Explain SMBC — the wiki for Saturday Morning Breakfast Cereal

This comic is a multi-panel sequence in which a person prays to God asking mathematical questions about prime numbers, with each answer revealing something more unsettling.

The person first asks God whether there are infinitely many primes in a set of numbers. God confirms there are infinitely many primes, but says "I'm not gonna tell" the specifics. The human then asks about primes of the form N = 2^p - 1 (Mersenne primes), and God confirms there are infinitely many of those too. Next the human asks about primes in the sequence 1, 11, 111, 1111, 11111... (repunit primes), and God again confirms infinitely many, calling it "classic." Finally, the human asks whether there are infinitely many primes in a set made up of the counting numbers rearranged in some specific way (possibly a constructed sequence designed to be maximally difficult to analyze), and God becomes agitated and says "I don't know."

The punchline comes when the human asks "You gonna be okay?" and God, now visibly distressed and sweating, replies "Prove that I can't... AHHHHHHH!" — suggesting God is having an existential crisis because there exists a mathematical question even an omniscient being cannot answer, or that the question touches on undecidability (statements that are true but unprovable within a given formal system, a la Godel's incompleteness theorems).

The humor operates on several levels. First, it plays on the common SMBC trope of humans pestering God with questions. Second, it escalates through real open problems in number theory — whether there are infinitely many Mersenne primes and repunit primes are both genuine unsolved conjectures. Third, the final question pushes into territory that may be formally undecidable, which would mean even an omniscient God who knows all true statements might not be able to "prove" the answer within any formal system — hence God's panicked challenge to "prove that I can't." This touches on Godel's incompleteness theorems, which show that in any sufficiently powerful formal system, there are true statements that cannot be proven within that system.