What are the average and maximum lifespans of a photon?

Once emitted, a photon is stable and lasts until it strikes an object and is absorbed. The maximum lifespan of a photon is the age of the universe, minus the 380,000 or so years it took for the universe to become transparent to photons after the Big Bang. The average lifespan of a photon would depend on the average density of photon-absorbing matter in the universe (more specifically, the mean separation between photon sources and photon absorbers), and I have not found any calculations or estimates for this figure.

A photon does not decay spontaneously in empty space. It is stable. 6 months is an unfounded answer.

What is your source for the answer 'don5601'? ee.buffalo.edu/faculty/cartwright/java_a... -The photon lifetime is a time constant that describes the decay (or the growth) of energy in a cavity. We can calculate the photon lifetime by considering the rate equation (a differential equation with time as the independent variable) for the decay of an initial bunch of photons, Np, in the cavity.

The applet IN THE ABOVE LINK shows a simple two mirror cavity with a pulse of photons bouncing back and forth. Interesting article - blogs.zdnet.com/emergingtech/?p=517.

Maximum life span of approximately 6 months, . I think my red bull is kicking in!

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.