The fascination of origins—the very long view.
Curiosity about personal ancestry has made Ancestry DNA and 23andMe booming businesses. Marketing has grown this kind of curiosity into a lucrative appetite. Indications are that the customer base is doubling annually.
Curiosity about cosmic origins might be growing more slowly, but the explosion of new information about the early universe thrills a lot of folks, without much money changing hands. To consider where we come from on the largest time scales has a calming effect in this tempestuous, maddening, frightening, and tragic moment in human history. Launching one’s imagination into the vastness of space leaves behind much of the craziness of our political, social, and cultural (melo)dramas.
TABLE OF CONTENTS
This is a very long post, perhaps of little interest to those who don’t share my fascination with cosmic origins. I present a table of contents of the sections below as a guide to what’s in store.
- Not just another pretty face: ancient spiral galaxy.
- The unmiraculous miracle of gravitational lensing
- Implications of the age of the earliest spiral galaxy
- Galactic structure, supermassive black holes, and a question of timing
- Primordial black holes to the rescue!
- An aside on supermassive black holes at the centers of galaxies
- More on spirals
- A Family Tree of galaxies
- THE END
Not just another pretty face: ancient spiral galaxy
Don’t we just love our spiral galaxies?!? It’s not so much love, it’s more like being awestruck by ineffable beauty, combined with the knowledge that each typically contains hundreds of billions of stars spread out across distances up to hundreds of thousands of light years. (Another plus is that we actually live in one.) I’ve cheated a bit here by picking a particularly gorgeous example, the Pinwheel Galaxy—a kind of canonical form of which all spirals are variations on a starry theme. (For a spectacular collection of spiral galaxy images, follow the link: glorious spirals in abundance .)