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View Article  The Cold-Chain Chronicles: Why it Doesn't Pay to Argue With Your Wife

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.

Mpemba believed his teacher at the time. Later that year he met a friend of his who made and sold ice cream in his town. His friend told Mpemba that when making ice cream, he put the hot liquids in the refrigerator to make them freeze faster.  Mpemba found that other ice cream sellers in town had the same practice.

Later, when in high school, Mpemba learned Newton's law of cooling, that describes how hot bodies are supposed to cool (under certain simplifying assumptions).  Mpemba asked his teacher why hot milk froze before cold milk when he put them in the freezer.  The teacher answered that Mpemba must have been confused.  When Mpemba kept arguing, the teacher said "All I can say is that is Mpemba's physics and not the universal physics". But when Mpemba later tried the experiment with hot and cold water in the biology laboratory of his school, he again found that the hot water froze sooner.

A Dr. Osborne, a professor of physics, had visited Mpemba's high school.  The student asked him to explain why hot water would freeze before cold water.  Dr .Osborne said that he could not think of any explanation, but would try the experiment later.  When back in his laboratory, he asked a young technician to test Mpemba's claim.  The technician later reported that the hot water froze first, and said "But we'll keep on repeating the experiment until we get the right result." However, repeated tests gave the same result, and in 1969 Mpemba and Osborne published their results.[1.]

When I contritely revealed what I had discovered to my wife, she responded with only a satisfied smile. I know that smile. It's one she will hold in reserve for the next time I try to assert my supposed intellectual superiority.

[1.]  Mpemba and Osborne, "Cool", Physics Education vol. 4, pgs 172--5 (1969)

[2.]  I. Firth, "Cooler?", Phys. Educ. vol. 6, pgs 32--41 (1979)

[3.]  B. Wojciechowski, "Freezing of Aqueous Solutions Containing Gases", Cryst. Res. Technol., vol. 23, #7, pgs 843--8 (1988)

 
View Article  The Cold-Chain Chronicles: Lake Superior, The World's Largest "Gel Pack"

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 

 

 

 

View Article  Is Hell Exothermic or Endothermic?

According to urban legend, the following was an actual question on a University of Washington chemistry mid-term exam. The answer by one student was so "profound" that the professor shared it with his colleagues via the Internet, which is, of course, why we have the pleasure of enjoying it as well.

Bonus Question: Is Hell exothermic (formed by the evolution of heat) or endothermic (formed by the absorbtion heat)?

Most of the students wrote proofs on their beliefs by applying some variant of Boyle's Law (gas cools when it expands and heats when it is compressed). One creative student however, wrote the following:

"First, we need to know how the mass of Hell is changing in time. So, we need to know the rate at which souls are moving into Hell and the rate at which they are leaving. I think we can safely assume that once a soul gets to Hell, it will not leave.

Therefore, no souls are leaving. As for how many souls are entering  Hell, let's first look at the different religions that exist in the world today.

Most of these religions state that if you are not a member of their religion, you will go to Hell. Since there is more than one of these religions - and since people do not belong to more than one religion - we can project that all souls go to Hell.

With the birth and death rates as they are, we can expect the number of souls in Hell to increase exponentially.

Now, we look at the rate of change of the volume in Hell because Boyle's Law states that in order for the temperature and pressure in Hell to stay the same, the volume of Hell has to expand proportionately as souls are added.

This gives us two possibilities:

(1) If Hell is expanding at a slower rate than the rate at which souls enter Hell, then the temperature and pressure in Hell will increase until all Hell breaks loose.

(2) If Hell is expanding at a rate faster than the increase of souls in Hell, then the temperature will drop until Hell freezes over.

So, which is it?

If we accept the postulate given to me by Theresa during my Freshman year that, "...it will be a cold day in Hell before I sleep with you," and take into account the fact that I still have not succeeded in having an affair with her, then #2 above cannot be true, and thus I am sure that Hell is exothermic and will not freeze over."

The student received the only "A" in the class.

My thanks to my colleague, Jeff Wodrich, for bringing this little gem to my attention.

View Article  The Cold-Chain Chronicles: Okay, Crazy Man...

Sometimes, the littlest, most insignificant events in our lives can lie dormant or forgotten, like a seed scattered in the wind, only to bloom, and be appreciated years later. 

In 1985, six years into my career at Abbott Laboratories, I was involved in the package development of (yet another) diagnostic test kit for the hematology business unit. I had worked on several before this and would work on several after, and at the time, this was just another deadline to meet. It was the first diagnostic test kit approved by the FDA to detect the presence in whole blood of  HTLV-1, the newly discovered class of retrovirus. There was a global race competing to be first to the market. The opportunistic virus, was implicated in the spread of several diseases. Identifying the virus would eventually lead to discovery of the infectious agent responsible for AIDS. Screening for it was impossible, posing a real and serious threat of contaminating the world's blood supply. As a result of this urgency and determination of all those involved, the product sped from its initial development to full FDA approval and launch in a record eight months.

This project was also my introduction to cold-chain packaging, rudimentary as it was. The finished kits had to be over-packed and transported internationally in a pallet-sized insulated container in order to protect them from environmental extremes. I was responsible for qualifying that packaging.

Thanks to the efforts of many, the product launched on time, with great success and publicity. I paid little attention, having already become deeply engrossed in the next project.

Dozens of projects later, in 1997, on a business trip to Washington D.C., I took advantage of some free time and visited the Smithsonian Institution's National Museum of American History. I meandered through the displays, reveling in the artifacts that have become vital relics of our nations heritage. By late afternoon my gluttony for history led me to the Health & Medicine wing, where a familiar object caught my eye. In a small, dark gallery entitled "Significant Medical Advances of the Twentieth Century", between Jonas Salk's story of the polio vaccine and the Jarvic-7 artificial heart, was the Abbott HTLV-1 Diagnostic Test Kit.

I stepped closer, and began to inspect each of the kits components and recalled how, at one time or another, I was involved in their development. The kit was a thermoformed clam-shell made of HIPS. The open cell foam insert was 1.9 lb/ft3 density polyether. The reagent bottles were 12 ml, HDPE, the ones with the .031" wall and 10% zinc sterate. The closures, 20 mm with a 1-3/4 turn modified buttress thread and an F-217 flow-in liner. The reagent labels contained S-246 hot melt adhesive to prevent flagging. It seemed a little surreal to me that they were locked away behind glass and on display at the Smithsonian Institution. A woman visitor leisurely approached me as she gave the display case a cursory review. I glanced at her, and with an enthusiastic grin I proudly murmured, "I worked on that." She gave me a startled "okay crazy man" look and scurried away. I realized my hands and elbows were now planted firmly on the glass, my nose millimeters from the case. "No, really!" I shouted as I heard her footsteps quicken and fade.

The experience made me realize that the tapestries that comprise our lives are unique and that every stitch of every thread holds its own importance.

While we focus our attentions and aspirations on life's bigger goals like earning a degree, raising a family, or retiring at fifty, it's what happens in between these milestones that often carries the greatest influence. Life, after all, is what happens to us while we're busy planning our future. We convince ourselves that we can script it in an effort to parlay our happiness and increase our fulfillment, but it never turns out the way we planned. I never planned to be a cold-chain packaging engineer - but here I am. We constantly readjust, recalibrate, realign and re-prioritize - and no matter what our calling, many of life's most cherished rewards remain hidden in plain sight in the day-to-day details. We just have to know to look for them.

View Article  The Cold-Chain Cronicles: Balto, Continued

Last week I arrived in New York City a day before Interphex began and had the rare opportunity to meet with and spend the day with my daughter, Haley. We took a stroll through Central Park where she captured these photos of the Balto sculpture - meaningless unless you read the March 16th Posting "Cold-Chain Chronicles: A Sled-Dog, A Bacterium And A Pharmaceutical Company."

Click below on attachments to view the photos. It is an inspiring piece in a perfect setting and location. Enjoy.

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