Lightning

Lightning is a sudden electrostatic discharge during an electrical storm between electrically charged regions of a cloud (called intra-cloud lightning or IC), between that cloud and another cloud (CC lightning), or between a cloud and the ground (CG lightning). The charged regions in the atmosphere temporarily equalize themselves through this discharge referred to as a strike if it hits an object on the ground. Although lightning is always accompanied by the sound of thunder, distant lightning may be seen but be too far away for the thunder to be heard. A lightning strike forms a visible plasma.

General considerations

On Earth, the lightning frequency is approximately 40–50 times a second or nearly 1.4 billion flashes per year and the average duration is 0.2 seconds made up from a number of much shorter flashes (strokes) of around 30 microseconds.

Many factors affect the frequency, distribution, strength and physical properties of a "typical" lightning flash in a particular region of the world. These factors include ground elevation, latitude, prevailing wind currents, relative humidity, proximity to warm and cold bodies of water, etc. To a certain degree, the ratio between IC, CC and CG lightning may also vary by season in middle latitudes. Because human beings are terrestrial and most of their possessions are on the Earth, where lightning can damage or destroy them, CG lightning is the most studied and best understood of the three types, even though IC and CC are more common types of lightning. Lightning's relative unpredictability limits a complete explanation of how or why it occurs, even after hundreds of years of scientific investigation.

Lightning (connector)

Lightning is a proprietary computer bus and power connector created by Apple Inc. to replace its previous proprietary 30-pin dock connector, and is used to connect Apple mobile devices like iPhones, iPads and iPods to host computers, external monitors, cameras, USB battery chargers and other peripherals. Using eight pins instead of thirty, Lightning is significantly more compact than the 30-pin dock connector and can be inserted with either side facing up. However, it is incompatible with cables and peripherals designed for its predecessor, unless used with an adapter. It was introduced in 2012, and as of August 2015 is used by the iPhone 5, iPhone 5C, iPhone 5S, iPhone 6/6 Plus, iPhone 6S/6S Plus, iPod Touch (5th generation), iPod Touch (6th generation), iPad (4th generation), iPad Air, iPad Air 2, iPad Pro, iPad Mini (1st generation), iPad Mini (2nd generation), iPad Mini 3, iPad Mini 4, iPod Nano (7th generation), Apple Pencil, Beats Pill+, Magic Keyboard, Magic Mouse 2, Magic Trackpad 2, the Siri Remote, and the Apple TV Remote where Siri is unavailable.

Apple

The apple tree (Malus domestica) is a deciduous tree in the rose family best known for its sweet, pomaceous fruit, the apple. It is cultivated worldwide as a fruit tree, and is the most widely grown species in the genus Malus. The tree originated in Central Asia, where its wild ancestor, Malus sieversii, is still found today. Apples have been grown for thousands of years in Asia and Europe, and were brought to North America by European colonists. Apples have religious and mythological significance in many cultures, including Norse, Greek and European Christian traditions.

Apple trees are large if grown from seed, but small if grafted onto roots (rootstock). There are more than 7,500 known cultivars of apples, resulting in a range of desired characteristics. Different cultivars are bred for various tastes and uses, including cooking, eating raw and cider production. Apples are generally propagated by grafting, although wild apples grow readily from seed. Trees and fruit are prone to a number of fungal, bacterial and pest problems, which can be controlled by a number of organic and non-organic means. In 2010, the fruit's genome was decoded as part of research on disease control and selective breeding in apple production.

Webcam

A webcam is a video camera that feeds or streams its image in real time to or through a computer to computer network. When "captured" by the computer, the video stream may be saved, viewed or sent on to other networks via systems such as the internet, and email as an attachment. When sent to a remote location, the video stream may be saved, viewed or on sent there. Unlike an IP camera (which connects using Ethernet or Wi-Fi), a webcam is generally connected by a USB cable, or similar cable, or built into computer hardware, such as laptops.

The term 'webcam' (a clipped compound) may also be used in its original sense of a video camera connected to the Web continuously for an indefinite time, rather than for a particular session, generally supplying a view for anyone who visits its web page over the Internet. Some of them, for example, those used as online traffic cameras, are expensive, rugged professional video cameras.

Characteristics

Webcams are known for their low manufacturing cost and their high flexibility, making them the lowest cost form of videotelephony. Despite the low cost, the resolution offered at present (2015) is rather impressive, with low end webcams offering resolutions of 320x240, medium webcams offering 640x480 resolution, and high-end webcams offering 1280x720 (aka 720p) or even 1920x1080 (aka 1080p) resolution.

Secure Digital

Secure Digital (SD) is a non-volatile memory card format developed by the SD Card Association (SDA) for use in portable devices. The standard was introduced in August 1999 as an improvement over MultiMediaCards (MMC), and has become the de facto industry standard.

Secure Digital includes four card families available in three different form factors. The four families are the original Standard-Capacity (SDSC), the High-Capacity (SDHC), the eXtended-Capacity (SDXC), and the SDIO, which combines input/output functions with data storage. The three form factors are the original size, the mini size, and the micro size. Electrically passive adapters allow a smaller card to fit and function in a device built for a larger card.

There are many combinations of form factors and device families, although as of 2013, the prevailing formats are full- or micro-size SDHC and full or micro SDXC.

The SDA uses several trademarked logos to enforce compliance with its specifications and assure users of compatibility.