What is a Light Year? A question many ask as they ponder what the future may hold for mankind and the exploration of space. The question may also be asked of those who are interested in technology and exploration and those who are interested in studying how our solar system and galaxy are formed and developed.
The answer to the question ‘what is a light year?’ is quite simple and it is a measurement of the rotational speed of the earth relative to the sun as it revolves around the sun at a particular angle. The light-hour is a unit of time equivalent to the amount of light emitted per minute and is usually expressed as Lumpy (Lumpy – hour) where L is the meridian passing through the Earth and H the earth’s radius from the Sun at the time of the brightest light at the equator. As defined by the International Astronomical Union a light year is the distance light travels in a year in vacuum at uniform velocity.
The other question that arises is ‘What is a Light Year in other words where do I find out what the distance between the Earth and the Sun is’. This too is an easy question to answer as the amount of light received on earth at any given moment is directly proportional to the distance from the Earth to the Sun. So we easily see then, that the Earth and the Sun are in orbit about the center of the solar system and this orbit is not affected by the Earth’s mass.
To complicate things further still there is another factor to consider, which is slightly more complex than the motion of the earth around the sun and that is the fact that the light received from stars is not constant as it varies with time and place. This light then passes through the atmosphere of varying temperatures, which slightly affects the intensity as well as the wavelength. Finally there are atmospheric gases which affect the light passing through and cause a red light while the green light is produced by ozone. In short, light emitted by heavenly bodies such as the sun, helps us learn about the solar system and the nature of space travel.
A ‘light year’ is a measure of time and distance traveled by light. It is comparable to measuring the length of a football, but instead of being a number like the football it is an actual measurement of the distance the light has gone. Any good reference book on space travel or astronomy will have a table of contents with the distances traveled by various celestial bodies listed in ascending or descending order. This information is used to determine a “light year” of the solar system and the terrestrial, solar system.
If you were interested in determining the age of the Earth, you would need to know how many light years (light years is units of time and distance) have passed since the Earth was created and its age. How do you get this amount of time and distance? You use a formula for calculating light years using the known age of the Earth as a baseline. Then multiply the unknown years by the current age of the Earth and you get the number of light years. That number is then divided by the period of time it takes for the planet to make one complete orbit. This tells you the number of years it takes for the light from the star to reach our planet.
Using this information we can figure out how old the Earth is, and how long ago it was created and became habitable. Knowing this information is important in understanding the formation of the Solar System, the evolution of life on Earth, and the likelihood of life elsewhere in the Universe. We can also estimate the number of planets that are likely to have life in the next few million years or so. That is all provided by our current understanding of the processes that go on in deep space and the great galaxy.
If you are asking what is a light year, the answer may surprise you. It is not a simple calculation. In fact, it is probably more complicated than you think. But, with some hard work, you can learn enough about the process to be able to answer the question for yourself. The math involved may be difficult, but it is definitely worth your while.