Starship Asterisk*

Is it likely that all spiral galaxies have a black hole at the centre? I ask as I'm looking at today's image of Andromeda and noting that it's often compared to the Milky Way. The thought that we're all being sucked inevitably down a plughole, no matter what galaxy we travel to, is a bit bewildering
I've just started reading 'A Brief History of Time' as I got it for Xmas. Has anyone else read it? Does it explain black holes in galaxy cores?

Yours is an interesting question, and I hope someone more knowledgeable than I will address it.

It seems all spirals do indeed have enormous black holes at their centers. Andromeda apparently has two. I wonder if black holes exist in irregular and elliptical galaxies as well, and how these black holes may have partiicpated in the formation and evolution of galaxies.

Galaxies apparently are sufficiently stable such that the vast number of stars continue to rotate around the center rather than sprialing in. This issue of stability also explains why the planets of our solar system do not spin towards the sun and why the stars in globular clusters do not themselves coalesce.

If the current theory of an accelerating universe is correct, then galaxies will eventually fly apart, the planets of solar systems will leave their orbits, and eventually planets and then atoms themselves will explode.

I read Hawking's Brief History of Time some years back. I do not recall it explaining black holes at galactic centers, and even if it did, advances in the field would have augmented or even supplanted any explanation. Nonetheless, the book is well worth reading.

Two other authors well worth reading are Timothy Ferris (The Red Limit and The Whole Shebang) and Ken Croswell (The Alchemy of the Heavens).

RJ Emery wrote: Two other authors well worth reading are Timothy Ferris (The Red Limit and The Whole Shebang) and Ken Croswell (The Alchemy of the Heavens).

Thanks for the tips. I just ordered those books.

Cross