No Free Lunch: the Second Law of Thermodynamics

Why is it easier to mess up your bedroom than to make it tidy? Why does a warm cup of tea cool off in your living room? Why doesn't a 500-calorie cheeseburger you've eaten turn into 500 calories of you? These examples reflect one of the fundamental laws of nature: the second law of thermodynamics. In this course students will learn about this most important of laws with hands-on experiments in the laboratory using physical and biological systems. We will design our experiments, make predictions, carry out the experiments, and analyze our results. An understanding of this law has implications for our own personal behavior, the behavior of our society, and the behavior of our species.

Fall 2010
Mon & Thurs
4:10 p.m. to 6:00 p.m.

Betsy Sherman
Dickinson 106
Office hours sign-up posted outside office each week

First Law of Thermodynamics

The total amount of energy in the universe remains the same; energy can be neither created nor destroyed.

  • Heat and temperature; potential and kinetic energy
  • Change of states
  • Chemical reactions: energy requiring, energy liberating
  • Energy transfer
    • Heat-conduction, convection, radiation
    • Mechanical energy transfer from friction
    • Effect on organisms

Second Law of Thermodynamics

In any transfer of energy, while the total energy in the universe remains the same, the amount of energy available to organize matter (free energy) decreases, as some of the energy is "lost" to the system as heat (which cannot organize matter). The consequence of less and less energy being available to organize matter is that matter becomes less organized over time. In other words, the second law predicts that disorganization of matter i.e. entropy, will increase over time.

  • Direction of heat energy transfer
  • Illustrative activities
  • Probability and simulations
  • Jumping beans (an analogy)

Consequences of the Second Law

  • Time's arrow
  • Evolution
  • How do organisms maintain themselves
  • Energy transfers among different trophic levels in ecosystems
  • Thermal pollution

Course Requirements

Attendance is required. There will be a few short readings. Our work will be to design and carry out experiments that illustrate energy transfer in physical and biological systems. Bring a notebook and writing implement. Bring enthusiasm. You will be asked to graph and interpret the results of your experiments (that will be facilitated by our discussions).