What is a light year?
Light year is the distance that light travels in one year of vacuum or empty space. However, light is a vacuum for just over 186 282 miles (299,792 km) per second, which achieves a stunning 5.8 trillion miles (9.4 trillion km) in one year. With such large distances, relative terms such as "miles" and "kilometers" become inefficient and insignificant. Instead, astronomers speak in terms of light years to describe long distances.
Before we can appreciate speaking of light years, it helps to understand how far one light year is spreading. As for our own solar system, defined for this exercise in the orbit of the former Pluto planet, the solar system would have to be 800 times larger to be the only light year. In other words, the sun is about 93 million miles from Earth, and one would have to record 31,620 round trips from the ground to the sun to travel over the distances of the light year.
In addition to the light year, scientists tIf they speak in the therms of light seconds and light minutes. One astronomical unit (AU) - distance from ground to sun - is 8.3 light minutes. In other words, it takes 8.3 minutes to light the sun on the ground. On the contrary, the sun is 8.3 light minutes from the ground.
There is no star to lie exactly one light year from our solar system. The nearest neighboring star is Proxima Centauri at a distance of 4.2 light. Another is the double star of Alpha Centauri A and Alpha Centauri B, 4.3 light -years from here.
knowing how fast light travels can begin to appreciate the great distances of the universe when they speak in terms of light years. For example, Alpha Centauri will take 4.2 years to get to the ground, so when we observe this star, we see it as it was 4.2 years ago. We basically look back in time when we look into space.
In addition to the light year is anotherThe astronomical unit of measurement parsec , covering 3,26 light -years. Star Trek fans undoubtedly remember countless mention of habitable planets, enemy ships or the much needed port "in the next Parsek" or "several parsecs".