2014-02-01
Explanation
The Joke
A woman with glasses (a chemist) is speaking to two messy, disheveled children. She says: "I believe we can decrease the disorder of your bodies by introducing energy into them." The caption below reads: "Chemists make the best babysitters."
The Humor
The chemist is describing the simple act of feeding the children and cleaning them up, but she phrases it in the language of thermodynamics. In chemistry and physics, "disorder" refers to entropy -- the tendency of systems to move toward disorganization. Living organisms maintain low entropy (order) by consuming energy (food). So "decreasing the disorder of your bodies by introducing energy" is a technically accurate but absurdly overcomplicated way of saying "I think you kids need to eat something and get cleaned up." The humor lies in the gap between the mundane reality of babysitting dirty children and the formal scientific language used to describe it. The caption, "Chemists make the best babysitters," is delivered with dry irony -- a chemist who talks to children in thermodynamic jargon would arguably make a terrible babysitter, not the best one.
References
The comic references the second law of thermodynamics, which states that the entropy (disorder) of an isolated system tends to increase over time. Living organisms are open systems that maintain order by taking in energy from their environment (food), which temporarily decreases local entropy at the cost of increasing entropy elsewhere in the universe.