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,
Financial cost of the Iraq War book "The Three Trillion Dollar War" and possibly more in the most recent published study, published in March 2008. Stiglitz has stated: "The figure we arrive at is more than $3 trillion. Our calculations are based on conservative assumptions...Needless to say, this number represents the cost only to the United States. It does not reflect the enormous cost to the rest of the world, or to Iraq." A 2013 updated study pointed out that U.S. medical and disability claims for veterans after a decade of war had risen to $134.7 billion from $33 billion two years earlier. The extended combat