Penrose describes his black hole theory, which sparks an idea in Stephen's mind. Stephen reverses Penrose's theory and develops one of his own. Stephen suggests that the universe was born from a black hole exploding. The black hole has such strong space-time singularity that nothing can escape from it, even light. The black hole is triggered by the collapse of a star.
The doctor explains to Stephen Hawking that Motor Neuron Disease is affecting his ability to use any muscle activity, such as speaking, walking, breathing, and swallowing. The signals that tell the muscles to move are disrupted, and the result is gradual muscle decay.