Explain SMBC — the wiki for Saturday Morning Breakfast Cereal

The Joke

The comic is a graph with two curves plotted against "Knowledge of Magnets" on the x-axis. The red curve represents "Great Ideas for a Perpetual Motion Machine" and the blue curve represents "Sadness." The red curve (perpetual motion ideas) spikes early when someone has just a little knowledge of magnets -- enough to think magnets could power a perpetual motion machine -- then drops off sharply as one learns more and realizes it is impossible. Meanwhile, the blue curve (sadness) steadily rises as magnet knowledge increases, peaking at the point where one fully understands that perpetual motion machines are thermodynamically impossible.

The Humor

The joke plays on the Dunning-Kruger effect and the common pattern of "a little knowledge is a dangerous thing." People with a superficial understanding of magnets often believe they have discovered a way to create a perpetual motion machine (a device that violates the laws of thermodynamics). As their knowledge increases, they lose these exciting but wrong ideas, and all they are left with is the sadness of understanding why it cannot work. There is also a secondary dip and bump in the red curve at moderate knowledge, suggesting that at an intermediate level, people briefly think they have found a cleverer workaround before once again realizing it does not work. The steadily increasing sadness line is a humorous commentary on how deeper scientific understanding can be emotionally deflating.

References

• Perpetual motion machines are hypothetical devices that would operate indefinitely without an energy source, violating the first or second law of thermodynamics. They are a classic target of pseudoscientific claims.
• The Dunning-Kruger effect describes how people with limited knowledge in a domain tend to overestimate their competence, while experts tend to be more aware of the limitations of their knowledge.