National Maximum Speed Law for the 55 mph speed limit offered, "Speed limit 55. It's not just a good idea. It's the law.". Intelligentsia riffed that with a more absolute statement based on the speed of light: "186,000 miles per second. It's not just a good idea, it's the law." National Maximum Speed Law The National Maximum Speed Law (NMSL) in the United States was a provision of the Federal 1974 Emergency Highway Energy Conservation Act that prohibited speed limits higher than . It was drafted in response to oil price spikes and supply disruptions during the 1973 oil crisis. While Federal officials hoped
Rømer's determination of the speed of light This anonymous report was translated into English and published in "Philosophical Transactions of the Royal Society" in London on 25 July 1677. Rømer starts with an order of magnitude demonstration that the speed of light must be so great that it takes much less than one second to travel a distance equal to Earth's diameter. The point L on the diagram represents the second quadrature of Jupiter, when the angle between Jupiter and the Sun (as seen from Earth) is 90°. Rømer assumes that an observer could see an emergence of Io at the second quadrature (L), and the emergence