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,
USS PC-823 York, ROKN’s first ocean-going naval vessel, Baek-du-san (PC-701) was born. Sailing from New York, a 3-inch main deck gun was attached at the Hawaii Naval Station, and 100 shells were purchased at Guam. PC-701 finally arrived at Jinhae Naval Base, South Korea, on 10 April 1950, barely two months before the June 1950 outbreak of the Korean War. With only 100 rounds ammunition, the sailors could only practice aiming the main gun, not firing it. On the night of 25/26 June 1950, on the South Korean eastern coast, she patrolled against infiltrators from the north. About twenty miles from the