| Year | 2006 |
| Date | 29-Sep |
| Volume | 197 |
| Issue | 4,283 |
| Page | 377 |
| Category | General |
| Part | 93 |
| Title | Letters to a Grandson |
| Author | M.J.H. Ellis |
| Notes | On the nature of light. Optical interference, addition of two sine waves, interference: straight bands, when interference occurs, interference: circular bands |