When Do Fish Sleep? Read Online Free Page A
Author: David Feldman
Tags: Reference, Curiosities & Wonders
0.01 centimeters in diameter, that their descent is not even noticeable to the human eye.
Submitted by Ronald C. Semone of Washington, D.C .
Why Are There More Holes in the Mouthpiece of a Telephone than in the Earpiece?
We just checked the telephone closest to us and were shocked. There are thirty-six holes on our mouthpiece, and a measly seven on the earpiece. What gives?
Tucked underneath the mouthpiece is a tiny transmitter that duplicates our voices, and underneath the earpiece is a receiver. Those old enough to remember telephones that constantly howled will appreciate the problems inherent in having a receiver and transmitter close together enough to produce audible transmission without creating feedback.
Before the handset, deskstand telephones were not portable, and the speaker had to talk into a stationary transmitter. Handsets added convenience to the user but potential pitfalls in transmission. While developing the telephone handset, engineers were aware that it was imperative for the lips of a speaker to be as close as possible to the transmitter. If a caller increases the distance between his lips and the transmitter from half an inch to one inch, the output volume will be reduced by three decibels. According to AT&T, in 1919 more than four thousand measurements of head dimensions were made to determine the proper dimensions of the handset. The goal, of course, was to design a headset that would best cup the ear and bring the transmitter close to the lips.
One of the realities that the Bell engineers faced was that there was no way to force customers to talk directly into the mouthpiece. Watch most people talking on the phone and you will see their ears virtually covered by the receiver. But most people do not hold their mouths as close to the transmitter. This is the real reason why there are usually more holes in the mouthpiece than in the earpiece. The more holes there are, the more sensitive to sound the transmitter is, and the more likely that a mumbled aside will be heard three thousand miles away.
Submitted by Tammy Madill of Millington, Tennessee .
How Do Fish Return to a Lake or Pond that Has Dried Up?
Our correspondent, Michael J. Catalana, rightfully wonders how even a small pond replenishes itself with fish after it has totally dried up. Is there a Johnny Fishseed who roams around the world restocking ponds and lakes with fish?
We contacted several experts on fish to solve this mystery, and they wouldn’t answer until we cross-examined you a little bit, Michael. “How carefully did you look at that supposedly dried-up pond?” they wanted to know. Many species, such as the appropriately named mudminnows, can survive in mud. R. Bruce Gebhardt, of the North American Native Fishes Association, suggested that perhaps your eyesight was misdirected: “If there are small pools, fish may be able to hide in mud or weeds while you’re standing there looking into the pool.” When you leave, they re-emerge. Some tropical fish lay eggs that develop while the pond is dry; when rain comes and the pond is refilled with water, the eggs hatch quickly.
For the sake of argument, Michael, we’ll assume that you communed with nature, getting down on your hands and knees to squeeze the mud searching for fish or eggs. You found no evidence of marine life. How can fish appear from out of thin air? We return to R. Bruce Gebhardt for the explanation:
There are ways in which fish can return to a pond after total elimination. The most common is that most ponds or lakes have outlets and inlets; fish just swim back into the formerly hostile area. They are able to traverse and circumvent small rivulets, waterfalls, and pollution sources with surprising efficiency. If they find a pond with no fish in it, they may stay just because there’s a lot of food with no competition for it.
Submitted by Michael J. Catalana of Ben Lomond, California .
Why Do We Call Our
Submitted by Ronald C. Semone of Washington, D.C .
Why Are There More Holes in the Mouthpiece of a Telephone than in the Earpiece?
We just checked the telephone closest to us and were shocked. There are thirty-six holes on our mouthpiece, and a measly seven on the earpiece. What gives?
Tucked underneath the mouthpiece is a tiny transmitter that duplicates our voices, and underneath the earpiece is a receiver. Those old enough to remember telephones that constantly howled will appreciate the problems inherent in having a receiver and transmitter close together enough to produce audible transmission without creating feedback.
Before the handset, deskstand telephones were not portable, and the speaker had to talk into a stationary transmitter. Handsets added convenience to the user but potential pitfalls in transmission. While developing the telephone handset, engineers were aware that it was imperative for the lips of a speaker to be as close as possible to the transmitter. If a caller increases the distance between his lips and the transmitter from half an inch to one inch, the output volume will be reduced by three decibels. According to AT&T, in 1919 more than four thousand measurements of head dimensions were made to determine the proper dimensions of the handset. The goal, of course, was to design a headset that would best cup the ear and bring the transmitter close to the lips.
One of the realities that the Bell engineers faced was that there was no way to force customers to talk directly into the mouthpiece. Watch most people talking on the phone and you will see their ears virtually covered by the receiver. But most people do not hold their mouths as close to the transmitter. This is the real reason why there are usually more holes in the mouthpiece than in the earpiece. The more holes there are, the more sensitive to sound the transmitter is, and the more likely that a mumbled aside will be heard three thousand miles away.
Submitted by Tammy Madill of Millington, Tennessee .
How Do Fish Return to a Lake or Pond that Has Dried Up?
Our correspondent, Michael J. Catalana, rightfully wonders how even a small pond replenishes itself with fish after it has totally dried up. Is there a Johnny Fishseed who roams around the world restocking ponds and lakes with fish?
We contacted several experts on fish to solve this mystery, and they wouldn’t answer until we cross-examined you a little bit, Michael. “How carefully did you look at that supposedly dried-up pond?” they wanted to know. Many species, such as the appropriately named mudminnows, can survive in mud. R. Bruce Gebhardt, of the North American Native Fishes Association, suggested that perhaps your eyesight was misdirected: “If there are small pools, fish may be able to hide in mud or weeds while you’re standing there looking into the pool.” When you leave, they re-emerge. Some tropical fish lay eggs that develop while the pond is dry; when rain comes and the pond is refilled with water, the eggs hatch quickly.
For the sake of argument, Michael, we’ll assume that you communed with nature, getting down on your hands and knees to squeeze the mud searching for fish or eggs. You found no evidence of marine life. How can fish appear from out of thin air? We return to R. Bruce Gebhardt for the explanation:
There are ways in which fish can return to a pond after total elimination. The most common is that most ponds or lakes have outlets and inlets; fish just swim back into the formerly hostile area. They are able to traverse and circumvent small rivulets, waterfalls, and pollution sources with surprising efficiency. If they find a pond with no fish in it, they may stay just because there’s a lot of food with no competition for it.
Submitted by Michael J. Catalana of Ben Lomond, California .
Why Do We Call Our
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