Coupling (physics)

The connection affects the oscillatory pattern of both objects.

These equations represent the simple harmonic motion of the pendulum with an added coupling factor of the spring.

[1] This behavior is also seen in certain molecules (such as CO2 and H2O), wherein two of the atoms will vibrate around a central one in a similar manner.

In practice, however, there is often leakage, so most systems are not perfectly coupled.

If coupling is present, then there will be a triplet, one larger peak with two smaller ones to either side.

This occurs due to the spins of the individual atoms oscillating in tandem.

[2] Objects in space which are coupled to each other are under the mutual influence of each other's gravity.

For instance, the Earth is coupled to both the Sun and the Moon, as it is under the gravitational influence of both.

Common in space are binary systems, two objects gravitationally coupled to each other.

Multiple objects may also be coupled to each other simultaneously, such as with globular clusters and galaxy groups.

When smaller particles, such as dust, which are coupled together over time accumulate into much larger objects, accretion is occurring.

[3] The coupling constant of a plasma is given by the ratio of its average Coulomb-interaction energy to its average kinetic energy—or how strongly the electric force of each atom holds the plasma together.

Two coupled quantum systems can be modeled by a Hamiltonian of the form

which is the addition of the two Hamiltonians in isolation with an added interaction factor.

[5] When angular momenta from two separate sources interact with each other, they are said to be coupled.

[6] For example, two electrons orbiting around the same nucleus may have coupled angular momenta.

Specifically, it is the interaction between the intrinsic spin of a particle, S, and its orbital angular momentum, L. As they are both forms of angular momentum, they must be conserved.

Even if energy is transferred between the two, the total angular momentum, J, of the system must be constant,

This interaction is caused by one of the fundamental forces, whose strengths are usually given by a dimensionless coupling constant.

In quantum electrodynamics, this value is known as the fine-structure constant α, approximately equal to 1/137.

For quantum chromodynamics, the constant changes with respect to the distance between the particles.