Reviewing a middle-school book in physical science

Science Insights: Exploring Matter and Energy
1994. 672 pages. ISBN of the student's edition: 0-201-81002-6.
Addison-Wesley Publishing Company, Inc., 2725 Sand Hill Road,
Menlo Park, California 94025.

Phony "Science" and Nonsensical Numbers
in a Brainless Book

Lawrence S. Lerner

Today most of us know better. We recognize that the atmosphere rotates with the rest of the planet. The writers of Addison-Wesley's Exploring Matter and Energy, however, haven't yet caught up with Galileo, as they show on page 38:

The rotation of the earth is important to airplane pilots and navigators. When a plane enters the air, the earth continues to rotate beneath it. The plane's destination actually moves toward the plane or away from it. . . . A plane flying from Los Angeles to New York travels east -- the same direction as the rotation of the earth. The eastbound plane must overtake New York, which is also moving east as the earth rotates. To determine arrival time, pilots must consider the flight direction and the latitude of the ground beneath them.

Indeed they must, but not for the reason that Addison-Wesley's writers suggest in that farrago of nonsense. Obviously, the writers are still clinging to the notion that Earth spins while the air remains fixed in space -- and we can be sure that these writers have never thought quantitatively about a "plane flying from Los Angeles to New York." It is easy to show that, at the mean latitude between Los Angeles and New York, the eastward speed of Earth's surface is about 830 miles an hour, which is some 60% greater than the cruising airspeed of a typical commercial airliner. If the atmosphere were standing still in space, instead of rotating eastward with the rest of Earth, no airliner could ever fly eastward from Los Angeles and "overtake New York": The eastbound airplane would continuously lose ground and would slip farther and farther to the west. If the plane headed steadily eastward at an airspeed of 500 miles an hour, and if it had enough fuel to fly for 17 hours or so, it would eventually reach Osaka -- some 6,000 miles west of Los Angeles.

Is the writers' error just a bit of carelessness? No, they really imagine that the atmosphere is fixed: On page 52 they invite the student to "apply" that silliness in answering a question about a plane that flies from Miami to Toronto and back.

I have chosen these cases to introduce two fundamental traits of Exploring Matter and Energy. First, this middle-school book is the product of writers whose knowledge of science is not merely spotty but absent. Second, the writers continually affirm their ignorance by showing that they have no understanding of measurement, no sense of real-world quantities, and no respect for numbers.

A respect for numbers is one of the essential features that characterize all science. When numbers are used by scientists, they mean something; they describe, quantitatively, some aspect of the real world. But numbers are also used by ignorant practitioners of one-upmanship, who hope to pass themselves off as erudite and "scientific" by throwing numbers around. This form of lying appears often in Exploring Matter and Energy. I shall pay special attention to it in this review, because it is a practice that can instill in young people a lifelong insouciance toward measurement and quantification.

The first two pages of Exploring Matter and Energy present a stately saraband in which five "authors" and ten "content reviewers" exhibit their advanced degrees and their impressive titles. Alas, that splendid display is to no avail. The illusion of erudition disintegrates as soon as we read the book's first chapter and see the writers' notions about the SI system of measurement. They don't understand that system, and their list of the system's "basic units" includes such things as the square meter (which is a derived unit, not a base unit) and the liter (which isn't an SI unit at all). In fact, five of the seven items on the list are false, and five genuine base units are absent.

At age 5, the table says, Rosa was 45 cm tall. That, folks, is 18 inches! As a reality check, notice that the average length of newborn girls is 50 cm (20 inches), and even those in the shortest 5% are 45 cm long. At age 5, the mean height of girls is 108 cm (43 inches), and even the shortest 5% have attained 101 cm (38 inches) -- more than twice the height of poor Rosa. (The averages that I am citing have been derived from data collected by the National Center for Health Statistics. This information is well known, and physicians use it in evaluating the growth of children. Graphical summaries of the NCHS figures can be obtained easily from any pediatrician's office.)

Raul, too, was marvelously miniaturized. At age 5 he measured only 60 cm (24 inches), though the average height of 5-year-old boys is nearly twice as great as that. The 5-year-old Raul, it seems, was about the size of a 3-month-old infant.

Addison-Wesley's table indicates that Rosa partially recovered from her poor start by doing a lot of growing. Indeed, between ages 13 and 14 she grew from 123 cm to 148 cm -- a spurt of 25 cm (or 10 inches) in only one year! (In reality, even the tallest girls add less than 5 cm in their 14th year.) Despite that extraordinary performance, however, Rosa never caught up with the rest of her sex. After age 14 she experienced no growth at all; when she was 18 years old, her height was still 148 cm (4 feet, 10 inches). In the real world, the average height of 18-year-old girls is 164 cm (or 5 feet, 5 inches), and even the shortest 5% have reached 153 cm (5 feet).

Raul, too, stayed runty. At age 14 he was only as tall as Rosa had been at 13, and at 18 he measured 160 cm (5 feet, 3 inches). Yet the average height of 18-year-old boys is about 177 cm, and the shortest 5% measure 165 cm (5 feet, 5 inches).

(Noticing that the twins have Hispanic names, I wonder whether Addison-Wesley's writers have been influenced by a notorious canard put forth by Ronald Reagan. Reagan said that Hispanics are suited to using el cortado (the back-breaking short-handled hoe) because they are "built low and close to the ground.")

Now, the writers' concocting of absurd numbers is bad enough, but look at what happens when Addison-Wesley's technical draftsman tries to show how those numbers can be converted into a line graph. After plotting the first data point (height at age 5) for each twin, the artist connects each data point to the origin. This is exactly what students must learn not to do! It represents a fundamental misconception, and in this case it produces a plainly ridiculous result: Addison-Wesley's graph reports that, at birth, Rosa and Raul each had a length of zero! So much for the pretense that Addison-Wesley's people are fit to tell students about graphs!

Perhaps you think that I have made too much of a few isolated mistakes, so let's look at some of the other instances in which Addison-Wesley's writers have invented nonsensical numbers and have failed to think quantitatively about the things that they supposedly are describing:

• Figure 2.16 shows a bowling ball that is rolling down a street on a fairly steep hill. After starting from the top of the hill and rolling past two houses (in other words, after rolling 35 meters or so), the ball moves at 45 m/s, or 100 miles an hour! The ball's acceleration, therefore, is more than 3 g -- more than three times the acceleration of an object in free fall.

• On page 35 a "distance-time graph for a marathon runner" tells that he covered the 42-kilometer course in 6 hours -- a far-from-world-class performance in which his average speed was 7 kilometers (or about 4 miles) an hour. That pace corresponds to a brisk walk; real marathon runners finish a 42-kilometer race in 2 hours or so.

• In a problem on page 41, a car accelerates at 3.5 g -- which would excite the envy of even the hottest drag racers.

• In a worked-out problem on page 42, a cheetah accelerates to 3 km/min (108 miles an hour) in 2 seconds, achieving a phenomenal acceleration of 2.5 g. Yet this exorbitant result didn't set off any alarms in the heads of the writers.

• On page 76 the ratio of the Moon's mass to Earth's mass is given as 1/6; the actual ratio is 1/81. A picture indicates that the solar tide is greater than the lunar tide; the opposite is true.

Inevitably, the writers' ignorance of quantities blends into, and exacerbates, their failure to understand concepts. We already have seen this in their fantasy about the airplane traveling from Los Angeles to New York. Here are some more cases in point:

• On page 42 they ask the student to compute an "acceleration" that doesn't exist: "A light breeze blows at 6 km/h. After 1 h the breeze becomes a strong wind that is traveling at 120 km/h. What is the acceleration of the wind?" A student can plug in some numbers and get an answer -- but in doing so, he will acquire a completely false impression of what acceleration means. A wind isn't a discrete body; the cubic meter of air that is blowing past me right now is not the same cubic meter that blew past me an hour ago, so the idea of "acceleration" has no relevance here.

• On page 69 the writers pose this problem: "A 28-kg meteor hits the surface of the moon at 130 km/s. What is the force of the meteor?" The problem evidently has something to do with momentum, but the writers don't understand how momentum is related to force. The problem can't be solved.

• On page 78 a picture caption says that mysterious "special equipment" will enable a scientist to determine "the amount of radioactive elements" in a carved stone, and that the results "will reveal the age of the carving." Wrong. The results may show the age of the stone, but they cannot show when the carving was done. (Much later, on page 568, the writers reaffirm that they don't understand radioactive dating: They try to relate carbon-14 dating to a triceratops, a beast that lived millions of years ago, during the Cretaceous Period. In reality, carbon-14 dating can be used only on objects whose ages are less than 70,000 years or so.)

Even when they stay away from numbers as such, Addison-Wesley's people manage to muck things up: "Because potential and kinetic energy can change from one kind to the other, energy can't be created or destroyed. This is known as the law of conservation of energy. . . . Maintaining and transferring momentum is called the law of the conservation of momentum. . . . all forms of nuclear medicine produce hazardous radioactive waste. . . ." Wrong, wrong, and wrong! The diagrams of an electric motor and a galvanometer are both erroneous, and neither device will work as shown. The complicated diagram of a steel-making process misses the point and implies that steel is simply purified iron. And so on, and so on.

• "Should Cars Use Solar-Powered Engines?" The "issues" surrounding this question are stated in an idiotically oversimplified fashion. They are also skewed so that the student can have no doubt about what he should do when the writers tell him to "Write a paper stating your position for or against using solar-powered cars"; he is expected to take the "for" position.

• "Should Seat Belts and Air Bags Be Required?" Here too, the issues are idiotically oversimplified and the "correct" answer is telegraphed. Worse, perhaps, the writers include a paragraph (labeled "Think About It") in which they ask: "Does the risk of personal injury outweigh the inconvenience of using seat belts and the cost increase of air bags?" Here they are urging the student to buy into a practice that often is used in false "cost-benefit analyses" -- the lumping of measurable and immeasurable factors. The cost increase associated with air bags can be quantified in dollars, but "inconvenience" certainly cannot.

• "Should People Avoid Low-Level Magnetic Fields?" The writers (who guess that electric fields are "low-frequency current") present a jumble of false claims and misleading, unsupported allegations. This seems to be another case in which textbook-writers have tried to look trendy (and to scare students) by hawking superstition. See Max G. Rodel's review of Environmental Science: A Global Concern in the May-June issue of TTL.

• "Are Biodegradable Plastics Good for the Environment?" Here the "issues" are fuzzy statements about things that people allegedly "say" or "feel" or "claim," with no attempt to give real information. A "Think About It" paragraph asks, "Which strategy would use less of the world's petroleum reserve -- using biodegradable plastic or recyclable plastic?" The question is unanswerable.

The best that can be said about Exploring Matter and Energy is that some of its chemistry chapters aren't as bad as its physics chapters. But even there, the writers don't really know the material. They give a lot of this-is-how-it-is description, but they don't convey any real feeling of chemistry's thrust and meaning.

As a whole, Exploring Matter and Energy strikes me as the work of people who haven't the foggiest notion of what science is about. Like the competing, equally reprehensible text sold by Prentice Hall, this is a book that educators should shun.

Lawrence S. Lerner is a professor in the Department of Physics and Astronomy at California State University, Long Beach. He served on the panel that wrote the current framework for science education in California's public schools, and he is a director of The Textbook League.

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