because they realize the job implications of doing so or because they really love their engineering field. The problem, for those in this group, is that their small number makes them liable to be categorized into one of the other groups.

Placing ourselves in the position of Google, for example, the decision to consider a candidate who's been out of formal education for several years versus considering one that's just graduated --- even if Google believes that the energy of youth can be balanced by the temper of experience --- comes down to which of the three groups above the older candidate will fall into.

In the absence of good information, statistically the older candidate will be in the first group, in other words, aged, not experienced, a distinction that most of the engineers can but will not make (as it defeats their case).

(The younger candidate's type is irrelevant, because being fresh from school means an up-to-date skill set, at least for the near future.)

There are obviously many confounds: consider a choice between a newly minted computer engineer from Idaho State - Tubertown with no code to show (not even from school projects) versus a 45-year-old Caltech graduate class of '95 who has code on GitHub that is particularly relevant to the job, for example.

For the other engineers, who have been lax in their updating of skills, there's a solution: it's never too late to learn. And then: show, don't tell.

Wednesday, October 5, 2016

Midweek Nerd Pride Post

The thunder down under [brought down the electrical grid]

The South Australia state of, well, Australia serves as a reminder that correlated risks aren't just for financial crises:

Australia: proof the correlated risks aren't just for finance

Source for the timeline and quote: "PRELIMINARY REPORT – BLACK SYSTEM EVENT IN SOUTH AUSTRALIA ON 28 SEPTEMBER 2016" by AEMO  (PDF file)

(My previous analysis, from preliminary and incomplete data, suffered from lack of granularity.)

The memes started immediately:

I don't think the australians deserve this meme, though eight people have sent it to me so far, so it's clearly popular. The problem isn't the wind generation per se, it's the lack of large scale batteries, as explained here by Donald Sadoway of MIT.

Video killed the radio star bad science popularizer

I wrote a post on Sunday that was a little negative on popular science popularizers, but forgot to mention that the emergence of alternative media platforms, like YouTube, could counter the decline in the quality of science popularization on mass media. So here are a few examples from this week.

There's always something fun to watch on the Numberphile YouTube channel:

I watched the Norwegian TV show "The Heavy Water War" on Netflix in the last three evenings (two episodes per evening, not really a 'marathon') and therefore rewatched these fun videos from the YouTube Periodic Videos channel:

Walter Lewin shows how to make teaching come alive, teaching optics to high-school science teachers. He has the advantage of teaching Physics, with practical demonstrations (that is, using real physical objects), unlike those of us who teach more indirect material (like, say, decision-making or strategy or analytics):

As a contrasting example (of how not to talk about Physics), here's the announcement for the 2016 Nobel Prize in Physics:

I'm sure there are pretty good Physics instructors in Sweden. But instead they did the European bureaucratic thing and had a member of the committee give the talk, apparently without any sense of how to weave a narrative or what to emphasize. Yes, I understand that he's a physicist, but not one that can present physics to a regular audience. (Compare with Walter Lewin above.)

As a bonus, the announcement also showcases the total lack of interest in science of the reporters assigned to cover this scientific prize. But that's par for what passes for journalism these days. Why bother with knowledge when you can ask "human interest" stories?

Staying with Physics, here's a fun lecture that basically tells us how much we don't know about the universe. Really, we know very little:

And, given the section title, here are the Buggles singing "Video killed the radio star"

Still geeky, but more technical…

Stats… Yesterday was the official October BARUG (Bay Area R User Group) MeetUp at Santa Clara University, so I went early and enjoyed their beautiful campus:

At Santa Clara University for the October BARUG meetup.

There was a talk about Benford's law (a statistical regularity of the distribution of the first digit of large sets of numbers. It was inspired by this Business Insider piece.

Two presentations showed political forecasting; not my thing, but one was an interesting application of kernel methods, particularly KRLS (kernel regularized least squares): Slides on GitHub here. Definitely worth checking out.

More stats… Nassim Nicholas Taleb (backed by Pasqualle Cirillo) is locked in a deathmatch with Steven Pinker and some of his more statistically-proficient supporters. Alas, I think this is game, set, and match for Taleb:

Even more stats… Andrew Gelman finds closure in his argument with Amy Cuddy and co-authors, from an unexpected side: one of the co-authors has now all but retracted the paper.

Some commenters raise an interesting question, for which I have no answer: given that the work on which hiring, promotion, and tenure of these authors was base is at best incompetent and at worst fraudulent, should these authors resign (or their institutions fire them)?

On the one hand, it might seem reasonable that when the work that supported some institutional decisions (hiring, promoting, tenure) is shown to have been invalid, those decisions should be revisited. There are legal questions that make this point moot, but in principle it appears to be a reasonable idea.

On the other hand, any such actions may make it less likely that people might own up to problems with their papers in the future. This isn't a small thing, as some of these errors might be" par for the field" at the time of writing but unacceptable a few years later.

In a follow up post, Andrew asks "Why is the scientific replication crisis centered on Psychology?" Good read, but here's a thought: When a paper "fails to replicate," the problem isn't in the replication, it's in the original research.

Linkage galore

Nobel Prize in Chemistry 2016 awarded to three pioneers of molecular machines via Kurzweil Accelerating Intelligence.

Designer Babies, by Peter Diamandis.

Bacterial molecule trains the immune system to tolerate infection without inducing illness, on Medical Xpress, via

California eyes unusual power source: its gridlocked roads via No, not Solar Roadways nonsense; piezoelectric generation. Still probably nonsense in any appreciable scale, though.

This Huge Robot Will Drive Up and Build You a House, via Singularity Hub.

Privately-developed rocket aces abort test, via Spaceflight Now. Blue Origin's puddle jumper passed its abort test, so it's one step close to being able to take passengers to "space."

A book that's going on my reading list: The Paradox of Stupidity
As Jan Wallander, the ex-chairman of Sweden’s Handelsbanken, said: ‘Business leaders are just as fashion-conscious as teenage girls choosing jeans.’ Many companies adopt the latest management fads, no matter how unsuitable they are. If Google is doing it, then it’s good enough reason to introduce nearly any practice, from mindfulness to big-data analytics. - You Don't Have To Be Stupid To Work Here, But It Helps.

Sunday, October 2, 2016

Much ado about "loving" science

Science identity products

Science identity products like t-shirts, mugs, posters, and computer wallpapers are used to signal that the owner has an interest in science; unfortunately, because this interest in science has become fashionable -- at least in some segments of the population -- poseurs also buy these objects, lowering the quality of the signal.

I've written often (one, two, three, four, five times at least) about the problems with using science as an identity product, as with the people who "love science" as long as they don't have to learn any.

These products aren't necessarily only appealing to poseurs, though. People with a real interest in science and in science education also like them for, among other reasons,

1. Identity signaling. Like the poseurs, except it this case it's a real signal. People want to communicate their interest in science and the beauty of some scientific results and natural phenomena. (I own quite a few science identity products myself.)

2. Recruitment. These products can be useful motivators for bringing newcomers into an appreciation of science. By showing that there are other nerds geeks people interested in science, they create social conditions for others to come out as nerds geeks people interested in science.

3. Mere exposure. People like or at least feel more comfortable with things that appear familiar. The more exposure people have to scientific concepts and images, even if as part of jokes or background material in sitcoms like The Big Bang Theory, the less aversion they may feel when science content is presented to them.

There's one possible disconnect undermining these three points, though: that people who are influenced by exposure to the science identity products only like the aesthetics:

Problem with science popularization

The big problem with the poseurs, which is a real problem not just my "I liked that band before it was cool" complaint, is not that they use the products to pretend to like science, though that would be bad enough. The real problem is that poseurs know that they don't actually like (or know) real science, so they feel threatened by those who do and take action to counter that threat, usually distracting from the science.

As my previous post showed, many poseurs in the media try to be "sciencey" but they fail miserably because in the end they don't understand that science is not like literature or art where the judgment of some other people is what matters. In science, reality is what matters. Poseurs don't get that, because to them reality is whether others buy into their pose.

Popular science content

Making science accessible to the general public is one of the most effective ways to improve society: it allows more people to partake of the benefits of knowledge (for example, avoiding junk science and quackery), it helps garner support for scientific enterprises that require public funding, and it creates the foundations for new generations with more and better scientists.

My ideal science popularization

The problem is that popularizers can be real science popularizers or they too can be poseurs. And the poseur popularizers tend to be more popular. The glaring exception is Carl Sagan, but that's because he was both a pioneer in popularization and a real research scientist prior to that.

The most obvious difference is that Carl Sagan's Cosmos was designed to impress people with the power of science, while many current popularizers design their programs to impress upon the audience (a) how special they, the audience, are; and (b) how smart, knowledgeable, and suave the popularizer is. There are some exceptions, but they aren't the most successful popularizers, at least not on TV.

A rule-of-thumb that works for me is to ask whether the popularizer is an active researcher (or was until recently active) in the field. People whose job is some variation of "science popularizer" tout-court, even if they have some scientific training (which many of them don't), tend to focus on people and events rather than concepts and principles. In other words, they popularize the story of science rather than the actual science. (In many cases they either avoid the science completely, or they get most of it wrong.)

This rule works for two reasons:

First, an active researcher will know the science better than a non-researcher popularizer. This IMNSHO more than balances any communication advantages the non-researcher might have. One of the hilarious examples of this advantage is The Igon Value Problem, where active researcher Steven Pinker takes on the intellectual lightweight Malcolm Gladwell. (But supporting my observation above, Gladwell is more popular than Pinker.)

Second, an active researcher has to protect his/her reputation in the field. This adds motivation to get things right to the knowledge (the ability to do things right). When no one in Astrophysics takes you seriously (because you  call yourself a scientist but your career total citations of 150 mark you as a museum manager), you can say ignorant things on twitter about planes and helicopters. An engineer who wrote nonsense like this would be mocked at any future technical conferences he/she attended:

Personally I decided to read textbooks in lieu of popularization books,* but there are some popular books I've read that I found worthy of recommendation, so here are two for now:

Deep science (or other technical) content

Leaning technical material is something that requires audience (perhaps in this case "student" would be the better term) participation.

Lectures can motivate study and are a good introduction to the material, but only self-paced study and practice exercises can make technical material stick.

There's a qualitative difference between (to quote again from my old post about Heisenberg) understanding that this is a joke, i.e. popularizer-level understanding:
Police officer: "Sir, do you realize you were going 67.58 MPH?
Werner Heisenberg: "Oh great. Now I'm lost."
and being able to completely spoil the joke by computing the actual uncertainty (deep understanding):
A simplified form of Heisenberg's inequality, good enough for our purposes, is 
$\qquad \Delta p \, \Delta x \ge h $ 
Going by orders of magnitude alone, assuming that the mass of Heisenberg plus car is in the order of 1000 kg, and noting that the speed is given to a precision of 0.01 mi/h, an order of magnitude of 10 m/s, with $h \approx 10^{-34}$ Js, we get a $\Delta x$ of the order of 
$\qquad \Delta x  \approx \frac{ 10^{-34} }{10 000} = 10^{-38}$ m.
Only practice and study can create the kind of deep understanding that allows you to spoil people's fun at parties with numerical sidebars like this. Certainly something to aspire to...

That's not to say that lectures don't have value; I think of them as the warm-up sets you do before actually exercising. In that sense, they are very important, since they provide a passive experience that gets the material into context, setting up the active experiences of self-paced study and practice exercises.

Walter Lewin, shamefully retconned out of OCW and their official YouTube channels by MIT for undisclosed non-scientific transgressions, was one of the best Physics instructors online; even better than Feynman, since Lewin used actual in-class demonstrations and calculations matched to the examples. Here's a great class on standing waves:

As for most MOOCs, I already wrote my views in my post "MOOC-rize this," and the TL;DR is:

1. MOOCs have economies of scale in production and diffusion, but the difficult parts of education, personalized attention, for example, don't scale.

2. MOOCs can derive brand equity from the institutions associated with the teaching, but whether that brand equity is deserved is an open question: there are many components to education beyond what most MOOCs offer. I made some observations about that regarding the Kenan-Flagler Online MBA.

3. MOOCs built out of classroom teaching and associated materials are audience-targeted; a course like Lewin's works well at MIT and possibly CalTech, but the speed of exposition and the amount of off-classroom work that Lewin expected from his students will not work for most other universities. Other materials, like textbooks, may partially make up for this, but even so most students would probably prefer better match between materials and audiences.

4. The major weakness of MOOCs as they exist now is the lack of evaluation and, in many cases, of ways to check your exercises. Since audiences (students) learn from these exercises, done individually and then corrected by a knowledgeable instructor, this is actually a much bigger weakness than I noted on the "MOOC-rize this" post.

In conclusion

There's nothing wrong about being out and proud as a nerd geek someone who likes science; take care to avoid poseurs, both individuals and media darlings who don't have a track record of research; and if you want to learn more (kudos to you), there are plenty of MOOCs and other free resources to help you. One of those resources is called a Public Library and for the effort of getting a library card you can get a good education because in the end what matters is that you want to learn.

In the end what matters is that you want to learn. Poseurs don't want to.

-- -- -- -- -- -- FOOTNOTE -- -- -- -- -- --

* I find textbooks to do a better job than popularization books since I want to learn things at a more proficient level than a passing understanding. This requires time and effort, but I like it. (Hey, I lift heavy weights for no reason other than I like lifting heavy weights, so this isn't that different.)

The one enormous barrier to this approach is the ridiculous cost of textbooks in the US. I was interested in molecular biology, so I got Molecular Biology of the Gene, I believe for its weight in gold. There's now a new edition which costs its weight in diamonds, so I won't get that. Note that this is a personal interest in molecular biology; this is not work-related or anything monetizable, so the $\$200$ are a hobby expenditure. Which is fine, but still could discourage others from buying such an expensive book for a hobby.

I rationalize the cost by reminding myself of an old business associate who spent $\$150$ on a date with someone who, according to his later report, made Lady Macbeth sound warm and cuddly. So, that's about 3/4 of a textbook he could have bought there...

Friday, September 30, 2016

Ah, "science" in the media, always good for a laugh

There's nothing wrong with the idea of science in the media, per se: I want more and better science in the media. But there's a lot wrong when people who clearly don't know any science write (or illustrate) pieces about science or related matters like engineering, the environment, and space exploration.

The Wall St. Journal, where people who don't understand basic Physics units write tweets about trading systems designed by hordes of Math and Physics PhDs:

With friends like Engadget "green" writers, the environment won't improve.

The Motley Fool, being its foolish self.

That's it for September. A lot of incipient posts in the hamper, but paid work got in the way of blogging. Such is life.

Saturday, September 24, 2016

Carbon capture, perpetual motion machines, and IGORs

There's one quick rule to evaluate energy-related technologies: if you can turn them into perpetual motion machines, they aren't real.

In conversation with an IGOR (Ignorant Grandstanding Oblivious Rabble-rouser), I pointed out that the idea of using atmospheric carbon dioxide to make fuel isn't entirely new (Nature did it first), but the technologies being proposed aren't realistic, for the reason above.

IGOR countered that these processes could, in his view, be the solution to our energy crisis (do we have one?), because the fuel produced by carbon-capture will provide the energy to keep the process going.

Ahem. Let's think about this, with a diagram:

What reasonable people say is that the energy extracted from the fuel will partially cover the energy needs of the capture and conversion process (that is $x > y$ but not by much); what IGORs say is that $y>x$. But if that were so, we could feed the exhaust from the energy production system into the input for the capture system, and get a perpetual motion machine that generates free energy.

Some of the more reasonable proponents of this carbon-capture and conversion idea suggest that the energy coming in can itself be green energy, like solar, and therefore there's a net "carbon-based" energy coming out of the system. Two points:
First, that's fine, but then why use part of that solar energy to create carbon-based fuels, instead of using the solar energy to replace the carbon-based fuels? Note that any $\mathrm{CO}_2$ that gets turned into fuel will yield another $\mathrm{CO}_2$ after the energy generation (conservation of the carbon), so no advantage there.
Second, the designs proposed look extremely wasteful of energy: capturing $\mathrm{CO}_2$ after it has diffused into the atmosphere is bound to require a lot of energy to flow non-$\mathrm{CO}_2$ gases in the atmosphere through the carbon-capture process. Better to stop $\mathrm{CO}_2$ at the source, if that's what you're after.
Of course, as I mentioned, Nature does provide us with a technology to use solar power to capture $\mathrm{CO}_2$ and turn it into fuel:

It also has the advantage of being pretty, giving shade, operating in silence, and bearing fruit. Trees. It's trees. Let's plant more trees. I like trees.

One particularly oblivious IGOR insinuated I was anti-environment because I prefer trees to useless noisy subsidy-harvesting machines.

With friends like that, the environment is doomed.