British physicist Stephen Hawking and his daughter Lucy Hawking give a lecture entitled 'Why We Should Go Into Space' during the 50 Years of NASA lecture series at George Washington University in Washington, DC. (Jim Watson/AFP/Getty Images)

Regarding the March 15 front-page obituary for Stephen Hawking, “ He saw a universe without limits ”:

Despite his almost unbelievable conquest of his disabilities, Stephen Hawking should be remembered for at least four other reasons:

First, and many times with collaborators, for his seminal work on black holes, entropy and the radiation emitted from the black holes. Second, for his copious and popular writings of both nonfiction and fiction, making physics more interesting and understandable to the general public. Third, his heated and unsuccessful arguments with other physicists that the Higgs boson, if it existed, could never be found. (Incidentally, he was proved wrong in 2012.) Fourth and finally, his vitriolic attacks on Israel, motivated by his mentor Noam Chomsky, that included support of boycott, divestment and sanctions and questioning the need for a Jewish state.

Which Hawking will be remembered? The one who overcame his disabilities, achieved and helped popularize science. Hopefully, his scientific career will be his heritage.

Nelson Marans, New York

Along with his many achievements, Stephen Hawking also contributed to the widespread misunderstanding of physics by insisting that space-time is four-dimensional. 

The four-dimensional notation is just a convenient way of handling the mathematical relationship between space evolution and time evolution. 

In fact, as I wrote in my book “Fields of Color,” “one might almost say that physicists couldn’t live without it. Nevertheless, space and time are fundamentally different, and I say shame on those who try to foist and force the four-dimensional concept onto the public as essential to the understanding of relativity theory.”

Further, while “searching for a way to reconcile Einstein’s theory of relativity with quantum physics,” Hawking (along with most physicists) ignored the papers in Physical Review by Nobel laureate Julian Schwinger that united them (“The quantized gravitational field,” 1963). 

The neglect and ignorance of Schwinger’s formulation of quantum field theory is why I wrote my book.

Rodney Brooks, Silver Spring