Its Time to Put an End to Junk Mail :: Postal Service Letters Essays

Its Time to Put an End to Junk Mail It is another Wednesday morning, and I am again posing at the front desk of my dormitory at 9 am. The US Postal Service just delivered todays mail, and the other Wednesday-morning deskworker and I argon preparing to search for names, check mailbox numbers, sort the mail, and place it into mailboxes. I hate working the mail shift, but I do it because I get paid nine dollars an hour for relatively brainless work. Even though I lose a few hours of sleep, I get some good laughs and entertainment in return, especially on a day like today when an array of catalogs stocks two entire mail bins. After three years at this job, I continue to be amazed at both the number of catalogs certain people receive and the type of items that can be acquired through a catalog. Take, for example, Resident Jane Doe, who gets J. cabal, L.L. Bean, Ann Taylor, Victorias Secret, Pottery Barn, spang & Bath and Beyond, and Staples catalogs, each of which arri ve on average once per month. Residents like Jane Doe are notorious amongst deskworkers for the volume of mail they receive, and their room numbers are firmly imprinted on our brains because we have looked them up so many times. I can always tell when residents like Jane Doe have been away for a long weekend, because their mailboxes become so packed that they cannot hold even one additional piece of mail. Of course, 80% of the mail in her mailbox consists of catalogs and other throw out mail. The companies themselves contribute greatly to the number of catalogs these residents receive. Jane Doe probably purchased one item from J. Crew through mail order or at a J. Crew store, and as a result, she will always receive catalogs from J. Crew at this address, even after she has moved away from this dorm. Furthermore, the fact that she receives other clothing catalogs may also be attributed to this one purchase. Since its already almost two months into the semester, I do not mind this never-ending stream of catalogs as much because I can generally identify the residents who do not reside in my dorm building anymore and can quickly sort through their mail.

Physics of Echolocation :: physics echo echolocation

While visiting the Grand Canyons, you couldnt honestly tell me that you didnt scream into the canyon just to hear your reprise start out back to you. Dont be ashamed, we all do it. Many kinds of animals actually use their echo to find out where they are in a closed area or to find out if there are any other animals close by. One classic example is the bat.To understand what an echo is, you first have to understand what sound is. In Websters Fourth Edition College Dictionary, sound is vibrations in air, water, etc. that stimulate the auditory nerves and scram the sensation of hearing. Vibrations through the air can be thought of as oscillation of molecules. As the molecules oscillate, they pass zero on to surrounding molecules, and those molecules pass energy on to other surrounding molecules. This is how sound journeys, and the oscillation of the molecules is often referred to as sound waves.An echo happens when the sound waves reach a surface, bounce off of it and travel in the opposite advocate. For optimum echoes, the surface should be perpendicular to the waves, and as frictionless as possible. In places like the Grand Canyons, you can hear many an(prenominal) echoes because the sound waves bounce off of surfaces, then others bounce off of other surfaces, and some will bounce back to you, but at different times.In echolocation, bats send out short pulses that have a higher(prenominal) frequency. The short pulses that the bats send out have such a high frequency that the average human cannot hear them. The waves that the bats send ripple out from them circularly and will bounce off of anything that is in the bats way, and will also go back to the bat in the form of an echo. By instinctively examining the echoes that they receive, the bats will be able to tell the direction that the object is coming or going from, how fast it is going that way and how far away it is from the bat. Some bats can even tell how speculative the object is that is in their way. If bats didnt have the use of echolocation, theyd need some other way to stay alive, because echolocation is the bats way of life. It is the primary reason that it is able to live in its environment.