Rather generic name, and a generic plot. I've no idea why the guy is firing a weapon while manipulating a lever in open space. Review:

Cummings was most famous for his stories ("The Girl in the Golden Atom"; "Beyond the Vanishing Point", etc.) about shrinking drugs which enabled humans to visit worlds which exist in our universe only as atoms. In this novel, he goes in the other direction. Some super-science is developed which will make a spaceship far exceed the speed of light, and expand at the same time, and at a fantastic rate. The goal is to find the next level UP, wherein our universe is composed of their atoms.

Ah, the embedded cosmos of the Squeez-Pleez Ketchup Waitress. I know the concept well.