These are more powerful than run-of-the-mill supernovae, which occur when a star runs out of fuel and implodes with a sudden loss of radiation pressure akin to demolishing the supports holding up a roof.

During the star-forming phases, the radiation pressure from the stars would blast out dust, making the galaxies appear bright and blue.

Solar radiation pressure is exceedingly weak, however, which is why practical solar sails must be so large.

“I’m making an analogy to the Casimir effect, where you can push plates together with a noticeable radiation pressure from the vacuum,’’ he says.

Spacecraft powered by novel propulsion methods, such as light sails accelerated by a laser beam from Earth or by solar radiation pressure, are another option, but they involve difficulties of their own.