Edwin Hubble

Edwin Powell Hubble was an American astronomer. He profoundly changed astronomers' understanding of the nature of the universe by demonstrating the existence of other galaxies besides the Milky Way. He also discovered that the degree of redshift observed in light coming from a galaxy increased in proportion to the distance of that galaxy from the Milky Way. This became known as Hubble's law, and would help establish that the universe is expanding.

Hubble died of a cerebral thrombosis on September 28, 1953, in San Marino, California.

Niels Bohr

Niels Henrik David Bohr was a Danish physicist who made fundamental contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. Bohr mentored and collaborated with many of the top physicists of the century at his institute in Copenhagen. He was also part of the team of physicists working on the Manhattan Project. Bohr has been described as one of the most influential physicists of the 20th century.

He died in Copenhagen in 1962.