The Ultimate Structure of Matter Chapter 13 Great Idea: All matter is made of quarks and leptons, which are the most fundamental building blocks of the universe that we know.

Chapter Outline Of What is the Universe Made? Discovering Elementary Particles The Elementary Particle Zoo The Four Fundamental Forces

Of What is the Universe Made?

The Library Superficial description –Fundamental building blocks Books Rules for organization Basic –Words –grammer Ultimate description –Letters –Spelling

Reductionism –Ultimate building blocks How simplicity gives rise to complexity True nature –Thought, experiment, observation

The Building Blocks of Matter Fundamental building blocks –Changed over time Atom Nuclei and electrons Elementary particles

Discovering Elementary Particles

Cosmic Rays –Particles emitted by stars Used to understand nucleus –Found new elementary particles

Particle Accelerators: The Essential Tool Particle Accelerator –Artificial cosmic rays Ernest O. Lawrence –cyclotron Synchrotron Linear accelerator

The Elementary Particle Zoo

Leptons, Hadrons, and Antimatter

Quarks and Leptons Quark –Fundamental building blocks of hadrons –Fractional electrical charge –Only six kinds Leptons –Six kinds –Outside nucleus

Quark Confinement Individual quarks –No experimental isolation of a quark Elementary particles –Difficult to isolate

The Four Fundamental Forces

Force as an Exchange Forces cause matter to accelerate Gauge particle –Produce fundamental forces

Unified Field Theories –Fundamental forces seen as different aspects of one force –Four fundamental forces may be different aspects of a single force Electroweak force Standard model Theories of Everything

String Theories –Smallest building blocks as vibrating strings –Vibrate in 11 or more dimensions