I have had several delegates at recent Cold Chain Conferences requesting a copy of the 24 Hour Worldwide Air Traffic video which I have included as an introduction to many of my IATA presentations. Here's the link to the Zurich School of Engineering who produced the video. Enjoy!

BTW: Care to guess how many flights this video represents in a 24 hour period?

Answer: Globally, there are approximately 85,000 flights daily!

My son, Rory, and I recently returned from twelve days in Ireland. It rained only twice, once for seven days and once for five days. Where ever you go throughout Ireland, the people are always apologetic about the weather. It's as if they are embarrassed by it. But if you're going to Ireland for the weather, then you're going for the wrong reason - although, it helps to explain why the country is so lush and green, the people so pale, and why there is such an intense, natural inclination to drink so much.

The purpose of our trip was to inaugurate my son to the island home of his paternal Grandfather, and introduce him to his innumerable cousins on the Island of Arranmore, located in the remote northwest corner of County Donegal.

Arranmore is one of those places you can't get to by accident. It takes real determination and effort - but once there, it is like taking a giant step backwards in time. The rhythm of their days is still governed by the tide and Irish (Gaelic) is still spoken by all the residents and the preferred language of many. They still spade turf, and tend to flocks of sheep. There is no permanent Gardai Siocha (police) on the island and so, the pubs never close! The young people can often be seen walking the hills at daybreak, making their way home from the island's popular disco.

It is a beautiful, rugged and peaceful place where fishing was once a major industry. No more. The shoals of herring are gone, the Cod, too. The North Atlantic Salmon have dwindled to the point where the government has intervened and taken over their management. Salmon fishing is now illegal in Irish waters.

But there are a few who continue to comb the rocky harbors of the Donegal coast for European Lobster and Brown Crab. I jumped at the invitation to accompany a long-time friend and island resident, Jerry Early, to "pull pots" one morning. We set out in a light drizzle (did I mention it rained a lot?) and harvested several lobster from stringers Jerry had set the day before in coves on the north side of the island. I found it to be back-breaking and invigorating work, but handled with effortless routine by my fisherman friend. It was one of those once-in-a-lifetime experiences and an incredible education.

 Before docking, my son took a few pictures. I  didn't notice until I was looking through the pictures yesterday, that in the background of one of the photos is a 20 foot insulated sea container - the kind pharmaceutical companies consign for temperature-sensitive ocean shipments. Jerry uses it to store his fishing gear and bait. Where it came from and how it got to such a remote location, I haven't a clue and I didn't ask. The thrifty and ingenious islanders make practical use of just about everything. I thought the accidental photo qualified for a "cooler head sighting".

Some photos of the adventure are attached. (Click on the paper clip icon below). The final photo shows me and Jerry rewarding ourselves for the days' work by engaging in some traditional Irish craic in one of the quaint pubs on Arranmore.

I should know better. After all these years of marriage you think I would have learned by now - that right or wrong, there are long-term ramifications for attempting to contradict the Mrs. by asserting any measure of intellectual superiority.

My wife, bless her heart, is a firm believer in old wives tales. She cuts the ends off of cucumbers and rubs them vigorously against the rest of the uncut portion prior to slicing it "to draw out the flavor". She won't go swimming after she eats without waiting for an hour, and believes that if you swallow your gum it will stay in your system for 7 years. (How does it know?). There are others, all harmless enough, and I attribute her beliefs to her staunch Irish-Catholic upbringing and small, mid-west town sensibility. They are an inexorable part of her charm.

I, on the other hand, dismiss such folklore completely. As an engineer, my reality exists on facts and data and until last week, I never challenged my wife on the validity of her wives tales. Here is where it begins to get ugly. 

"Why are you filling the ice cube trays with steaming hot water before putting them in the freezer?" I asked.

"Because it will freeze faster than cold water." She replied. 

I shook my head in pitiful disbelief.

"What? Everybody knows that!" She exclaimed.

I gently explained to her that it was simply not true. In fact, it was impossible. "Look", I said. "Let's say you have a tray of initially cooler water whose temperature is at 30° C and it takes 10 minutes to freeze, and an identical tray of warmer water equal in volume that starts out at 70° C.  Now the initially warmer water has to spend some time cooling to get to get down to 30° C, and after that, it's going to take 10 more minutes to freeze.  So, since the initially warmer water has to do everything that the initially cooler water has to do, plus a little more, it will take at least a little longer, right?"

"I suppose that makes sense." She said thoughtfully.

I went to the computer to find a reliable reference and prove my point. It turns out that she was right! Well, at least she may be right. There is at least some validity to this old wives tale. It is a phenomenon known as the "Mpemba effect". 

What I implicitly assumed in my proof to my wife, is that the water is characterized solely by a single number -- the average temperature.  But if other factors besides the average temperature are important, then when the initially warmer water has cooled to an average temperature of 30° C, it may look very different than the initially cooler water (at a uniform 30° C) did at the start.  The water, in fact, may have changed when it cooled down from a uniform 70° C to an average 30° C.  It could have less mass as a result of evaporation, less dissolved gas, or convection currents producing a non-uniform temperature distribution.  The change could occur as a result of the effects of supercooling. Or it could have changed the environment around the container in the freezer.  All of these changes are conceivably important. [1., 2., 3.]

Apparently, the fact that hot water freezes faster than cold water has been known for many centuries.  The earliest reference to this phenomenon dates back to Aristotle in 300 B.C.  The phenomenon was later discussed in the medieval era, as European physicists struggled to come up with a theory of heat.  But by the 20th century the phenomenon was only known as common folklore, until it was reintroduced to the scientific community in 1969 by Mpemba, a Tanzanian high school student.  Since then, numerous experiments have confirmed the existence of the "Mpemba effect", but have not settled on any single explanation.

The genesis of Mpemba's experiments began in 1963 when he was making ice cream at school, by mixing boiling milk with sugar.  He was supposed to wait for the milk to cool before placing it the refrigerator, but in a rush to get scarce refrigerator space, put his milk in without cooling it.  To his surprise, he found that his hot milk froze into ice cream before that of other students.  He asked his physics teacher for an explanation, but was told that he must have been confused, since his observation was impossible.

I have lived nearly all my life within ten miles of Lake Michigan's shoreline. I don't sail. I am not a fisherman. In fact, water sports of any kind don't appeal to me. But there is something about the lake that does - and the feeling of comfort and familiarity that it gives me, extends beyond its shores to its sister Great Lakes. My affinity for them, like the lakes themselves, is inter-connected.

I have spent many vacations exploring the small towns, islands, bays and beaches of the more than 10,000 miles of shoreline that contain the Great Lakes. I have discovered that each of the five lakes has its own personality, character and mood. They are as different and unique from each other as can be.

One thing I have learned through my travels around America is that - beyond those who live in the upper Midwest, the Great Lakes are a bit of a geographic mystery - an incongruous break in the landscape of flatland prairie and evergreen forests somewhere around Chicago or Detroit or Cleveland.

To truly appreciate these jewels, you have to spend time with them - get to know them and the people who call the lakes their own. The most common experience of those who visit these lakes for the first time is the realization of their nearly incomprehensible enormity, their importance to local culture, economy, and weather. The phrase "cooler by the lake" is a common mantra of all television meteorologists who boast their forecasts from the cities throughout the region.

The power and volume of these fresh water giants are humbling. Consider this: a full 20% of the Earth's fresh water is contained within four of the Great Lakes. 750,000 thousand gallons a second spills over the falls at Niagara and into Lake Ontario in relentless pursuit of draining the excess water from the other four lakes. These five sisters are beautiful and bountiful, languid and lurid - effortlessly producing 40 pound salmon, 40 foot waves, 40 inch snowfalls or 40 knot winds from a dead calm - known as white squalls. And they are treacherous, having claimed more than 6,000 commercial vessels in their short maritime history. 

But for as beautiful and as overwhelming as they are, there is one among them that is deeper, darker, more mysterious, and far more brooding than the rest - Lake Superior. Its chalcedony beaches, thick, tree-lined coasts, and soaring mineral cliffs form the edges of the largest concentration of fresh water in the world. So large and so deep is Superior that it could contain the volume of all the other Great Lakes combined - with enough room left over for another three lakes the size of Lake Erie. It's 3,000 cubic miles of water is retained for 191 years before it is fully turned over to the Saint Mary's River to co-mingle with Lake Huron. These facts, if you'll pardon the pun, are unfathomable to most. 

"Superior sings in the rooms of her ice water mansion."(1)  Gordon Lightfoot's lyric regarding the greatest of the Great Lakes vividly describes not only its vastness and clarity, but also its character. It's 31,700 square miles of surface water - approximately the size of the state of South Carolina, can, with equal disregard, cradle kayakers on mirrored perfect stillness or, in its fury, swallow a 729 foot steamship (The Edmond Fitzgerald). 

Superior does not benefit from trade winds, currents and tides like the open and less dense salt oceans of the world. Her confinement and depth, which runs to a maximum of 1,332 feet, makes her waters dark and dense, and with essentially no agricultural run-off -clear as Waterford crystal. Visibility in many places can be to 100 feet. But above all, Superior is cold. Extremely cold. The average water temperature is 5 degrees C. Its effects on its surroundings works in the exact same way a gel pack would within an insulated package... only on a scale millions of times larger.

A related posting to this blog, "Gel Packs - How Frozen Is Frozen?" (Technical Discussion archives) addresses, among other things, water's amazing specific heat capacity. With that knowledge in mind, it seems almost unimaginable that there is not enough energy emitted from months of blazing summer suns to warm Superior's waters to a temperature that won't stop your heart. Nor do the long, bone-chilling winters ever cause the waters to freeze. From summer to winter the water temperature of the lake never deviates by more than a few degrees. 

One of the more remote and mystical places I have traveled along the Great Lakes, is to the Kewenaw - a crooked finger of land that juts into Lake Superior's south shore in Michigan's Upper Peninsula (U.P.). It's one of those places you can't get to by accident. You have to want to get there. Few do. Fewer still have the resolve to stay. 

Among the many peculiarities you will notice in the once-proud copper mining towns rusting among the pine forests of the Kewenaw, are that the parking meters are not located at the curb but attached to nearby buildings; fire hydrants and mail boxes stand 6 feet out of the ground; and many of the houses have, where second story windows should be, entry doors with no porches, railings or stairways. Then, you realize that these are not remedial construction blunders by local Finnish craftsmen, but clever adaptations to the Kewenaw winters.

Winters are particularly long and challenging as residents there are frequent recipients of massive amounts of a rare phenomenon known as "lake effect" snow. It is caused when the frigid Arctic air, locally known as an Alberta clipper, comes whistling down the Manitoba plains. When the dry air reaches the warm, open waters of Lake Superior, it condenses. By the time it reaches the first significant landmass; the colder air hovering over the Kewenaw Peninsula, it precipitates in the form of snow. Lots and lots of snow. It can snow steadily for days on end. A friend of mine from the Kewenaw town of Calumet once told me that in February, 1979, it snowed only twice - once for 17 days, and the other for 11 - and that he was tired of having to call his dog off the roof. They received over 390 inches of snow that winter. It's difficult to imagine nearly 400 inches of snow on the ground. The picture below from a Detroit Free Press article puts it into perspective.

All this reminiscing about my Great Lakes travels has rekindled my affection for them. My wife, Colleen, and I are are leaving in the morning on a 900 mile circle tour of Lake Michigan, to view the on-set of fall colors in the U.P., and spend a few relaxing days up where Lakes' Michigan and Huron wed their waters - the Grand Hotel on Mackinac Island. Until next time...

(1) Gordon Lightfoot. "The Wreck of The Edmond Fitzgerald". Copyright 1976, Warner Bros. Music