Monday, August 1, 2011

Quantum physics Quickie

Quantum mechanics deals mainly with the extremely small such as atoms and subatomic particles. While it works on the macroscopic level as well, with few a exceptions; such as superconductors and superfluids; the results are usually the same as Classical mechanics. It is mainly at the subatomic level that the differences become significant.
Quantum mechanics was developed out of an effort to understand why atoms emit only discrete frequencies of light, but it works outside the atom as well.
There several classes of phenomena called "quantum effects" that have no counter part in Classical mechanics. They included:
  1. Quantization.
  2. The uncertainty principle.
  3. Wave-particle duality.
  4. Quantum tunneling.
  5. Quantum entanglement.
  6. Quantum teleportation.
  7. Quantum Non-Locality
  8. Superconductors
  9. Superfluids
While Quantum mechanics has been questioned by some creationists, but it turns out that it can be a useful tool after all.

Quantization.

Quantization is the situation where physical quantities like position, energy and momentum can have only certain discrete values. For a particle free in empty space these physical quantities are continuous, but when a particle is bound to an area of space it can only have certain discrete values.
The energy contained in a given frequency of electromagnetic waves is also quantized in that it always has the same value at the same frequency. The energy is found in discrete packets or particles called photons
Quantization of electron energy within an atom explains much of their behavior, such as why atoms emit only discrete frequencies of light.

The uncertainty principle.

Uncertainty principle basically states that there is a limit on the accuracy of simultaneous measurement of physical quantities like a particle's position and momentum. This can bee expressed as:
Dx Dp ³ h / 4p
  • x is a particle's position.
  • p is a particle's momentum.
  • h is Planck's constant
The result is that the more accurately one measures a particle's position the less accurately one can measure its momentum and vice versa. This is not the case because the act of measurement disturbs the system; which it only does sometimes; but it is related to Wave-particle duality.
There are similar uncertainty relations between other physical quantities as well, but Planck's constant is too small ( h = 6.626 X 10-34 J * S ) for the uncertainty principle show up in the macroscopic world.

Wave-particle duality.

Wave-particle duality is the tendency of for light and matter to exhibit both wave and particle like properties. It is a key concept of quantum mechanics.
Some times they behave like particles, exhibiting properties like scattering, but under the right circumstances they behave like waves, exhibiting properties like interference and diffraction. The particle's wave length is calculated by l = h / p. Where h is Planck's constant and p is momentum. The wave's wave function ( Y ) is related to the probability of finding the particle a given point in pace. The relationship is based on the square of the absolute value of  the amplitude of the wave function. ( |Y(x)|2 ) It is called the probability density.
Some Interpretations of quantum mechanics particularly the wave function collapses, this aspect of Quantum mechanics is of interest to Creation science.

Quantum tunneling.

Quantum tunneling is related to Wave-particle duality in that it is a result of the wave nature of a particle. It is the process by which a particle gets across a barrier that it can not classically pass. The probability of the particle getting through the barrier drops exponentially with the thickness of the barrier, based on the formula:
  • Yx) = Y0) e-k x
  • Where Y is the wave function, k it is particles wave number inside the barrier, and x it the distance.
It needs to be noted the particles wave number inside the barrier is not the same as it is out side, though they are mathematically related, based on the properties of the barrier.
In Quantum tunneling the travel time across the barrier is zero, thus it is an instantaneous process, and there by faster than the speed of light. While it suggests a possible mechanism for faster than light travel and transmission, it would take an exceedingly large barrier wave number to get any significant distance, thus it may never be practical for long distances.

Quantum entanglement.

Quantum entanglement is a phenomenon in which the quantum states of two or more objects have to be described with reference to each other, even though the individual objects may be separated in space. The result is a correlation between the observable physical properties of the systems, such that a change in one object causes an instantaneous change in the other.
It is currently thought that classical information can not by this means. One reason is two particles need to be near each other to become entangled, except by an intermediate particle, which has to be near one particle and then the other.

Quantum teleportation.

Quantum teleportation is the transporting of a quantum mechanical state, between two entangled particles by way of some form some classical information, usually light. The process Quantum teleportation  destroys or disturbs the particle at one end and makes a copy of it at the other end. The result is the only thing that actually transported is quantum mechanical states, not the actual particles.

Quantum Non-Locality

Quantum Nonlocality is the phenomenon by which subatomic measurements refute notions of local realism. This based largely on Bell's theorem which states that no physical theory of local hidden variables is capable of reproducing all of the predictions of Quantum mechanics. However Bell's theorem  does not eliminate the possibility of non-local Hidden Variables.


Superconductors

Superconduction is the property where certain materials have an electrical resistance of exactly zero when their  temperature gets below their respective characteristic temperature. The most well known effect superconductivity is magnetic levitation. It  is a purely quantum effect that has no counter part in classical physics and it is one of two quantum effects that show up on a macroscopic scale.

Superfluids

A superfluid  is a liquid with no viscosity and infinite thermal conductivity. A superfluid moves a unit and even can flow up the sides of it container. Superfluity is a purely quantum effect that has no counter part in classical physics and it is one of two quantum effects that show up on a macroscopic scale.


Interpretations

There are several Interpretations of quantum mechanics.
  • Copenhagen interpretation of quantum mechanics: According this interpretation the only thing that matters are the experimental results. This is currently the most popular interpretation, but it is losing ground.
  • Consistent histories: According to this interpretation of quantum mechanics simply predicts the probabilities of various alternative histories.
  • Transactional interpretation: This interpretation sees quantum mechanical waves as stand waves in space time that constructively interfere were the particle is and destructively interfere every place else.
  • Bohm interpretation According to this interpretation the wave guides the particle, while it is totally deterministic; it requires a large number of hidden variables that can not be directly measured.
  • Many-worlds interpretation of quantum mechanics: This interpretation sees the world constantly splitting off into multiple universes in which possible quantum event occurs. This fits perfectly with Evolution since in some universe the extremely improbable event of life spontaneously coming from non life would have occurred as would all the extremely improbable events needed to evolve that life to man. According to this view our existence by natural processes would be a quantum certainty.
  • Consciousness causes collapse : According to this interpretation it is consciousness causes collapses the quantum mechanical waves. While this view fits well with Hinduism, it also fits well with the Christian world view. See below.
  • General Grand Unification (GGU), also known as General Intelligent Design: According to this interpretation quantum mechanical waves and their collapse are the result of intelligent agents that determine the states resulting from the waves' collapse. These intelligent agents could be intelligent beings or mechanisms preprogrammed by an intelligent being. This interpretation fits well with the Christian world view. See below.

Biblical Significance

The consciousness causes collapse interpretation fits the Biblical worldview well. Since according to this interpretation quantum mechanical waves are collapse consciousness it provides a scientific model for a link between physical and the spiritual. For example it could provide a model for soul body interaction.

Also a sufficiently powerful consciousness would be capable of collapsing quantum mechanical waves to highly improbable states; such an event would by definition be a miracle. This provides a scientific bases for miracles. God being the most powerful consciousness of all would be capable of collapsing quantum mechanical waves to even the most improbable of states, including making the universe from nothing. This opens the door to a possible scientific model for creation.

General Grand Unification fits the Biblical worldview well. It allows for the intelligent design and control of the universe. It shows how the universe could have been created from nothing and provides a scientific model for creation. 


Both models show compatibility between quantum physics and God, suggesting that quantum mechanical indeterminacy results from God working in the universe.


References

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