Submitted by R. A. Pickett of Danville, Illinois.
What makes cotton shrink more when washed than wool when cleaned?
If we had known how complicated this subject was, we might have tried tackling an easier problem, perhaps solving the unresolved issues in quantum physics or conducting an exhaustive search to find either a scintilla of humor or a decent female role in an Oliver Stone movie.
Trade groups in both the wool and cotton industry sent us literature full of equations and formulas, the likes of which we hadn’t seen since we glanced at the textbook for that math class in college that we decided not to take because it was too difficult or, rather, not relevant to solving the social ills of our country. But since we are stuck with the issue at hand, please believe us when we tell you we are simplifying our answer.
All the processes that turn cotton into a finished garment (e.g., spinning, weaving or knitting, dyeing, finishing) strain and contract the fabric. Cotton shrinks when this strain is relaxed. Although many factors can contribute to shrinkage, by far the biggest factor is swelling of the yarn when exposed to water.
One might think that swollen yarn would increase the size of the garment, but what happens is that a greater length of yarn, known as warp yarn, is required to interweave the greater diameter of the swollen filling threads if the fibers are to remain in position. But the knitting process doesn’t allow enough extra yarn to interweave, so the filling threads are drawn together. This results in a relaxation of the internal strain and shrinkage in length. This shrinkage can occur in the clothes dryer as well as in the washing machine, as anyone who has ever seen an extra-large T-shirt turn into a medium after a prolonged spin can attest. Chemical processes, such as Sanforizing, can eliminate all but about 1 percent of this shrinkage, but the treatment affects the feel and wear characteristics of the cotton.
Despite wool’s reputation as a relatively shrink-free material, it is susceptible to the same relaxation of strains problems as cotton, and one more as well: felting shrinkage. Felting shrinkage is why you can’t put most wool garments in the washing machine, as the American Wool Council explains:
Felting shrinkage occurs when wool is subjected to heat, moisture, and friction, the kind of friction that takes place in washing agitation. The microscopic scale-like structures of the wool fiber interlock; the fabric becomes thicker and smaller; it shrinks or felts. This kind of shrinkage is irreversible.
So why doesn’t wool shrink when exposed to the heat in dry cleaning? Because as part of the finishing process of making a wool garment, the wool is preshrunk in a process called “fulling” or “milling.” Heat, moisture, and friction are applied to the fabric so that it shrinks a specified amount in length and width. Fulling tightens the weave and helps provide the softer texture desired of wool garments. Many chemical processes have been invented to allow treated wool garments to be machine washed and dried.
One advantage of wool over cotton is that shrinkage caused by relaxation of fiber strains can often be reversed. We have been testing this hypothesis by bravely, and without regard to our own welfare, gaining weight over the years. We can conclusively state that our old cotton T-shirts, which once fit perfectly, are not capable of expanding to fit our now ampler frame.
Submitted by John Clark of Pittsburgh, Pennsylvania.
Why are powdered laundry detergents sold in such odd weights?
Call it rigid and boring, but there is something comforting about the sizing of liquid detergents. Most brands, such as the largest-selling liquid detergent in the United States, Tide, manufacture 32-ounce, 64-ounce, 96-ounce, 128-ounce, and 156-ounce sizes. But compare these nice, even sizes (which make sense both as even pound equivalents and as units of quarts and gallons) to Tide’s “regular” and “Ultra” powdered detergents. According to Procter & Gamble spokesperson Joe Mastrullo, the company now produces only two sizes of “regular” detergent—in two rather strange sizes: 39 ounces and 136 ounces.
What gives? According to Edna Leurck, of P&G’s consumer services,
When detergents were first introduced, the weight selected was chosen to make the products compatible with those laundry soaps that were in general use. Over the years, increased detergent technology led to changes in the products, which have caused the standard weights to jump around a bit.
The sizes selected are not arbitrary, though. Sheryl B. Zapcic, of Lever Brothers Company, explains that powdered detergents are sold to provide consumers with
an approximate number of standard dry measured uses. For instance, if a detergent is packaged to provide the consumer with 20 uses and each use measures ½ cup of detergent, the weight of the package is calculated by multiplying 20 times the weight of each ½-cup use. Therefore, the consumer gets an “even” number of washing uses, rather than an “even” number of ounces.
This explains the odd sizes of regular Tide packages we mentioned. The 39-ounce size is meant to clean thirteen loads; the 136-ounce size should handle forty-six loads.
We thought that when concentrated detergents swept the supermarket aisles, their weights might be rounded off like their liquid counterparts, but alas, the tradition of the weird sizing continues. Ultra Tide, the best-selling concentrated powdered detergent, is marketed in five configurations: 23 ounces (ten loads); 42 ounces (eighteen loads); 70 ounces (thirty loads); 98 ounces (forty-two loads); and 198 ounces (eight-five loads).
If you calculate the weight per load, you will see that the definition of a “load” isn’t absolutely precise. But then how many of us are meticulous in measuring the amount of detergent we toss into the washing machine, anyway?
Submitted by Chris Allingham of Sacramento, California.
What are we smelling when it “smells like rain is coming”?
This isn’t the type of question that meteorologists study in graduate school or that receives learned exegeses in scholarly journals, but we got several experts to speculate for us. They came down into two camps.
1. It ain’t the rain, it’s the humidity. Biophysicist Joe Doyle blames the humidity, which rises before rainfall. Of course, humidity itself doesn’t smell, but it accentuates the smells of all the objects around it. Everything from garbage to grass smells stronger when it gets damp. Doyle believes that the heightened smell of the flora and fauna around us tips us off subliminally to the feeling that it is going to rain. Richard Anthes, of the National Center for Atmospheric Research, points out that many gaseous pollutants also are picked up more by our smell receptors when it is humid.
2. The ozone did it. Dr. Keith Seitter, assistant to the executive director of the American Meteorology Association, reminds us that before a thunderstorm, lightning produces ozone, a gas with a distinctive smell. He reports that people who are near lightning recognize the ozone smell (as do those who work with electrical motors, which emit ozone).
Kelly Redmond, meteorologist at the Western Regional Climate Center, in Reno, Nevada, also subscribes to the ozone theory, with one proviso. Ozone emissions are common during thunderstorms in the summer, but not from the rains from stratiform clouds during the cold season. So if it’s “smelling like rain” during the winter in Alaska, chances are you are not smelling the ozone at all but the soil, plants, and vegetation you see around you, enhanced by the humidity.
Submitted by Dr. Thomas H. Rich of Melbourne, Victoria, Australia. Thanks also to George Gudz of Prescott, Arizona; Anne Thrall of Pocatello, Idaho; Dr. Allan Wilke of Toledo, Ohio; Matthew Whitfield of Hurdle Mills, North Carolina; Philip Fultz of Twentynine Palms, California; and William Lee of Melville, New York.
Why do unopened jars of mayonnaise, salad dressing, fruit, and many other foods stay fresh indefinitely on the shelf but require refrigeration after being opened?
The three main enemies of freshness in perishable foods are air, heat, and low acidity. Foods such as mayonnaise, salad dressing, and canned fruit all undergo processing to eliminate these hazards. Burton Kallman, director of science and technology for the Nati
onal Nutritional Foods Association, explains:
Unopened jars of perishable foods can remain at room temperature because they are sealed with low oxygen levels (sometimes under vacuum), are often sterilized or at least pasteurized, and may contain preservatives which help maintain their freshness.
All three of these foods contain natural ingredients that act as preservatives. Roger E. Coleman, senior vice-president of public communications for the National Food Processors Association, differentiates between foods that must be refrigerated immediately and those that can remain unopened on the shelf:
Products such as marinated vegetables, salad dressings, and fruits, which contain adequate amounts of added acid ingredients such as vinegar and/or lemon juice, will not support the growth of hazardous microorganisms and only need to be refrigerated after opening to prevent them from spoiling. Other products, such as canned meats and vegetables, do not contain acidic ingredients and, thus, can support the growth of hazardous microorganisms. These products must be refrigerated, not only to retard spoilage but to keep them safe to eat after opening.
This last point is particularly important, for many foods that state “Refrigerate after opening” are perfectly safe to store back on the shelf after they are opened. So why the warning? Barbara Preston, executive director of the Association for Dressings and Sauces, writes:
Most commercial dressings (with the exception of those bought from a refrigerated display case) are perfectly safe stored at room temperature. The words ‘Refrigerate After Opening’ on the label are intended only to help preserve their taste, aroma, and appearance. They do not relate to spoilage. If an already opened jar of salad dressing is accidentally left out for several hours, don’t throw it away. There is no danger of spoiling…it just may not taste as fresh.
Submitted by Nancy Schmidt of West New York, New Jersey.
Why are matchbooks assembled so that the sharp side of the staple is on the striking side, risking injury to the fingers?
What piece of legislation in 1978 has affected and changed American life most profoundly? Some would argue it was the Senate’s vote to turn the Panama Canal over to the Panamanians. Or Jimmy Carter’s signing the Humphrey-Hawkins bill, which attempted to ensure full employment while keeping inflation in check. But some, with great sincerity, will point to the federal regulations enacted requiring the striking strip to be moved to the back of the matchbook.
We all know that the federal bureaucracy gets blamed for imposing too many regulations, but this one actually made some sense. Although matchbooks before 1978 were clearly marked “Close Cover Before Striking,” macho types or those in the throes of a nicotine fit often struck the matches without closing the cover; with the striking strip on the front, the exposed matches often came in contact with the heat, or even the flame, of the match, causing burns.
Manufacturers were required to move the strip to the back of the book. Couldn’t they simply reverse the staple position on the new books, lessening the chances of staple cuts?
The problem is that the matchbook industry would have had to retrofit all of their existing machinery. So instead of changing the position of the staple, today a machine clinches the staple to ensure it is properly closed. Furthermore, the striker is placed high enough above the staple so that even shaky smokers can avoid hitting the staple. The staple should not penetrate the striking strip at all.
We asked Iain Walton, customer service representative for match manufacturer D.D. Bean & Sons, if they have encountered problems with the staples in post-1978 matchbooks. He replied that there weren’t problems with staple cuts, but…
Some people do complain that the staple was responsible for causing flying heads from the matches. In all cases, if the match is struck correctly, the staple is in no way responsible. In fact, the reason this happens is that the match was not struck along the length of the striking strip, as is intended. Instead, it is struck across the width of the striking surface and into the staple.
We have often wondered about this Imponderable ourselves. But we still find it amusing that staple cuts are the health hazard smokers worry about.
Submitted by Pete Johnson of Fargo, North Dakota.
Why are paper (book) matches dark on one side and light on the other?
If 1992 seemed like an especially exciting year to you, and you didn’t quite understand why, may we suggest the reason. Even if you didn’t know it consciously, you were celebrating the hundredth anniversary of the book match. Certainly Iain K. Watson was excited about the August centennial celebration in Jaffrey, New Hampshire. Even so, he took a little time out to provide us with a precise answer to this Imponderable.
We may take for granted the design of a match book, but manufacturers don’t. Who would have thought that the reason for the different colors of matches was…aesthetics?
If you look at a book of matches, you will notice that one side is brown, or “kraft” [the type of strong wrapping paper used in paper shopping bags], while the other is either blue or white. Match stems are manufactured from recycled paper stock, which in its finished form is the ugly brown color of the match backs.
In order to enhance its appearance, in the final stages that this brown paper pulp is being pressed, additional processes are added. In the case of the blue color of the front of the stem stock, blue dye is added to the paper. When this dye is added, the blue coloring only goes partway through the stock. Hence the brown remains the color of the back.
In the case of the white-fronted match sticks, during the final pressing processes of the recycled paper stock, cleaner, whiter recycled paper pulp is added, giving the final layers a whiter appearance than the bulk of the brown recycled board. Generally, the whiter recycled stock is comprised of papers such as white envelopes and white bond papers, whereas the majority of the match stem stock is composed of a mishmash of recycled papers.
We don’t know of anyone who ever selected, or for that matter refused, to use book matches (which, after all, are usually given out for free) based on the color of the matches themselves. But match manufacturers hardly want to test the hypothesis. For there are other alternatives, like lighters, lurking around for consumers to use.
Submitted by Rory Sellers of Carmel, California.
How can the blades of electric can openers be sharp enough to cut through metal yet not sharp enough to cut our fingers when touched?
The blade of a can opener is far from dull, but it need not be as sharp as a scalpel to open cans. As Marilyn Myers, of Norelco Consumer Products, put it, “The metal in the opener is made of sturdier stuff than the can it opens.”
Just as important, the blade has a lot of help in opening the can. Liz Wentland, of Sunbeam-Oster, explains that pressure is exerted on the blade by the can opener lever to drive it into the can. Once the drive wheel of the can opener pushes the blade through the lid so that the seal is broken, a razor-sharp blade isn’t necessary. On an electric can opener, the drive wheel obtains its power from the motor; on hand models, the crank (and human hands) provides the power.
Myers adds that can opener blades do occasionally need replacement. Why? “Mainly because they get clogged with goo.”
Submitted by Patti Willis of Endicott, New York.
Why do most retail establishments with double doors usually lock one of the two leaves?
In every Imponderables book, one chapter becomes an obsession. This time around, we were fixated on solving the double door dilemma, mainly because we face this predicament on a daily basis.
We approach a store. We see double doors in front of us with both leaves closed. Which leaf is locked? Should we try the left or the right? And should we pull? Or should we push? Four possible combinations. Invariably, we succeed. On the fourth try.
We spoke to or received letters from dozens of sources about this Imponderable over the last five years. We heard no consensus and not much sense, either. In despair, we asked trusty researcher Sherry Spitzer to speak to store managers, architects, door
manufacturers, and safety inspectors to see if she could make sense out of a confusing assemblage of responses. After many person-hours of work by both of us, all we can report is that while there are many theories to explain why proprietors might lock one leaf of a double door, few of the people who actually do lock them could provide a reasonable explanation for their behavior.
Still, we’ll share what we’ve come up with, and pray that an empathic reader will help relieve the pounding sensation in our brain.
First of all, why do stores have double doors in the first place? Local fire codes mandate the minimum width of doors used as exits in public buildings. Double doors are lighter and more practical than single doors to cover a wide area. Electric sliding doors, one possibility, are extremely expensive, while one wide door would sweep over a tremendous area within and outside of the store, posing the threat of accidents and occupying valuable store space. Double doors also allow for easier movement in and out of the store, particularly if customers are trying to enter while others are trying to exit. Double doors also make it possible to move in furniture or other wide objects if the service entrance is impassable.
Are Lobsters Ambidextrous? Page 15
