Week 1 (March 9)

Chapter 1:  The Reluctant Revolutionary  –  Points to ponder: 

• • • • Why was Planck considered a “reluctant revolutionary”?  Did that make him more or less credible than someone who would immediately believe in quanta of energy?

• • • • Why was Planck not satisfied just to have an equation that gave an excellent fit the blackbody radiation data (Hint: the answer is the essence of being a physicist)?

• • • • What do you think would happen if Planck’s constant were a much larger number?

• • • • Can you think of anything that comes in discrete units that are not divisible? Try to travel back to 1900 to ask yourself that question.

• • • • An extended definition of entropy is that it is a measure of disorder, and that entropy always increases. Think of some examples in your daily life that illustrate how something once ordered becomes disordered (e.g., falls apart), but cannot spontaneously become ordered again.

Chapter 2:  The Patent Slave  –  Points to ponder:

• • • • The history of quantum theory is full of the debate of whether light is a wave or a particle. How would you characterize a wave, and how would you characterize a particle? Are their features totally contradictory, or are there any similarities? Think of some examples of waves and of particles.

• • • • So “what would it be like to ride on a beam of light”, do you think (p. 35)?  Suppose you could ride on a beam of light holding a flashlight pointed forward in the light direction of travel, or pointed backward.  How fast would the light from the flashlight travel in either of those cases as seen by a stationary observer?

The size of Planck's constant:

 h  =  6.626 x 10 -27   erg seconds   (with units of energy x time,  or momentum x distance)

=  6.626  /  10 27   =  6.626  /  1,000,000,000,000,000,000,000,000,000  erg seconds

where  1 erg  =  1 gram (cm / sec) 2 

How small is this?  Compared to a 1 gram mass moving a distance of 1 cm in 1 second  =>  1 erg second, it's extremely tiny. 

Updated Feb. 27, 2023