- published: 09 Oct 2014
- views: 207249
A light-year (or light year, abbreviation: ly) is a unit of length used informally to express astronomical distances. It is well over 9 trillion kilometres (or about 6 trillion miles). As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year. Because it includes the word year, the term light-year is sometimes misinterpreted as a unit of time.
The light-year is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist and popular science publications. The unit usually used in professional astrometry is the parsec (symbol: pc, approximately 3.26 light-years; the distance at which one astronomical unit subtends an angle of one second of arc).
As defined by the IAU, the light-year is the product of the Julian year (365.25 days as opposed to the 365.2425-day Gregorian year) and the speed of light (7008299792458000000♠299792458 m/s). Both these values are included in the IAU (1976) System of Astronomical Constants, used since 1984. From this the following conversions can be derived. The internationally recognized abbreviation for light-year is "l.y.").
Tread lightly
Speak dearly
Enough of this
I'm a fucking passive counterfeit
Won't hide my
Hide my head in the rain
The weakness leaves me
Much stronger with every grain
Another reason
My prettiest
Just picture this
I'm fucked if I know
The whole procedure
I'm running and falling
I'm tearless, I need ya
Some indecision
This isn't working any more
Save us two some pain
A face to ignore
A self-expression
Conjures up your name
A concentration
Of times that we were the same
And my confidence has left me too
I'm fucked if I know
The whole procedure
I'm running and falling
I'm tearless, I need ya
Some indecision
This isn't working any more
Save us two some pain
A face to ignore
I'm fucked if I know
The whole procedure
I'm running and falling
I'm tearless, I need ya
Some indecision
This isn't working any more