Novel about a civilization escaping from their world, breaking through the alien experimnent in their silver spaceships into the alien universe [duplicate]

Question

I remember reading a novel as a teenager, all I remember is at the end of the book, a civilization was able to finally escape their dying world.

The book described little silver spaceships breaking through the outer shell of some alien experiment (A simulation?), and into this alien world. I think it was in a shed. Sorry I don't have anymore on it. I keep thinking it was "the Weapon Makers" but when I read the synopsis of that novel, it doesn't match that.

I think the "aliens" were doing a experiment that created a small universe and manipulated it study the evolution of the inhabitants, and they was able to break free and escape. I recall at the end the alien (child?) watched as several small silver spaceships broke through the outer shell (?) and escaped up into the sky...

Answer 1

This might be The Edge of Time by David Grinnell (Donald A. Wollheim) (1958, 1959) as described here:

Earthlings create and interact with a pocket universe; universe inhabitants eventually desire to escape1

Answer 2

This sounds like "The Crystal Spheres" by David Brin. (See Wikipedia: https://en.wikipedia.org/wiki/The_Crystal_Spheres)

It was published 1984. The basic plot is out first attempt at interstellar travel ends with the ship destroyed at the edge of interstellar space by a transparent barrier. It turns out that all Earth-like solar systems are surrounded by crystal spheres, but not the uninhabitable systems are not. They can't be broken from the outside. In the story, there is an expedition to a just-discovered habitable solar system with a shattered sphere and the remnants of an alien civilization, the Nataral. It turns out that you can bust out, but not bust in. (Neat solution to the Fermi Paradox!)

But no shed!