I have seen proposals for long distance spacecraft (early early proposals) that basically make the ship powered by a (for lack of a better term) a Hydrogen Ramjet. It's supposed to uses magnetic fields to "scoop" the hydrogen into the engine and use the whole fusion process to power the ship forward. However, all that being said, it was a proposed slower than light ship, and is possibly prone to energy spike issues if too much hydrogen is ingested when the crew is unawares.
So if dust hits a deflector dish at high speeds, wouldn't there be a fireworks show?
The only way dust would hit the dish would be if the dish was non-functional.
The discussion is about accumlation of atoms. Just what kind of show would result from a non-functional dish hitting atoms at near light speed I don't know. The article this thread is based on states that radiation would result which doesn't indicate there would be a show at all one way or the other. The article does not suggest the ship would explode or suffer structual damage from a few atoms, though indeed they'd be passing right through the structure.