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Archive for the ‘Personal Notebook’ Category


“Eye for Science” and Android Wallpaper

Posted by jns on September 14, 2011

You may recall my mentioning Scienticity’s “Eye for Science” project, a Flickr group to which members contribute interesting and provocative images that tell a story about science or nature or something related, which images we then try to get in front of others to provide a brief science moment. One way we do this is through a widget that shows a clickable thumbnail of the image; you can see it in action right there on the right of this blog page (or the left, if I’ve redesigned the theme). Every time the page is reloaded, a different image, chosen randomly from the group, shows up. At the time of my writing this the project has been going for a little over two years and the group has 97 members who’ve contributed 994 images. Why not consider joining us?

Ever since smartphones started to appear I’ve wanted to have an “Eye for Science” app that would serve up a random image from the collection whenever the user accessed the app. But, I’ve never taken the time to learn how to program in the necessary way to create such an app. Very recently I upgraded my own phone to something “smart”, an Android model as it turns out, and the thought crossed my mind again, and I made a happy discovery : no programming required!

Well, nearly. Which is to say that I could accomplish the best part of what I wanted with tools that existed on my phone, without writing an app. What I decided I wanted one afternoon was to use an eye-for-science image for my phone’s wallpaper and be able to change it easily whenever the whim arrived to do so, maybe every day (or more often). I did have to do a little behind-the-scenes programming with the Scienticity-hosted webpage that accesses the Flickr database, but that I knew how to do.

So, here’s how I have a pseudo-app–a bookmark, actually–on my Android home page that let’s me view a random sciency image and make it my wallpaper.

I used the “web” app (browser) to access the url, http://scienticity.net/efsm/ ; you can do this in your regular browser, too, there’s nothing magical about it. Accessing this URL returns a random, full-sized image from the Flickr database, along with the title and caption, the same thing you’d get by clicking the thumbnail in the widget on this page.

Once I have this page in my browser I can make a bookmark (“menu / more / add shortcut to home”) on my home screen. From my home screen, then, touching the bookmark opens this URL in my browser with a new random image. If I’m already looking at an image page I can get a new image, randomly selected, by touching “menu / refresh”, because each time I access the URL I get a new random image. Then, I can keep trying images (and enjoying what I see) until I get to one that strikes me as something that will make good wallpaper.

Then — on my phone at least — all I have to do is touch the image on my screen and hold my finger there until I get a menu of options, one of which is “set as wallpaper”. I touch that option and I have new wallpaper!

I’m a little embarrassed to say how inordinately pleased I am to be able to set my wallpaper so easily to new eye-for-science images whenever I feel moved to do so, but there you go.

Please, I invite you to give it a try, It’s quick, it’s easy, and you’ll see interesting things that might make you think “hunh”, which is the goal of the project. Have fun!


It Was Hot

Posted by jns on September 27, 2010

Well, how nice. Our area of the country, greater Washington DC, has been acclaimed by The Weather Channel as having had the worst summer of any major area in the US in 2010 (Jon Erdman, Tim Ballisty and Chris Dolce, “Top 5 Worst Summers“, not dated/accessed 24 September 2010). There are several extreme conditions, like storms and drought, that were part of their judgement, but heat was a big factor, of course. The big factor was the one that I noticed myself, namely the number of days when the high temperature was over 90 F.

I had the impression, as early as the beginning of July, that we were having an unusual number of days at a time with temperatures over 90 F. That obviously led to the question of whether my impression was correct that, in my memory, we rarely had more than, say, two days in a row so hot, maybe one week a summer with each day so hot, but not endless strings of days over 90 F and close to, if not exceeding, 100 F. (That latter only happened on about three days, which is more typical.)

Phew, I wasn’t just imagining it:

The summer of 2010 was a scorcher in many parts of the world, including the eastern U.S., where Washington, D.C. and New York, N.Y. broke records for their warmest summer since recordkeeping began. According to the Washington Post’s “Capital Weather Gang” blog, (full discosure: I write a weekly climate science column for that site) this year marked the first time that city has experienced an average summer high temperature that was greater than 90 degrees Fahrenheit. Temperatures in D.C. reached or exceeded the 90 degree threshold on 52 days during June, July, and August, which together comprise the meteorological summer months. The average low temperature this summer was also far above average in D.C., with 71 days having had a low temperature of 70 degrees or higher, the Post reported.

[Andrew Freedman, "Warmest Summer on Record for DC and New York", Climate Central, 1 September 2010.]

Now, there are interesting questions we might consider about just what it means to say this was our “hottest” summer. Average high temperatures, average low temperatures, number of days above a certain temperature, and others. These are derive, really, from the idea that it’s very hard to describe a statistical population with a single statistic, like an “average”, although that rarely impedes our attempts to do so.

But number of days over 90 F is useful (similar to a median measurement) and it was certainly noticeable to me. Any temperature in the 70s seems mostly comfortable to me, the 80s generally feel “warm” to me, but cross 90 F and the air feels “hot” to me. The good part, I suppose, is that once it’s “hot” I wilt but it doesn’t much matter to me whether it’s 95 F or 105 F.

Here’s another interesting way to look at this idea of “hotter summer”. This graph takes each day’s “average temperature” (itself a slippery concept) [source] against a 30-year average and reporting the difference, showing us that most days were notably hotter than “average”:

It doesn’t provide relief from the heat, but I get some sense of vindication out of it.


The Orthography of Equations

Posted by jns on July 21, 2010

Every now and then this little image appears on my Facebook page, as a sponsored ad, with the headline “Become a Physics Teacher”. The sponsors claim that they will help me get a master’s degree online in education so that I can become a physics teacher.

Now tell me, if you were considering paying someone to help you get certified in, say, programming C++, how would you respond if the image in their add had this programming fragment:

i = i + 1;

I don’t know that the above is a very clear analogy to any of you, but the point is this: if the ad in question displays a lack of knowledge of the idioms of the discipline, should you trust the advertiser to provide what’s on offer in a reliable way?

Why do I object to this little image? May I see a show of hands from the physical scientists who know the answer please?

Yes, that’s right. In this most famous equation from physics, a result of Einstein’s Special Theory of Relativity, the letters ‘m’, representing mass, and ‘c’, representing the speed of light in vacuum, are never, ever written as upper-case letters; they are always, invariably written in lower case. I should, perhaps, be more grateful that the ’2′ is at least written as a superscript.

A tiny detail, a nit that I’m picking? Would you trust a brain surgeon with dirty fingernails? A car mechanic who’s not aware of what a “spark plug” is called?

Long ago I started to draft a blog entry called “On the Orthography of Equations”, but I never got around to it. It was going to relate a story and draw some interesting conclusions.

The events of the story happened, now, some 20 years ago. I was talking to a secretary in our University department who was typing (yes, on a typewriter) a paper for another faculty member. She asked for some advice on how to type an equation. While I was answering her question I mentioned that if she put some space between two symbols and moved another to a slightly different place that the equation would be significantly easier to read.

“Easier to read?” she exclaimed. Clearly the idea that equations were somehow “read” rather than merely looked at surprised her. And that was when I realized that, to this secretary and likely to most people with relatively little mathematical training, the symbols in equation were mostly decorative and they did not realize that how the symbols are deployed affect the meaning and readability of the equations.

I was nearly as surprised as she to discover this, although it’s an observation I’ve never yet figured out what to do with. Neither am I sure that this was the blog post that I was going to write, but there you go–it’s the one you got.


Shortest Day vs. Earliest Night

Posted by jns on December 21, 2009

I am always happy to celebrate the decision of our sun to return to a higher point in our northern sky, a decision it routinely takes about this time of year: 21 December. It seems so delightful that the days seem to start getting longer immediately it makes the decision.

And then, whenever the topic comes up, as it certainly has today, I always make a pest of myself by pointing out my favorite astronomical fact for those of us in the northern hemisphere: although the winter solstice marks the shortest amount of daylight in the year, the earliest sunset of the year actually happened three weeks ago, on 7 December. The last time I mentioned it in this space (in 2006) I didn’t have any really good, clear explanation to offer and I don’t this time, either. I posted a few links previously — look at them if you feel yourself the intrepid explorer of orbital dynamics — but for now we’ll just wave our hands and say it’s because of the tilt of the Earth, and the fact that it’s roughly spherical (at least, I think this would not happen if the Earth were cylindrical along its axis of rotation).

But anyway, the point I always make is this: by the time we get to the solstice, the sunset is already getting noticeably later and psychologically (to me, at least, since I rarely encounter sunrise) this makes us feel the day is getting longer at a rather brisk pace once the solstice is passed. The reason for that sensation, of course, is that it started three weeks ago. (Have fun verifying this for yourself with the NOAA Sunrise/Sunset calendar.)

For those who key on the sunrise to judge the length of their day–I’m sorry, but the latest sunrise falls on 7 January.


The Majestic Unity of the Natural World

Posted by jns on August 15, 2008

Awhile back I was doing my lunchtime reading in the very interesting book The two-mile time machine : ice cores, abrupt climate change, and our future, by Richard B. Alley. In short, the book is about deep ice cores taken from the ice cap in Greenland and the incredible amount of information they give us about climate in ancient and prehistoric times and then expands on all matter of topics impinging on paleoclimatology, a word that just sounds cool to me (no pun intended). I loved the book and recommend it highly for a number of reasons; my book note is here. Overall the book is a careful and considered look at the history of climate change and the potential for humans to affect it.

I marveled. Even though I am a scientist and I’m accustomed to a naturalistic and reductionist view of the natural world, it is still incredible sometimes to see just how well amazingly intricate and lengthy deductions about how nature must operate actually do work together, fitting one to another like the most precise gears to make a clockwork mechanism of surprising accuracy and precision.

Detractors of science and those who lob in their bizarre “theories” from the fringe usually do not appreciate that new scientific theories are exceedingly constrained things. Any new theory not only has to provide an explanation for some new and troublesome observation, but it has to explain everything in its domain that was explained by the theory it replaces, and it must coexist harmoniously with the very large number of existing theories that surround it in the system of science. That’s rarely an easy task.

So I marveled. From those two-mile long ice cores flowed an amazing amount of intricate analyses and consequent deductions about the history of climate before there were humans to record it–or even think of recording it. One could look at the layers of the ice core like tree rings–and fit some of those observations with tree-ring timing. They could tell how much snow fell. They could measure the conductivity of sections of the ice core. They could analyze the relative abundance of gases at various times by actually measuring tiny bubbles of air trapped in the ice. Mass spectroscopy told them about the relative abundance of heavy water and how it varied in the past 100,000 years.

Ah, but that’s just the beginning. From some of those observations they first had to build a reliable way of measuring time, answering the question: how old is a particular layer of ice core? Deductions there had to give a consistent picture with every other dating technique it could be made to line up with. Then one could start to build a picture of what the climate was doing, and every deduction was made in a milieu of other deductions and existing scientific knowledge so that everything cohered.

Accomplishing that is an amazing feat although it is what science does all the time. Every bit of scientific theory and observational data is continually subjected to a barrage of attacks from all sides probing for any inconsistency with existing knowledge. It’s a remarkable process, but it’s maybe even more remarkable that it works at all. That may be the crowning achievement of science.

Of course, the mystery is that it is even possible to create such a coherent whole. This, of course, is the point Einstein was making when he said “The most incomprehensible thing about the universe is that it is comprehensible.”*

While pondering this great mystery I had a brief moment–a very brief moment–of feeling sorry for people like young-earth creationists and “intelligent-design” creationists, a group that is rarely the object of my pity. But think for a moment on these pitiable ones and all others whose core belief is that their god created all the details of the universe that they can see and the explanation for all of it is “god did it that way”.

Young-earthers see–must see–”nature” as a capricious trickster with, for example, fossils laid down according to the whim of their creator and thus allowing no meaningful patterns to be observed, no deductions to be made, no connections to any other physical phenomenon save through the arbitrary hand of their creator. There is no sense that observations must make a coherent whole, nor that historic puzzle pieces have to fit together into any sort of comprehensible, indisputable larger picture.

What poverty of thought that is, what a barren wasteland, an infinity of random and unconnected details about the world that need make no sense. Is this not a recipe for confusion, a path to alienation and despair? How can one move through a world, an existence, where anything is free to change from moment to moment, where nothing can be expected to be predictable, let alone understandable?

For me, nothing rivals the majestic unity of the natural world.
* [note added 25 august 2008] Or maybe it was this version that Richard Dawkins attributes to J.B.S. Haldane that I was mentally grasping at: “Now, my own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose. I suspect that there are more things in heaven and earth than are dreamed of, or can be dreamed of, in any philosophy.”


A Fresh Perspective

Posted by jns on February 24, 2008

This week’s beard belongs to Albrecht Dürer, easily in my top-10 of most extraordinary artists ever. This amazing self-portrait was painted when the artist was 29 years old, in the year 1500. Is it symbolic that Dürer paints himself in this remarkably self-possessed, self-confident pose, looking directly at the viewer? It’s also interesting that he paints himself more as an aristocrat rather than with the commonly affected palette in hand, as a painter. What is the power in this painting that makes it feel so much as though it communicates directly with the viewer across the more than five centuries since Dürer painted it. Honestly, it creates for me a frisson that very few works of art manage to do.

Dürer was born in Nuremberg, Germany in 1471 (21 May), and he died in Nuremberg, Germany in 1528 (6 April). He did not stay his entire life in Nuremberg, but it seems that it was his center and he returned there after his various excursions to Italy and the Netherlands. He was a master of drawing, painting, printmaking, and engraving. He helped develop the newly emerging technique of perspective. He died relatively wealthy, apparently making his money from his prints, for which he was justly celebrated across Europe. (The Wikipedia biography of Dürer is nicely done; I also enjoyed the biography and the lovely images of stamps featuring works by Dürer on this page from Art History on Stamps.)

This page from WebMuseum, Paris has a nice collection of images, some biography, and a useful discussion of his portraiture. I don’t see much point in trying to name any particular favorites, although this self-portrait I certainly put on his list of masterworks. Also famous, and for good reason, are his smallish, early watercolors “A Young Hare” and “The Large Turf“. Both are breathtaking in their amazing realism, yet they go beyond mere realism and seem to breathe with a vitality beyond what any photograph could conjure for these subjects.

When we were in Rome in 2001, we happened upon a small exhibit concerning prints and printmaking through history, and there we saw some Dürer first hand. There was a copy of his notorious print of a Rhinoceros (notorious for being notably inaccurate, apparently drawn from a verbal description of the first rhino to arrive in Europe). We also saw two amazing “oversized” woodcuts (describing them as “oversized” seems such an understatement!) “The Triumphal Arch and the Large Triumphal Carriage of Maximilian I”, which are discussed at some length, along with some remarkable photographs of the works, on this page.

Seeing these things first hand was quite an experience that still feels very close to me.


Ceci N’est Pas Une Blog

Posted by jns on February 20, 2008

This is a blog posting about itself. According to the blog-software statistics, this is my one-thousandth posting [at my personal blog, the source for this essay] since the first one I posted on 18 October 2004.* To be honest, I’m a bit surprised that I’m still writing here regularly three-plus years later. Evidently it works for me somehow.

I’ve noticed that one-thousand is an accepted milestone at which one is to reflect, look back, and perhaps look forward. Well, you can look back as easily as I can, and I don’t see much reason to try predicting the future since we’re going to go through it together anyway. Therefore I thought this article should be about itself.

Or, rather, the topic is things that are about themselves. So called self-referential (SR) things.

I believe that my introduction to SR things, at least as an idea, came when I read Douglas Hofstadter’s remarkable book “Gödel, Escher, Bach: An Eternal Golden Braid”. The book was published in 1979; my book of books tells me that I finished reading it on 17 August 1986, but I expect that that date is the second time that I read the book. I can remember conversations I had about the book taking place about 1980–and I didn’t start keeping my book of books until 1982.

Broadly speaking, GEB was about intelligence–possible consciousness–as an emergent property of complex systems or, in other words, about how the human brain can think about itself. Hofstadter described the book as a “metaphorical fugue” on the subject, and that’s a pretty fair description for so few words. Most of his points are made through analogy, metaphor, and allegory, and the weaving together of several themes. All in all, he took a very indirect approach to a topic that is hard to approach directly, and I thought it worked magnificently. In a rare fit of immodesty, I also thought that I was one of his few readers who would likely understand and appreciate the musical, mathematical, and artistic approaches he took to his thesis, not to mention how each was reflected in the structure of the book itself–a necessary nod to SR, I’d say, for a book that includes SR. There were parts of it that I thought didn’t work so successfully as other parts, but I find that acceptable in such an adventurous work. (The Wikipedia article on the book manages to give a sense of what went on between its covers, and mentions SR as well.)

The SR aspect comes about because Hofstadter feels that it may be central to the workings of consciousness, or at least central to one way of understanding it, which shouldn’t be too surprising since we think of consciousness as self-awareness. Bringing in SR for the sake of consciousness then explains why Kurt Gödel should get woven into the book: Gödel’s notorious “incompleteness theorems” is the great mathematical example of SR, not to mention possibly the pinnacle of modern mathematical thought.

Gödel published his results in 1931, not so long after Alfred Whitehead and Bertrand Russell published their Principia Mathematica (1910–1913). Their goal was to develop an axiomatic basis for all of number theory. They believed they had done it, but Gödel’s result proved that doing what they thought they’d done was impossible. How devastating! (More Wikipedia to the rescue: about Whitehead & Russel’s PM, and about Gödel’s Incompleteness Theorems.)

Gödel’s result says (in my words) that any sufficiently complex arithmetical system (i.e., the system of PM, which aimed to be complete) is necessarily incomplete, meaning that there are self-consistent statements of the system that can be made that are manifestly true but yet are unprovable within the system, which makes it incomplete, or that there are false statements that can be proven, which makes it inconsistent. Such statements are known as formally undecidable propositions.

This would seem to straying pretty far from SR and consciousness, but hold on. How did Gödel prove this remarkable result?# The proof itself was the still-more remarkable result. Gödel showed how one could construct a proposition within the confines of the formal system, which is to say using the mathematical language of the arithmetical system, that said, in effect, “I am a true statement that cannot be proven”.

Pause to consider this SR proposition, and you’ll see that either 1) it is true that it cannot be proven, which makes it a true proposition of the formal system, therefore the formal system is incomplete; or 2) it can be proven, in which case the proposition is untrue and the formal system in inconsistent (contradictory). Do you feel that sinking, painted-into-the-corner feeling?

Of course, it’s the self-reference that causes the whole formal system to crumble. Suddenly the formal system is battling a paradox hemorrhage that feels rather like the Liar’s Paradox (“All Cretans are liars”) meets Russell’s own Barber Paradox (“the barber shaves all those in the town who do not shave themselves; who shaves the barber?”). When these things hit my brain it feels a little like stepping between parallel mirrors, or looking at a TV screen showing its own image taken with a TV camera: instant infinite regress and an intellectual feeling of free-fall.

Does Gödel’s Incompleteness Theorems and SR have anything to do with consciousness? Well, that’s hard to say, but that wasn’t Hofstadter’s point, really. Instead, he was using SR and the Incompleteness Theorems as metaphors for that nature of consciousness, to try to get a handle on how it is that consciousness could arise from a biologically deterministic brain, to take a reductionist viewpoint.

At about the same time I read GEB for the second time, I remember having a vivid experience of SR in action. I was reading a book, Loitering with Intent, by the extraordinary Muriel Spark (about whom more later someday). It is a novel, although at times one identifies the first-person narrative voice with the author. There came a moment about mid-way through the book when the narrator was describing having finished her book, which was in production with her publisher, how she submitted to having a publicity photograph taken for use on the back jacket of the book.

The description seemed eerier and eerier until I was forced to close the book for a moment and stare at the photograph on the back jacket. It mirrored exactly what had happened in the text, which was fiction, unless of course it wasn’t, etc. Reality and fiction vibrated against each other like blue printing on bright-orange paper. It was another creepy hall-of-mirrors moment, but also felt a moment of unrivaled verisimilitude. I think it marked the beginning of my devotion to Dame Muriel.

And that’s what this article is about. I suppose I could have used “untitled” as the title, but I’ve never figured out whether “untitled” is a title or a description. I think “undescribed” might be a still-bigger problem, though.

Now, on to the one-thousand-and-first.%
* You’ll notice that neither the first nor the thousandth have serial numbers that correspond; the first is numbered “2″, the thousandth is numbered “1091″. Clearly I do not publish every article that I begin, evidently discarding, on average, about 9% of them. Some get started and never finished, and some seem less of a good idea when I’m finished with them than when I started.

# And please note, this is mathematically proven, it is not a conjecture.

% I’ve been reading stuff lately that described how arabic numerals were only adopted in the 15th century; can you imagine doing arithmetic with spelled-out numbers! Not only that, but before the invention of double-entry bookkeeping–also in the 15th century–and sometimes even after, business transactions were recorded in narrative form. Yikes!


My Sputnik Childhood

Posted by jns on October 4, 2007

I nearly let pass this notable milestone: 50 years ago today the Soviet Union* launched the first artificial Earth-satellite, called Sputnik. It was a tiny thing — suitable I suppose to being the first baby of the birth of the space age — just 24 inches across and weighing only 184 pounds. It was made of shiny polished aluminum, so that it reflected sunlight and was easy to see from Earth. It carried two radio transmitters that emitted continuous signals that didn’t say anything, not that they had to. The message was obvious.

Launching a satellite, in principle, is a simple thing. Point it in the right direction, accelerate it to a speed of something like 11 km/s (or about 7&miles/s)# and it goes into orbit around the Earth. In practice this is not so easy. It takes a lot of rocket fuel to accelerate even 184 pounds to a speed near 7 miles/second, and that fuel takes more fuel to accelerate it, and that fuel takes more fuel to accelerate it, and so on.& After you figure all that out, you end up with a very tall, multi-stage rocket that is very impressive when it takes off, even for the smallest payloads.**

Then there’s all that goes into getting all the stuff to the launch-pad so it can take off. There’s a remarkable amount of engineering, mission planning, fabrication, transportation, and organization that goes into one of these events, and they only got bigger as the missions got more sophisticated. A modern space-shuttle launch comes at the end of years of planning and months of preparing the payloads; the launch itself involves hundreds of people at locations scattered around the world.

And it all started with that tiny little Sputnik. I was not quite two years old at the time, so I don’t remember its happening. I didn’t have any memorable artificial-satellite experiences until I went outside one night to see a transit of an Echo communications satellite some years later.

It surely affected my life, though. Sputnik was so alarming to the powers in Washington — perhaps to the average American, too — that we, the entire country, suddenly developed a keen, new interest in science and engineering, and in science, engineering, and mathematics education, and I was undoubtedly a product of that. When people today wring their hands about a shortage of scientists and engineers — which hasn’t been true for decades — I imagine it’s an echo from that time.

People looking to justify our commitment to sending a man to the moon thought of all sorts of alleged “spin-offs” from the space program, and proclaimed the marvels of Tang, Teflon, and Velcro, none of which were invented by NASA, nor invented for NASA. Computer systems and microelectronics got some boost, but the average computer user today would be shocked to see the primitive computer hardware that got Neil Armstrong to the moon.

One of the things that was touted as an accomplishment of NASA, a spin-off of the moon program, was project management. I think that may be a real contribution. My experience from doing a couple of space-shuttle missions is that the planning process is not fast nor particularly efficient, but it accomplishes its goals with deliberation and thoroughness. That care and deliberation has suffered some in recent years, perhaps a result of political and management hubris that believed we must know how to cut corners by now.

As a product of the Sputnik age, I take the growth of modern technology and America’s leading role in developing it rather for granted, but it’s far from established that we shall always be the leader. I believe that our remarkable achievements from the 80s and 90s in developing the personal computer, for instance, resulted from the investment our country made in science and technology education in the 60s, coupled with national interest, motivation, and pride.

Those emotions and commitments take nurturing; they musn’t be taken for granted or they whither. I fear that that’s been happening in recent years, and that our complacency will catch up with us if we do nothing about it. The renewal won’t be fast, because it takes new generations to grow into it, although current generations can do the plowing and fertilizing.

That’s part of the reason that I started Ars Hermeneutica, Limited in 2004, and that’s the big motivation behind our vision of a scientifically literate America.

I didn’t set out to write this as a justification or a motivational piece or an advertisement — or even as a fund-raising appeal## — but I guess these all have one thing in common: that I care deeply about them.
*Which, one notes in passing, no longer exists. Things change, and even countries don’t last on forever.

#The speeds are near the escape velocity from Earth, which is a bit more speed than is needed to establish an orbit, but it gives an idea of the speeds involved.

&It’s not an infinite sum — the sequence does converge, and it has an exponential form, for roughly the same reason that the equation for compound interest has an exponential form. If you want details, Google “rocket equation”.

**Note, however, that there are big differences in actual acceleration depending on the payload and the rocket chosen to launch it. Those of us accustomed to the Saturn V rockets launching an Apollo mission, or the rockets for shuttle launches, imagine a stately launch in which the heavy payloads seem like they’re never going to move, then they finally stroll off into the wild blue yonder. With that in mind, seeing once the launch of a sounding rocket, which doesn’t even attain orbit, was a surprise: it jumped off its launch-pad like a startled rabbit.

## Although, it bears repeating that Ars Hermeneutica is a 501(c)(3) tax-exempt corporation, and contributions are tax deductible. Click to see how to Support Ars Hermeneutica.


APS Openness

Posted by jns on March 9, 2007

Today in Bob Park’s What’s New (9 March 2007 edition) was this tidbit:


The commitment of physicists to the principle of openness was tested this very morning in Denver at the APS March meeting, as it has been every year for 108 years. Roy Masters, author of “God Science and Free Energy from Gravity,” was to deliver “Electricity from Gravity” at 9:36 a.m. Anyone can deliver a paper at the March Meeting. What if Masters actually succeeded in using up our gravity to keep the lights on? Not to worry.

I think all physics graduate students, sometime during their years’ long hazing, have noticed this phenomenon. It’s always good for a few giggles. But what Park says is true: any member of the APS may submit an abstract and deliver a 10-minute paper at general meetings of the society. Especially in the days when programs of abstracts were printed and distributed on paper, it was common for a few abstracts to appear for which no speaker materialized at the appointed time.

In my day there was someone who submitted an abstract at every opportunity, but who never appeared at the meetings; I don’t remember his name or where he was from. In those days one had a piece of paper on which a rectangle was inscribed; one’s abstract would be photographically reproduced and everything that was to be printed must appear withing the bounds. Said person always included a photograph of some geological feature, around which he typed his abstract, and then he filled the remaining bits of space with arrows to bits of the photo and handwritten notes. In the physics world I suppose it’s what passes for conceptual art.

Similarly, for years while I was in graduate school, there was every month, without fail, a small advertisement in the back of Physics Today from a person whose name now escapes me, who was searching for his “gamma-gamma correlations”. None of us knew what “gamma-gamma correlations” were — mostly because there is no such thing — but the advertiser never gave up hope.

Then, when I was nearing the end of graduate school, the advertisements disappeared. We were all a bit bereft at the loss of this institution. Then, after a couple of months another advertisement appeared in which the previous advertiser now promised to sell, for a small fee, something like all the secrets of the universe based on his theory about “gamma-gamma correlations”, or something like that. He had apparently found them and we could all rest again, knowing that the integrity of fringe science was safe again.


Welcome the Sun!

Posted by jns on December 7, 2006

This is the day of the year, 7 December, when I celebrate my own festival of light to welcome the return of the sun.

No, it is not the shortest day of the year, the day with the least amount of sunlight where I am (about 39 degrees north, 76 degrees, 46 minutes west — but the effect only depends on latitude), because it is not the Winter Solstice, which occurs about 21 December.

It is, however, the earliest sunset of the year, a more interesting inflection point. Since I rarely experience sunrise, at least by choice, this is psychologically much more important. Beyond today, the day will appear to me ever so slowly to be getting longer again because after today the sun will start going down later in the evening.

The effect is hardly noticeable at first,* but by the time we get to the Solstice the day-to-day change in sun-setting time will be noticeably larger. I was happy when I learned about this, the pre-Solstice early-sun-setting day, because it explained for me the feeling I’d always had that once we got past the Solstice it seemed as though the days started getting longer very quickly.#

The reason for the phenomenon is tougher to explain than to comprehend; I looked at three different versions (one, two, and three), none of which struck me as entirely satisfactory, but feel free to have a go. To make a long story short, I can point out that if the earth weren’t tilted then this curious misalignment of times wouldn’t happen. But then, neither would the seasons, and neither would the apparent position of the sun’s zenith in the sky** change from day to day.##

Regardless of all that, I’m always happy to see the sun starting to linger longer at the end of each day.
*For those with a calculus vocabulary, the curve of earliest sunset times as a function of date has just passed an extremum and the derivative is still very near zero.

#Finally, this gives you something to do with those previously useless reports in the newspaper or in the nightly weather forecast that give you sunset and sunrise time: plot the curves for yourself and see when the minima and maxima in sunset and sunrise occur at your latitude.

**Known as the “analemma”, the figure-8 shape found on precision sun-dials and on globes of the Earth.

##How much it changes day-to-day depends on one’s latitude and is described by the grandly named “Equation of Time”.