30.5 The Standard Model

Even though the standard model explains three of the fundamental forces, it cannot explain how gravity works.  At the extremely small scale of the atom, gravity is so weak as to be nonexistent and, therefore, does not affect subatomic actions. However, one of the goals of physicists is to develop a single theory and set of equations that describe everything in the universe, optimistically called the grand unified theory or the theory of everything.

Current theoretical research is moving toward a grand unified theory that could connect the electroweak force with chromodynamics and gravity.  At the same time, research continues into string theory, which may connect gravity with the other three fundamental forces.  In this theory the particles are treated as tiny vibrating strings of mass-energy that are quantized similarly to standing waves.  At the moment these are just theories waiting to be tested, refined, rejected, and revised in a similar way to the thousands of ideas and theories that have come before them.  In many respects, the inside of the atom remains undiscovered territory.  Like the furthest reaches of deep space, it can only be explored with powerful and continually evolving human technology and ingenuity.

Read Read "Quarks and the Standard Model" on pages 845 to 849 of your textbook.

 

Answer the following self-check questions then click the "Check your work" bar to assess your responses.

SC 1. What are the 12 particles of the standard model?

SC 2. Rank the four natural forces from weakest to strongest.