I spend more time than I should trying to make sense of black holes, exactly because I struggle to make sense of them. I try, without success, to visualise what they might look like, if you could see them. Well, maybe you can’t see them, that’s why they’re called black holes. As it happens, I’m not the only one who is mystified by these objects.
In fact, there’s a lot that even those who study them full time, still don’t know. That’s reassuring. As I have discovered though, they do last for a long time, and may be some of the few remaining objects left when the universe itself finally reaches the end of its existence.
Nothing can escape from the immense gravitational attraction of a black hole. Not even light. Nor information either. Information, in this context, being a more palatable reference to the crushed and mangled remnants of whatever was captured by said black hole.
So it’s not data we that we might be able to do something useful with, were we ever to, somehow, retrieve it. Which we can’t. British physicist Stephen Hawking has been in the news recently, talking about this information, and offered a real world, easy to understand, explanation of this… stuff:
At Monday’s public lecture, he explained this jumbled return of information was like burning an encyclopedia: You wouldn’t technically lose any information if you kept all of the ashes in one place, but you’d have a hard time looking up the capital of Minnesota.
Doing so is probably a good idea, the only problem is the images would never make it back to us. Remember, nothing can escape from a black hole, not even light, to say nothing of photos. So much for that then.
According to Einstein’s theory of relativity, there is no problem sending a camera (or anything else) into a black hole (meaning that it goes in past the horizon). Getting it (or its photographs) back out is an entirely different issue. This is not possible.
This calls for some Amy Winehouse… Back to Black therefore seems appropriate. See if you can spot the lyric line here that didn’t escape the censorship black hole…
When you reach the horizon, Anne sees you freeze, like someone has hit the pause button. You remain plastered there, motionless, stretched across the surface of the horizon as a growing heat begins to engulf you. According to Anne, you are slowly obliterated by the stretching of space, the stopping of time and the fires of Hawking radiation. Before you ever cross over into the black hole’s darkness, you’re reduced to ash. But before we plan your funeral, let’s forget about Anne and view this gruesome scene from your point of view. Now, something even stranger happens: nothing.
The new VLT results indicate that the rotation axes of the quasars tend to be parallel to the large-scale structures in which they find themselves. So, if the quasars are in a long filament then the spins of the central black holes will point along the filament. The researchers estimate that the probability that these alignments are simply the result of chance is less than 1%.
Around 3.5 billion light-years away, this galaxy is estimated to contain the largest black hole presently known, at 18 billion solar masses. (Although, the error bars for this one and NGC 1277’s overlap substantially.) But the most spectacular part of this galaxy – and why we’re able to learn so much about it’s central region – is because there’s a 100 million Solar mass black hole (that’s 25 times larger than the one at the Milky Way’s core) that’s orbiting the even larger one!
But one compelling idea is that the seed of a universe is similar to the seed of a plant: It’s a chunk of essential material, tightly compressed, hidden inside a protective shell. This precisely describes what is created inside a black hole. Black holes are the corpses of giant stars. When such a star runs out of fuel, its core collapses inward. Gravity pulls everything into an increasingly fierce grip. Temperatures reach 100 billion degrees. Atoms are smashed. Electrons are shredded. Those pieces are further crumpled.
There are three ways, apparently, that an astronaut could fall into a black hole – it’s a good thing they’ve been catalogued then – and while the chances of survival are pretty slim, non existent really, at least “information” about the astronaut would be preserved, even if the hapless space explorer were to be completely crushed:
This original picture of black holes holds that they essentially destroy all information about anything that ventures past their event horizons – astronauts included. But quantum physics, the best description so far of how the universe behaves on a subatomic level, includes a principle known as unitarity, which maintains that information cannot be destroyed. To resolve this conflict, some scientists have recently (and controversially) suggested that black holes have “firewalls” at their event horizons. These are zones of extraordinarily destructive radiation. In this scenario, our astronaut would be instantly incinerated when crossing the event horizon, as would anything else falling into a black hole. The radiation released by the firewall would preserve information about the destroyed objects, astronauts included.
As if the universe were not weird enough… some recent thought on the topic, with the aim of going one better than the Big Bang theory, now suggests that the cosmos we reside in might have come to be as a result of a four-dimensional star collapsing into a black hole.
It could be time to bid the Big Bang bye-bye. Cosmologists have speculated that the Universe formed from the debris ejected when a four-dimensional star collapsed into a black hole – a scenario that would help to explain why the cosmos seems to be so uniform in all directions. The standard Big Bang model tells us that the Universe exploded out of an infinitely dense point, or singularity. But nobody knows what would have triggered this outburst: the known laws of physics cannot tell us what happened at that moment.
A four-dimensional star? That’s a new one on me… ever seen one of those before? I’m pretty sure I haven’t.
Ever wondered what a black hole actually looks like? The Event Horizon Telescope, a joint venture project combining the efforts of some twenty astronomical and scientific groups, which will attempt to capture high resolution images of the huge black hole located at the centre of the Milky Way, may soon enlighten us.
Over the next decade, our group proposes to combine existing and planned millimeter/submillimeter facilities into a high-sensitivity, high angular resolution Event Horizon Telescope that will bring us as close to the edge of black hole as we will ever come.