Published April 14, 2011
I mentioned Avogadro’s number in an older column and had to relearn it to write about it, chemistry classes being several decades past for me. “The American Heritage Science Dictionary” provided the answer.
I found listings in the AHSD under Avogadro, Amedeo (“Italian chemist and physicist …”); Avogadro’s law (“The principle that equal volumes of all gases under identical conditions of pressure and temperature contain the same number of molecules. …”); Avogadro’s number (“The number of atoms or molecules in a mole of a substance …”); and mole (“The amount of an element, compound, or other substance that has the same number of basic particles as 12 grams of Carbon-12. …”).
Using the AHSD, I performed a practice calculation on glucose, C6H12O6, consulted it to find glucose and learn its molecular structure, consulted the Periodic Table in the AHSD to find the atomic weights of carbon, hydrogen and oxygen, and arrived at 180g of glucose in a mole. I checked my finding with my high school chemistry teacher (initials pH), and he confirmed it was right.
I delight in browsing through the AHSD, which offers brief but informative glosses on all the major sciences: physics, chemistry, biology, mathematics, earth science, medicine, technology and anthropology. Open the dictionary to any page and you can get lost in a world of magmatic differentiation, probability waves, the common cold, magic squares and pollination.
Entries titled “A Closer Look” offer expanded explanations, such as that at color, which discusses the color spectrum and the three primary colors forming all other colors: “Mixing the three additive primaries in equal proportions reconstitutes white light.”
Usage notes clarify meanings, such as the difference between meteor, meteorite and meteoroid. “A meteoroid is a rock in space that has the potential to collide with the Earth’s atmosphere. … When a meteoroid enters the atmosphere, it becomes a meteor. … If the rock is not obliterated by the friction and lands on the ground, it is called a meteorite.”
Biographies give expanded information on people such as chemist Linus Pauling, a peace activist who, with his wife, led the fight to end nuclear testing.
All Closer Look entries, biographies and usage entries are listed on page iv, making it easy to find these expanded entries. Many illustrations augment the text, such as a map of North America showing the jet stream, a diagram of the diaphragm under the respiration entry, and a cutaway drawing of a laser.
American Heritage has been publishing dictionaries since the 1960s, its first in answer to Merriam- Webster’s decision to eliminate usage notes from the New International Dictionary, Third Edition, copyright 1961. If I remember correctly, AH was so discombobulated at the changes M-W wrought it offered to buy the company, but no go, so AH entered the dictionary business, to the great benefit of dictionary users. AH is one of a trio of dictionaries I consult regularly, including M-W and Webster’s New World. I own the large Fourth Edition and the abridged College Dictionary, both of which include an appendix of Indo-European roots that takes the etymologies a long step further back in time.
Closing the AHSD is the Timeline of Scientific Discovery, which starts with 2000 BCE, when “Egyptian priests develop the world’s first sophisticated medical practice,” and ends with 2003, “The Human Genome Project is completed.” (My book is copyright 2005; a newer edition was published in 2008.)
I can get lost in this book. In the column to the left of meteorite is metatarsal, and to the right is meter- kilogram-second system. Each entry can send me wandering throughout the AHSD in the quest for related topics. What a fun book.
- American Indians
- C. History
- Civil War
- D. Books
- E. Clothing
- Historical Clothing
- Historical Festivals
- Musical Instruments
- Ohio History
- Old West
- Revolutionary War
- World War II