Mass is not a dead pile of stuff. It is energy wearing a quieter costume. E = mc² says a tiny amount of mass stores an enormous amount of energy — because c, the speed of light, is huge, and squared it becomes almost unimaginable.

Imagination is not the opposite of science. It is one of science's sharpest tools. Before the equation, there is a picture: an elevator falling, a beam that will not slow, a geometry that bends. If you cannot picture it, you may not yet understand it.

On this day in 1955, the Russell–Einstein Manifesto called scientists and citizens to face the danger of nuclear war with clear eyes. Knowledge without responsibility is incomplete. The manifesto asked a blunt question: shall we put an end to the human race, or shall we renounce war?

Imagination must be held by the reins of science, or it bolts into fantasy. Yet science without imagination is a ledger with no horizon. Hold both: the dream that asks, and the proof that answers.

A good question is a lamp, not a snare. Ask to understand the other person's meaning. If you only ask to win, you will win — and remain unwise.

The unexamined life is not worth living — or so the story goes of my defense. Examination is not self-obsession. It is refusing to sleepwalk through your own choices.