A bicycle is a two-wheeled vehicle that is powered by pedals and steered by handlebars. It is an efficient means of transportation that is environmentally friendly and economically practical. It requires relatively little maintenance and can travel long distances at reasonable speeds. It can carry riders, cargo, and even people in wheelchairs. Its simple design and efficient operation make it an appealing form of transport for children and adults.

A person can learn to ride a bike in as few as 10 steps. A new rider must concentrate on balance and coordination, but after a few practice rides can easily ride with confidence. More experienced riders often experiment with different techniques to improve their speed or endurance. Some cyclists take their bikes to races or other events where they compete with other riders.

The frame of a bicycle is usually made from steel, but more expensive models are often constructed from aluminum alloys or carbon fiber. These materials allow designers to produce lightweight frames that can also be strong enough to support a large amount of weight. The wheels of a bicycle are typically made from a hub, spokes, and a metal or rubber tire. The ball bearings in these components are held in a cup that screws into one of the cones on the bicycle’s crank axle. A bit of grease in the bearings makes the wheel and pedal assembly run smoothly.

Bicycle tires are designed to handle a variety of terrains, and the tires on a road bike are typically sturdier than those on a mountain bike. Some cyclists also add mud or snow tires for use in inclement weather. In addition to tires, bicycles have a wide variety of other accessories available for purchase. Many bicycles come equipped with racks to hold bags or other gear. Child seats or trailers can be attached to the rear of a bicycle to carry extra riders. Pegs can be fastened to a bike’s frame to help perform tricks or to provide a place for a rider to stand.

People who regularly ride a bicycle experience a variety of health benefits. Cycling is a great cardiovascular exercise that helps to strengthen the heart and blood vessels and improve the health of the lungs. It can also be a relaxing activity that helps to relieve stress. Some studies have shown that regular cycling reduces the risk of certain cancers, such as colon and breast cancer. Moreover, it can help to prevent type 2 diabetes by replacing sedentary time with healthy exercise. However, it is important for people to use bicycles responsibly, as they can be dangerous if ridden recklessly. For this reason, they should always obey traffic laws and signal before turning. They should also wear bright, reflective clothing and be aware of their surroundings at all times. If they encounter a car, they should move to the right of the roadway to avoid being hit. They should also be prepared to stop quickly if needed.

Since 1975 NOAA’s Geostationary Operational Environmental Satellites (GOES) have provided continuous imagery and data on atmospheric conditions as well as solar activity (“space weather”). They have aided in the search and rescue of people in distress, contributed to more accurate and timely weather forecasts and enabled us to better understand long-term climate conditions. NASA builds and launches the GOES, and NOAA operates them.

Two GOES spacecraft provide real-time weather data over the eastern and western United States at all times of day and night. The primary payload instruments are the Imager and Sounder, both of which employ a servo-driven, two-axis gimballed mirror system and a 31 cm Cassegrain telescope. The Imager has a multichannel capability that senses infrared radiation and visible reflected sunlight, while the Sounder gathers vertical air temperature and moisture profiles and ocean surface temperatures. Both sensors can scan the Earth’s full disk and are able to zoom in on severe storms.

The Imager on GOES-16 has three times more spectral channels, four times the resolution and five times the scanning speed than previous GOES satellites. The Sounder on GOES-16 can gather data on air temperature and humidity, cloud tops, surface water vapor, precipitation rate and motion, and ozone distribution. In addition, the GOES-16 Imager includes a suite of “first light” products, including the SUVI (Severe Urban and Rural Interface), that show the characteristics of a variety of meteorological phenomena at their early stages of development.

GOES satellites are also able to detect the atmospheric conditions that lead to tornadoes, flash floods, hail storms and hurricanes. These conditions are called atmospheric “triggers.” In addition, GOES satellite data are used to monitor the amount of rainfall during thunderstorms and hurricanes for the issuing of flash flood warnings. They are also used to estimate snowfall accumulations to issue winter storm warnings and to track the movement of ice sheets and lake and sea ice cover.

The National Oceanic and Atmospheric Administration (NOAA) has a GOES Imagery Archive with a wide range of real time images from the GOES satellites. There are also a number of websites where you can access GOES imagery and information, including: