I would have liked to contribute to the bad physics joke contest that I was complaining about the other day… but unfortunately I only know mathematician jokes and engineer jokes. Any physicists that appear in those jokes are incidental. Yes, this is a weird oversight in my education. Frankly, I think I deserve at least a partial tuition refund.

Anyway, in light of recent events, I thought I would share one of my favorite engineer jokes that at least involves a physicist. And hunting!

A biologist, a physicist, and an engineer go duck quail hunting. Suddenly, a single quail gets flushed from the undergrowth.

The biologist, being very familiar with natural quail behavior and quail flight patterns, takes careful aim… BLAM! He just misses, a little to the right.

At almost exactly the same time, the physicist quickly calculates the distance, the velocity of the bullet, the velocity of the quail, corrects for wind and air resistance… BLAM! He just misses, a little to the left.

The engineer starts jumping up and down excitedly. “We got him! We got him!”

But wait! There’s a sequel to this joke!

Miracle of miracles, our hunting party succeeds in downing a duck quail. They return to the campsite, where their philosopher friend has been waiting for them. Triumphant, they show the philosopher the quail.

The philosopher looks up from his book. “Hmmm, well, how do you know it’s a quail?”

The biologist is taken aback. “Well, just look at the morphology,” he says. “It’s got quail feathers, a quail beak, quail wings…”

The physicist doesn’t quite know what to say either. “I guess we could take a DNA sample from the bird and run it to the lab…?”

The engineer just shrugs. “We went hunting for quail. Therefore, it’s a quail.”

Thank you! I’ll be here all the week!

Over at Cosmic Variance, my second-favorite physics blog, they are attempting to tell bad physics jokes.

Well, the jokes are very bad. As in BAD bad, not good bad. Please, please help these people.

As I was reading Jacques’s post about UT’s undergraduate math requirements for upper-division physics, I knew he would get at least one comment or trackback about the general watering down of standards, or some such. I was not disappointed.

The issue Jacques describes has nothing to do with watering down of standards. Four semesters of math is (or should be) sufficient to get through upper-division Quantum Mechanics. Linear Algebra issues aside, the difficulty of upper-division Quantum Mechanics stems from the conceptual issues, not the math. The problem, as Jacques points out, is a mismatch between the math curriculum and the physics curriculum.

The UT physics department could do one of three things to fix this problem.

• Require all physics students to take, or test out of, both the Advanced Calculus class and the Linear Algebra class. Physics majors really ought to have both under their belts.

• Forget about those two a la carte classes. Instead, require all upper-division majors to take a “Mathematical Methods for Physicists” class, designed to ensure that everyone has the right machinery to forge through their upper-division work.

• Coordinate with the math department; adjust the mathematical core accordingly.

My alma mater used the third approach. The math, engineering, computer science, and natural science departments all coordinated closely on the base four-semester mathematics core. Individual departments could then layer additional requirements, but at least everyone had a common foundation, even the biologists and computer scientists. This solution worked great for a school with 700 undergrads, where all the professors knew each other personally, shared babysitters, and so on. It would probably work less well for UT.^[1]

1. The main disadvantage of this “Grand Unified Core” approach is that it generates a great deal of whining from certain students over “taking math that I’ll never use!” Long ago, I used to sympathize with my oppressed computer science and biology brethren. But now… not so much. Over the last few years, I have run into senior developers who did not understand that ln (A + B) is not equal to ln A + ln B. And who when queried about this responded, “Look, I have a mathematical background, I really can’t explain it to you.” Professors of All and Sundry Technical Disciplines: please don’t let this happen to your graduating seniors. Thank you.

Or, my official “this journal is not yet moribund” post. Err, well, you be the judge.

• The U.S. Energy Dept. is taking another look at Cold Fusion [via Slashdot].

  Ah, cold fusion. The field of inquiry that is predicated on the belief that chemical reactions of ~5 eV can affect the threshold energies of reactions that require 50,000 eV or more. Of course, this being Slashdot, it wasn’t too hard to find a conspiracy theorist or two modded up. Actually, if you want a better conspiracy theory, physicist Chad Orzel has one for you: if the DOE is thinking about funding cold fusion research, that enables the administration to say that they are “researching alternative energy sources” without, actually, like, researching any alternative energy sources. I wouldn’t listen to Orzel though; as he himself admits, he’s just a nutbar conspiracy theorist.

• Well, forget about cold fusion. If you’re jonesin’ for some real physics (and who isn’t?), one need look no further than Britney Spears’s Guide to Semiconductor Physics.

  “It is a little known fact that Ms Spears is an expert in semiconductor physics. Not content with just singing and acting, in the following pages, she will guide you in the fundamentals of the vital laser components that have made it possible to hear her super music in a digital format.”

  It actually looks to be a pretty informative introduction to semiconductor physics,^[1] although high school or college students looking for term paper material should note that it is probably not a good idea to list this reference explicitly in your bibliography. Just lie and say it came from the IEEE. You should also probably avoid cribbing this illustration of the conduction and valence bands.

• And speaking of the IEEE, they have another article that takes a look at music encoding algorithms [also via Slashdot]. “At its heart, the MP3 format uses an algorithm that takes the data contained in CD music relating loudness to specific points in time and transforms it instead into data relating loudness to specific frequencies.” When I first read this, I thought, “This is the IEEE and they can’t bring themselves to say ‘Fourier Transform’?” Then I started googling, and discovered you don’t necessarily have to use FFT to do the encoding. You can come up with whatever algorithm you like, and you can even charge people for it if you like. How ’bout that, you learn something new on the Intarweb every day.

  Now, if I was going to write an MP3 encoder, I would use a Laplace Transform. If you think that’s perverse, I apologize… I can’t help it, it’s the way I was brought up.

• I saw a bumper sticker yesterday, “Bush is a Muggle.” At first I thought, well, of course he’s a Muggle, we’re all Muggles in the strict sense of the definition. Then I thought, maybe that was the bumper sticker’s point? Maybe it’s a very subtle pro-Bush bumper sticker?

  1. Bush is a Muggle.
  2. I’m a Muggle, you’re a Muggle.
  3. We’re all just happy Muggles together. Revel in our common Muggle-osity!
  4. …

  Then I thought, I’m thinking a little too hard about this.

Time to go make the mint syrup for the mojitos for today’s barbeque. It’s a quadruple batch, Yum!

1. Not only informative, but entertaining as well:

Note that in this technical region [temperature range] if the counter doping is negligible, N_a << N_d or N_d << N_a, (35) and (37) simplify to

n = N_d (39)

p = N_a (40)

which is what we tell the engineers.

A quick exercise:

1. Think of an area of knowledge where you have acknowledged, real-world expertise.

2. Think of the last journalism piece you encountered that touched on that area of knowledge.

3. How accurate was that piece?

I don’t know about you, but more often than not, I dread reading mainstream articles on fields that I know a little something about. Take physics. Okay, yes, I expect to read piles of dreck in my old field of nanomechanics, what with the active campaign to spread dreck and all. But even discounting nanomechanics, there’s no shortage of the dreck in other areas of physics.

Case in point: Brad DeLong recently picked apart a picks apart an article by TNR columnist Gregg Easterbrook on the Stephen Hawking black hole information loss bet. Easterbrook not only attacks physicists as mumbo-jumbo-spouting medieval priests, but also manages to make an appalling number of scientific errors. I’ve actually liked reading Easterbrook in the past, but now I’m wishing I had taken his writing with a much larger grain of salt. If you think modern physics is worth snarking over because The Physics of the Very Large and The Physics of the Very Small does not match our common-sense intuitions about The Physics of Tables and Chairs — well, as DeLong points out, you’re about 300 years too late to that party.

No doubt one of the main reasons The New Republic published Easterbrook’s article is because it behooves them to take a generally contrarian view. And let’s face it, the mainstream take on the Hawking story was pretty darn boring. Cute, gnomish High Priest of Physics pronounces to his fellow white-haired, gnomish physicists that he has lost an old bet about — something wacky, something to do with black holes. Gnomish men scurry off to check their leader’s calculations, muttering that they don’t quite understand what he’s talking about. Cricket and baseball are somehow involved. Those darned physicists! The End.

The sad part is that there really was a non-boring version of the story; namely Jacques’s take, where we learn that A) mainstream theoretical physics solved this problem quite some time ago, and B) Hawking’s concession argument is rather strange and incomplete to say the least! Unfortunately, Jacques wrote his article for people who have at least a passing acquaintance with Anti de Sitter / Conformal Field Theory, a group that probably excludes you and definitely excludes me. Still, there is in fact a real story there.¹

If only The New Republic had thought to hire a geniune physicist to write about physics, the way Slate has thought to hire a genuine Wall Street scoundrel to write about Wall Street shenanigans. Oh, well.

1. And the good news is, it can’t possibly be lost! We think.

Via science writer Clive Thompson: the NY Times reports that a Creationist minister has opened up a dinosaur theme park in Pensacola, Florida:

“My kids kept recognizing flaws in the [Disney World] presentation,” said Mrs. Passmore, of Jackson, Ala. “You know — the whole ‘millions of years ago dinosaurs ruled the earth’ thing.”

Clearly, the worrisome trend to build an entirely parallel system of pseudo-science continues apace. Why have we suddenly decided that now is a good time to start tearing down the mechanism of scientific inquiry? I guess that after several centuries of constant evolution and refinement, the whole “science thing” is starting to look a little dusty. Out with the old, in with the, um, new.

As for those of you who are snickering over the silly Creationists: be sure to take a good hard look in the mirror first.

So Slashdot is wondering whether the Diamond Age is approaching. After skimming through the comments, I found not one that had anything sensible to say whatsoever. In a sense, this is cheering. It means that not one irate graduate student lost their temper and leaped into the fray. In turn, this implies that our current crop of physics and chemistry Ph.D. candidates is gifted with an uncommon dose of common sense. The future of Western Civilization is looking brighter every day.

The original source of the Slashdot post was about what one would expect. A collection of breathless press releases on the wonders and terrors of nanotechnology, the usual suspects sitting on the board, not a professional physicist or chemist in sight.

I suppose this is as good a time as any to share my Eric Drexler story. Nearly five years ago, my former employer held a large three-day symposium for its system engineers. The goal was partly education, but mostly entertainment. The seminars were divided into three categories. Category 1 was the nuts-and-bolts practical stuff. How to tune Solaris, that sort of thing. Category 2 dealt with upcoming stuff, products two to five years out (many of which are now cancelled). Category 3 was the really far-out stuff, completely non-practical, the just-for-fun stuff.

Eric Drexler was scheduled in Category 3. Naturally, I was keenly interested in hearing a popular speaker talk about my former field. As an aside: maybe it’s just me, but I love it when any expert manages to explain to a lay audience what makes their field so fascinating. It’s a hard thing to do without mangling the message, confusing the audience, or simply dumbing things down beyond recognition. When it’s done well, it’s a sight to see. Anyway, I was expecting an interesting discourse on current activity in nanotechnology, perhaps with an emphasis on future directions in computing.

Instead, what we got was nanobots.

The lecture opened with Drexler asking us to consider the strawberry. A strawberry is a fantastically complex object — and yet it’s built molecule by molecule, from carbon, oxygen, hydrogen, and nitrogen. If Nature can build a strawberry, why can’t we?

Drexler then observed that on the nano scale, mechanical operations are incredibly fast. (Which is true, crudely speaking.) Consider a mechanical arm in an auto factory, said Drexler. When it assembles a car, it moves with speeds on the order of meters per second. If we scale down a billion-fold, the operation of our mechanical arm speeds up commensurately. We can do orders of magnitude more operations per second.

Drexler then proceeded to show us a series of computer-generated 3-D drawings of atoms assembled into structures that looked vaguely like things you would find in an auto factory. There was a “robotic pincer arm” made from a few hundred carbon atoms. There were a number of elaborate gear-and-sprockety looking structures. The piece-de-resistance was a structure that looked a heck of a lot like a several-thousand-atom turbine. (There was no word as to whether these structures were molecularly stable, but let’s give Drexler the benefit of the doubt and assume that he had crunched the numbers correctly — that the pretty pictures weren’t simply assembled in a CAD program.)

Now, let’s review the structure of Drexler’s argument:

1. Molecular operations are millions of times faster than the mechanical operations of a robotic arm in a factory.
2. Here is a molecular robotic arm.
3. Here is a set of useful-looking molecular structures.
4. …
5. Profit!¹

What made the whole experience even more irritating was Drexler’s breezy insistence that not only was the Age of Molecular Factories quite real, but that it would solve all of our current-day problems. The lecture was sprinkled with all sorts of little ruminations on what our grandchildren would think of us. For example: why were there food shortages in your day, grandfather? Why didn’t you just make more food? Or: why did you worry about global warming? Why didn’t you guys just fix it?

After stewing for the entire hour, I was determined to ask Drexler (politely) what was going on. Clearly he didn’t actually believe this nonsense. I waited until the lecture was over, introduced myself politely, and mentioned that I was a bit concerned that he had, err, glossed over the quantum mechnical issues a bit. I don’t know what I was expecting, really. Maybe a half-hearted admission that yes, he had oversimplified a bit, but you’ve got to fire up the troops somehow. That would have made me grit my teeth a bit, but I could have accepted it.

Instead, he cheerfully brushed my objection aside. Yes, maybe the intermediate quantum states would be unstable. “But we’ll just build a SCAFFOLDING!” he said.

At that point my forebrain mercifully short-circuited, forcing my autonomous social functions to take over. I vaguely remember politely shaking his hand and wandering off in a daze. Crisis averted. A couple of years later, I was gratified to dicover that in his debate with Nobel-prize winning chemist Richard Smalley, Drexler essentially proffered a fancier version of the scaffolding argument.³ So now I don’t feel quite so bad.

Anyway, we can at least draw a few lessons from all this nonsense:

1. Science education in this country for engineers and programmers is woefully inadequate. Here we had a room of smart, very well-paid Sun engineers, and not one was anything but credulous (unless there were a few like me who were sitting there silently with steam coming out of our ears.) This is freshman chemistry, people.

2. The appeal of Drexler’s snake oil to Silicon Valley techies is obvious. Take global hunger, which is a terrible problem that requires efforts on many fronts — scientific, political, logistical, environmental, legal, you name it. But never mind all that! In a generation or two we’ll work around all those nasty, corrupt politicians and lawyers and just make all the food we’ll ever need.

3. Tremendous effort is being wasted discussing the non-existent benefits and non-existent risks of a non-existent technology. Meanwhile, real nanotechnology (dismissed by uninformed pundits as “nanopants”) has real (but less sexy) benefits and real (but less sexy) risks. The danger is that over time, funding will be diverted to service the Drexlerians. Fortunately, the grownups seem to be in charge. For now.

So what can be done about this? For starters, chemists and condensed-matter physicists could do a hell of a better job of educating the public on what nanotechnology really is and is not. I suspect that most Ph.Ds are reluctant to do so — partly because they think the Drexlerians are pretty harmless or even creating positive interest in the field, but mostly because they feel it really isn’t their job to wade into the messy fray. Unfortunately, this is short-sighted. Here’s one way to look at it, guys: string theorists can deal with their crackpots by simply tossing the occasional envelope or email into the trash. Meanwhile, your crackpots have well-funded institutes and get invited to fancy corporate conferences. At this point, the average engineer can’t tell the difference between you and them. Think about it.

1. Needless to say, anyone who has bothered to take a college chemistry or physics class should understand the problem with this reasoning, namely that assembling molecules is not like unto assembling automobiles. Even if we grant that Drexler’s fantastical molecular turbine is stable, the thousands of intermediate states required to assemble the turbine atom-by-atom are almost certainly not. To bring the analogy into the world of automobiles, it would be like if you remove the rearview mirror, the entire vehicle falls apart.²

2. Hmmm, would that make the Ford Pinto the world’s first quantum mechanical car? Err, anyway…

3. Unlike me, Smalley has apparently protected his brain with some sort of Stupidity Faraday Cage, which allowed him to continue his debate with Drexler without risking permanent brain damage.

When I was a sophomore in college, I read a fascinating book about the large-scale distribution of galactic clusters. One might expect galactic clusters to be scattered randomly, but they aren’t. Instead, galactic clusters seem to be distributed along the surface of nearly empty “bubbles” that tens of megaparsecs in diameter. In fact, if you map the structure of the visible universe using galactic clusters, at the largest scales it looks a lot like… bubbly, frothy beer! Pretty neat. And similarly, at the most extreme end of the small scale, physicists theorize that spacetime breaks down into “quantum foam”, a seething chaotic morass of fluctuating loops and bubbles. Bubbles… foam… like beer! At all length scales, the universe seems to be trying to tell us something…

I’m sad to report that this is what passed for deep insight when I was 20.

Now according to a recent article in Nature, the universe could be finite and shaped like a soccer ball. Or more properly, a dodecahedron. If we couple that with the observation that some of our universe’s more interesting carbon molecules are also shaped like soccer balls, we are led to a rather disturbing conclusion. God clearly likes beer. God might like soccer. The question theologians have pondered for centuries lingers in the air… could God be a soccer hooligan?

Fortunately for all of us who are not soccer hooligans,^[1] Jacques doesn’t think much of the Soccer Ball proposal:

Most likely, this is just foreground junk, and once the foreground subtraction is done better, these two datapoints will cease to stand out, and the apparent lack of isotropy at large angular scales will go away.

The data from the WMAP probe is still very preliminary, so it seems reasonable not to get excited over this yet. But of course I don’t need Jacques with all his fancy math to tell me that Soccer Ball hypothesis is in trouble. Just look at the hyperactive response on Slashdot. I can’t imagine that Luminet, Weeks, and colleagues could look at the raving fanboy response on Slashdot and not realize that the whole thing is doomed, doomed. At least we can be grateful that the Slashdot weenies don’t read Jacques on a regular basis. Otherwise one of them might read his post and discover that another possibly valid topology for the universe is an icosahedron. Lord only knows the tidal wave of dorky speculation that little idea would unleash.

1. Oh all right, so it’s really “football hooligans.” Excuuuuse me.

Well, it looks like the prophetic vision of Mel Brooks is about to be fulfilled. The world’s first Israeli astronaut, Ilan Ramon, is set to head up on the space shuttle Columbia shortly. Unfortunately, the shuttle launch was delayed, so Ramon will miss out on celebrating the first Yom Kippur ever in space. However, there is still the issue of the Sabbath. The Sabbath is traditionally demarcated by sunset and sunrise, but the space shuttle orbits the Earth once every ninety minutes. That’s sixteen “days” per 24-hour period, or two Sabbaths per day. Very confusing. Fortunately, Ramon’s local Floridian rabbi has consulted with his colleages and determined that the Sabbath actually depends on the rotation of the Earth, not sunset:

“This has been a theoretical question for some time,” says Rabbi Konikov. “But rabbinical scholars have now been confronted with this as a real life situation.” The rabbis have resolved it, says Rabbi Konikov, explaining that “Col. Ramon will mark the Sabbath according to Cape Canaveral time — the site of the launch.”

Very sensible, although I should note that (surprise!) some of the rabbis begged to differ:

One of the scholars consulted, Rabbi Levy Yitzhak Halperin, has already ruled the colonel should be relieved of his obligations as he will not be experiencing “Earth time”. This opinion is not shared by a British colleague, who insists that since one cannot exist in space without recreating Earth-like conditions that make it habitable, one should follow the same routine in Space as they would on Earth.

One wonders what the rabbis would say about far-future space colonies on distant planets. Is the Sabbath tied to the local sunset and sunrise, or is it still tied to the “place of launch” back on Earth? If it’s the former, what if the planet rotates in such a way that its synodic day is very long? To use Venus as an example, the Sabbath would arrive every 4,088 Earth-days, and the Day of Rest itself would last 584 days. Not an ideal solution. On the other hand, if it’s the latter, what about people who are born on the planet itself, who have no “site of launch”? And then there’s the voyage itself, where we have to account for relativistic effects. Would we celebrate the Sabbath based on the flow of time in the ship’s frame or the launch site’s frame? Furthermore, what if through genetic engineering or cybernetic enhancements, our descendants are able to survive in “non-Earthlike” environments? Would they still celebrate the Sabbath? Are they still even Jews? It looks like we’ll have to leave these questions of Talmudic importance for future scholars to ponder.