the.com/light years
a unit of distance wearing a unit of time as a disguise.
means the distance light travels in one year, roughly 5.88 trillion miles, used to measure cosmic distances not cosmic dates.
from coined in the 1800s once astronomers realized stars were so far apart that miles became useless and light's constant speed became the only ruler big enough.
common mistakepeople use it as a time unit constantly
nearest starproxima centauri sits 4.24 light years away
lookback effectyou see stars as they existed long ago