I am most grateful to Andr' e Heck for his invitation to write a foreword to OSA Volume 4 - I will use this valued opportunity to emphasise those topics in Vol. 4 which I consider important even if other topics may be of even greater importance in the universal scale of things. At the outset let me say that I commend Vol. 4 to its readers - it contains much of very great interest for organisations and strategies in astronomy. A topic which I consider to be of very great importance at this time is Adverse Environmental Impact on Astronomy. There are two papers on this topic in OSA 4 - Cohen on Strategies for Protecting Radio Ast- nomy and Schwarz on Light Pollution Control. The growth in the extent of use, the power and spectral demand for radio transmission continues to increase virtually exponentially. The impact on the 'listening' services such as radio astronomy has been severe. Only by creativity in developing new techniques for radio noise (including legal transmissions) reduction and by participating fully in the allocation process for radio frequencies has radio astronomy developed to the powerful investigative tool it is today.

I am most grateful to Andr' e Heck for his invitation to write a foreword to OSA Volume 4 - I will use this valued opportunity to emphasise those topics in Vol. 4 which I consider important even if other topics may be of even greater importance in the universal scale of things. At the outset let me say that I commend Vol. 4 to its readers - it contains much of very great interest for organisations and strategies in astronomy. A topic which I consider to be of very great importance at this time is Adverse Environmental Impact on Astronomy. There are two papers on this topic in OSA 4 - Cohen on Strategies for Protecting Radio Ast- nomy and Schwarz on Light Pollution Control. The growth in the extent of use, the power and spectral demand for radio transmission continues to increase virtually exponentially. The impact on the 'listening' services such as radio astronomy has been severe. Only by creativity in developing new techniques for radio noise (including legal transmissions) reduction and by participating fully in the allocation process for radio frequencies has radio astronomy developed to the powerful investigative tool it is today.