The discovery of the Crab Pulsar, with a period of only 1/30 s, ruled out a number of possible explanations for pulsars. These included all of the following EXCEPT ONE. Which one was the exception?

Question

Quizplus · Accepted Answer

The discovery of the Crab Pulsar ruled out eclipsing binaries, variable stars, and rotating white dwarfs as possible explanations for pulsars, but did not rule out the possibility of rapidly shifting dark dust clouds as an explanation.

The Discovery of the Crab Pulsar, with a Period of Only