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quote:Quantum physics predicts the existence of an underlying sea of zero-point energy at every point in the universe. This is different from the cosmic microwave background and is also referred to as the electromagnetic quantum vacuum since it is the lowest state of otherwise empty space. This energy is so enormous that most physicists believe that even though zero-point energy seems to be an inescapable consequence of elementary quantum theory, it cannot be physically real, and so is subtracted away in calculations. A minority of physicists accept it as real energy which we cannot directly sense since it is the same everywhere, even inside our bodies and measuring devices. From this perspective, the ordinary world of matter and energy is like a foam atop the quantum vacuum sea. It does not matter to a ship how deep the ocean is below it. If the zero-point energy is real, there is the possibility that it can be tapped as a source of power or be harnassed to generate a propulsive force for space travel. When a passenger in an airplane feels pushed against his seat as the airplane accelerates down the runway, or when a driver feels pushed to the left when her car makes a sharp turn to the right, what is doing the pushing? Since the time of Newton, this has been attributed to an innate property of matter called inertia. In 1994 a process was discovered whereby the zero-point fluctuations could be the source of the push one feels when changing speed or direction, both being forms of acceleration. The zero-point fluctuations could be the underlying cause of inertia. If that is the case, then we are actually sensing the zero-point energy with every move we make The principle of equivalence would require an analogous connection for gravitation. Einstein's general relativity successfully accounts for the motions of freely-falling objects on geodesics (the "shortest" distance between two points in curved space-time), but does not provide a mechanism for generating a gravitational force for objects when they are forced to deviate from geodesic tracks. It has been found that an object undergoing acceleration or one held fixed in a gravitational field would experience the same kind of asymmetric pattern in the zero-point field giving rise to such a reaction force. The weight you measure on a scale would therefore be due to zero-point energy (see gravitation). The possibility that electromagnetic zero-point energy may be involved in the production of inertial and gravitational forces opens the possibility that both inertia and gravitation might someday be controlled and manipulated. This could have a profound impact on propulsion and space travel.
quote:Stochastic electrodynamics (SED) is a theory that attempts to derive quantum mechanics to provide a local realist explanation of numerous phenomena including inertia, gravity and the radiation paradox of the Bohr model of the atom in terms of a fluctuating electromagnetic field associated with zero-point energy. This field consists of a superposition of random waves of all frequencies and phases in all directions, with a power spectrum proportional to the cube of frequency, up to a very high frequency cutoff on the order of Planck time (presumed to be due to quark interactions).The zero-point field's existence is theoretically derived from the fact that in quantum mechanics the lowest-energy state of a harmonic oscillator (such as a single mode of an electromagnetic field in vacuum) is not exactly zero. This is assumed to be merely an abstract mathematical result in quantum mechanics, but stochastic electrodynamics starts by assuming that the implied field is real, and treats it as a random (stochastic) classical field acting on classical point particles. The frequency-cubed form of the power spectrum is derived from the requirement that the power spectrum be invariant under Lorentz transformation.Stochastic electrodynamics is currently regarded as a speculative theory in physics; its confirmation or rejection will depend on the development and performance of experiments which unambiguously distinguish between it and competing theories such as quantum electrodynamics. However, it would also be confirmed if proven to be observationally equivalent to currently accepted theories.Phenomena explained by stochastic electrodynamicsInertiaInertia is predicted by stochastic electrodynamics as an electomagnetic drag force on accelerating particles, produced by the zero-point field.GravityGravity is predicted by stochastic electrodynamics as an electomagnetic induced dipole shielding effect similar in nature to the Van der Waals force.The commonality of mechanisms of inertia and gravity provides an elegant explanation for the equality of gravitational and inertial mass, which is assumed but not derived in general relativity. This also allows the Planck constant to be correctly calculated from the gravitational constant, or vice versa.The observed deflection of light in a gravitational field is a major unsolved problem for SED, because the current formulation of SED does not appear to predict any deflection.Atomic structureAtomic structure is predicted as a result of a thermal equilibrium between a particle in a potential well and the background field. This avoids the radiation paradox of the Bohr model of the atom, in which an orbiting classical electron will quickly radiate all its energy away and collapse into the nucleus. In stochastic electrodynamics the orbiting electrons absorb exactly as much energy from the zero-point field as they radiate. An additional interesting result is that the absorption and re-emission by the electrons in an atom preserves both the frequency distribution and isotropic random phase character of the zero-point field.An intuitive way to visualize this is that the electron is constantly trying to collapse into the nucleus but is blown off course by "gusts" from the background field and so always misses.
quote:Originally posted by ukmickyGeorge & harry thankyouCould there be regions of space that have different densities. Could areas between the galaxies deep in intergalactic space have different densities compared to space within or surrounding a galaxy, and if that were possible.Could gravity be variable due to different densities.Could the speed of lIght be variable due to different densities. Could the levels of zero point energy,vacuum energy be variable due to different densities. If space does have a density could the gravitational effects of galaxies suns etc moving through it cause it to flow like a liquid.Michael
quote:he Unruh effect, discovered in 1976 by Bill Unruh of the University of British Columbia, is the prediction that an accelerating observer will observe black-body radiation where an inertial observer would observe none. In other words, the accelerating observer will find themselves in a warm background. The quantum state which is seen as ground state for observers in inertial systems is seen as a thermodynamic equilibrium for the uniformly accelerated observer.Unruh demonstrated that the very notion of vacuum depends on the path of the observer through spacetime. From the viewpoint of the accelerating observer, the vacuum of the inertial observer will look like a state containing many particles in thermal equilibrium ó a warm gas. Although the Unruh effect came as a shock, it makes intuitive sense if the word vacuum is interpreted appropriately, as below.In modern terms, the concept of "vacuum" is not the same as "empty space", as all of space is filled with the quantized fields that make up a universe. Vacuum is simply the lowest possible energy state of these fields, a very different concept than "empty". The energy states of any quantized field are defined by the Hamiltonian, based on local conditions, including the time coordinate. According to special relativity, two observers moving relative to each other must use different time coordinates. If those observers are accelerating, there may be no shared coordinate system. Hence, the observers will see different quantum states and thus different vacua.In some cases, the vacuum of one observer is not even in the space of quantum states of the other. In technical terms, this comes about because the two vacua lead to unitarily inequivalent representations of the quantum field canonical commutation relations. This is because two mutually accelerating observers may not be able to find a globally defined coordinate transformation relating their coordinate choices. In fact, an accelerating observer will perceive an apparent event horizon forming (see Rindler spacetime). The existence of Unruh radiation can be linked to this apparent event horizon, putting it in the same conceptual framework as Hawking radiation. On the other hand, the Unruh effect shows that the definition of what constitutes a "particle" depends on the state of motion of the observer.We need to decompose the (free) field into positive and negative frequency components before defining the creation and annihilation operators. This can only be done in spacetimes with a timelike Killing vector field. This decomposition happens to be different in Cartesian and Rindler coordinates (although the two are related by a Bogoliubov transformation). This explains why the "particle numbers", which are defined in terms of the creation and annihilation operators, are different in both coordinates.Just as the Rindler spacetime can be seen as a toy model for black holes and cosmological horizons, the Unruh effect provides a toy model to explain Hawking radiation.CalculationsThe equivalent energy kT of a uniformly accelerating particle is: So the temperature of vacuum, seen by a particle accelerated by the Earth's gravitational acceleration of g=9.81 m/s≤, is only 4◊10#8722;20 K. For an experimental test of the Unruh effect it is planned to use accelerations up to 1026 m/s≤, which would give a temperature of about 400,000 K.
quote:Originally posted by ukmickyDoes space have a density, could gravity be the result of increased density around an object of mass.