Tag: black holes

Detection of black holes

As we have described a black hole, we never can observe one of them because they would not reflect or emit any radiation or particle. But there are certain effects that can be detected. One of these effects is the gravitational effect on a neighboring star.

Suppose a binary star system (two stars so close to turning the one around the other) in which one of the stars is visible and than we can calculate its distance from Earth, and its mass. The visible star will make a few oscillatory movements in space due to the gravitational attraction of the invisible star. From these movements we can calculate the mass of the invisible star .

If this invisible star exceeds a mass of about 2.5 times the mass of our Sun, we must assume that it’s a black hole.

Continue reading “Detection of black holes”

Special Relativity Theory And Black Holes

It is possible to find the relationship between the mass and the radius of a spherical black hole keeping in mind that the maximum speed that could reach an object, according to the theory of relativity, it is the speed of light.

The scape velocity in the surface of a spherical star will be the maximum velocity that could reach an object in order to stay in orbit around the star. This will happen when the kinetic energy of one object is equal to the potential energy due to the star gravitational attraction. Continue reading “Special Relativity Theory And Black Holes”

Introducction to black holes

We are studying an object, that people may think from recent conception, but that it was conceived more than two centuries ago.

In their initial conception, a black hole was an object with a gravity force in their surface so big that nothing could escape from him; not even light if it were affected by gravity (this was not known 200 years ago). Before measuring the speed of light and before the theory of relativity, by means of which it was demonstrated that nothing could surpass the speed of light, people thought that a body could reach an infinite speed and therefore the black hole was a body in which the scape speed was also infinite. This could only happen in the case of a infinite mass star or infinite density star. This cases were illogical cases and the scientists did not give any importance to the matter, falling it in the oblivion.
Continue reading “Introducction to black holes”

How a black hole is formed

Suppose a star like the sun that is exhausting its nuclear fuel turning its hydrogen into helium and this into carbon, oxygen and finally iron coming a time when the heat produced by nuclear reactions is short to produce a dilation of the Sun and thus compensate the force of gravity. Then the sun collapses increasing its density, being only slowed down this collapse by the repulsion between the electron shells of atoms. But if the mass of the sun is high enough it will be overcome this repulsion (exceeding the Chandrasekar limit) being able to get to merge the protons and electrons of the atoms, forming neutrons and reducing the volume of the star leaving no space between the nuclei of the atoms. The Sun was to become a sphere of neutrons and therefore would have a very high density. It would be what is called “neutron star”.

 

explosión de estrella

Continue reading “How a black hole is formed”