You know, after looking at the stars in a clear night sky I started to wonder about what a light year really means, trying to figure out a way to really imagine the huge distances that exist between the stars.
A light year is defined as the distance that light travels through space in a year. Simple definition, but then... How can we imagine it? How can we picture in our minds what a light year means for real? The goal is to come up with an example comparable to things that we know, using simple mathematics instead of equations...
I think that I have a pretty good illustration of a light year:
The first step is to transform the monstrous light year into a unit of measure that we are more familiar with, the kilometer- The speed of light is about 300000 kilometers per second, right? Well, in reality the speed is a little slower than that, but let's use the 300000 number to facilitate things a little.
1- One hour has 3600 seconds. So, 3600x24 is equal to 86400 seconds in a day. 86400x365 means that there are 31536000 seconds in a year.
2- The second step is to multiply 31536000 by the number of kilometers that every second represents. In this case, that will be 0.3 expressed in millions of kilometers= 9460800.
3- So, we know that a light year is approximately 9460800 millions of kilometers... The problem is that such a huge number is still nearly impossible to picture in our heads.
I have decided that the largest object that we are familiar with is our planet, Earth. The Earth has a diameter of 12756 kilometers. 12756 kilometers is 0.012756 in million kilometers. That means that it would take 741674506 Earths put together in a straight line to represent a light year.
That remains quite unimaginable... How to better represent such a colossal distance in our minds?
Imagine that you could take Earth and reduce it to the size of a glass marble, with a diameter of one centimeter. Then, you keep placing other micro-Earths one after the other, and another...
And so on, until you have a straight line of micro-Earths that stretches for over 7400 kilometers, which is about the distance from central Wyoming to London, England.
That gives me shivers, really... but at least, it's an easier way to imagine what a Light Year really means.
A light year is defined as the distance that light travels through space in a year. Simple definition, but then... How can we imagine it? How can we picture in our minds what a light year means for real? The goal is to come up with an example comparable to things that we know, using simple mathematics instead of equations...
I think that I have a pretty good illustration of a light year:
The first step is to transform the monstrous light year into a unit of measure that we are more familiar with, the kilometer- The speed of light is about 300000 kilometers per second, right? Well, in reality the speed is a little slower than that, but let's use the 300000 number to facilitate things a little.
1- One hour has 3600 seconds. So, 3600x24 is equal to 86400 seconds in a day. 86400x365 means that there are 31536000 seconds in a year.
2- The second step is to multiply 31536000 by the number of kilometers that every second represents. In this case, that will be 0.3 expressed in millions of kilometers= 9460800.
3- So, we know that a light year is approximately 9460800 millions of kilometers... The problem is that such a huge number is still nearly impossible to picture in our heads.
I have decided that the largest object that we are familiar with is our planet, Earth. The Earth has a diameter of 12756 kilometers. 12756 kilometers is 0.012756 in million kilometers. That means that it would take 741674506 Earths put together in a straight line to represent a light year.
That remains quite unimaginable... How to better represent such a colossal distance in our minds?
Imagine that you could take Earth and reduce it to the size of a glass marble, with a diameter of one centimeter. Then, you keep placing other micro-Earths one after the other, and another...
And so on, until you have a straight line of micro-Earths that stretches for over 7400 kilometers, which is about the distance from central Wyoming to London, England.
That gives me shivers, really... but at least, it's an easier way to imagine what a Light Year really means.