To date, the smallest known black hole is only three times the mass of the sun, and it also happens to be the closest known black hole at only 1,500 light years away. Three solar masses is exceedingly small for a black hole, and as of yet, scientists do not know how a black hole of this size could have formed.
A black hole of this mass would be about the size of an atomic nucleus. Physicists have speculated that, when the universe was very young and hot, copious numbers of miniature black holes may have been produced. (To our knowledge, tiny black holes cannot form today.)
The remnant is located some 26,000 light-years from Earth and is just over a thousand years old (which is extremely young in cosmological terms). In fact, W49B is believed to be the youngest black hole that has been discovered in the Milky Way. But this beautiful object isn't unique simply because of its age.
As black holes evaporate, they get smaller and smaller and their event horizons get uncomfortably close to the central singularities. In the final moments of black holes' lives, the gravity becomes too strong, and the black holes become too small, for us to properly describe them with our current knowledge.
One hour for a black hole observer would equate to 100,000,000 years for a person on Earth. Therefore one minute in a black hole would be roughly 1,700,000 years.
The inequality suggests that to destroy a black hole, all you need to do is to feed it angular momentum and charge. But that hides a multitude of problems. For a start, things with angular momentum and charge also tend to have mass. And in any case, the equation above describes a steady state.
The possibility that a black hole could actually impact Earth may seem straight out of science fiction, but the reality is that microscopic primordial black holes could actually hit Earth. If one did, it wouldn't just impact like an asteroid, it'd pass straight through the entire Earth and exit the other side.
The Earth would be destroyed, but the whole planet would not be swallowed up by the black hole. A black hole with a Schwarzschild radius of about a centimeter, which would make it about the size of a coin, would have about the same mass as the Earth.
A light-year is a measurement of distance and not time (as the name might imply). A light-year is the distance a beam of light travels in a single Earth year, which equates to approximately 6 trillion miles (9.7 trillion kilometers).
The sound waves were discovered in 2003, when, after 53 hours of observation, researchers with NASA's Chandra X-Ray Observatory “discovered that pressure waves sent out by the black hole caused ripples in the cluster's hot gas that could be translated into a note.”
"Black holes form inside their host galaxies and grow inproportion to them, forming an accretion disc which will eventually destroy thehost," he added. "In this sense they can be described as viral innature."
Anything outside this surface —including astronauts, rockets, or light—can escape from the black hole. But once this surface is crossed, nothing can escape, regardless of its speed, because of the strong gravitational pull toward the center of the black hole.
It is possible for two black holes to collide. Once they come so close that they cannot escape each other's gravity, they will merge to become one bigger black hole.
Near a black hole, the slowing of time is extreme. From the viewpoint of an observer outside the black hole, time stops. For example, an object falling into the hole would appear frozen in time at the edge of the hole.
The singularity at the center of a black hole is the ultimate no man's land: a place where matter is compressed down to an infinitely tiny point, and all conceptions of time and space completely break down.
Time does stop at the event horizon of a black hole, but only as seen by someone outside the black hole. This is because any physical signal will get infinitely redshifted at the event horizon, thus never reaching the outside observer. Someone falling into a black hole, however, would not see time stop.
Will the Sun become a black hole? No, it's too small for that! The Sun would need to be about 20 times more massive to end its life as a black hole.
The short answer, unfortunately, is no. White holes are really just something scientists have imagined — they could exist, but we've never seen one, or even seen clues that one may exist. For now, they are an idea. To put it simply, you can imagine a white hole as being a black hole in reverse.
Going faster than the speed of light
Astronomers agreed that the black hole was spinning really fast, but obviously not as faster than the speed of light — the universal speed limit. Yet, Chandra's X-ray data showed that M87 was spinning between 2.4 to 6.3 times faster.
The known laws of physics suggest that by about 10100 (the No. 1 followed by 100 zeros) years from now, star birth will cease, galaxies will go dark, and even black holes will evaporate through a process known as Hawking radiation, leaving little more than simple subatomic particles and energy.
Jim Fuller. The loudest sound in the universe definitely comes from black hole mergers. In this case the “sound” comes out in gravitational waves and not ordinary sound waves.
That's a note played at a frequency a million, billion times lower than anything the human ear can detect. And the output is a whopping ten-to-the-power-of-thirty-seven watts, or about ten billion times the energy of our Sun.