What will be the time taken to cover one lightyear? If we were able to go to outer space how much time will take to reach the nearest galaxy Proxima Centauri?
Stars other than our sun are so far distant that astronomers speak of their distances not in terms of kilometers or miles – but in light-years. Light is the fastest-moving stuff in the universe. If we simply express light-years as miles and kilometers, we end up with impossibly huge numbers.
One Astronomical Unit, or AU, equals about 93 million miles (150 million km). Robert Burnham noticed that, quite by coincidence, the number of astronomical units in one light-year and the number of inches in one mile is virtually the same.
For general reference, there are 63,000 astronomical units in one light-year, and 63,000 inches (160,000 cm) in one mile (1.6 km).
This wonderful coincidence enables us to bring the light-year down to Earth. If we scale the astronomical unit – the Earth-sun distance – at one inch, then the light-year on this scale represents one mile (1.6 km).
The closest star to Earth, other than the sun, is Alpha Centauri at some 4.4 light-years away. Scaling the Earth-sun distance at one-inch places this star at 4.4 miles (7 km) distant.
Stars other than our sun are so far distant that astronomers speak of their distances not in terms of kilometers or miles – but in light-years. Light is the fastest-moving stuff in the universe. If we simply express light-years as miles and kilometers, we end up with impossibly huge numbers.
One Astronomical Unit, or AU, equals about 93 million miles (150 million km). Robert Burnham noticed that, quite by coincidence, the number of astronomical units in one light-year and the number of inches in one mile is virtually the same.
For general reference, there are 63,000 astronomical units in one light-year, and 63,000 inches (160,000 cm) in one mile (1.6 km).
This wonderful coincidence enables us to bring the light-year down to Earth. If we scale the astronomical unit – the Earth-sun distance – at one inch, then the light-year on this scale represents one mile (1.6 km).
The closest star to Earth, other than the sun, is Alpha Centauri at some 4.4 light-years away. Scaling the Earth-sun distance at one-inch places this star at 4.4 miles (7 km) distant.
