Joseph Silk is Homewood Professor of Physics and Astronomy at Johns Hopkins. He studied at Cambridge, earned his PhD from Harvard in 1968, was a postdoctoral fellow at Cambridge and Princeton, and taught at the University of California, Berkeley, and the University of Oxford. He joined Johns Hopkins in 2010.

Silk has written or co-authored more than 500 publications. He has conducted important early work on homogeneities in the cosmic microwave background and how they are influenced by density fluctuations in the matter of the early universe, in particular by a damping effect that bears his name. These were decisive contributions that helped transform cosmology into a high-precision science. He has also made pioneering advances in understanding the nature of dark matter, and explored novel indirect methods for its detection. The latter have inspired very large experiments with new types of telescopes. Silk‘s studies of galaxy formation and his work on the dynamics of mass loss and the feedback mechanisms from star formation and evolution have formed a very significant basis for subsequent work in this important field.

Silk was awarded the 2011 Balzan Prize for his pioneering work on the infant universe. The $950,000 award is given annually to people or organizations that have made outstanding achievements in the fields of the natural sciences, humanities and culture, as well as for peace-promoting endeavors.