Gravity Model Definition and Examples

Gravity Model Definition and Examples For decades, social scientists have been using a modified version of  Isaac Newtons Law of Gravitation  to predict the movement of people, information, and commodities between cities and even continents. The gravity model, as social scientists refer to the modified law of gravitation, takes into account the population size of two places and their distance. Since larger places attract people, ideas, and commodities more than smaller places and places closer together have a greater attraction, the gravity model incorporates these two features. The relative strength of a bond between two places is determined by multiplying the population of city A by the population of city B and then dividing the product by the distance between the two cities squared. The Gravity Model Population 1 x Population 2_________________________   Ã‚  Ã‚  Ã‚  Ã‚  distance ² Examples If we compare the bond between the New York and Los Angeles metropolitan areas, we first multiply their 1998 populations (20,124,377 and 15,781,273, respectively) to get 317,588,287,391,921 and then we divide that number by the  distance  (2462 miles) squared (6,061,444). The result is 52,394,823. We can shorten our math by reducing the numbers to the millions place: 20.12 times 15.78 equals 317.5 and then divide by 6 with a result of 52.9. Now, lets try two metropolitan areas a bit closer: El Paso (Texas) and Tucson (Arizona). We multiply their populations (703,127 and 790,755) to get 556,001,190,885 and then we divide that number by the distance (263 miles) squared (69,169) and the result is 8,038,300. Therefore, the bond between New York and Los Angeles is greater than that of El Paso and Tucson. How about El Paso and Los Angeles? Theyre 712 miles apart, 2.7 times farther than El Paso and Tucson! Well, Los Angeles is so large that it provides a huge gravitational force for El Paso. Their relative force is 21,888,491, a surprising 2.7 times greater than the gravitational force between El Paso and Tucson. While the gravity model was created to anticipate migration between cities (and we can expect that more people migrate between LA and NYC than between El Paso and Tucson), it can also be used to anticipate the traffic between two places, the number of telephone calls, the transportation of goods and mail, and other types of movement between places. The gravity model can also be used to compare the gravitational attraction between two continents, two countries, two states, two counties, or even two neighborhoods within the same city. Some prefer to use the functional distance between cities instead of the actual distance. The functional distance can be the driving distance or can even be flight time between cities. The gravity model was expanded by William J. Reilly in 1931 into Reillys law of retail gravitation to calculate the breaking point between two places where customers will be drawn to one or another of two competing commercial centers. Opponents of the gravity model explain that it can not be confirmed scientifically, that its only based on observation. They also state that the gravity model is an unfair method of predicting movement because its biased toward historic ties and toward the largest population centers. Thus, it can be used to perpetuate the status quo.

Sad Plays - Tragedies and Tear-jerkers

Sad Plays - Tragedies and Tear-jerkers Have you ever noticed how some plays are such a downer? Even some plays that are supposed to be comedies, such as Anton Chekovs masterpieces, are dour and cynical and downright depressing. Of course, the theater like life isnt all about comedy and happy endings. To be reflective of human nature, playwrights often delve into the tears-soaked corners of their souls, producing literary works that are timeless tragedies that evoke both terror and pity, just how Aristotle likes it! Here is a list of theaters most hauntingly sad plays: #10 - Night Mother There are many plays that explore the topic of suicide, but few are as direct and, dare I say, as persuasive as Marsha Normans play, night Mother. During the course of a single evening, an adult daughter has a sincere conversation with her mother, clearly explaining how she plans to take her own life before dawn. The daughters miserable life has been plagued with tragedy and mental illness. However, now that she has made her decision, she has gained clarity. No matter how her mother argues and begs, the daughter will not change her mind. New York theater critic John Simon praise the playwright stating that Marsha Norman conveys the simultaneous monstrousness and ordinariness of this event: that Jessie both solicitously provides for her mothers future and abandons her, coolly matter-of-fact about what strikes most of us as the ultimate irrational act. As with many sad, tragic and controversial plays, Night Mother ends with much to contemplate and discuss. #9 - Romeo and Juliet Millions of people think of Shakespeares classic Romeo and Juliet as the ultimate love story. Romantics view the two star-crossed lovers as the quintessential young couple, forgoing the wishes of their parents, throwing caution to the proverbial wind and settling for nothing less than true love, even if it comes at the cost of death. However, theres a more cynical way of looking at this story: Two hormone-driven teenagers kill themselves because of the stubborn hatred of ignorant adults. The tragedy may be overrated and overdone, but consider the ending of the play: Juliet lies asleep but Romeo believes that she is dead so he prepares to drink poison in order to join her. The situation remains one of the most devastating examples of dramatic irony in the history of the stage. #8 - Oedipus the King Also known as Oedipus Rex, this tragedy is the most famous work of Sophocles, a Greek playwright who lived over two thousand years ago. In case you have never heard the plot of this famous myth, you may want to skip to the next play on the list. Spoiler Alert: Oedipus discovers that years ago he murdered his biological father and unknowingly married his biological mother. The circumstances are grotesque, but the real tragedy stems from the bloody reactions of the characters as each participant learns the unbearable truth. The citizens are filled with shock and pity. Jocasta hangs herself. And Oedipus uses the pins from her dress to gauge out his eyes. Well, we all cope in different ways I guess. Creon, Jocastas brother, takes over the throne. Oedipus will wander around Greece as a wretched example of mans folly. (And I assume Zeus and his fellow Olympians enjoy a mean-spirited chuckle.) Read the complete plot summary of Oedipus the King. #7 - Death of a Salesman Playwright Arthur Miller doesnt just kill off his protagonist, Willy Loman, by the end of the play. He also does his best to euthanize the American Dream. The aging salesman once believed that charisma, obedience, and persistence would lead to prosperity. Now that his sanity is wearing thin, and his sons have failed to live up to his expectations, Loman determines that he is worth more dead than alive. In my review of the play, I explain how this drama may not be my favorite of Millers work, but the play clearly accomplishes its goal: To make us understand the painfulness of mediocrity. And we learn a valuable, common sense lesson: Things dont always go the way we want them to go. #6 - Wit: There is a lot of humorous, heartwarming dialogue to be found in Margaret Edsons Wit. Yet, despite the plays many life affirming moments, Wit is filled with clinical studies, chemotherapy, and long stretches of painful, introspective loneliness. Its the story of Dr. Vivian Bearing, a hard-as-nails English professor. Her callousness is most evident during the plays flashbacks. While she narrates directly to the audience, Dr. Bearing recalls several encounters with her former students. As the pupils struggle with the material, often embarrassed by their intellectual inadequacy, Dr. Bearing responds by saying intimidating and insulting them. Yet, as Dr. Bearing revisits her past, she realizes she should have offered more human kindness to her students. Kindness is something Dr. Bearing will come to desperately crave as the play continues. If you have already experienced Wit then you know you will never look at John Donnes poetry the same way. The main character uses the cryptic sonnets to keep her intellect sharp, but by the end of the play she learns that academic excellence is no match for human compassion, and perhaps a bedtime story. Continue reading the Top Ten List of the Worlds Saddest Plays.