The Opacity of Spiral Disks

We are well aware of how dust influences our observations of distant stars and how easily dust may mislead us with regard to the way in which stars are distributed within the Galaxy, but how does dust affect our view of other galaxies? This is the question that was posed to those who attended this meeting. By its very nature dust is illusive: as dust obscures by both scattering and absorption, it can effectively disguise its very own existence. It was not until the mid-1930's that astronomers generally agreed that dust did redden and dim stars in our own Galaxy, and it was not until the late 1950's that astronomers began to seriously inquire of its effects in other galaxies To the best of our knowledge, this is the first international meeting to have been held devoted solely towards understanding the observational effects of dust in other galaxies. Because of this we have been fortunate in attracting many of the major workers in this field, both observers and theorists. Among these pages the reader will find a wide range of opinion about how much dust there is in the disks of galaxies, where that dust is, and how to model the effects of dust. We tried to structure this meeting so that there was a ready and easy exchange between the speaker and the audience, and so that there was a large amount of time for discussion.