This seems to strike people I've talked to as a ridiculously simple question but no one can give me a simple answer. I thought this might be the place to get my explanation. I don't see how light can continue to travel millions of years through space after the star has died and it has no energy source. One fellow tried to compare it to water coming through pipes which is not a good comparison for when you turn the pump off there is no energy source to push the water. Starlight does not create a self sustaining energy as it travels, when you turn a laser off the beam does not continue onward, same with a flash light. So what am I missing here that explains how one light with no energy can travel for a million years but when I hit the button on my Maglite the beam ceases to be? Thanks in advance for answers, please be specific and explain in laymans terms.