What is the significance of the Dirac Sea in modern quantum theory?

[sol2]

Imagine for one moment that a bubble arises out of dirac's sea. This bubble is a summmation of brane worlds?

The Dirac sea is an interpretation of the negative energy states that comprises the vacuum In physics, a vacuum is the absence of matter (molecules, atoms...) in a volume of space. A partial vacuum is expressed in pressure units. The SI unit of pressure is pascal (Pa). It can also be expressed as a percentage of atmospheric pressure using the bar or barometer scale.


Degrees of vacuum
atmospheric pressure = 760 torr or 100 kPa
vacuum cleaner = around 300 torr or 40 kPa
mechanical vacuum pump = around 10 millitorr or 1.3 Pa
near Earth outer space = around 10-6 torr or 130 μPa
pressure on the Moon = around 10-8 torr or 1.3 μPa
interstellar space = around 10-10 torr or 13 nPa

The Dirac sea of particles and antiparticles is part of the foundation of modern quantum theory.

Paul Adrien Maurice Dirac
Paul Adrien Maurice Dirac, (August 8 1902 - October 20 1984) was a physicist and a founder of the field of quantum physics.

BiographyDirac was born in Bristol, Gloucestershire, England. In 1926 he developed a version of quantum mechanics, which included “Matrix Mechanics” and “Wave Mechanics” as special cases.

In 1928, building on Pauli's work on nonrelativistic spin systems, he derived the Dirac equation, a relativistic equation describing the electron. This allowed Dirac to formulate the Dirac sea and predict the existence of the positron, the electron's anti-particle; the positron was subsequently observed by Anderson in 1932. Dirac explained the origin of quantum spin as a relativistic phenomenon.

The "sea" has an infinite background charge and may play a role in the perceptions of spacetime

In special relativity and general relativity, time and three-dimensional space are treated together as a single four-dimensional manifold called spacetime (alternatively, space-time). A point in spacetime may be referred to as an event. Each event has four coordinates (t, x, y, z); or, in angular coordinates, t, r, θ, and φ. structures.
Dirac studied the electron in complex spacetime

In special relativity and general relativity, time and three-dimensional space are treated together as a single four-dimensional manifold called spacetime (alternatively, space-time). A point in spacetime may be referred to as an event. Each event has four coordinates (t, x, y, z); or, in angular coordinates, t, r, θ, and φ.
, Dirac published the Dirac equation. With the Dirac formalism, electron description is a particle to the proton. After others (including Hermann Weyl, Robert Oppenheimer, and Igor Tamm) disproved this possibility, Dirac predicted a new particle, the positron. If negative energy is transformed into a positive energy state, the energy is perceived as a positron. Positron is the antiparticle of electron. Positrons are produced through pair production (bipolar coupling).

In relativistic quantum mechanics, Dirac's equation admits both positive and negative energy states. So, what is there to prevent a fermion from constantly radiating away energy, resulting in lesser and lesser energy, resulting in a huge instability? Dirac proposed almost all the negative energy states are filled by a sea of negative energy fermions. In modern treatments of quantum field theory, the Dirac sea is subtly introduced by having different definitions for the occupation number for positive and negative frequency decompositions.

The model of a negative energy "sea" of electrons has critics.

http://encyclopedia.thefreedictionary.com/Dirac sea

This bubble encloses all possible dimensions? M stands for mother, and out of the waters of this world, the children(universes) are born?

 

[sol2]

I stumbled upon the words of Sakharov in relation to Dirac's Sea.

For some of us who had gather at a earlier time, the effective electron-positron questions all of a sudden presenrted other solutions as to how we could percieve dynamical movement.

On that point we can only conjecture. Sakharov suggested accounting for the effects of general relativity by introducing the concept of an "elasticity of space," analogous to the well-known curvature of space-time. The answer could also lie in the proper treatment of the so-called Dirac sea of particle-antiparticle pairs. The question of general relativistic effects, however, is a valid concern that legitimately challenges the interrelated ZPF concepts of gravity and inertia.

http://www.calphysics.org/haisch/sciences.html

 

[selfAdjoint]

J. A. Schifflet has added a large cosmological constant representing ZPF to the unified field theory of Einstein and Schroedinger to get a consistent theory which in a suitable approximation yields correct electromagnetism and general relativity (it was the failure to do this which led the EUFT to be abandoned all those years ago). What the non-approximate theory (~nonperturbative) has in it is not yet known.

(Added in edit) See also http://arxiv.org/PS_cache/gr-qc/pdf/0403/0403052.pdf (PDF).