Exactly what are black holes, and what would happen to things that travel into them?

Question

I have heard numerous stories about black holes and that they contain "worlds" inside them or that they can be used for space travel from one point in the universe to the next point. Seriously though, what is up with black holes? What is the story?

Answer 1

A black hole is produced when a very massive star runs out of fuel. When the energy of fusion stops, the explosive energy keeping the star "inflated" at it's present size ends, and there's nothing but it's immense gravity acting on it's mass. The star collapses, creating a super-dense mass, and a massive explosion - blowing OUT huge amounts of matter, while at the same time, compressing an extremely massive core.

What happens to the core is based on the mass of the star and the force of the explosion. If the core is compressed such that the electrons and protons of it's atoms are merged, you end up with a mass made up of nothing but neutrons - a neutron star. Usually, these spin very rapidly (The Crab Nebula is the end result of a supernova, with a neutron star rotating at about 30 times a second.)

If the force of the explosion and mass is even more powerful, collapse doesn't stop there - it compresses the core down to a dimensionless point in space - a black hole. Surrounding this black hole, is the Event Horizon - a border between the realm of a black hole - where escape velocity is greater than the speed of light, and normal space.

Answer 2

nothing more than imploded stars. after the stars die..... (supernova) or whatever, some collapse in on themselves (implode)...... it has such "intense gravity" that it attracts everything with mass around it (pulling 'space' and even including light) into it. Light travels at a speed of 186,282.397 miles per hour..(" 1 foot per nanoscond") and is completely massless.... and not even light can escape the gravitational pull of a black hole. (thus, the terminology) The event horizon is what is considered the "edge" of the black hole..... it is the last place of possible escape. The "point of no return". Once an object passes over/crosses the event horizon, there is no possible way to escape the intense gravitational pull of the dead star. And everything gets sucked into the centre of the hole, being litterally ripped apart to a sub atomic level......
hence, there no "worlds" inside of them. it is not possible.

Answer 3

Black holes are just objects like planets or stars, but they are so dense that gravity on their surface is so strong that a bullet shot up even at the speed of light would eventually fall back. They do not contain other worlds, they are not gateways to other parts of the universe. If you landed on one, gravity would crush you. If you got too close to one, tidal forces (the same kind of tidal forces that make the ocean rise up and down a few feet every day on Earth) would tear your apart.

Answer 4

It would crush u to almost nothing ,possible the size of a pin point.The black hole is always in the center of the Galaxy and provides the gravity that holds every thing in orbit. It provides a true dimension to infinity . As the sun collapses the mass increases and increases the gravity until the parts reach the speed of light and at that point its mass is to become infinity.

Answer 5

when stars complete their red giant phase they collapse into a dense ball of gas , which becomes so dense that it starts collapsing under its own gravitational force.
now whoever or whatever goes near these gets strongly attracted towards it and can never escape the fall.

now scientist have predicted that there exist some points in the universe through which we can travel from one point to another in space.
THESE ARE CALLED "WORMHOLES".
they have a spiral shape which helps in the space travel. it is also predicted that we can have time-travel through these holes.

Answer 6

Black holes are formed when stars collapse on themselves - i.e. when the force of gravity overcomes the force of gases expanding due to heat from fusion. They are "black holes" because their gravity is so strong that the escape velocity - the speed needed for any object to escape from its surface is greater than the speed of light - so even light cannot escape them - making them "black". Scientists use the effect their gravity has on surrounding heavenly bodies to actually detect black holes. They cannot be seen.
Other worlds etc - theres no way wecan find out. There are many theoretical possibilities...

Answer 7

There is nothing inside black holes except an infinitely dense singularity into which everything that enters is crushed. There are no other worlds or portals inside them.

There's quite a bit of information on the subject at Wikipedia, or any of the *dozens* of replies on Y-Answers to this exact question.

Answer 8

Nunyabizness provided a very detailed and accurate account of the process. In an interesting aside, Neil DeGrasse Tyson (host of Nova Science Now) has written a series of essays on the oddities of cosmology, including the "stretching" process Nunya described. Tyson calls this process "spaghettification".

Answer 9

Black holes are the evolutionary endpoints of stars at least 10 to 15 times as massive as the Sun. If a star that massive or larger undergoes a supernova explosion, it may leave behind a fairly massive burned out stellar remnant. With no outward forces to oppose gravitational forces, the remnant will collapse in on itself. The star eventually collapses to the point of zero volume and infinite density, creating what is known as a " singularity ". As the density increases, the path of light rays emitted from the star are bent and eventually wrapped irrevocably around the star. Any emitted photons are trapped into an orbit by the intense gravitational field; they will never leave it. Because no light escapes after the star reaches this infinite density, it is called a black hole.

But contrary to popular myth, a black hole is not a cosmic vacuum cleaner. If our Sun was suddenly replaced with a black hole of the same mass, the earth's orbit around the Sun would be unchanged. (Of course the Earth's temperature would change, and there would be no solar wind or solar magnetic storms affecting us.) To be "sucked" into a black hole, one has to cross inside the Schwarzschild radius. At this radius, the escape speed is equal to the speed of light, and once light passes through, even it cannot escape.
What would happen to me if I fell into a black hole?
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Let's suppose that you get into your spaceship and point it straight towards the million-solar-mass black hole in the center of our galaxy. (Actually, there's some debate about whether our galaxy contains a central black hole, but let's assume it does for the moment.) Starting from a long way away from the black hole, you just turn off your rockets and coast in. What happens?

At first, you don't feel any gravitational forces at all. Since you're in free fall, every part of your body and your spaceship is being pulled in the same way, and so you feel weightless. (This is exactly the same thing that happens to astronauts in Earth orbit: even though both astronauts and space shuttle are being pulled by the Earth's gravity, they don't feel any gravitational force because everything is being pulled in exactly the same way.) As you get closer and closer to the center of the hole, though, you start to feel "tidal" gravitational forces. Imagine that your feet are closer to the center than your head. The gravitational pull gets stronger as you get closer to the center of the hole, so your feet feel a stronger pull than your head does. As a result you feel "stretched." (This force is called a tidal force because it is exactly like the forces that cause tides on earth.) These tidal forces get more and more intense as you get closer to the center, and eventually they will rip you apart.

For a very large black hole like the one you're falling into, the tidal forces are not really noticeable until you get within about 600,000 kilometers of the center. Note that this is after you've crossed the horizon. If you were falling into a smaller black hole, say one that weighed as much as the Sun, tidal forces would start to make you quite uncomfortable when you were about 6000 kilometers away from the center, and you would have been torn apart by them long before you crossed the horizon. (That's why we decided to let you jump into a big black hole instead of a small one: we wanted you to survive at least until you got inside.)

What do you see as you are falling in? Surprisingly, you don't necessarily see anything particularly interesting. Images of faraway objects may be distorted in strange ways, since the black hole's gravity bends light, but that's about it. In particular, nothing special happens at the moment when you cross the horizon. Even after you've crossed the horizon, you can still see things on the outside: after all, the light from the things on the outside can still reach you. No one on the outside can see you, of course, since the light from you can't escape past the horizon.

How long does the whole process take? Well, of course, it depends on how far away you start from. Let's say you start at rest from a point whose distance from the singularity is ten times the black hole's radius. Then for a million-solar-mass black hole, it takes you about 8 minutes to reach the horizon. Once you've gotten that far, it takes you only another seven seconds to hit the singularity. By the way, this time scales with the size of the black hole, so if you'd jumped into a smaller black hole, your time of death would be that much sooner.

Once you've crossed the horizon, in your remaining seven seconds, you might panic and start to fire your rockets in a desperate attempt to avoid the singularity. Unfortunately, it's hopeless, since the singularity lies in your future, and there's no way to avoid your future. In fact, the harder you fire your rockets, the sooner you hit the singularity. It's best just to sit back and enjoy the ride.

Answer 10

what!!!