I have mixed feelings when people fight so fiercily against the "trying all possibilities at the same time" explanation. It makes it sound false, when in fact it is only incomplete. "Trying all possibilities at the same time such as they all add up constructively to the right answer" would be a better way to fix it.
From the article:
The goal in devising an algorithm for a quantum computer is to choreograph a pattern of constructive and destructive interference so that for each wrong answer the contributions to its amplitude cancel each other out, whereas for the right answer the contributions reinforce each other.
From the article: The goal in devising an algorithm for a quantum computer is to choreograph a pattern of constructive and destructive interference so that for each wrong answer the contributions to its amplitude cancel each other out, whereas for the right answer the contributions reinforce each other.