| The properties of dust grains in the general interstellar medium are presented, along with the discovery of, and evidence supporting, an obscuring interstellar medium. Grain formation in the exospheres of cool red giant stars is investigated and the post ejection gathering of grains in clouds is discussed. The computer simulation of radiative transport through circumstellar disc using Monte Carlo number generation is also discussed, and the code is used to reproduce observed I-band isophotal maps of HH30. The main results are: 1. Virgin radiation swamps the results of scattering simulations. 2. Bipolar outflows are not produced by scattering processes. |