I recently finished reading The Carbon Age : How Life’s Core Element has Become Civilization’s Greatest Threat, by Eric Roston (New York : Walker & Company, 2008. 308 pages). I very much enjoyed the act of reading it, but it was only when I was writing about it that I realized that is really an excellent book on all counts. My book note is here.
In this case I think what I admired the most was the author’s scienticity, which is how we refer to a scientific / rational / analytical / naturalistic perspective combined with the fortitude to integrate science moments into a larger cultural context. Mr. Roston did an excellent job of it, making it entertaining and informative without being the least bit silly or imprecise. As you may recall, I’m easily irritated by authors writing about science who do not take the trouble to be precise and thoughtful in their scientific exposition, but I had no such reaction here. If my memory is correct, I thought there was one explanation, out of the 300 pages, where the concept being explained was slightly befuddled–not a bad record!
But, our purpose here is to provide a place for a few excerpts that just didn’t fit into the book note for some reason or that I marked specially for blogging. (It’s true! Sometimes there are bits of the text that I think are a must-share but they don’t share the tone of a book note, so it’s lucky you!)
In this first excerpt, we’re in the midst of a long discussion about carbon’s place in the origins of life and how its central role may have come about. One of the great steps forward happened very, very early in the process. In a world of one-celled life, one cell managed to trap another cell inside it and the two continue to reproduce together to this day. Eukaryotes are organisms, including humans and most everything we think of as life except bacteria, whose cells are complex systems containing a nucleus and other parts, including mitochondira, which produce the energy the cell runs on by breaking down (“burning”) carbohydrates. I liked this terse, elegant, and altogether sensible paragraph about that moment.
The capture and integration of one cell by another is called endosymbiosis. Nearly all eukaryotes have little organs (“organelles”) called mitochondria. These cellular energy centers descend from purple sulfur bacteria, inhabitants of stomatolites in Shark Bay. This class of bacteria has made its living for as long as 3 billion years by using oxygen to burn carbohydrate fuel. Deep in the evolutionary past, some oxygen-breathing bacteria became engulfed within anaerobic cells, which needed help thriving in an atmosphere of increasing oxygen. These bacteria are the ancestors of our cellular power plants. The evidence is that bacteria and mitochondria share much of the same DNA. [p. 73]
In this next short excerpt, Roston comments on the familial culture of experimental scientists. I’ve known this phenomenon myself. I started out in low-temperature physics, an experimental discipline that appeared early in the 20th century when Heike Kamerlingh Onnes, the Dutch physicist, first liquefied helium in 1908. We were a small community and everyone could trace their lineage; there are only a couple of major branches of the family. I don’t think I’ve seen this written about elsewhere and I thought Roston’s observations were very perceptive.
Labs are structured as intellectual family fiefdoms. A professor “raises” his graduate students, who grow up and fan out across the world of research universities and private industry. Virtually everyone’s intellectual ancestors [in chemical synthesis] can be traced back to J.J. Berzelius, the Swedish chemist who first called carbon “C”. Every generation tends the repository of knowledge, weeding out its predecessor’s bad ideas, answering some of their questions, and asking many of their own. [p. 135]
The name of this extraordinary film is “SX-70″; it was made by Charles and Ray Eames. (Whether you should watch first or read first I can’t say; if you have the time, watch then read then watch again.)
Some of us will be old enough to remember the Polaroid SX-70 camera and how exciting and modern it was. Such advanced technology! As the narrator says near the beginning:
Since 1947, Edwin Land and Polaroid have pursued a central concept, one single thread: the removal of the barriers between the photographer and his subject. [Title: "SX-70"] And now, a compact, folding, electronically controlled, motor-driven, single-lens reflex camera, capable of focusing from infinity down to ten inches, has been developed to exploit integral self-processing film units which, when exposed, are automatically ejected from the camera, with no parts to peel or discard, and whose final images emerge without timing, in daylight, where the viewer can see them materialize within the same transparent protective plastic cover through which the film was originally exposed.
The SX-70 looked like no other camera before or after, and worked like no other camera, either. The film was the culmination of this dream of Edwin Land’s, and the camera’s design and engineering gave the distinct impression that it had been thought about without preconceptions of how a camera should look.
But this isn’t just about the camera, which is a marvel. I’m more interested right now in this film about the camera, and the film itself is a marvel.
Presentation of the revolutionary SX-70 Land camera and its aesthetic potential that becomes a meditation on the nature of photography. A tour-de-force of filmmaking that gives the audience a real understanding of the workings of the camera. Filmmakers: Charles and Ray Eames Sponsor: Polaroid Composer: Elmer Bernstein Narrator: concluding statement by Philip Morrison Date: 1972
Charles and Ray Eames were the remarkably creative and remarkably influential husband-and-wife design team working mostly from the 40s through the 60s (a quick biographical survey). Many of their designs have become so iconic that they are recognizable by countless people who have never heard of the Eames. There is just so much that I can’t begin to organize my thoughts about them here, where my focus is on this one film anyway. When you have time, explore Charles & Ray Eames: A Legacy of Invention.
Next in the credits is Elmer Bernstein, noted composer of many, many famous film scores like those for “To Kill a Mockingbird”, “The Ten Commandments”, “The Blues Brothers”, and “Ghostbusters”, to name a small fraction. The score is just a few instruments, nothing that’s going to take a lot of time assembling and orchestrating, but nevertheless thoughtfully written and quite suitable for the film.
Then there’s Philip Morrison, whose distinctive voice appears near the end, where he takes over from the anonymous narrator in the rest of the film. Morrison, who died in 2005, was a physicist of some renown, but I think his more important contribution was as an explainer and popularizer of science, as he did with his remarkable television series (and book), “The Ring of Truth” (1987). Then there was the “Powers of Ten” project (1977), the justly famous film of which he worked on with the Eames (watch the nine-minute film). He had also been the main reviewer of books for Scientific American since 1965, a remarkable legacy.
But this list of luminaries would contribute empty celebrity if the film itself weren’t brilliant, and it is. It was shown originally at a Polaroid shareholders meeting and subsequently used internally as a sales tool. It was not made for average viewers, perhaps, and wouldn’t be the right tone for a television advertisement, but it’s not intended for a predominantly technical audience, either. Instead, it’s made for viewers of some intelligence who are willing to give it their attention and learn some amazing things.
I am particularly delighted at how the language is kept clear and understandable, particularly as it’s supported by the visuals, without being patronizing or gratuitously simplified. Amidst the poetical and metaphysical thoughts about photography as an art form, watch for the exposition about the camera, how it operates, and all the technical advances it contains. Pay attention: it’s all too easy to be drawn into the narrative without realizing that all that technical information is entering your mind with relative ease.
As you might expect, there are plenty of people taking pictures with the camera, demonstrating what fun it is and how it is used and its various special features. But look at what they’re taking pictures of: several appear to be scientists, or even amateurs of science, documenting the natural world. Of course, there are also proud parents taking pictures of their children, but they’re just part of the panorama. But even while we see the parents photographing their kids, we are also shown that the SX-70 has a fast lens, a short focal length, a quick shutter that can stop action, and the ability to take exposures in quick succession. The Eames are not merely marketing the SX-70 in this film, they are demonstrating its capabilities and technologies and making that look easy.
I love the attitude that includes the scientific as part of the cultural, a film that combines poetry and philosophy and technical explanations and kids and nature into one amazing whole that’s so amazing one hardly notices that all that’s going on. I like how the technical specifications of the camera are explored and shown rather than explained–before the narrated explanation (beginning at about the 4:15 mark) of the internal workings of the camera–assuming a viewer without special technical knowledge but sophisticated enough to absorb the ideas.
Then, when you do get to the technical narrative, notice how crisp and concise the narration is, and how it’s so beautifully documented by the combined animation and live action (done in the days before CGI). I don’t think it hurts anyone to hear the word “aspheric”, even if it’s not a familiar word–yet. And while we’re there, let’s not overlook the achievement of the Eames’ documenting the internal mechanisms of the camera. There are as many shots in there as Hitchcock used in that famous murder scene in “Psycho”.
Amazing. It inspires me and intimidates me at the same time, which I expect is a good thing.
I recently finished reading the book Hydrogen : The Essential Element, by John S. Rigden (Cambridge, MA : Harvard University Press, 2002. vii + 280 pages). Here’s my book note. It’s a book I can recommend.
As I mentioned in the book note, the “hydrogen” of this book is the physicist’s “hydrogen”,* the simple atom of electron + proton (with some isotopic variations) that is the simple test case for all physical theories that deal with things atomic: if it doesn’t work for hydrogen, it’s not going to work.
Hydrogen is overwhelmingly the most abundant atomic species in the universe, making up about 74% (by weight) of the matter we can see. It is the predominant fuel that stars burn through fusion (to make helium nuclei). Hydrogen is the earliest element in the cosmos, protons condensing from a universe of quarks when the temperature finally became low enough, in the period (the “hadron epoch”) between one microsecond to one second after the big bang.† It was some time longer before the universe cooled enough (some 380,000 years!) for the protons to capture and hold onto electrons, thus becoming actual atoms of hydrogen (Of course, there had to be electrons to capture; they condensed around one second ABB.#)
Anyway, the history of our modern understanding of the hydrogen atom, and the efforts to gain that understanding, is virtually identical to the history of “modern physics”, by which we loosely mean all that physics stuff from the early twentieth century: quantum mechanics and its friends. Lots of other interesting things get thrown in, too, from all the attention the hydrogen atom got. A couple of the more interesting: the development of the hydrogen maser and very high precision time keeping (i.e., “atomic clocks”, leading to the GPS), and the invention of a technique known to physicists as NMR (nuclear magnetic resonance), which in recent decades developed into the familiar MRI (magnetic-resonance imaging‡).
Anyway, that’s book-note stuff. What we’re all about here is a couple of leftover quotations from the book that go under the heading: “Physicist’s and their Strange Sense of Humor”. The first two quotations reveal things that physicists find almost knee-slappingly funny but may remain inscrutable to nonscientists (and I wouldn’t worry about that either, if I were you–you’re not missing all that much).
Paul Dirac was a[n] unusual person. Perhaps because Dirac’s father demanded that his young son use French rather than his native English to converse with him, the young Dirac adopted the habit of silence during his childhood simply because he could not express his thoughts in French. Whatever the reason, the adult Paul Dirac was a a man of silence. Dirac’s silence was so intense that it inspired a little levity among physicists. In physics, the units given to physical quantities like time or length are important. Physicists, clearly in jest [!], have defined the unit of silence as the dirac. [p. 89]
For this second joke, I might mention that it was Ed Purcell who pioneered the NMR technique, and that the technique uses magnetic properties of the hydrogen atom, which moves much like a gyroscope when magnetically disturbed (hence the reference to “precessing”**).
I remember, in the winter of our first experiments, just seven years ago, looking at snow…around my doorstep–great heaps of protons quietly precessing in the earth’s magnetic field.
–Edward M. Purcell [quoted on p. 137]
Finally, this one goes into that file where we put really bad predictions of what the future might hold.
In 1952, neither Purcell nor Bloch could have predicted the ways their discovery would advance understanding of solids, of the structure of chemical molecules, and even more. In fact, a representative from Dupont Chemical Company visited Purcell soon after the paper announcing the discovery was published. The Dupont scientist asked Purcell what the practical applications of NMR might be. Purcell responded that he could see no practical applications. In this, Purcell was very wrong. [p. 147]
———- * Rather than, say, a chemist’s “hydrogen” with discussions of interesting molecules and acids and reducing reactions and carbohydrates, etc. Nor is it an engineer’s “hydrogen”, nor a politician’s “hydrogen” (as in “hydrogen economy”). They’re all stories for another book for someone else to write. What a publishing opportunity!
† I just read this the other day about the big bang and the origin of the cosmos (and now I forget who gets the attribution): “In the beginning there was nothing, then it exploded.”
# We could just say “it happened at one second”, since the current understanding has it that time (whatever it is besides a whole other story) began with the big bang.
‡ I’m sure I’ve expressed my peevishness before about how the perfectly good word “nuclear” had to be expunged before MRI could be a commercial success.
** When some body, like the Earth or a hydrogen nucleus, rotates about an axis, and that axis is tilted relative to some other axis about which the tilted axis itself executes a (generally much slower) rotation (a kind of wobble), that latter motion is referred to as “precession”. The precession of the Earth’s axis takes about 26,000 years. Hydrogen atoms do it at about 500 megahertz (or 500,000,000 times each second).
In my post about noise yesterday [at my personal blog] I added a rather inscrutable footnote about noise and power spectra. Thoughtfully, Mel asked:
I don’t quite understand this, though: “Pink noise” has a power spectrum that rolls off as the inverse of the frequency. Could you explain what that would look like, for really elementary level brains like mine?
This is just one reason why I love my Canadian friends.
Let’s look at a couple of graphs. It doesn’t even matter that we can’t read the numbers or anything written on the graphs. We don’t have to understand them in any detail, although they’re not very complicated. We get most of what we want to understand just from the shapes of the blue parts.
On the left is a power spectrum of white noise (Wikipedia source); on the right is a power spectrum of pink noise (Wikipedia source). Follow the links and click on the little graphs if you want to see the big versions.
The power spectrum graph plots acoustic power (loosely, how loud the component is) on the vertical axis and frequency on the horizontal axis. Frequency increases towards the right, and frequency is just what you expect: high frequencies are high pitches, low frequencies are low pitches.
If you were looking at the power spectrum of a single, pure tone (like the sounds we used to hear in the US for the emergency broadcasting system test signal, but in recent years they’ve switched to something buzzy), you would see one very narrow, tall blue spike located at the frequency of the pitch in question. If you were looking at the power spectrum of a musical instrument you would see a collection of individual, thick spikes at different frequencies that are part of that instrument’s overtone series and identify its characteristic sound.
But these are power spectra of noise, so they have components at all frequencies, which is why the graphs show solid blue regions rather than a lot of spikes–that blue region is really a huge number of blue spikes at every frequency on the graph.
It’s the shape of the top of the blue region that we want to focus on. In the spectrum on the left, the top is flat (and level), telling us that the loudness of each frequency component in the noise is equal to the loudness of every other component over the entire range we can measure.* That’s white noise: the power spectrum is flat and every frequency component is present with equal loudness.
With pink noise, there is a shape–a specific shape–to the spectrum, as shown on the right. The top of the blue region slants downward on the right side, meaning that the loudness of any given component of the noise decreases as the frequency increases. That’s all I meant by “rolls off” really, that the curve goes down as the frequency goes up.
With the pink noise, as I said, the shape is specific. The top of the curve slants to the right but it is a flat slope† and, for pink noise, it has a specific slope indicating that the loudness (actually the “power spectral density”, but let’s fudge it a bit and just say “loudness”) is changing exactly as the inverse of the frequency (1/f).
You can guess there’s a lot more mathematics one can delve into, but that’s more than we needed anyway. Once you see the idea of loudness vs. frequency for the graphs (“power spectra”), you can see the difference between white noise (totally flat spectrum) and pink noise (“rolls off as 1/f”).
You can hear the difference, too. Those two Wikipedia pages I linked to above have very short sound samples of synthesized white noise (approximate) and pink noise (approximate). If you listen you will notice that the white noise sounds very hissy (as I said, like TVs did in analog days when stations were off the air)–that’s because of all the relatively loud, high-frequency components. On the other hand, the pink noise sounds kind of like hearing noise under water, because the lower frequencies predominate in pink noise (water tends to filter out high frequency sounds).
———- *This is where practicalities come into play. Theoretical white noise would have frequency components at every possible frequency, but in practice a sound like that cannot be produced, if for no other reason than that the sound could not have gone on forever, so there are low (very, very, very low) frequency components that could not be present because there wasn’t time. Besides, audio equipment doesn’t recreate all frequencies equally, etc., and that’s why the graph of the white noise on the left isn’t exactly level but tilts up slightly towards the right side. And, of course, the top edge is fuzzy and jaggy because this is noise, and noise is random. If you were watching this on a device that measured power spectra (a spectrum analyzer–nice, but very expensive), you’d see the jagginess dance around randomly but, on average, the top would remain flat and level.
† The graphs have logarithmic vertical and horizontal axes, with power given in decibels. However, I don’t think we need to complicate our understanding with that right now, just so long as we accept that in this kind of graph this particular straight-line slope down to the right represents the mathematical 1/f shape.
At the most recent presidential so-called “debate” (that would be debate #2, the “town hall meeting” format), John McCain, trying to score cheap points against rival Barack Obama, referred to earmark money Obama voted for that included “$3 million for an overhead projector at a planetarium in Chicago, Illinois”.
Of course, as many of us knew at the time, and as many, many more now know, that “overhead projector” was actually a sophisticated piece of optical equipment, a Zeiss Mark VI star projector, the programmable star projector that recreates a view of the heavens on the ceiling of planetariums. These instruments are slightly different from an “overhead projector”.
The Adler Planetarium even felt the need to defend its honor with a press release commenting on the issues. From that press release:
To clarify, the Adler Planetarium requested federal support – which was not funded – to replace the projector in its historic Sky Theater, the first planetarium theater in the Western Hemisphere. The Adler’s Zeiss Mark VI projector – not an overhead projector – is the instrument that re-creates the night sky in a dome theater, the quintessential planetarium experience. The Adler’s projector is nearly 40 years old and is no longer supported with parts or service by the manufacturer. It is only the second planetarium projector in the Adler’s 78 years of operation.
Science literacy is an urgent issue in the United States. To remain competitive and ensure national security, it is vital that we educate and inspire the next generation of explorers to pursue careers in science, echnology, engineering and math.
McCain’s science illiteracy, as illustrated by this remarkably foolish gambit, is dangerous enough. (Either he didn’t know, or he did know and willfully used this tasty sound-bite about the “overhead projector” to prey on the electorate’s illiteracy.) However, I’m sure that he didn’t come up with this earmark tidbit–someone on his staff did. Someone on McCain’s staff should have been able to say “Wait a minute, John. That’s not an overhead projector–that’s one of those really expensive, complicated planetarium thingies!”
We can’t afford scientifically illiterate leaders, nor can we afford scientific illiteracy among their staff.
As we are inclined to say at Ars: “C’mon, it’s not as if it’s rocket science we’re talking about!”
