The discovery of spiral arms and — later — of molecular clouds in our Galaxy, combined with a rapidly growing understanding of the birth and decay process of stars, changed interstellar space from a stationary "medium" into an "environment" with great variations in space and time.


Evolution in Interstellar Dust and Related Topics (p. 5), North-Holland Publishing Company. Amsterdam, Netherlands, 1989

Hendrik C. van de Hulst Quotes

The discovery of spiral arms and — later — of molecular clouds in our Galaxy, combined with a rapidly growing understanding of the birth and...

The discovery of spiral arms and — later — of molecular clouds in our Galaxy, combined with a rapidly growing understanding of the birth and...

The discovery of spiral arms and — later — of molecular clouds in our Galaxy, combined with a rapidly growing understanding of the birth and...

The discovery of spiral arms and — later — of molecular clouds in our Galaxy, combined with a rapidly growing understanding of the birth and...