Tag Archives: einstein

Homework Takeaway (#1): Light Ain’t Old

I’m reading Brian Greene’s “The Elegant Universe”. I decided to start organizing some of the thoughts I’m having as I read this book.

The most interesting line I read so far today was about the age of light. Greene is discussing how objects use up their motion either in time or in space, with most objects expending most of their energy via movement through time – that’s why nothing can achieve light speed, except for light.

Therefore, this means that light expends all its motion by moving through space, and the inverse meaning is that light doesn’t age.

As he puts it in his book, “Thus light does not get old; a photon that emerged from the big bang is the same age today as it was then. There is no passage of time at light speed.”

Kind of makes me want to go back and watch the end of SUNSHINE again.