2430 A.D. is a science fiction short story by Isaac Asimov. It first appeared in the October 1970 issue of Think, the IBM house magazine, and was reprinted in Asimov's 1975 collection Buy Jupiter and Other Stories.

Early in 1970 the author was commissioned by Think to write a story based on a quotation by writer and social commentator J. B. Priestley:

Asimov, assuming that Think wanted a story that illustrated Priestley's quotation, crafted 2430 A.D. He selected the date because he calculated that at the then-current rate of human population growth, doubling every thirty-five years, that would be the year when the world's animal biomass would consist entirely of human beings. Asimov wrote the story on April 26, 1970 but it was rejected as Think had actually wanted a story that refuted the quotation. ("Well, they never said so," Asimov remarked later.) After Asimov wrote a second story that did refute the quotation, Think took the first story after all and published it in their October 1970 issue. The second story was later published in Analog magazine as The Greatest Asset. Both stories inspired by the Priestley quote were included in the 1975 collection Buy Jupiter and Other Stories.

Year 1500 (MD) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar.

The year was seen as being especially important by many Christians in Europe, who thought it would bring the beginning of the end of the world. Their belief was based on the phrase "half-time after the time", when the apocalypse was due to occur, which appears in the Book of Revelation and was seen as referring to 1500.

Events

January–June

July–December

Year 500 (D) was a leap year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Patricius and Hypatius (or, less frequently, year 1253 Ab urbe condita). The denomination 500 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Events

By place

Byzantine Empire

Britannia

An analog-to-digital converter (ADC, A/D, or A to D) is a device that converts a continuous physical quantity (usually voltage) to a digital number that represents the quantity's amplitude.

The conversion involves quantization of the input, so it necessarily introduces a small amount of error. Furthermore, instead of continuously performing the conversion, an ADC does the conversion periodically, sampling the input. The result is a sequence of digital values that have been converted from a continuous-time and continuous-amplitude analog signal to a discrete-time and discrete-amplitude digital signal.