Scientists from across the U.S. and around the world use Fermilab's resources to explore the most basic particles and forces of nature. You can explain this scientific research in simple terms by describing the ideas particle physicists study and the tools and research methods they use.
There is an amazing beauty and symmetry in nature. Think of snowflake, a daisy or a honeycomb. The shapes of these and all other natural objects depend on an underlying structure of matter. For centuries scientists have wondered what this structure might be. Their studies have led to a search for particles that are the smallest, simplest building blocks of matter, and for the forces that control their behavior. The particles are quarks and leptons; the forces are gravity, electromagnetism, the weak force and the strong force. Fermilab scientists are leading this international search to learn how the universe works.
When scientists study the subatomic particles and forces that bind them together,they also learn about the early history of the universe and how it began with the "Big Bang." When the universe was very young, atoms didn't exist, because it was too hot for them to form. The only form of matter was a sort of "primordial soup," consisting of the most basic particles, such as quarks and electrons. At Fermilab, scientists use the Tevatron to make the ingredients of primordial soup by smashing together protons and antiprotons at very high energies. The earlier we look in time, the fewer and more basic the particles become, and the fewer forces are needed to control their behavior. The laws of physics are valid in the whole universe and throughout the whole of time.
Methods: Collisions and Scattering
Scientists work by posing important new questions about the natural world. They develop theories, and invent tools and techniques to answer their questions and test their theories. Particle physicists are scientists who develop and test theories about the smallest particles of matter. Fermilab physicists create particles by accelerating protons and making them collide with particle targets. Sometimes the protons collide with fixed particle targets (hydrogen ions, iron, tungsten, for example); sometimes the protons collide head on with moving anti-protons (See the Animation). These collisions (also called events) create new particles. Scientists record and study how the newly created particles move away (or scatter) from the collision. By observing this behavior, scientists can learn about the particles and the forces that control their interactions, and sometimes discover particles not seen before.
Tools: Accelerators and Detectors
The instruments that particle physicists use for their studies include accelerators, detectors and powerful computers. Accelerators give the protons enormous energy. To study very small particles scientists need very high-energy protons and very big accelerators. The particles scientists want to study are so small that they cannot be seen by the human eye or the most powerful microscope. So physicists build huge detectors to track the particles as they move outward from a collision. Scientists need computers to collect, store and analyze the information. They need computers because the experiments create a lot of data over a very short period of time and because many of the newly created particles live for only an instant.Computers also allow scientists to use the data to reconstruct events in a collision. Subatomic particles behave like waves. Understanding the properties of waves helps scientists design their experiments and interpret the results.
The Fermilab Education Office developed the Quarks to Quasars exhibits and
Beauty and Charm program to bring the story of
Fermilab research to life for visiting students. Students explore hands-on exhibits at the
Lederman Science Center.