Article I, Section 8, of the Constitution, which enumerates the powers of Congress and provides Congress with the authority to make all laws necessary and proper to carry them out; also referred to as the elastic clause.
There is an exact numerical answer to this question. By definition, 1 light year is exactly 9,460,730,472,580,800 meters. By definition, 1 mile is exactly 1,609.344 meters. So, 1 light year is exactly 5,878,625,373,183 and 849/1397 miles, by definition.
One light-year is equal to: 1  exactly 9,460,730,472,580.8 km (about 9.5 Pm). 2  about 5,878,625,373,183.6 miles (about 6 trillion miles). 3  about 63,241.1 astronomical units. 4  about 0.306595 parsecs. 5  exactly 31,557,600 light-seconds.