What Is a Light Year? Understanding the Value of 1 Light Year

[lakshmi]

what is the value of 1 light year

 

[pmb_phy]

what is the value of 1 light year

It is the distance light travels in one year. It, in itself, is a measure of distance so perhaps you're interested in converting this to meters? Miles?

Pete

 

[GOD__AM]

It is the distance light travels in one year. It, in itself, is a measure of distance so perhaps you're interested in converting this to meters? Miles?

Pete

A measure of distance? How can light speed be an accurate measure of distance when it travels with respect to an observer?

 

[Nereid]

A measure of distance? How can light speed be an accurate measure of distance when it travels with respect to an observer?

'distance' as in 'within your own frame of reference' (or one not in relative motion to yours); to obtain a value for the distance as observed by someone in a different frame, just apply Relativity!

 

[decibel]

The valua at which light travels in a year is approx. 9,500,000,000,000 kilometers.

 

[pmb_phy]

A measure of distance? How can light speed be an accurate measure of distance when it travels with respect to an observer?

Because the speed of light is independent of the observer. Therefore since all observers measure the same speed of light, 1 light year is a well defined quantity (although different observers measure different distances between events, but that's a whole different topic).

Pete

 

[Nenad]

Here is the full Calculation:
$$v=\frac{d}{t}$$

$$d=vt$$
$$d=cy$$

$$d=(3.0*10^8\frac{m}{s})(3.15*10^7\frac{s}{year})(\frac{1km}{1000m})$$

$$d= 9 460 800 000 000km$$

 

[Prometheus]

The valua at which light travels in a year is approx. 9,500,000,000,000 kilometers.

I think that you are taking liberties with the meaning of the word value.

 

[pervect]

A measure of distance? How can light speed be an accurate measure of distance when it travels with respect to an observer?

Take a look at the definition of the SI meter sometime

 

[robphy]

Here's a nice order of magnitude calculation. (No calculators needed.)

$1\ yr \approx \pi\times 10^7\ s$
$c \approx 3\times 10^8\ m/s$

$1\ light\ yr=(c)(1\ yr) \approx (\pi\times 10^7\ s)(3\times 10^8\ m/s)=3\pi \times 10^{15}\ m$

You can work out the analogous approximation in feet using
$c \approx 1\ ft/ns$