Television also uses radio signals to send pictures and sound. Radio signals can start engines moving so that gates open on their own from a distance. ("See: Radio control."). Radio signals can be used to lock and unlock the doors in a car from a distance.
Sound can be sent by radio, sometimes through Frequency Modulation (FM) or Amplitude Modulation (AM).
Many people worked to make radio possible. After James Clerk Maxwell predicted them, Heinrich Rudolf Hertz in Germany first showed that radio waves exist. Guglielmo Marconi in Italy made radio into a practical tool of telegraphy, used mainly by ships at sea. He is sometimes said to have invented radio. Later inventors learned to transmit voices, which led to broadcasting of news, music and entertainment.
Radio was first created as a way to send telegraph messages between two people without wires, but soon two-way radio brought voice communication, including walkie-talkies and eventually mobile phones.
Now an important use is to broadcast music, news and entertainers including "talk radio". Radio shows were used before there were TV programs. In the 1930s the US President started sending a message about the country every week to the American people. Companies that make and send radio programming are called radio stations. These are sometimes run by governments, and sometimes by private companies, who make money by sending advertisements. Other radio stations are supported by local communities. These are called community radio stations. In the early days manufacturing companies would pay to broadcast complete stories on the radio. These were often plays or dramas. Because companies who made soap often paid for them, these were called "soap operas".
Radio waves are still used to send messages between people. Talking to someone with a radio is different than "talk radio". Citizens band radio and amateur radio use specific radios to talk back and forth. Policemen, firemen and other people who help in emergency use a radio emergency communication system to communicate (talk to each other). It is like a mobile phone, (which also uses radio signals) but the distance they reach is shorter and both people must use the same kind of radio.
The word "radio" is sometimes used to mean only voiceband broadcasting. Most voiceband broadcasting uses lower frequency and longer wavelength than most television broadcasting.
Microwaves have even higher frequency; shorter wavelength. They also are used to transmit television and radio programs, and for other purposes. Communications satellites relay microwaves around the world.
A radio receiver does not need to be directly in view of the transmitter to receive programme signals. Low frequency radio waves can bend around hills by diffraction, although repeater stations are often used to improve the quality of the signals.
Shortwave radio frequencies are also reflected from an electrically charged layer of the upper atmosphere, called the Ionosphere. The waves can bounce between the ionosphere and the earth to reach receivers that are not in the line of sight because of the curvature of the Earth's surface. They can reach very far, sometimes around the world.
Radio telescopes receive radio waves from the sky to study astronomical objects. Satellite navigation uses radio to determine location, and radar uses it to find and track things.
Vandalism
Vandalism is a crime that is done by destroying or damaging the property of someone else. This can include graffiti and website damage.
A person that does this is called a vandal. The name comes from the Vandals, a tribe that attacked and damaged the city of Rome in 455 CE.
Many websites, such as wikis (like Wikipedia), forums, and blogs, can be changed by anyone. Because of this, they can be "vandalized" by adding comments or replacing everything on the page with spam, nonsense or other silly content. It is a kind of trolling, and these websites have special users, called administrators, whose job is to remove the vandalism and to block users who do not stop vandalizing.
Examples of physical vandalism include salting lawns, cutting trees without permission, egg throwing, breaking windows, arson, spraying paint on others' properties, tagging,
Monopoly (game)
Monopoly is a board game played by two to eight players. In the game, players move around the spaces of the board, buying and selling land and buildings to try to become the richest player.
Many books give advice on how to win the game. An early book, "1000 Ways to Win Monopoly Games" was written by Jeffrey S. Lehman (who later became President of Cornell University) and Jay S. Walker (founder of priceline.com.)
"Monopoly" was created by Elizabeth Magie as a teaching tool based on the economic concept of land monopoly. Magie created the game in 1903, to explain the single tax theory of Henry George. She wanted her game to be an educational tool to highlight the negative aspects of concentrating land in private monopolies. Her game, which she called "The Landlord's Game", was self-published, beginning in 1906. The original rules included several ways to play the game, including one where players could agree to share the land rents and everyone would win.
In 1934, Charles Darrow in Philadelphia found The Landlord's Game and thought that the game was more exciting when players didn't share their land rents. He published his own version of the game where making money was the focus of the game, and called it "Monopoly." Later on, he sold his game to Parker Brothers, who falsely credited Charles Darrow as the creator of the game.
On the Monopoly board are 40 spaces. In the four corners of the board are "GO", "Free Parking", "JAIL", and "Go to Jail". Along the sides of the board are properties (streets and businesses) for sale. The properties are: 22 "streets" (each marked with one of eight colors), 4 "railroad stations", the "Electric Company" and the "Water Works". There are also spaces called "Income Tax", "Luxury Tax", "Community Chest" and "Chance".
In the original version, the properties and railroad stations were named after the streets in Atlantic City in New Jersey in the United States. In the British original version, they are named after streets in London.
To prepare for the game, the board is put in position. The Chance and Community Chest cards are shuffled and placed face down on the board. Each player chooses a token (a playing piece), such as a thimble, a rocking horse, a boot, a dog, etc. (the tokens vary depending on the edition), and places it on "GO". One player is chosen to be the banker - this player is trusted with handing out money from the bank and collecting players' spent money during the game.
The banker gives each player $1500 to start with. Each player rolls the dice, and the player who rolled the highest total takes the first turn.
The object of the game is to own as much land (property) and to be the richest player.
The rules can be found in every "Monopoly" box, but a summary is listed here.
On your turn, you roll the dice and move your token forward (clockwise around the edge of the board) the same number of spaces as the sum of the dice you rolled. You must then follow the instructions of whatever space your token lands on.
If you roll doubles (the same number on both dice), you get to take another turn after this one is over. However, if you roll doubles three times in a row, you don't get your third turn but you must go directly to Jail (see below).
The Jail space has two sections, labeled IN JAIL and JUST VISITING. If you land on Jail by your normal roll of the dice, place your token on JUST VISITING and nothing bad (or good) happens to you. But there are three ways to be placed IN JAIL: