More than you ever imagined.  In simplest terms, they use their knowledge of the fundamental laws of nature to solve problems and develop new materials and products.  Physicists put their theoretical knowledge of science to practical use in fields like electronics, optics, communication, aerospace technology and medicine.  The world of the physicist is limitless, stretching from the tiniest particle of subatomic matter to the farthest galaxy. 

• Physicists developed new materials, electronics and lasers which make fiber optic communications faster, cheaper, and less noisy than copper wire.
• Lasers, from CD players to national defense, were a fundamental development of physicists.
• Nuclear Magnetic Resonance (NMR) was developed by physicists and eventually applied by engineers to medical Magnetic Resonance Imaging (MRI).
• The transistor, invented by four physicists at Bell Labs, opened the way to the telecommunications revolution and the information age.
• See Physics Success Stories for other examples of physics research applied to real world problems.
• See Contributions of Physics to The Information Age

  
  

How Many Physicists Are There?

• There are about 125,000 physics degree holders in the workforce (BS, MS, PhD).
• About 27% of the physics bachelors get a PhD in physics.
• Of these 34,000 PhDs, only about 40% are teaching or doing long-range physics research.

Thus, of the 125,000 physicists in the workforce, only 11% (14,000) are doing physics research.

See Career Profiles.

Physicists Have Made Important Contributions in Fields Other Than Physics

Hidden Physicists are people with a physics background, but without a typical physics job. Physicists can be found in nearly every job sector in some of the coolest and most farfetched careers imaginable from the surreal to the strange, from the essential to the eccentric, from the typical to the crazy. Check out Profiles of physicists in various fields.

Here Are Just a Few Examples of Physics Majors Who Have Had an Impact in Fields Other Than Physics:

Computing

• Tim Berners-Lee created the World Wide Web in 1989 to ease research collaboration among a dispersed group of high-energy physicists. He graduated from Queen's College at Oxford University, England, with 1st class Honors in Physics in 1976. He is a Mac OS X user.
• Jim Clark founded and served as chairman of the board for Silicon Graphics and was cofounder and chairman of the board of Netscape. He received bachelor of science and a master of science degrees in physics from Louisiana State University.

Biology

• Francis Crick, one of the two co-discovers of the structure of DNA, was a physicist.
• Molecular biologist Walter Gilbert earned degrees in physics at Harvard where he taught successively physics, biophysics, biochemistry, and molecular biology. The technique he developed (with Allan Maxam) for rapidly sequencing genes earned him a share of the 1980 Nobel Prize in Chemistry and was critical in launching the new field of genetic engineering. In the 1980s he contributed to efforts to identify the basic components of proteins. He founded Biogen, a genetic engineering firm and was a major force in launching the Human Genome Project.
• Geneticist Seymour Benzer studied physics at Purdue University, and taught biophysics there until 1965, when he moved to the CalTech. He first showed that genes can be split and then recombined, and he did much to relate genes as chemical entities to their observed behavior in biological systems.

Medicine

• In 1977 Rosalyn Yalow, Ph.D. in nuclear physics, shared the Nobel Prize in Physiology or Medicine for her work in creating a new analytic technique called the radioimmunoassay, or the RIA, which allowed quantifying very small amounts of biological substances in body fluids using radioactive-labeled material. They made it possible for doctors to diagnose conditions caused by minute changes in hormone levels.

Paleontology

• In 1980 physicist Luis Alvarez (1969 Nobel Prize in Physics) and his son Walter Alvarez, a geologist, proposed the landmark theory of the extinction of the dinosaurs; that an asteroid 4-9 miles (6-15 km) in diameter hit the Earth about 65 million years ago. The asteroid is believed to have hit off the Yucatan peninsula. The crater was discovered in 1981 by two geophysicists, Glen Penfield and Antonio Carmargo while searching for oil in the Gulf of Mexico.

Invention

• Physicist Chester F. Carlson invented the photocopier. In 1947 the new Xerox Corporation negotiated rights to his xerographic development.
• American inventor and physicist, Edwin Herbert Land invented Polaroid photography. His one-step process for developing and printing photographs created a revolution in photography - instant photography.
• British physicist John Randall with his colleague Harry Boot invented the cavity magnetron to generate radio waves of very short wavelength (less than 10 cms), essential for radar, in 1940. Their device is now also used in microwave ovens.
• Robert Noyce invented the integrated chip and was cofounder of Fairchild Semiconductor and Intel.

Music

• Rock star Brian May of Queen graduated from Imperial College London with an honors degree in physics and math. Now, almost four decades later, the two strands of his life, music and astronomy, are coming back together. He is currently finishing the PhD he started at Imperial College London back when Queen was just beginning to take off. He has also co-authored a popular book on cosmology, "Bang! The Complete History of the Universe".
• Physicist Robert Moog invented the synthesizer (electronic keyboard) used extensively in music.
• Musician and composer Wendy Carlos studied a hybrid major in music and physics. Her albums Switched-On Bach and Well-Tempered Synthesizer propelled the Moog synthesizer into the public consciousness and won three Grammy Awards. Her movie music includes The Shining and Tron.

Art

• Woodworker Edwin Allen Moulthorp was a professor of both architecture and physics at Georgia Institute of Technology, as well as a practicing architect. He is noted for his large bowls that he would treat and finish after turning them out of green Southern woods. Basic in shape, they are almost sculptural in the purity of their form and material. His works are owned by many museums and private collectors.

Government

• Angela Merkel, Germany's first woman chancellor, has a a doctorate in physics.
• Jimmy Carter, 39th President, studied graduate physics at Union College. He was awarded the 2002 The Nobel Peace Prize.
• Congressman Rush Holt is the U.S. House Representative for New Jersey's Twelth District. He received his B.A. in Physics from Carleton College in Minnesota and earned his Master’s and Ph.D. at NYU. He was Assistant Director of the Princeton Plasma Physics Laboratory, and a five-time winner of the game show "Jeopardy."
  
• Congressman Vern Ehlers is the U.S. House Representative for Michigan's Third District. He also holds a Ph.D. in nuclear physics.
• Harold Brown was 14th Secretary of Defense under the Carter Administration. Brown took three degrees at Columbia University, including, at age 21 in 1949, a Ph.D. in physics.
• Ehud Barak is a former Prime Minister of Israel and has a BS in physics and mathematics.
• John Poindexter, PhD physicist from Caltech and a vice admiral in the U.S. Navy (retired). As National Security Advisor to President Reagan, he was at the center of the Iran-Contra scandal and was convicted of lying to Congress about it. Poindexter appealed the conviction, and in 1991, a federal appeals court panel reversed the conviction.

Space Exploration

• Physicist Sally Ride was America's first woman astronaut.
• Robert Goddard was a rocket and space pioneer and became the father of modern rocketry. Said to have been inspired by H. G. Wells's War of the Worlds, he laid the basis for his lifelong work with studies at Worcester Polytechnic Institute and Clark University, where he taught and headed the physics department.
• While earning a Ph.D. in physics at MIT, Ronald McNair helped develop the chemical HF/DR and high-pressure CO lasers. Selected as an astronaut, he served on Space Shuttle Mission 41-B, and became only the second African-American astronaut in space. In 1986, McNair, along with six fellow crew members died when the space shuttle Challenger exploded just after takeoff in Cape Canaveral, Florida.

Acting/Directing

• Irish-born actor Liam Neeson originally sought a career as a teacher, and attended Queens College, Belfast majoring in physics, math and drama.
• Actress Jane Mansfield started out as a physics major, but switched to drama.
• Movie director Brian De Palma (Mission Impossible, The Untouchables, Carrie) studied physics.
• Director and screenwriter James Cameron (The Terminator, Alien, Titanic), the son of an engineer majored in physics at the California State University.
• Actor Judd Hirsch (A Beautiful Mind, TV's Taxie) has a degree in physics.

Business

• Akio Morita founder of Sony Corporation studied physics at Osaka Imperial University in Japan.
• W. Edwards Deming is famed business guru and statistician. He is considered the father of modern manufacturing efficiency. Japanese manufacturers created the annual Deming Prize in his honor, the highest business honor in Japan.
• Emanuel Derman wrote the book "My Life as a Quant: Reflections on Physics and Finance." While at Goldman Sachs, he co-invented a tool for pricing options on Treasury bonds and was named "Financial Engineer of the Year" in 2000. He has a PhD in Physics.
• Ralph Izzo, President and Chief Operating Officer of Public Service Electric and Gas Company, has a PhD in Applied Physics.

Sports/Games

• Allan Steinfeld is the man responsible for ensuring that every November approximately thirty-thousand people run together in a smooth and orderly fashion. As President of the New York Road Runners Club, he orchestrate the New York City Marathon and over a hundred of other road races sponsored by his running club. He has a Masters degree in astronomy and physics.
• Legendary Green Bay Packer's football coach, Vince Lombardi, taught physics at St. Cecelia High School in Englewood, New Jersey. Oh yes, he was also their assistant football coach.
• Alburt Lev was a former Russian chess Grandmaster who defected from the USSR in 1979. He has won the U.S. Championship 3 times and the U.S. Open twice. He has a doctorate in physics.

Writing

• Science fiction writer Robert A. Heinlein wrote 45 books and was the winner of an unprecedented four Hugo awards. He did graduate work in physics and mathematics at the UCLA.
• The famous Russian writer and Soviet dissident Alexander Isayevich Solzhenitsyn, author of One Day in the Life of Ivan Denisovich, Cancer Ward, and The Gulag Archipelago, was awarded the Nobel Prize for Literature in 1970. His degrees were in physics and mathematics.
• Science fiction and screenwriter Arthur C. Clarke obtained first class honors in Physics and Mathematics at the King's College, London. He shared an Oscar Academy Award nomination with him for the film version of 2001: A Space Odyssey.
• Writer, producer, teacher Carl Sagan was a physicist.

Philosophy

• Philosopher Moritz Schlick was one of the leaders of the Vienna Circle of logical positivists, born in Berlin. He studied physics at Heidelberg, Lausanne, and Berlin, taught at Rostock and Kiel, and later was professor of inductive sciences at Vienna. His major works include General Theory of Knowledge and Problems of Ethics. He was shot down on the steps of the university by a deranged student.
• Philosopher Hans Reichenbach was a physics professor at the University of Berlin. Fleeing Adolf Hitler, he went to Turkey (1933) and to America (1938), where he taught at the UCLA from then on. His works include The Rise of Scientific Philosophy (1951).