fastartcee wrote:I am always struck by the nearly-perfect spherical shape of these 200-odd clusters. (Yeah, I know... they're called 'spherical clusters'!) I cannot understand how there could have been all these spherical hydrogen clouds at the outset, all with well-distributed denser regions ready to condense into stars. Rather, spherical clusters look for all the world like the products of mega-explosions, with chaotic interaction of its denser portions giving rise to stars with various highly elliptical orbits around the center of combined mass.
A wilder idea I've had is that these 200 mega-explosions were, in fact, 200 Mini-Big-Bangs... some kind of 'echoes' of the original Big Bang. Would this not result in spherical mini-galaxies--nearly as old as the Universe--made up of stars having the observed radial distribution: densest in the middle, grading to vacuum at the periphery? I do not pretend to have even the vaguest idea as to how this could be; it is only wild speculation from a non-astrophysicist!
The only naturally occurring powerful explosions in space that astronomers definitely know about are the explosions of supernovas. (It is possible that, say, the merger of two supermassive black holes might cause the kind of titanic upheaval that can only be described as an explosion.)
While supernova explosions can indeed trigger star formation - by compressing nearby gas clouds so that they reach the critical density where they start forming stars - a single supernova explosion will not cause the kind of massive star formation that leads to the birth of a globular cluster.
Massive star formation in the nearby universe is often caused by galactic interaction and mergers. Take a look at this animation
, showing the interaction and ongoing merger between the two galaxies NGC 4038 and 4039, which are also known as the Antennae Galaxies