how is light years measured? what is the process?

Answer 1

It isn't measured, it is calculated. The speed of light in miles per second is multiplied by the number of seconds in a year to get the length of a light year in miles.

Measuring the speed of light can be done in many ways, and is not as hard to do as it was before electronics were invented. Early methods relied on flashes of light from rotating mirrors miles apart. Today laser pulses are timed very accurately with electronics over short distances. Also, amazingly, Maxwell's equations calculate the speed of light theoretically from a number of other unrelated electric and magnetic measurements.

Measuring the distance to remote stars is another topic, but the results are usually expressed in light years because the numbers are just inconveniently large when expressed in miles.

Answer 2

I guess what you're asking is: How are the distances of remote objects from the earth, the light years, actually measured, especially those millions of light years away? Am I right? I want to know, too.

The following link may help. Good luck!

Answer 3

I would like to correct the previous responder. A light year is a unit of astronomical distance. It is the distance light will travel in the period of a solar year (approximately 365 and a quarter days). If one does the math (the speed of light being about 186,000 miles per second!), this works out to nearly 6 trillion statute miles!! The nearest known star from the Earth is 4.22 light years away. In other words, when you look at that star, what you see is light that started its journey to your eyes 4.22 years ago. Its facsinating to realize that when we look at the night sky, what we see in many cases is light that originated from these stellar sources in times that humans had not even existed on Earth. You are looking at a "pre-historic" light! I am always awe struck by that thought....

Answer 4

One light year is the distance light travels in one earth calendar year.

One light year is 186,000 miles per second (speed of light) times the number of seconds in a year 365 days X 24 hours X 60 min. X 60 sec = 31,536,000 seconds X 186,000 = 6,010,296,000,000 or nine (6) trillion 10 billion, 296 million miles.

Answer 5

A light year is the distance light travels in a year.

The process is simple and fun. You start with the speed of light, and go from there. I will start it, and you can finish it ...

1) The Speed of Light is 186,000 miles/second.
2) The means in one second, light travels 186,000 miles.
3) ... in two seconds, light travels 372,000 miles.
4) ... in three seconds, light travels 558,000 miles.
5) ... in six seconds, light travels 1,116,000 miles.
6) ... in sixty seconds, light travels 11,160,000 miles.
7) ... in one minute, light travels 11,160,000 miles ...

now, you continue on out to six minutes, then sixty minutes, then one hour, then 24 hours, then one day, then 365 days ... and arrive at ONE YEAR.

That's the process, and soon you'll know the distance.

As a bonus question, did you know that light "also" travels 300 million meters per second? (meters and miles are different measuring system). That comes out to 3.0 x 10^8 meters per second. How far does light travel, measured in meters, in one year?

Best ...

Answer 6

One light year is how far light can travel in one year. The light year was long ago adopted by all astronomers as a kind of short hand. Astronomers have to deal with extremely long distances, and it's much easier to write "1 light year" than it is to write that same distance in miles -- 5,878,499,810,000 miles. One light year = 5,878,499,810,000 miles.

Answer 7

there is an intrument called sextant thru which by measuring the angle of elevation of the star(with the help of the angle of the shadow it makes) during different instances of time u can calculate it's distance using simple trignometrical mathematics ........this is the process to measure the distance ......now to convert this distance to light years...u may use the definition mentioned above by the others........

Answer 8

A light year is the distance equal to the speed of light (182,000 miles per second) times the number of seconds in a year (31,536,000). This comes out to be 5,739,552,000,000 miles.

Answer 9

A light year is the time a ray of light travels to a distant place in space.

Answer 10

We got a really long tape measure one day, superglued it to a photon, and then let the photon go. And boy did it go! Anyway, a year later (Aug 18, 1983), we snipped off the end of the tape measure, and voila! we knew just how far that photon had travelled in one year.