Astrophysics

According to the particle theory of light, light is made us of particles called photon. Black hole has very high gravity. Its escape velocity being more than that of speed of light, light is attracted towards it and it even cannot escape

by lunizah: black holes attract every thing even the light because they have a very strong attractive force and that's the reason why black holes attract light!! ^_^

Yes, massive blue stars can eventually collapse and form black holes at the end of their lives. When a blue star exhausts its nuclear fuel, it undergoes a supernova explosion and if the remaining core is massive enough, it can collapse into a black hole due to gravitational forces.

It's safe to presume there are already enough black holes around to accomplish this - it's commonly accepted now that most, if not all, galaxies have a supermassive black hole at their center. However there's nothing intrinsically different about the kind of gravitational influence they have; for example, if the sun was replaced by a black hole of the same mass, the planets would continue to orbit the same as always (enjoying less light, of course). So all the stars in our galaxy and most others are safely orbiting the central mass and not getting sucked in, by virtue of the fact they are in an orbit - constantly accelerating towards the central mass and constantly missing it, the same way that planets are pulled towards the sun but not sucked in.

In the unlikely event that enough mass was added to all black holes to enlarge them sufficiently (remembering their radius is in direct proportion to their mass) to suck up all matter around them, then all galaxies would cease to visibly radiate and eventually the universe would be a very dark and uninteresting place indeed. But then, nobody would be around to observe the phenomenon.

One source calculates that if all the mass of the universe were in one place, it would form a black hole about ten billion light years across. That's pretty big, but, small compared to a universe which is likely vastly larger than what we can observe - and still it wouldn't have the ability to suck up the actual universe itself.

The shape of any planet's orbit is an ellipse. What changes over time isn't the shape, but the size of it, which is constantly, albeit very very very slowly, increasing, due to the constant loss of mass that the Sun experiences through fusion. Additionally, due to the number of planets, asteroids, comets, etc. in the solar system, one can only calculate the Earth's orbit with relative certainty for the next 100 million years or so. After that, nobody knows! This is why the Solar System is said to be chaotic.

Images are formed naturally through the reflection and refraction of light in our eyes. When light bounces off an object, it enters our eyes and is focused onto the retina by the lens, creating an upside-down image. This image is then converted into electrical signals that travel to the brain, where it is interpreted and perceived as a right-side-up image.

The Keck telescopes are optical, so no. The only possible exception being the super-luminous flash of Hawking radiation that theoretically occurs in certain-sized black holes, although orbital telescopes have a much better chance of detecting this light. Most of the electromagnetic radiation emitted from black holes has energies in the range of x-rays, an energy range that the Keck telescopes aren't designed for.

However, the most likely way that a black hole will be experimentally proven to exist is through the indirect method of measuring stellar orbits. Believe it or not, simple calculations from the ultra-precise, Keplerian orbital measurements of distant stars can be made to show the necessary size and mass of whatever object it is those stars are orbiting. If that size and mass fit the necessary conditions required of black holes, then there's your proof. The Keck telescopes are VERY well-equipped to make those kinds of measurements.

Some of the furthest galaxies are believed to be "travelling" faster than the speed of light.

They are not actually "travelling" faster than the speed of light, but creating space, faster than the speed of light.

It is generally believed that the mass of a black hole can indeed decrease, through the mechanism of Hawking radiation. A simplified view of this is that quantum fluctuations near the event horizon, influenced by gravity, can generate particle pairs, one of which can escape the vicinity of the black hole and thus carry away energy or mass. In effect this is a thermodynamic interaction with the universe as of black body radiation; the apparent temperature of the black hole being inversely proportional to the its mass. By this mechanism a black hole could 'evaporate', with the rate of evaporation increasing as the mass decreases.

This does of course presume that the amount of radiation emitted (Hawking radiation is calculated to be quite weak) is not balanced by the rate at which matter or energy is being absorbed by the black hole.

Yes, both black holes and neutron stars are remnants of the death of massive stars. Neutron stars form when the core of a massive star collapses but does not produce a black hole. Black holes are formed when the core of a massive star collapses beyond the neutron star stage.

Astronomers hypothesize that a massive black hole lies at the center of M87 because of the high speeds of stars orbiting the center, which indicate a very massive object. Observations also show a jet of energetic particles emanating from the center, which is commonly associated with supermassive black holes. Additionally, the size of the dark central region in M87 matches what is expected for a black hole event horizon.

Light that enters a black hole cannot escape due to the immense gravitational pull, resulting in the light being trapped within the event horizon and unable to be observed from the outside. It is thought to contribute to increasing the black hole's mass.

Strictly speaking, gamma rays don't exit a black hole; they are electromagnetic radiation just like visible light - although they carry a higher energy - and neither light nor matter can exit a black hole. However, a black hole can cause gamma radiation to be created near it - for example, by processes at quasars or active galactic nuclei, which, powered by a supermassive black hole, can generate immensely powerful jets or beams which can accelerate particles to relativistic speeds, boost lower energy photons, and generate powerful x-rays and gamma rays. Another possible source of gamma rays is the so-called black hole evaporation, through which a black hole could potentially lose its mass and end its life with an explosive gamma burst.

One common term used is black hole evaporation. This relates to a mechanism wherein the black hole's mass is gradually lost through Hawking radiation; but the rate of loss is inversely proportional to the black hole's size and thus accelerates as it shrinks. At the moment it vanishes it is thought to do so with a burst of gamma radiation; the Fermi space telescope is intended to search for such gamma flashes.

Our planet Earth will probably not spontaneously turn into a black hole under its own gravity since it lacks sufficient mass - it would need several solar masses to so collapse, and the Earth is just a tiny fraction of the mass of the Sun.

Good question.

Light cannot escape a black hole - that's how it gets it's name. To escape a Black hole, you would have to travel at faster than the speed of light.

That means matter approaching the center of the black hole must be accelerating to speeds approaching the speed of light.

If you were to approach the event-horizon (the edge of the black-hole where things turn nasty and there is no chance of escape, looking back things would red-shift, but you wouldn't notice much difference. As you then accelerated to light speed, time would slow down (according to Einstein's theories) and you would take an infinite amount of time to reach the center. You would die of old age long before you got there.

Observer's outside the event horizon however would see you shrink to nothing and disappear in a flash!

Yes, a planet could orbit a black hole, just like it could orbit a star. Gravity would

bind them together.

A planet orbiting 93 million miles from the sun feels exactly the same as if it were

orbiting 93 million miles away from a black hole with the same mass as the sun has.

I don't quite know what you mean by predicted (please try to make your questions very clear) but assuming you mean 'can their creation be predicted', then the answer is 'yes'. We know that very massive stars will leave a remnant that exceeds about 3-4 solar masses after they go supernova. If the stellar ruminant is above this mass then a black hole will form.

We can also predict where black holes 'are' by their effect on nearby bodies, this is how we know were and how massive the black hole in the centre of our galaxy is. Also although black holes do not emit light they do distort light passing near them and we can predict what this would look like (see related link below).

The larger the black hole, the weaker the tidal forces experienced by an object near its event horizon. Therefore, the black hole with the weakest tidal forces would be the most massive and least compact one.

The mass of a black hole can be measured by observing the orbits of objects around it, such as stars or gas clouds. By studying the gravitational effects of the black hole on these objects, astronomers can calculate its mass. Another method is to measure the distortion of light from objects behind the black hole, known as gravitational lensing, which can provide information about the black hole's mass.

The event horizon of a 100-solar-mass black hole is about 295 kilometers in radius. It represents the point of no return beyond which nothing, not even light, can escape the gravitational pull of the black hole.

First of all, every black hole has the same size ... its length, width, height, radius,

depth, diameter, area, and volume are all zero. What varies from one black hole

to another is their mass.

Next, black holes don't reach out and grab things that happen to be passing by.

Outside of the hole's "event horizon" it has the same influence as any other object

with the same mass. Other bodies that pass a black hole at a distance at which

they're moving slower than escape velocity will settle into orbit around the hole.

Light cannot escape from a black hole due to its extremely strong gravitational pull. The gravity of a black hole is so intense that not even light, the fastest thing in the universe, can escape its grasp.