It was the 1960′s before anyone had an observatory strong enough to separate out quasars from the rest of the starlight, even though those quasars were the brightest spots of light in the sky.
Initially, there was suspicion that little green men or magic mushrooms were involved the observations (it was the sixties, after all) when astronomers spotted those intense beacons of light waves coming from as far away as it was possible to see.
But actually, quasars turned out to be more mysterious than little green men. They were black holes firing off beams of intense synchrotron radiation from the accretion disks whirling around outside their event horizon.
What’s more, their Doppler red shifts revealed quasars were pretty close to the oldest structures in the sky. About thirteen billion years old.
But these black holes in the middle of these quasars were not just old and not just very bright. They were also really big, big. Sag X in our Milky Way is about four million times the size of our sun, but a quasar is billions of times heavier than that. Yes, billions. Makes Sag X look like a firecracker.
But every theory of black hole formation, including Einstein’s theory of General Relativity, said that wasn’t possible. Something that formed so early in the life of the universe just could not be that large with so much concentrated energy.
To get an idea of the problem, let’s start with how a regular black hole like our own Sag X is created. Black holes are formed when a big enough (bigger than our star) runs out of material to keep firing the internal nuclear fusion that allows it to resist when gravity tries to collapse it.
Gravity is not a friend to stars.
When the star can’t keep its nuclear fusion plant going, gravity makes it implode into a giant explosion that blows the elements it’s created in its nuclear fusion factory all over space, and collapses what’s left into a black hole.
Fine, but still nothing like the size, radiation, distance or age of these massive blacks in the middle of a quasar.
A theory about how those supermassive black holes formed that most astronomers like is that a whole galaxy has to collapse to make a supermassive black hole. How would that work?
Well, remember that the universe was a lot smaller thirteen billion years ago, so often that sometimes those young galaxies would be so soaked in ultraviolet light from newborn stars of neighboring galaxies that sometimes, a particular infant galaxy couldn’t cool down into a regular galaxy.
Instead that infant galaxy pulled in more and more hydrogen from their surroundings. Those hydrogen atoms collided like crazy, bumping everything into a higher energy state, and keeping everything inside the infant galaxy so hot that when it finally did cool, that cooling was such an abrupt event that brought on total collapse.
Baby galaxy fell into a giant black hole infinity.