Antedilution
Explanation
The Joke
An angel approaches God and tells him about homeopathy, explaining the concept: "You dilute something in water and you get more of it." God, represented as a large golden disc (a common SMBC depiction), responds with surprise: "Eh?" followed by an excited "Is that true?!" The caption at the bottom reads "Shortly before The Flood."
The comic provides a humorous origin story for the Biblical Flood. God hears about the pseudoscientific principle behind homeopathy -- the idea that diluting a substance in water makes it more potent -- and takes it at face value. Excited by this prospect, God apparently decides to flood the entire Earth, presumably to "dilute" something and get more of it. The title "Antedilution" is a portmanteau of "antediluvian" (meaning "before the flood") and "dilution," connecting the Flood narrative to homeopathic dilution.
The Humor
The joke operates on multiple levels. First, it satirizes homeopathy by pointing out how absurd its central premise sounds when stated plainly -- even God finds it too good to be true. Second, it provides a ridiculous alternative explanation for a major Biblical event: God flooded the world not out of wrath at human sin, but because he got excited about a pseudoscientific get-rich-quick scheme involving water dilution. The wordplay in the title ties the whole thing together elegantly.
References
Homeopathy is an alternative medicine system founded in 1796 by Samuel Hahnemann, based on the principle that substances causing symptoms in healthy people can cure similar symptoms in sick people when highly diluted. The "law of infinitesimals" holds that the more a substance is diluted, the more potent it becomes -- a claim that contradicts basic chemistry and physics. The Biblical Flood narrative appears in Genesis 6-9, describing God's decision to flood the Earth due to human wickedness.