Thanks LibWhacker.
· List topics · post a topic · subscribe · Google ·
Posted on 09/12/2013 6:29:02 PM PDT by LibWhacker
Nobody knows how the universe’s biggest black holes grow so large. Now one astrophysicist says it’s because they feed on the quantum foam that makes up the fabric of spacetime
One of the more fascinating astrophysical discoveries in recent years is that almost all galaxies hide supermassive black holes at their cores. Indeed, astronomers believe that galaxies and black holes have a kind of symbiotic relationship so that one cannot form or grow without the other.
The evidence comes from observations of galaxies both near and far—almost all contain huge black holes.
But that raises an interesting question. We see the most distant galaxies as they were soon after the universe began. Some of these contain black holes that are a billion times more massive than the Sun but are themselves only a billion years old. The problem for astrophysicists is how these black holes could have grown so massive in such a short space of time.
Today, we get an answer from Marco Spaans at the University of Groningen in the Netherlands. He says that black holes can grow by feeding on the quantum black holes that leap in and out of existence at the smallest scale. These quantum black holes are part of the so-called quantum foam that physicists believe makes up the fabric of the Universe.
If Spaans is right, black holes grow by feeding on spacetime itself and their quantum feeding habits effectively solve the problem of how the biggest black holes become so massive, so quickly. “Supermassive black holes can acquire a lot of their mass through these quantum contributions over the life time of the universe,” he says.
Here’s some useful background. In 1955, the American theoretical physicist John Wheeler suggested that at very small length scales, virtual particles, including quantum black holes, must constantly jump in and out of existence creating a kind of foamy structure that is very different from the smooth spacetime we see at larger scales.
Nobody has ever observed quantum foam but there is widespread agreement that the fabric of the universe must be made of something like it.
In ordinary circumstances, quantum foam has little impact. However, physicists think it must play an important role in the most extreme circumstances where the universe is being torn apart by the forces acting on it. Black holes are clearly one of these places.
Spaans’ approach is to ask what happens when a black hole meets quantum foam. The answer is straightforward. “Quantum fluctuations in the form of mini black holes can couple to macroscopic black holes and allow the latter to grow exponentially,” he concludes.
He says this kind of growth can easily account for the observed size of relatively young supermassive black holes. And he goes on to predict that this mechanism could allow smaller black holes to grow too. In fact, he suggests these smaller objects, which would be difficult to observe from Earth, could make up a significant fraction of the mysterious dark matter that astronomers believe the universe must contain.
That’s interesting stuff but new ideas are worth little unless they make experimentally testable predictions and Spaans does not disappoint in this respect. He says that this quantum feeding mechanism must apply to the supermassive black hole at the centre of our galaxy and that consequently, it must be growing at the rate of about 10^-3 solar masses per year.
And that ought to be measurable. Spaans says that signals produced by pulsars are particularly sensitive to their local gravitational conditions. So it should be possible to spot the the increasing gravitational field of a growing black hole by studying pulsars that orbit close by.
He points just such a pulsar was discovered earlier this year at the centre of our galaxy and that a long-time monitoring program of its behavior is now in order.
Such a program would take years or even decades to reveal the kind of changes that Spaans predicts. But when it comes to the feeding habits of black holes, knowing what’s on the menu could be priceless information.
“Almost all galaxies hide super massive black holes”
So that’s why the neighbors put up that tall fence. I suppose it will affect my property value.
Because you did not observe the black hole in the center of the Milky Way growing in mass at a rate of 0.001 solar masses per year!
“Over the life time of the universe”
Say what? Life time? The universe has a life time? Where are we at? Is it like shedding baby teeth or is it yelling at the kids to get off the lawn?
“What happens when a black hole meets quantum foam”
I don’t know. They exchange business cards?
“Where the universe is being torn apart”
The universe is being torn apart? It’s bad enough that it has a life time, but now it’s being torn apart? Oh, it’s gonna take a quart of tequila to fall asleep tonight.
Wait a minute. A blended Margarita has foam! Maybe the galaxy is like a margarita. A little sweet.....a little tangy......a little salty......So that means the planets are like tortilla chips and the stars are salsa? Why, it’s a fiesta!
Where the hell is Aaron Neville when you need him?
13.7 billion years young. Very young. See The five ages of the universe, according to Adams, et al.
Not only will the universe be torn apart, but all matter in it, right down to protons, neutrons, quarks, etc. But it’s only a theory (a very likely looking one at this point!).
If I only had a dollar for every time I've said that.
Well, I will say one thing.... If a black hole is destined to eat us, there’s not one damn thing we could ever do about it.
You want me to read? Did my Mom put you up to this? And why do they always have to put down what a glutton the guy is? “et al”? Why not? He probably paid for all the food.
I put all my money into Quantum Cream.
-PJ
Well, I want to meet the black hole that can tear apart a bag of that Costco Trail Mix. I’ve pulled on those and tried to chew a little tear.....nothing. Oh, the stars may all fall away, but there will still be those little bags of Costco Trail Mix still floating around. The ones with the teeth marks will be mine.
Dark matter, Dark Energy, Quantum foam.
Aren’t computer models fun!!!!
And all this time I thought it was the dryer eating my socks.
Now you want a dollar! In addition to all those chicks?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.