Light Years: Subjectivity and Distance Measurement

In summary: But there is no relation to visibility.In summary, light years are a unit of measurement for distance based on the speed of light, which is a constant. It has nothing to do with visibility. There are several methods used to measure distances in space, but none of them rely on visibility as an indicator.
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neugie92
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Light years-I just don't understand how something as subjective as visibilty, is used as a major indicator of distance. Isnt that subjective. What if some species had a million times the eye power than us humans, wouldn't they view the distance of let's say stars very differently because it wouldn't be as many 'light years' away from them.

Maybe I'm confused about how light years are actually measured, it just seems like using somethings visiblity to us, is a poor way to try to figure out actual distance.

Thoughts?
 
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  • #2


A light year is the distance that light travels in a year. It has nothing to do with visibility.
 
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mathman said:
A light year is the distance that light travels in a year. It has nothing to do with visibility.

but to meaure the distance traveled we base it on an increase or decrease in visibility? am I wrong?
 
  • #5


There is no relation to visibility.

A light year is the distance light travels in one year. As the speed of light in vacuum is constant, this length is constant, too. It does not matter how good some eyes are.Edit: Looks like two topics got merged, as I posted the other replys were not in the thread.
 
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neugie92 said:
but to meaure the distance traveled we base it on an increase or decrease in visibility? am I wrong?

Yes, you are wrong. I can turn on a laser beam and bounce it off of a mirror at a known distance from me to measure the speed of light. Then, knowing this speed, I just multiply it out and the resulting distance is 1 light-year. It has nothing to do with visibility. The laser could be a bazillion watts or 1 microwatt, it does not matter as that does not affect the speed of the beam.

Maybe you are confused over how we measure the distance to objects in space. There are a variety of methods, and Jimmy's links go over some of them.
 

1. What is a light year?

A light year is a unit of measurement used to represent distance in space. It is the distance that light travels in one year, which is approximately 9.46 trillion kilometers or 5.88 trillion miles.

2. How is a light year used to measure distance in space?

In astronomy, distances between celestial objects are often too large to be measured in kilometers or miles. Therefore, scientists use light years as a unit of measurement to represent these vast distances. For example, the distance between the Earth and the nearest star, Proxima Centauri, is about 4.2 light years.

3. Why is the concept of light years important in space exploration?

Light years allow scientists to understand the vastness of the universe and the distances between celestial objects. It helps in determining the positions and movements of these objects, as well as calculating the time it takes for light to reach us from distant stars and galaxies.

4. How does subjectivity play a role in the measurement of light years?

Subjectivity refers to the perspective and interpretation of an individual. In the context of light years, subjectivity can affect the accuracy of distance measurements in space. Different scientists may have different methods and techniques for measuring distances, leading to variations in calculated light years.

5. Can light years be used to measure the distance between objects within our own solar system?

No, light years are typically used for measuring interstellar distances, which are much larger than distances within our solar system. For example, the distance between the Earth and the Sun is about 8 light minutes, while the distance between the Earth and Pluto is about 5.5 light hours.

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