She always seemed to ask questions that were slightly unusual, off-center from the topic, speaking with a clipped staccato voice and with little expression. Here she was blurting out abruptly in the midst of his carefully crafted lecture. He had a finely timed lecture to give, yet he wished to be reasonable. Any serious deviations would mean he could not cover the critical experiments of Miller and Urey or Fox, and he certainly would not reach the climax of the lecture, to read a scientist's version of Genesis, which put the whole problem in perspective. The lecture hall was suddenly deadly silent.
Gravity is only a theory.