How can light travel time measure a cluster's age if it's older than Earth?

[wolram]

http://news.nationalgeographic.com/news/2005/02/0217_050217_space.html

How can we measure the cluster's age? Because astronomers are able to analyze light waves and thereby tell how long it took for the light, and the images the light creates, to reach Earth. The light that created the images of the galaxies in the photo above is about 12.7 billion years old, so you're actually looking into the distant past as well as the distant limits of the universe

Am i missing some thing? if the Earth is say 4 billion yrs old and the light travel time is 12.7 billion yrs that makes 16.7 billion yrs.

 

[ray b]

why are you adding two things that have nothing to do with each other
age of the light does NOT care how old the Earth is

example Hubble is about ten years old
what does that have to do with the age of the light recorded
by the ten year old scope