Wolff compares the speeds of what two objects within Paragraph 35?

Wolff states that once the bullet hits Anders's cranium, it is traveling at a speed of "900 feet per second" (35). However, he then points out that this pace is "sluggish and glacial" compared to the "synaptic lightning" (35) occurring within Anders's brain, giving Anders plenty of time to witness one particular memory at his leisure.