Neutrons do not, so they escape and go thudding into the shielding material around the reactor.

ECONOMIST: How to get an energy rush without doughnuts

He strolled the waterfront with the beer thudding inside his head, a lonely feeling pulling at his heart.

NEWYORKER: Fiction

It's midmorning when we leave, cool and sunny, the only noise the dull, rhythmic thudding of hooves on dirt.

FORBES: Hi-Ho, Nell

He was sent to the canvas with 30 seconds left in the opening round with a thudding straight right.

BBC: Incomparable drama in Glasgow on Burns' night

Romney comes on strong, holding his attackers close and thudding into them relentlessly.

BBC: Romney takes all in Las Vegas?

His first U.S. effort is full of bold, broad comic book strokes -- some of them pleasingly original, like a car chase through a cornfield, the husks of corn thudding against the windscreens like oversized bugs.

CNN: STORY HIGHLIGHTS

No matter how many times a person has daydreamed, acted it out with Barbie and Ken, and emotionally bolstered for the exchange, or if it's come thudding from the sky like an errant chunk of satellite, a proposal carries an impact that must be absorbed.

CNN: What's with public marriage proposals?