ブラックホールのジェットが宇宙のウェブのスケールで
関連する概念動画
Although black holes were theoretically postulated in the 1920s, they remained outside the domain of observational astronomy until the 1970s.
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
No object with a finite mass can travel faster than the speed of light in a vacuum. This fact has an interesting consequence in the domain of extremely high gravitational fields.
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape...
The gravitational potential energy between two spherically symmetric bodies can be calculated from the masses and the distance between the bodies, assuming that the center of mass is concentrated at the respective centers of the bodies.
Consider that a spherically symmetric mass distribution comprises multiple concentric spherical shells. A point mass is placed at a distance 'r' from the center of mass of the spherical shell. All the particles in a given spherical ring on the surface...
The magnetic field due to a volume current distribution given by the Biot–Savart Law can be expressed as follows:
To evaluate the divergence of the magnetic field, the divergence is applied to both sides of the Biot–Savart equation:
Applying the vector product rule, the term within the integral is simplified to the following equation:
The first term involving the curl of the current density function is zero since the current density is independent of the field coordinates. Using...
Free jets describe the flow of liquid exiting a reservoir through an opening into the atmosphere without resistance. The velocity (v) of the liquid jet is derived using Bernoulli's principle and expressed as:
Where h is the height of the liquid above the opening. This relationship assumes atmospheric pressure at both the reservoir surface and the jet exit. The fluid column's height governs the fluid's velocity at the nozzle in a reservoir, where the fluid's potential energy...
The principle of superposition applies to gravitational forces of objects that are sufficiently far apart. It states that the net gravitational force on a point object is the vector sum of the gravitational forces on it due to various objects. The principle helps calculate the force by listing the individual forces and then vectorially summing them up. However, it should be noted that the principle of superposition is not always apparent. In the presence of a second force, the first force could...

