Day 3: Energy

Question 1

The first ball gives something to the last ball. What is it that passes from the first ball to the last? When the ball comes to rest, what has happened to that which passed between them?

We will invent a category of "stuff" that passes from one ball to the next. Can we reach agreement on what the properties of this stuff are? What rules it seems to follow? Can we convince ourselves that it's something "real?" Under what conditions?

Lecture on speed, momentum, energy, movement - the range of models we have - and a focus on energy for today and tomorrow.

Question 2

Light from the sun reaches the Earth - then what happens? Does the light cease to exist? Does it turn into something else?

Lecture on energy conversions.

Question 3

Can energy ever disappear? Why do physicists generally believe the answer to this question is no?

Lecture on conservation, our commitment to energy conservation.