Speed of light they appeared 13 billion years ago, when the universe was less than a billion years old. The fact that more distant objects appear to be younger, due to the finite speed of light, allows astronomers to infer the evolution of stars, of galaxies, and of the universe itself. Astronomical distances are sometimes expressed in light-years, especially in popular science publications and media. A light-year is the distance light travels in one year, around 9461 billion kilometres, 5879 billion miles, or 0.3066 parsecs. In round figures, a light year is nearly 10 trillion kilometres or nearly 6 trillion miles. Proxima Centauri,
Lotus 1-2-3 cartridges but otherwise identical. By early 1984 the software was a killer app for the IBM PC and compatibles, while hurting sales of computers that could not run it. "They're looking for 1-2-3. Boy, are they looking for 1-2-3!" "InfoWorld" wrote. Noting that computer purchasers did not want PC compatibility as much as compatibility with certain PC software, the magazine suggested "let's tell it like it is. Let's not say 'PC compatible,' or even 'MS-DOS compatible.' Instead, let's say '1-2-3 compatible.'" PC clones' advertising did often prominently state that they were compatible with 1-2-3. An Apple II software company promised