1. The “Wandering Photon” An Animation Found on the Internet
The “Wandering Photon” An Animation Found on the Internet! Animated Illustration of the Random Walk Problem

2. The “Wandering Photon”
A photon walks straight for a random distance.
It stops random,lywith probability g . It turns
in a random direction with probability (1-g).

3. A One-Dimensional
“Wandering Photon”

4. After walking to the right for a random distance x, it stops
with probability g. After each stop, there is a probability
(1-g)/2 for it to continue to the right & a probability
(1-g)/2 for it to continue to the left.

5. x

6. x

7. x

8. x

9. x

10. x

11. What is the Probability P of a photon being absorbed at x?
pdf of the length of the first step
1/h = average step length γ = absorption probability

12. P(photon absorbed at x) = f (|x|,g,η)
pdf of the length of the first step
pdf of the length of the first step
1/h = average step length γ = absorption probability

13. “The Sleepy Photon” or
“The Sleepy Drunk”
in higher dimensions

14. After walking a random distance r, it stops with
probability g. Then, with probability (1-g ), it picks a
random direction to continue walking.

24. “The Sleepy Photon” or
“The Sleepy Drunk”
in higher dimensions r
P(absorbed at r) = f (r,g,h)