Debate about how a light year can be used

In summary: The distance is solely a measurement of distance. The two cannot be used interchangeably. Therefore, you cannot say that the star will die after 50 million Earth years based on its distance of 50 million light years. In summary, distance and time are not interchangeable and therefore, it is incorrect to use a unit of distance, such as light years, as a unit of time.
  • #1
Harshu Pande
3
0
If I say that a star will die after 50 million light years, can I also say that that after 50 million EARTH years, the star will die

BECAUSE DISTANCE AND TIME ARE
INTER-CHANGABLE (if a airplane travels from point A to point B and the distance is 200 miles, I can also say that the distance is 2 plane hours, which is a unit of time)
 
Astronomy news on Phys.org
  • #3
Harshu Pande said:
If I say that a star will die after 50 million light years
Then you would be saying that the star will die after approximately 2.5E19 miles, which of course is just silly.
 
  • Like
Likes Harshu Pande and russ_watters
  • #4
phinds said:
Then you would be saying that the star will die after approximately 2.5E19 miles, which of course is just silly.
Phinds, so basically you are saying that light year cannot be used as a unit of time right?
 
  • #5
Harshu Pande said:
Phinds, so basically you are saying that light year cannot be used as a unit of time right?
right

because the statement you made in your first post

Harshu Pande said:
BECAUSE DISTANCE AND TIME ARE
INTER-CHANGABLE

is not correct
 
  • Like
Likes Harshu Pande
  • #6
A light year is an explicit way to make a length corresponding to a time. It doesn’t make sense to use that as a time unit again. Just say year.
 
  • Like
Likes ohwilleke and Harshu Pande
  • #7
HP, I would suggest that you consider the problem (as you stated it) in reverse.

What is the distance a photon travels in an Earth Year?
 
  • Like
Likes Harshu Pande
  • #8
r8chard said:
...What is the distance a photon travels in an Earth Year?

Depends on what the photon bounces off of. Also could be effected by the curvature. For instance in the LIGO apparatus the beam generates photons at the same time but occasionally they do not arrive in the detector at the same time.
 
  • Like
Likes Harshu Pande
  • #9
All right guys I got the answer I needed! thank you so much for all of your feedback!
 
  • #10
Harshu Pande said:
If I say that a star will die after 50 million light years, can I also say that that after 50 million EARTH years, the star will die

BECAUSE DISTANCE AND TIME ARE
INTER-CHANGABLE (if a airplane travels from point A to point B and the distance is 200 miles, I can also say that the distance is 2 plane hours, which is a unit of time)

A light year is a unit of distance not a unit of time.
Distance and time are not interchangeable.
If a plane travels 200 miles in 2 hours that means it was traveling 100 mph. Calling it a distance of 2 plane hours is only relevant if the plane is going 100 mph. If the plane were going 200 mph then it's distance would change to 1 plane hour which makes no sense.

We only use the term light year because the speed of light is the universal speed limit and it never changes in the same medium. And saying a distance of 1 light year is much easier than saying a distance of 5,880,000,000,000 miles.
 
  • #11
Harshu Pande said:
If I say that a star will die after 50 million light years, can I also say that that after 50 million EARTH years, the star will die

BECAUSE DISTANCE AND TIME ARE
INTER-CHANGABLE (if a airplane travels from point A to point B and the distance is 200 miles, I can also say that the distance is 2 plane hours, which is a unit of time)

They are not interchangeable. The 2 hours is measurement of velocity and time.
 

1. What is a light year and how is it used in debates?

A light year is a unit of measurement that is used to measure astronomical distances. It is the distance that light travels in one year, which is equivalent to about 9.46 trillion kilometers. In debates, a light year is often used to discuss the vastness of the universe and to compare the distances between celestial objects.

2. Can a light year be used to measure time?

No, a light year is a unit of distance and cannot be used to measure time. It is often confused with a "light year" as a unit of time, which is equal to one year of light traveling at the speed of light. However, this is not a scientifically recognized unit of time.

3. How accurate is a light year as a unit of measurement?

A light year is a very accurate unit of measurement for astronomical distances. It is based on the speed of light, which is a constant in the universe. However, as with any measurement, there can be slight variations and uncertainties in the exact distance of a light year.

4. Can a light year be used to measure distances on Earth?

No, a light year is too large of a unit of measurement to be used on Earth. It is typically used for astronomical distances, such as the distance between stars and galaxies. On Earth, more commonly used units of measurement include meters, kilometers, and miles.

5. How does the concept of a light year impact our understanding of the universe?

The concept of a light year allows us to comprehend the vastness and scale of the universe. It gives us a way to measure and compare distances between celestial objects. It also helps us understand the limitations of our technology and our ability to explore and understand the universe.

Similar threads

  • Astronomy and Astrophysics
Replies
6
Views
2K
  • Astronomy and Astrophysics
Replies
12
Views
1K
  • Astronomy and Astrophysics
Replies
2
Views
1K
  • Astronomy and Astrophysics
3
Replies
80
Views
4K
  • Astronomy and Astrophysics
Replies
1
Views
1K
  • Astronomy and Astrophysics
Replies
24
Views
1K
  • Astronomy and Astrophysics
Replies
13
Views
1K
  • Astronomy and Astrophysics
Replies
13
Views
2K
  • Astronomy and Astrophysics
Replies
8
Views
2K
  • Astronomy and Astrophysics
Replies
4
Views
2K
Back
Top