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A smartphone is a mobile phone with an advanced mobile operating system which combines features of a personal computer operating system with other features useful for mobile or handheld use. [1] [2] [3] Smartphones, which are usually pocket-sized, typically combine the features of a cell phone, such as the abilities to place and receive voice calls and create and receive text messages, with those of other popular digital mobile devices like personal digital assistants (PDAs) , such as an event calendar, media player, video games, GPS navigation, digital camera and digital video camera. Most smartphones can access the Internet and can run a variety of third-party software components ( “apps”). They typically have a color display with a graphical user interface that covers 70% or more of the front surface. The display is often a touchscreen, which enables the user to use a virtual keyboard to type words and numbers and press the onscreen icons to activate the “app” features.

In 1999, the Japanese firm NTT DoCoMo released the first smartphones to achieve mass adoption within the country. [4] Smartphones became widespread in the 21st century. Most of those produced from 2012 onward have high-speed mobile broadband 4G LTE, motion sensors, and mobile payment features. In the third quarter of 2012, one billion smartphones were in use worldwide. [5] Global smartphone sales surpassed the sales figures for regular cell phones in early 2013. [6] As of 2013, 65% of U.S. mobile consumers own smartphones. [7] By January 2016, smartphones held over 79% of the U.S. mobile market
Devices that combined telephony and computing were first conceptualized by Nikola Tesla in 1909 and Theodore Paraskevakos in 1971 and patented in 1974, and were offered for sale beginning in 1993. Paraskevakos was the first to introduce the concepts of intelligence, data processing and visual display screens into telephones. In 1971, while he was working with Boeing in Huntsville, Paraskevakos demonstrated a transmitter and receiver that provided additional ways to communicate with remote equipment, however it did not yet have a general purpose PDA applications and a wireless device typical of smartphones. They were installed at Peoples’ Telephone Company in Leesburg, Alabama and were demonstrated to several telephone companies. The original and historic working models are still in the possession of Paraskevakos.

The first mobile phone to incorporate PDA features was an IBM prototype developed in 1992 and demonstrated that year at the COMDEX computer industry trade show. It included PDA features and other visionary mobile applications such as maps, stock reports and news. A refined version was marketed to consumers in 1994 by BellSouth under the name Simon Personal Communicator. The Simon was the first commercially available device that can be properly referred to as a “smartphone,” although it was not called that in 1994. [11] [12] [13] In addition to placing and receiving cellular calls, Simon could send and receive faxes and emails and included an address book, calendar, appointment scheduler, calculator, world time clock and notepad, utilizing its touch screen display. [14] The term “smart phone” appeared in print in 1995, describing AT & T’s PhoneWriter Communicator.

In the late 1990s, many mobile phone users carried a separate dedicated PDA device, running early versions of operating systems such as Palm OS, Blackberry OS or Windows CE / Pocket PC. [1] These operating systems would later evolve into mobile operating systems. In March 1996, Hewlett-Packard released the OmniG 700LX, 200LX and modified PDA that supported the Nokia 2110-compatible phone with ROM-based software to support it. It had a 640×200 resolution CGA compatible 4-shade gray-scale LCD screen and could be used to place and receive calls, and to create and receive text messages, emails and faxes. It was also 100% DOS 5.0 compatible, allowing it to run thousands of existing software titles, including early versions of Windows.

In September 1996, Nokia released the Nokia 9000 Communicator, a digital cellular phone based on the Nokia 2110 with an integrated PDA based on the GEOS V3.0 operating system from GeoWorks. The two components were attached by a hinge in what became known as a clamshell design, with the above display and a physical QWERTY keyboard below. The PDA provided e-mail; calendar, address book, calculator and notebook applications; text-based Web browsing; and could send and receive faxes. When closed, the device could be used as a digital cellular phone. In June 1999 Qualcomm released the “PDQ Smartphone”, a CDMA digital PCS Smartphone with an integrated Palm PDA and Internet connectivity. [16]

Subsequent landmark devices included:

The Ericsson R380 (2000) by Sony Ericsson Mobile Communications. [17] The first device marketed as a “smartphone”, [18] it combined the functions of a mobile phone and PDA, and supported limited web browsing with a resistive touchscreen utilizing a stylus. [19]
The Kyocera 6035 (early 2001), introduced by Palm, Inc. Combining a PDA with a mobile phone, it operated on the Verizon network, and supported limited web browsing. [20] [21]
Handspring’s Treo 180 (2002), the first smartphone to combine the Palm OS and a GSM phone with telephony, text messaging and Internet access fully integrated into the OS. [22]

Smartphones before present-day Android-, iOS- and BlackBerry-based phones typically used the Symbian operating system. Originally developed by Psion, it was the world’s most widely used smartphone operating system until the last quarter of 2010

Much of the Venusian surface appears to have been shaped by volcanic activity. Venus has several times as many volcanoes as Earth, and it has 167 large volcanoes that are over 100 km across. The only volcanic complex of this size on Earth is the Big Island of Hawaii.[30]:154 This is not because Venus is more volcanically active than Earth, but because its crust is older. Earth’s oceanic crust is continually recycled by subduction at the boundaries of tectonic plates, and has an average age of about 100 million years,[36] whereas the Venusian surface is estimated to be 300–600 million years old.[28][30]

Several lines of evidence point to ongoing volcanic activity on Venus. During the Soviet Venera program, the Venera 9 orbiter obtained spectroscopic evidence of lightning on Venus,[37] and the Venera 12 descent probe obtained additional evidence of lightning and thunder.[38][39] The European Space Agency’s Venus Express in 2007 detected whistler waves further confirming the occurrence of lightning on Venus.[40][41] Although rainfall drives thunderstorms on Earth, there is no rainfall on the surface of Venus (though sulfuric acid rain falls in the upper atmosphere, then evaporates around 25 km above the surface). One possibility is that ash from a volcanic eruption was generating the lightning. Another piece of evidence comes from measurements of sulfur dioxide concentrations in the atmosphere, which dropped by a factor of 10 between 1978 and 1986, jumped in 2006, and again declined 10-fold.[42] This may mean that levels had been boosted several times by large volcanic eruptions.[43][44]

In 2008 and 2009, the first direct evidence for ongoing volcanism was observed by Venus Express, in the form of four transient localized infrared hot spots within the rift zone Ganis Chasma,[45][n 1] near the shield volcano Maat Mons. Three of the spots were observed in more than one successive orbit. These spots are thought to represent lava freshly released by volcanic eruptions.[46][47] The actual temperatures are not known, because the size of the hot spots could not be measured, but are likely to have been in the 800–1100 K range, relative to a normal temperature of 740 K.

Almost a thousand impact craters on Venus are evenly distributed across its surface. On other cratered bodies, such as Earth and the Moon, craters show a range of states of degradation. On the Moon, degradation is caused by subsequent impacts, whereas on Earth it is caused by wind and rain erosion. On Venus, about 85% of the craters are in pristine condition. The number of craters, together with their well-preserved condition, indicates the planet underwent a global resurfacing event about 300–600 million years ago,[28][29] followed by a decay in volcanism.[49] Whereas Earth’s crust is in continuous motion, Venus is thought to be unable to sustain such a process. Without plate tectonics to dissipate heat from its mantle, Venus instead undergoes a cyclical process in which mantle temperatures rise until they reach a critical level that weakens the crust. Then, over a period of about 100 million years, subduction occurs on an enormous scale, completely recycling the crust.[30]

Venusian craters range from 3 km to 280 km in diameter. No craters are smaller than 3 km, because of the effects of the dense atmosphere on incoming objects. Objects with less than a certain kinetic energy are slowed down so much by the atmosphere that they do not create an impact crater.[50] Incoming projectiles less than 50 metres in diameter will fragment and burn up in the atmosphere before reaching the ground.
Without seismic data or knowledge of its moment of inertia, little direct information is available about the internal structure and geochemistry of Venus.[52] The similarity in size and density between Venus and Earth suggests they share a similar internal structure: a core, mantle, and crust. Like that of Earth, the Venusian core is at least partially liquid because the two planets have been cooling at about the same rate.[53] The slightly smaller size of Venus means pressures are 24% lower in its deep interior than Earth’s.[54] The principal difference between the two planets is the lack of evidence for plate tectonics on Venus, possibly because its crust is too strong to subduct without water to make it less viscous. This results in reduced heat loss from the planet, preventing it from cooling and providing a likely explanation for its lack of an internally generated magnetic field.[55] Instead, Venus may lose its internal heat in periodic major resurfacing events

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