US President Barack Obama awards the National Medal of Science to Dr. Simon Levin, Princeton University, for international leadership in environmental science, straddling ecology and applied mathematics, to promote conservation; for his impact on a generation of environmental scientists; and for his critical contributions to ecology, environmental economics, epidemiology, applied mathematics, and evolution at the White House in Washington, DC, on May 19, 2016. / AFP PHOTO / Nicholas KammNICHOLAS KAMM/AFP/Getty Images

US President Barack Obama awards the National Medal of Science to Dr. Rakesh Jain, Harvard Medical School and Massachusetts General Hospital for pioneering research at the interface of engineering and oncology, including tumor microenvironment, drug delivery and imaging, and for groundbreaking discoveries of principles leading to the development and novel use of drugs for treatment of cancer and non-cancerous diseases at the White House in Washington, DC, on May 19, 2016. / AFP PHOTO / Nicholas KammNICHOLAS KAMM/AFP/Getty Images

US President Barack Obama awards the National Medal of Science to Dr. Shirley Ann Jackson, Rensselaer Polytechnic Institute, NY, for her work in condensed matter physics and particle physics, for her science-rooted public policy achievements, and for her inspiration to the next generation of professionals in the science, technology, engineering, and math fields at the White House in Washington, DC, on May 19, 2016. / AFP PHOTO / Nicholas KammNICHOLAS KAMM/AFP/Getty Images

US President Barack Obama awards the National Medal of Science to Dr. Michael Artin, Massachusetts Institute of Technology for his leadership in modern algebraic geometry, including three major bodies of work: étale cohomology; algebraic approximation of formal solutions of equations; and non-commutative algebraic geometry at the White House in Wahington, DC, on May 19, 2016. / AFP PHOTO / Nicholas KammNICHOLAS KAMM/AFP/Getty Images

US President Barack Obama awards the National Medal of Science to Dr. Stanley Falkow, Stanford University School of Medicine, CA, for his contributions toward understanding how microbes cause disease and resist the effects of antibiotics, and for his mentorship that created the field of molecular microbial pathogenesis at the White House in Washington, DC, on May 19, 2016. / AFP PHOTO / Nicholas KammNICHOLAS KAMM/AFP/Getty Images

US President Barack Obama awards the National Medal of Science to Dr. Armand Paul Alivisatos, University of California, Berkeley and Lawrence Berkeley National Lab, CA for his foundational contributions to the field of nanoscience; for the development of nanocrystals as a building block of nanotechnologies; and for his leadership in the nanoscience community at the White House in Wahington, DC, on May 18, 2016. / AFP PHOTO / Nicholas KammNICHOLAS KAMM/AFP/Getty Images

WASHINGTON, DC - MAY 19: (L-R) Dr. Jonathan Rothberg, from 4catalyzer Corporation and Yale School of Medicine, shakes hands with President Barack Obama after receiving the National Medal of Technology And Innovation , during a ceremony in the East Room of the White House, May 19, 2016, in Washington, DC. Established in 1959, the National Medal of Science recognizes individuals who have made outstanding contributions to science and engineering. The National Medal of Technology and Innovation, created in 1980, recognizes those who have made contributions to America's competitiveness, quality of life, and helped strengthen the country's technological workforce. (Photo by Drew Angerer/Getty Images)

WASHINGTON, DC - MAY 19: (L-R) Dr. Jonathan Rothberg, from 4catalyzer Corporation and Yale School of Medicine, receives the National Medal of Technology And Innovation from President Barack Obama, during a ceremony in the East Room of the White House, May 19, 2016, in Washington, DC. Established in 1959, the National Medal of Science recognizes individuals who have made outstanding contributions to science and engineering. The National Medal of Technology and Innovation, created in 1980, recognizes those who have made contributions to America's competitiveness, quality of life, and helped strengthen the country's technological workforce. (Photo by Drew Angerer/Getty Images)