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[[Image:Roger_Federer.jpg|thumb|left|{{#ifexist:Template:Roger Federer.jpg/credit|{{Roger Federer.jpg/credit}}<br/>|}}Roger Federer, a professional tennis player, hitting a forehand against James Blake in the quarterfinals of the 2006 U.S. Open.]]
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<small>
'''Tennis''' is a sport played between either two players ("singles") or two teams of two players ("doubles"). Players use a stringed racquet to strike a hollow rubber ball covered with felt over a net into the opponent's court. In some places tennis is still called '''lawn tennis''' to distinguish it from ''real tennis'' (also known as ''royal tennis'' or ''court tennis''), an older form of the game that originated in France in the Middle Ages and is played indoors on a very different court. Originating in England in the late nineteenth century, lawn tennis first spread throughout the English-speaking world, particularly among the upper classes. Today tennis is an Olympic sport that is played at all levels of society, by all ages, and in many countries around the world.  Except for the adoption of the tie-breaker in the 1970s, its rules have remained remarkably unchanged since the 1890s.  Millions of people also follow tennis as a spectator sport, especially the four Grand Slam tournaments.
==Footnotes==
 
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===Manner of play===
</small>
====The court====
Tennis is played on a rectangular, flat surface that can be composed of various materials.  The court is 78 feet (23.77 meters) long and its width is 27 feet (8.23 m) for singles matches and 36 feet (10.97 m) for doubles matches. Additional clear space around the court is required in order for players to reach balls. A net is stretched across the full width of the court, parallel with the baselines, dividing it into two equal areas. The net is 3 feet 6 inches (1.07 m) high at the posts and 3 feet (914 mm) high in the center.
 
=====''The lines''=====
The two lines that delineate the width of the court are called the baseline.  The short mark in the center of each baseline is referred to as either the hash mark or the center mark.  The outermost lines that make up the length are both called the doubles sideline.  These are the boundaries used when doubles is being played.  The area between the doubles sideline and the lines next to them is called the doubles alley, which is considered to be "out" in singles play.  These lines next to the doubles sideline are the singles sidelines, and are used as boundaries in singles play.  The line that runs across the center of a player's side of the court is called the service line; despite its name this is not where a player legally stands when making a serve.  The line dividing the service line in two is called the center line or center service line.  The boxes that this center line creates are called the service boxes; depending on a player's position, they will have to hit the ball into one of these when serving.

Latest revision as of 10:19, 11 September 2020

Categories of smart home devices shown on Amazon's website in April 2023.

The phrase smart home refers to home automation devices that have internet access. Home automation, a broader category, includes any device that can be monitored or controlled via wireless radio signals, not just those having internet access. Whether the device is powered by the electrical grid or by battery, if it uses the home Wi-Fi network and if an internet logon needs to be created to use it, then it is smart home technology.

Collectively, all the smart home devices on every home's Wi-Fi network helps to make up what is called the Internet of Things (IoT), a huge sea of sensors and control devices across the world that are capable of being accessed from afar via the internet. One of the key reasons such devices need internet access is so that the manufacturer can periodically download updated firmware to the device to keep it up-to-date. However, being available via the internet also means that such devices are, potentially, available for spying or hacking. Today, homes may contain dozens or even hundreds of such devices, and consumers may enjoy their benefits while knowing little about how they work, or even realizing that they are present.

Not all home automation is "smart"

Many remotely controllable devices do not require internet access. They may instead have physical control devices that use either RF (“Radio Frequency”) or IR (“Infrared”) beams, two different kinds of energy used in remote controls to communicate commands. Non-"smart" home automation may also present security risks, because the control signals can be hijacked by bad actors with the right signaling equipment. Garage door openers are of particular note in this regard. Modern automobiles, in fact, are full of automation similar to home automation, and cars are hackable by bad actors in a number of ways. See Wikipedia's Automotive hacking article for more information.

Incompatibility hassles

At present, consumers must make sure that the smart device they wish to use is specified to be compatible whichever phone/tablet operating system they use (Apple vs. Android). Since smart home products emerged in the absence of any standard, a morass of competing methods for networking, control and monitoring now exist. For some products, consumers may need to buy an expensive hub, or bridge, a device that is specific to one vendor. Products made by different manufacturers but performing the same function are typically not interoperable. Consumers often need to open a different app on their smartphone or tablet in order to control devices by each manufacturer. This may make it too expensive and awkward to try out competing devices, leaving consumers stuck with the product they bought originally or else having to add yet more apps to their phones.

Security concerns

Security for smart home products has been uneven and sometimes seriously inadequate. Smart thermostats which can monitor whether a home's occupants are present or not, entry-way locks, robotic vacuums that work with a map of the house, and other smart home devices can present very real dangers if hackers can access their data.

Matter, an emerging standard

Matter is emerging standard in 2023 intended to increase security, reliability and inter-operability of smart-home devices. About ten years ago, industry consortiums formed to work on standards for smart home device communications, and their underlying wireless communications, which would make it possible for products from all vendors to work together seamlessly and provide fast performance, privacy, and security and would work even if there is not connection to the outside internet (i.e., no connection to "the cloud" or to servers).

Footnotes