Frank Morgan

February 7, 2002

OLD CHALLENGE. What is the loudest sound ever made on earth? the softest? ANSWER. The winning response comes from Sonny Kunnakkat:

The loudest sound made on earth was the sound of the meteorite that crashed on earth about 65 million years ago and killed off the dinosaurs. Honorable mention goes to the eruption of the volcano “krakatau” in the late 1800s. Apparently the sound circled the earth a few times. [Also worthy of mention are the US H-bomb tests on the Bikini Islands.] The sperm whale apparently makes a sound that is the loudest made by any animal on earth. (It is outside the hearing range of humans though.)

Romantics say that the loudest sound is the breaking of a human heart. New Agers say that the loudest sound is noise of your own thoughts. Sometimes the loudest sound is the sound of silence.

Among sounds heard by humans, the firing of military rifles can reach 150 dB. Sounds this powerful can apparently break bones in the ear, and so I assume would have to be the loudest sounds that we can hear.

For the softest sound, somewhere between 0 and 1 dB is where the human ear starts hearing. This is about the sound of air swishing around in a half empty glass.

Al Zimmermann suggests a snowflake landing on the top of Mount Everest (where the air is thin). Williams Physicist Daniel Aalberts gave perhaps the technically correct answer: two hydrogen atoms trapped in Kleppner’s very cold Boise Einstein Condensation Lab at MIT.

QUESTIONABLE MATHEMATICS. John Sullivan found this quote from Network World (8/6/01) at Edupage:

Fast Wireless Lans May Prove a Bargain: Newer, faster LAN products are expected to have prices almost 200 percent lower than were projected just a few months ago.

I guess that means that the prices will be negative?

Al Zimmermann did a web search for “200 percent lower” and found at www.exar.com:

According to Sramek, “The XRD4460 is the lowest power device incorporating this set of video functions available today, and power consumption is 30 to 200 percent lower than competitive solutions.”

And at www.web-ak.com:

Oil companies pay an Alaska corporate income tax rate that is 200 percent lower than any other nonoil corporation in Alaska.

[Additional points deducted from the above for questionable grammar.]

And at jlarc.state.va.us (an official page of the state of Virginia):

For example, the overall rate at which local prosecutors in high-density jurisdictions sought the death penalty in capital-eligible cases was 200 percent lower than was observed in medium-density localities.

Searching for “200 percent fewer” he found at espn.go.com:

And of the 20 players since 1900 who have hit for more than one cycle, [John Olerud] has accumulated nearly 200 percent fewer triples in his career (12) than the guy who had the next-fewest trifectas, Wally Westlake (who had 33).

Looking for “200 percent less” he found at www.business2.com:

The company’s stock was trading at $24.25 in early May, nearly 200 percent less than its all-time high last summer.

And at www.idph.state.il.us (an official page of the state of Illinois):

To be eligible, individuals must have an income at or less than 200 percent less of the federal poverty level, which is $17,180 a year for a single-person household.

[Additional points deducted from the above for questionable grammar.]

Readers are invited to submit more examples of questionable mathematics.

NEW CHALLENGE. (source with solution next week). Your opponent has a standard deck of 52 cards, half red and half black. He shuffles the deck thoroughly and turns the cards over one at a time. Your goal is to predict a red card just before it is turned over. What is your best strategy?

Copyright 2002, Frank Morgan.

Send answers, comments, and new questions by email to [email protected], to be eligible for Flatland and other book awards. Winning answers will appear in the next Math Chat. Math Chat appears on the first and third Thursdays of each month. Prof. Morgan’s homepage is at www.williams.edu/Mathematics/fmorgan.

THE MATH CHAT BOOK, including a $1000 Math Chat Book QUEST, questions and answers, and a list of past challenge winners, is now available from the MAA (800-331-1622).