Black holes?

Question

My husband and I have been talking about black holes. And I have read that there isn't anyone even remotely close to the Earth, and he claims otherwise. What do you think?

Answer 1

It depends on how you define "remotely close". In any case, they are nothing to worry about. The closest black hole to us is about 1600 lightyears away. For comparison, the Sun is only 8 lightminutes away, and the closest star to us outside the solar system is 4 lightyears away.

However, we are still influenced by black holes no matter how far away we are at. For example, it is theorized that the black holes at the center of the galaxy are what keeps the Sun orbiting the galaxy (it does not remain stationary). Also, while the forces they exert on us is negligible, they still exist.

Answer 2

To form a black hole, a star must have a mass at least 20 times that of our Sun. If an object like that were anywhere near our solar system, the effects of its gravity would be plain. There are no nearby black holes.

There may be "mini-" or "micro-" black holes in the universe, with masses much smaller than that of a star. But these can only exist if a body can have a negative diameter, and that has yet to be seen.

Answer 3

If a black hole could exist it would be a 2 to 3 solar mass entity 3 km in diameter whose surface gravity was such that the escape velocity would be greater than the speed of light.
It would not be visible but the influence of it's gravity anywhere in the solar system would be well known and the configuration of the solar system would be nothing like it is.

Answer 4

There truly isn't any one close to Gaia, yet... When the Hadron Collider is activated later this year or early next year, it may trigger a catatrosphic event akin to that of a super-magnetic black hole.

Then, we will have another worldwide concert entitled Live Supermassive Blackhole to raise funds. Artistes include Muse, Soundgarden, Smashing Pumpkins of course.

Answer 5

The closest known black hole is 1,600 light years from Earth. Each light year is just under 6 trillion miles. So it's about 94,055,997,000,000,000,000,000 miles from Earth. Not close enough to be concerned about.

Answer 6

I think there are black holes close to earth. In fact I believe earth is at the end of one. However, imagine the chaos in our society if the powers that be let on to that fact.

Answer 7

There might be a black hole at the center of our Galaxy also known as th milky way,so that would be the nearest one to us.But I think it is millions of light years away.

Answer 8

cosmic body of extremely intense gravity from which nothing, not even light, can escape. A black hole can be formed by the death of a massive star. When such a star has exhausted its internal thermonuclear fuels at the end of its life, it becomes unstable and gravitationally collapses inward upon itself. The crushing weight of constituent matter falling in from all sides compresses the dying star to a point of zero volume and infinite density called the singularity. Details of the structure of a black hole are calculated from Albert Einstein's general theory of relativity. The singularity constitutes the centre of a black hole and is hidden by the object's “surface,” the event horizon. Inside the event horizon the escape velocity (i.e., the velocity required for matter to escape from the gravitational field of a cosmic object) exceeds the speed of light, so that not even rays of light can escape into space. The radius of the event horizon is called the Schwarzschild radius, after the German astronomer Karl Schwarzschild, who in 1916 predicted the existence of collapsed stellar bodies that emit no radiation. The size of the Schwarzschild radius is thought to be proportional to the mass of the collapsing star. For a black hole with a mass 10 times as great as that of the Sun, the radius would be 30 km (18.6 miles).

Only the most massive stars—those of more than three solar masses—become black holes at the end of their lives. Stars with a smaller amount of mass evolve into less compressed bodies, either white dwarfs or neutron stars.

Black holes are difficult to observe on account of both their small size and the fact that they emit no light. They can be “observed,” however, by the effects of their enormous gravitational fields on nearby matter. For example, if a black hole is a member of a binary star system, matter flowing into it from its companion becomes intensely heated and then radiates X rays copiously before entering the event horizon of the black hole and disappearing forever. Many investigators believe that one of the component stars of the binary X-ray system Cygnus X-1 is a black hole. Discovered in 1971 in the constellation Cygnus, this binary consists of a blue supergiant and an invisible companion star that revolve about one another in a period of 5.6 days.

Some black holes apparently have nonstellar origins. Various astronomers have speculated that large volumes of interstellar gas collect and collapse into supermassive black holes at the centres of quasars and galaxies. A mass of gas falling rapidly into a black hole is estimated to give off more than 100 times as much energy as is released by the identical amount of mass through nuclear fusion. Accordingly, the collapse of millions or billions of solar masses of interstellar gas under gravitational force into a large black hole would account for the enormous energy output of quasars and certain galactic systems. In 1994 the Hubble Space Telescope provided conclusive evidence for the existence of a supermassive black hole at the centre of the M87 galaxy. It has a mass equal to two to three billion Suns but is no larger than the solar system. The black hole's existence can be strongly inferred from its energetic effects on an envelope of gas swirling around it at extremely high velocities. Similar evidence suggests that a massive black hole with a mass of about 2.6 million Suns lies at the centre of our own Milky Way Galaxy.

The existence of another kind of nonstellar black hole has been proposed by the British astrophysicist Stephen Hawking. According to Hawking's theory, numerous tiny primordial black holes, possibly with a mass equal to that of an asteroid or less, might have been created during the big bang, a state of extremely high temperatures and density in which the universe is thought to have originated roughly 10 billion years ago. These so-called mini black holes, unlike the more massive variety, lose mass over time and disappear. Subatomic particles such as protons and their antiparticles (i.e., antiprotons) may be created very near a mini black hole. If a proton and an antiproton escape its gravitational attraction, they annihilate each other and in so doing generate energy—energy that they in effect drain from the black hole. If this process is repeated again and again, the black hole evaporates, having lost all of its energy and thereby its mass, since these are equivalent.

Answer 9

There is a very large one near the center of our galaxy.

Supposedly there are millions throughout the universe, so who knows.

Answer 10

Ummm. Your question doesn't really make much sense. You might need to elaborate on that a little.