Here’s what’s gonna happen:
The black hole will instantaneously grow to the size of the orbit of the planetoid Pluto, then slow down its growth advance to a bit slower than the speed of light. We, being inside the black hole, will not notice a thing. Everything will look and feel exactly as it did before the Black Hole was created. The scientists will be disappointed because they will think that “nothing” happened, when actually it did happen, only they cannot see it. To an outside observer, on Alpha Centauri, for instance, they will see a star go out.............
... Meanwhile somewhere in Middle Earth... several creatures notice as “The Nothing” threatens their existence. On a different existence, the U.S.S. Enterprise is thrown through a quantum chronometric particle generator and thrown sideways into our own time line. John Titor says, “I told you so...”
Wouldn’t we see significant blue-shifting as the light from outside the sphere is pulled (elongated) towards us?
Either way, I’m gonna drink heavily and pray for Monday off.
If the black hole is that big (read: massive), no need to worry how it looks at Alpha Centauri because it will be inside with us!