Through The Sandglass

"I'm real concerned about the beach"

2009-11-16T22:11:23+00:00

So declared Dennis Dare, a Manager of Ocean City, Maryland, after the conspiracy of a nor'easter and the remnant of tropical storm Ida wrought havoc along the coasts of the northeastern US over the last few days. His concern was well placed - much of the beach simply wasn't there any more, instead there was a twelve-foot cliff marking the extent of relentless wave erosion. Ocean City engineer Terry McGean, after inspecting the scene, is reported as saying “We lost a lot of dune. We lost a fair amount of beach. We’ve seen worse. Certainly, the idea is that we lose sand and not buildings, so it did its job. Now we get everybody rolling to get it back together”; he went on to describe how when it comes time to reload the beach with sand next summer, it’s going to be more expensive and take more sand than they’d planned for. He said the beach lost between 25-50 percent of its dunes.

"Reload the beach" ? I suppose he must be referring to the time-honoured futility of beach nourishment.

The press reports contain many dramatic images and I shall simply reproduce some of my favourites here, with quotations from the accompanying descriptions.

"Coastal community leaders said Saturday they were crossing their fingers that the waves would send enough sand back up onto the beaches that human assistance wouldn't be needed to finish the replenishment, shoring up the resorts in time for the economically vital summer."

"In Delaware, tides washed out dunes, leaving several feet of water and 3 feet of sand along state Route 1. Transportation officials say it may take two days to clear the sand."

"Several vessels carrying hazardous cargo broke loose from their moorings in Virginia during the storm. Crews were working to stabilize a 570-foot barge carrying containers of chemicals in the Sandbridge area of Virginia Beach. Work crews boarded the barge and were riding out the storm with it, hoping it would run aground and could be towed away when the weather improves. A similar fate awaits a 700-foot oil tanker that broke loose and ran aground on a sandbar in the James River in Newport News, Va."

"But even if another storm were to hit today, the sand washed away from the dunes will still be of some help, creating a larger near-shore sandbar system that serves to break the waves' energy as they pound the coast. That effect was apparent Friday afternoon, Tony Pratt, Delaware's shorelines and waterway administrator said. "The waves really were breaking quite a distance from the dune by the end of the day ... and losing a tremendous amount of their energy," he said. 'I like it better when the dune is whole, [but] that sand is still serving a great service. ... It's not like a total loss.' "

"Beach replenishment is a costly endeavor. A project earlier this year in Dewey Beach alone cost $6 million. "We're hopeful that Mother Nature will do her job," said Carol Everhart, executive director of the Rehoboth Beach-Dewey Beach Chamber of Commerce. Since 2001, the Army Corps and others have spent $100 million pumping sand from the ocean onto Delaware's beaches. Building sea walls will cost much more -- a sea wall built in Galveston, Texas, cost $10,000 a foot."

"State and local beach officials have credited the dunes with defending their towns' homes and boardwalks from the storm's wrath.
Taking an opposite view is Orrin H. Pilkey, emeritus professor in the Nicholas School of the Environment at Duke University and author of "The Corps and the Shore" and this year's "The Rising Sea," which he co-authored.
Pilkey said it would be a huge error for Delaware to ignore science and not plan for the inevitable approach of climate change and rising seas. He pointed to the damaging Ash Wednesday storm of 1962, when the Army Corps of Engineers erected a dune along the shore in Ocean City, Md., and issued an advisory to restrict development inland of the protective barrier. But homes and hotels eventually moved oceanside, on top of and across the dune.
'The town paid no attention to it -- it had no teeth,' Pilkey said. 'Money speaks -- so away we went.' "

[I couldn't possibly comment further on all this - the images and the quotations speak for themselves. Many of the images are from http://www.delawareonline.com/, and http://www.nj.com/, credits Patti Sapone, Robert Sciarrino, Chuck Snyder, Laura Emmons]

Sand Puzzles #1: Cooking pasta

2009-11-14T16:05:28+00:00

Nina must cook some pasta for 15 minutes. The only way she has of measuring time is a 7-minute sand-timer and an 11-minute sand-timer.

How can she use these timers to measure exactly 15 minutes?

I just came across a website called NRICH, a superb UK-based resource for maths teachers at all levels, a joint project between the Mathematics and Education Departments at the University of Cambridge. I'll let them describe the aims of their project themselves:

NRICH aims to:

Enrich the experience of the mathematics curriculum for all learners

Offer challenging and engaging activities

Develop mathematical thinking and problem-solving skills

Show rich mathematics in meaningful contexts

Work in partnership with teachers, schools and other educational settings

For teachers of mathematics, we:

Offer you FREE enrichment material (Problems, Articles and Games) at all Key Stages that really can help to inspire and engage learners and embed RICH tasks into everyday practice.

Help to promote RICH thinking in classrooms by offering on-line and face-to-face support at Primary and Secondary level.

Deliver professional development courses and workshops in rich mathematics.

Help teachers to think strategically about 'next steps' and progression in problem solving.

And for those learning mathematics, we:

Provide FREE and interesting mathematical games, problems and articles.

Encourage you to share your solutions to our mathematical problems.

Have Mathematicians that can help you to solve problems - just 'Ask NRICH'!

Offer a safe online space where you can meet others with similar interests.

A note for parents:

NRICH is a joint project between the Faculties of Mathematics and Education at The University of Cambridge

Our FREE and extensive Rich Resource Bank has been designed to meet the needs of learners from ages 5 to 19 (Key Stages 1 to 5).

Our resources are tested and proven and do make a difference.

Rich tasks are suitable for learners of all ages and abilities.

I found several items in which sand cropped up (well, of course I would - as any reader of this blog is well-aware, the stuff is everywhere), but the puzzle caught my eye. It's geared towards kids in the 5-10 age group, but I'll readily admit that it took me a couple of minutes. And the interesting thing is that, if you go on the solution page, there are three different (but clearly related) methods of achieving what's needed.

So, this post is titled "Sand Puzzles #1" - anyone want to contribute number 2?

[Sandglasses image borrowed, with appreciation, from La Crosse McCormick, "Manufacturers of Fine Timepieces"]

An anniversary

2009-11-11T09:00:00+00:00

The Nima Sand Museum on the coast of Japan's main island of Honshu contains the world's largest sandglass. Six meters in height, it is ceremonially turned at midnight on December 31st every year - and takes until exactly a year later for all the sand to fall. If, instead of December 31st, the giant sandglass had been turned on November 11th, 2008, when the first post on Through the Sandglass was published, the last grains would be trickling through today. I find it difficult to believe that this rather eclectic blog has been on the go for a year; I started it initially at the suggestion of my publishers as a follow-up to the book, but it has taken on a life of its own. There remain endless topics deposited on the cutting room floor after the book was edited that I still haven't got round to covering - there just seem to be too many other things of interest (to me, at least) cropping up on a daily basis.

So, more than 120 posts later and after visits from people in 105 countries, I'm quietly celebrating my first year of blogging ("quietly" meaning a particularly good bottle of red wine, nothing more exuberant). It has been great fun and has given me the great pleasure of putting me in touch with all kinds of delightful people around the world - something that otherwise would never have happened.

So I want to sincerely thank everyone who reads this blog, whether routinely or just occasionally.

And please keep the comments, suggestions, links and references coming - they're much appreciated.

Meanwhile, I'll leave you with this: I sometimes fear that my obsession distorts the true frequency of mentions of my topic - but then I watched the news last week and, in one broadcast, were the images below (from the recent G20 finance meeting in St. Andrews, Scotland) and a description of yet another line being drawn in the sand. Put that phrase into google news search and there are 500 instances of its use in the last week. I rest my case.

P.S. it seems that almost all the images on the blog have spontaneously and unilaterally decided to de-centre and left-justify themselves, detracting from the appearance - I have no idea why and am seeking the help of the experts at Typepad. Any suggestions will be most welcome.

Ten things we don't know about sand: Number 2

2009-11-08T14:59:13+00:00

It just won't stop cropping up. After I returned from giving the talk in Manchester, checking through the news in the world of science, not only did I come across impressive progress in coastal research (my number 6 unknown ), but there, in Wired Science, was a report titled "Baffling Patterns Form in Scientific Sandbox." It began "With nothing more than beads in a glass box, physicists have revealed yet another mysterious property of granular solids, now recognized by scientists as a unique state of matter, like solids or gases" - my number 2 in the ten things we don't know about sand: "What is it?"

The report describes work by Ralf Stannarius and Frank Rietz of the Otto von Guericke-University Magdeburg in Germany; using, as is so often the case when investigating the bizarre behaviours of granular materials, very simple apparatus, they have produced some quite astonishing results. Results that demonstrate, yet again, that we don't really know how to describe granular materials - they are not consistently solids or liquids, but rather a state of matter in their own right. We don't really know how many states of matter there are - in addition to the solids, liquids, and gases, there are numerous other candidates, including liquid crystal, amorphous, Bose-Einstein condensates, and, of course, the notorious quark-gluon plasmas (all this, I will readily admit, from Wikipedia, where I also discovered something called a "superglass" - but the article was categorised as an "orphan"). As Heinrich Jaeger, the granular guru, remarked when talking about his recent work on the nano-scale forces causing droplet formation in falling streams of sand, these "experimental results open up new territory for which there is currently no theoretical framework."

The fact that granular materials do not like to remain mixed has long been observed, and Stannarius and Rietz describe earlier experimental work which their latest research continues. Put a granular mixture in a container and vibrate, shake, rotate, or otherwise disturb it and it will perpetrate an act of self-segregation. Stannarius and Rietz have shown that such a mixture not only self-segregates, but convects. In the image at the top of this post (from their publication), it almost seems as if the material is mocking us, saying "hey, you'll need better spectacles than these through which to understand what we're up to" (OK, blogger's poetic license). "On the Brink of Jamming: Granular Convection in Densely Filled Containers" by Rietz and Stannarius was first published last year, but last month they released an update with compelling and extraordinary videos of granular convection. The apparatus was, indeed, simple, but clever. As shown below, they used a simple mix of two sizes of glass sand-sized beads in a container that is essentially a Hele-Shaw cell, just like the home-made one I have used in my kitchen physics experiments. Once filled (and it is important that the cell is filled beyond a critical level), it's placed in a mechanism that simply rotates it, slowly, for hours. The cell is back-lit and photographed periodically.

The results are staggering. The movies, of various runs of the experiment and at various resolutions, can be found at the Magdeburg website (caution: if you go to the MIT Technology Review report, the movie link embedded there is for a 150 mb version - better to check out the link I've just mentioned). The movies are dramatic and well-worth watching, but just to whet your appetite, I've assembled a time-series of stills, shown below.

In a completely unpredictable (and unpredicted) way, the grains develop a graceful series of dynamically sustained convection rolls. As the authors wrote, "Known mechanisms for granular convection could not be applied." Another echo of Heinrich Jaeger's comment that "Physicists have a rich toolbox for dealing with solids, liquids and gases. But we don’t have a manual for when the old categories don’t apply." Whatever next in the mysterious world of granular materials?

Arenaceous sporting trivia - the baseball World Series

2009-11-05T17:30:43+00:00

My daughter and her grandfather, both in Philadelphia, will probably, to put it mildly, have less than kind words for me when they see this post. For the Phillies (last year's champions) were beaten in the baseball World Series last night by the New York Yankees - of all teams, it had to be the Yankees (for non-North American readers, I have appended some brief explanatory notes at the end of the post). Angst, tears, and rage in Philadelphia, exuberant celebration in New York. But, for Through the Sandglass, it's just another opportunity, to point out the ubiquity of my topic - in the continuing tradition of my daughter's Simpsons challenge.

For a start, like many sporting surfaces, the construction of a world-class baseball field relies on first-class sand. The iconic diamond, its grass and its surrounding "dirt," are made from specialty materials. Go to the website of the Beam Clay company of Great Meadows, New Jersey ("Your 'one-stop source' for America's baseball and sports turf surfaces and supplies!") and you will be bewildered by the choice of over 200 products for the construction, care, and maintenance of your dream infield - for example, their "Premium infield mix":

Made from uniform orange sand and red Beam Clay® with our special binding process that reduces wind and water erosion. Doesn’t separate and blow away! Doesn’t become dusty in stadiums! With proper maintenance, provides firm traction without tracking, good drainage while retaining playing moisture, distinctive reddish/orange color, works up readily, no separation of ingredients, long lasting, safe to slide on - for safe, attractive, consistent professional quality baseball diamonds.

The nature and performance of the materials used for the batter's and catcher's boxes are particularly important, but as in the action of a game, the pitcher's mound has to be a focus of attention. A good history of the pitcher's mound and how to construct one can be found here; the ingredients and recipes vary little - although the climatic environment of the stadium is important. This particular summary is from http://www.baseball-almanac.com/:

The mix used to build the pitcher's landing area (and often the batter's box and catcher's box) should have a significant concentration of clay to provide the necessary stability to resist degradation from increased traffic. A good material will be about 40% sand, 20% silt, and 40% clay. If necessary, you can mix individual components together. Just be sure that individual components are evenly distributed throughout the material.
A quality infield material will have a lower concentration of clay than the pitcher's mound. The infield skin should be moist and firm, not hard and baked dry. To achieve firmness, an infield mix should not be too sandy. An infield mix with greater than 75% sand causes unstable footing for ballplayers and increases infield skin maintenance problems. A sandy infield will create low spots more quickly and is more likely to create lips at the infield skin/turf interface. Ideally, the infield mix should be between 50% and 75% sand and 25% to 50% clay and silt. A combination that has been successfully used is a 60% sand, 20% silt, 20% clay base mix (sandy clay loam to sandy loam). The silt and clay give the mix firmness. If the mix contains too much silt and clay, compaction and hardness become a problem.

So, a skilful (and well-paid) pitcher can stride out to his patch with confidence that its consistency will provide a reliable foundation for his art. And, in the case of Mariano Rivera ("Mo"), who finished off the Phillies last night and has been called "the best closer in the history of the game," his appearance on the field - if the game is in New York - is accompanied by a loud rendition of Metallica's "Enter Sandman" - "we're off to never-never land." It is said that this is by no means Mo's favourite song, but that it is played on his entry because when he comes into a game, you can pretty much put it to bed. If you wish, you can see a video of this from last night's game at http://www.wikio.com/video/1925785.

And then, of course, there's sand lot baseball. And plastic baseball-shaped bottles that can be filled with coloured sand - but one example of a wide range of such things; I couldn't possibly comment on their artistic merit - but I suspect that Andrew Clemens will not be rolling in his grave.....

Notes for non-American readers:

The "World Series" has been widely derided by non-North Americans as being no such thing, since no countries other than the USA and Canada can compete for it. In order to combat such accusations of sporting arrogance, it has often been declared that the name originates from the original sponsorship of the championship by the newspaper, The New York World, early in the last century. Indeed, my (American) wife firmly corrected me to this effect a long time ago. But it's a myth - the "World Series" is, and always has been, exactly that (see Snopes). Not that I would in any way revert to my earlier derisive remarks ..... Always remember that the other life of Steve Gould, the extraordinary and revered evolutionary biologist and writer, was as a devoted and passionate baseball fan - of the Yankees.
I would no more attempt to explain baseball to non-Americans than I would cricket to baseball fans (both are challenges equivalent, in Shakespeare's words, to "numbering the sands and drinking the oceans dry.") Suffice it to say that both games are very much like the classic description of a soldier's life - long periods of boredom interrupted by brief moments of terror (well, generally not exactly terror, but action, something to actually engage the senses and the emotions).
In the later stages of a game, the starting pitcher is often replaced by a specialist finisher - a "closer" like Mariano Rivera.
A baseball signed by Mo and with the words "Enter Sandman" can be purchased from http://www.mlbfansite.com/ for a mere $399.99 (knocked down, so to speak, from the original price of $501.86).
Herewith, from http://www.baseball-almanac.com/stadium/baseball_field_construction.shtml, a simple illustration of the layout of the diamond and the infield. From now on, you're on your own.