Gas dioxide, and air expand to the same extent over the same 80 kelvin interval. He noted that, for an ideal gas at constant pressure, the volume is directly proportional to its temperature: In 1802, Joseph Louis Gay-Lussac published results of similar, though more extensive experiments. Gay-Lussac credited Charles' earlier work by naming the law in his honor. Gay-Lussac himself is credited with the law describing pressure, which he found in 1809. It states that the pressure exerted on a container's sides by an ideal gas is proportional to its temperature. In 1811, Amedeo Avogadro verified that equal volumes of pure
Same-sex marriage in the United States Same-sex marriage in the United States Same-sex marriage in the United States expanded from one state in 2004 to all fifty states in 2015 through various state court rulings, state legislation, direct popular votes, and federal court rulings. Same-sex marriage is also referred to as gay marriage, while the political status in which the marriages of same-sex couples and the marriages of opposite-sex couples are recognized as equal by the law is referred to as marriage equality. The fifty states each have separate marriage laws, which must adhere to rulings by the Supreme Court of the United States that recognize