One of the key differences between galaxies with super massive black holes is whether or not the black holes are lit up, because they are basically bingeing on a lot of material in its surroundings.
Andrea M. Ghez
An ordinary black hole is thought to be the end state of a really massive star's life.
How do you observe something you can't see? This is the basic question of somebody who's interested in finding and studying black holes. Because black holes are objects whose pull of gravity is so intense that nothing can escape it, not even light, so you can't see it directly.
The question that I started off with was, I thought, very simple. It was just 'Is there a massive black hole at the center of the Milky Way?' But one of the things I love about science is that you always end up with new questions.
One of the big mysteries about the black hole at the center of the galaxy is, 'Why don't we see emission from matter falling onto the black hole, or, rather, the black hole eating up its surroundings?'
Our galaxy's pretty ordinary, garden-variety. So if we believe our galaxy has a super massive black hole, that tells us that most, if not all, galaxies host such a black hole at their centers.
As an astronomer, I get to ignore the details of the things that we don't understand. There's a lot of work that we can do on scales that we do understand, and there is actually a finite size that I can associate with a super massive black hole.
Black holes are very exotic objects. Technically, a black hole puts a huge amount of mass inside of zero volume. So our understanding of the center of black holes doesn't make sense, which is a big clue to physicists that we don't have our physics quite right.
We have this interesting problem with black holes. What is a black hole? It is a region of space where you have mass that's confined to zero volume, which means that the density is infinitely large, which means we have no way of describing, really, what a black hole is!
The key to proving that there's a black hole is showing that there's a tremendous amount of mass in a very small volume. And you can do that with the motions of stars. The way the star moves around the center of the galaxy is very much like the way the planets orbit the sun.
Proof of the black hole is a tremendous amount of mass inside a very small volume. There's 4 million times the mass of our sun within a region that's comparable to the size of our solar system.
Fortunately, most things around the supermassive black hole are just going to go around it. They're going to orbit it. They don't actually get sucked in.
There's a large cluster of stars that are orbiting the center of our galaxy. And by measuring the motion of stars, and in particular, their orbits, we can figure out whether or not there's a central black hole.
I'm interested in finding whether or not there is a really massive, what we like to call 'super massive' black hole at the center of our galaxy. And the reason this is interesting is that it gives us an opportunity to prove whether or not these exotic objects really exist.
The key to proving that there's a black hole is showing that there's a tremendous amount of mass in a very small volume. And you can do that with the motions of stars.
Christmas sits like a black hole on the calendar. Just try scheduling a meeting at work the month of December.
Andrew Shaffer
Depression can take you into a black hole, so it is terrible.
Asha Parekh
My work indicated that if we consider smaller and smaller black holes, at some stage, the properties of black holes become indistinguishable from those of elementary particles.
Ashoke Sen
My work on black holes was on the connection between black holes and elementary particles.
There's a lot of cruelty going on all the time, and I'm not just talking about inter-human cruelty. I'm talking about whole species becoming extinct, asteroids hitting planets, black holes gobbling up stars.
Barbara Ehrenreich
When the signal reached LIGO from a collision of two stellar black holes that occurred 1.3 billion years ago, the 1,000-scientist-strong LIGO Scientific Collaboration was able to both identify the candidate event within minutes and perform the detailed analysis that convincingly demonstrated that gravitational waves exist.
The size of the effect that we measured from the first event, the merging of two black holes, the actual size of the signal was about one thousandth the size of a proton, what it did to our apparatus.
When I was four, I wrote a song about falling into a black hole.
Black holes provide theoreticians with an important theoretical laboratory to test ideas. Conditions within a black hole are so extreme, that by analyzing aspects of black holes we see space and time in an exotic environment, one that has shed important, and sometimes perplexing, new light on their fundamental nature.
Black holes, we all know, are these regions where if an object falls in, it can't get out, but the puzzle that many struggled with over the decades is, what happens to the information that an object contains when it falls into a black hole. Is it simply lost?
I've seen children's eyes light up when I tell them about black holes and the Big Bang.
Einstein got most of the things right about black holes. I'm not an expert, I must admit.
'Black Hole Sun' was written in a car when I was driving home from the studio one night. Pretty much everything that you hear was written in my head.
Six is the hardest number for me to experience, the smallest. It's the absence of something - it's cold, dark, almost like a black hole. If someone tells me they are depressed, I might imagine myself in the hole of a six to help me empathise.
I once had an extraordinary experience with former prime minister Ted Heath. Both of his eyes, including the whites, turned jet black, and I seemed to be looking into two black holes.
The Holocaust, taken by itself, is a black hole. To look at it directly is to be swallowed up by it.
Here's my definition of a great beach read - a fabulous story that sucks me in like a black hole and when it's over, it jettisons my bones across the galaxy with a hair on fire mission to convince everyone I know that they must read that book or they will die.
I wouldn't have thought that a wrong theory should lead us to understand better the ordinary quantum field theories or to have new insights about the quantum states of black holes.
An asteroid or a supervolcano could certainly destroy us, but we also face risks the dinosaurs never saw: An engineered virus, nuclear war, inadvertent creation of a micro black hole, or some as-yet-unknown technology could spell the end of us.
I'm just a black hole for stuff. No one should ever hand me anything, because I get so easily distracted. I'll be like, 'Oh, look, something shiny!' I'm glad I never learned how to drive. I would be really dangerous.
I just see religious freedom, as a category, as just being a black hole.
The daily calendar seemed, to me, like a kind of cartoon black hole, and you didn't have to be a rocket scientist to know that that couldn't be sustained indefinitely. That's why I pulled the plug on that one after the '02 edition. Kind of a preemptive strike.
We did a play of 'Frog and Toad' at my elementary school. And I'm not sure if this is part of the book or it was something that we made up on our own, but I auditioned to play the black hole, which somehow makes sense to me.
Auschwitz will forever remain the black hole of the entire human history.
It's hard to know which stars in the sky will turn into black holes. And which ones will open up worm holes into entire new universes.
Black holes are pretty scary when you ponder them. They seem nihilistic, infinitely destructive on an inconceivable scale, notwithstanding the ideas of Hawking radiation.
We would look up at the night sky together, and although Stephen wasn't actually very good at detecting constellations, he would tell me about the expanding universe and the possibility of it contracting again and describe a star collapsing in on itself to form a black hole in a way that was quite easy to understand.
Black holes can bang against space-time as mallets on a drum and have a very characteristic song.
Now, our Sun will not collapse to a black hole. It's actually not massive enough.
It's sometimes better to have a father figure to rebel against than nothing, than just a black hole or an absence.
The internet to me is kind of like a black hole, and I never really go on it.
So much of my sense of who I am is tied to mothering. When they left home, I fell into a huge, empty, black hole. Your children are grown and your career has slowed down - all the stuff that took up so much attention is gone, and you're left with expansive time and space.
I ended up moving to Miami and bartending, but the party atmosphere is a black hole down there. People party all the time, and if you're working in the industry, you're sleeping all day and at the club all night, day after day.
When the doctors showed me an X-ray of my brain, they pointed to a black hole on the upper left side and told me that all memory from that spot was dead. I thought to myself that I hoped that's where I kept 'The Orange Blossom Special.'
There has been a black hole in the bar business in Las Vegas, particularly on the Strip in tourist areas.