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'''Quantum mechanics''' is the branch of [[physics]] that describes the behavior of systems on very small length and energy scales, such as those found in [[atom]]ic and subatomic interactions.  The fundamental principle of quantum mechanics is that there is an uncertainty in the location of a subatomic particle until attention is focused on it by observing its location.  This insight is essential for understanding certain concepts that [[classical physics]] cannot explain, such as the discrete nature of small-scale interactions, [[wave-particle duality]], the [[uncertainty principle]], and [[quantum entanglement]].  Quantum mechanics forms the basis for our understanding of many phenomena, including [[chemical reaction]]s and [[radioactive decay]], and is used by all [[computer]]s and electronic devices today.

'''Quantum mechanics''' is the branch of [[physics]] that describes the behavior of systems on very small length and energy scales, such as those found in [[atom]]ic and subatomic interactions.  The fundamental principle of quantum mechanics is that there is an uncertainty in the location of a subatomic particle until attention is focused on it by observing its location.  This insight is essential for understanding certain concepts that [[classical physics]] cannot explain, such as the discrete nature of small-scale interactions, [[wave-particle duality]], the [[uncertainty principle]], and [[quantum entanglement]].  Quantum mechanics forms the basis for our understanding of many phenomena, including [[chemical reaction]]s and [[radioactive decay]], and is used by all [[computer]]s and electronic devices today.

'''''The order created by [[God]] is on a foundation of [[uncertainty]]'''''.  The [[Book of Genesis]] explains that the world was an abyss of [[chaos]] at the moment of [[creation]].  Quantum mechanics is predicted in several additional respects by the [[Biblical_scientific_foreknowledge#Quantum_mechanics|Biblical scientific foreknowledge]].

'''''The order created by [[God]] is on a foundation of [[uncertainty]]'''''.  The [[Book of Genesis]] explains that the world was an abyss of [[chaos]] at the moment of [[creation]].  Quantum mechanics is predicted in several additional respects by the [[Biblical scientific foreknowledge#Quantum mechanics|Biblical scientific foreknowledge]].

The name "Quantum Mechanics" comes from the idea that energy is transmitted in discrete quanta, and not continuous. Another historical name for "quantum mechanics" was "wave mechanics."

The name "Quantum Mechanics" comes from the idea that energy is transmitted in discrete quanta, and not continuous. Another historical name for "quantum mechanics" was "wave mechanics."

In 1915, [[Niels Bohr]] applied this to the electron problem by proposing that [[angular momentum]] is also quantized - electrons can only orbit at certain locations, so they cannot spiral into the nucleus.  While this model explained how atoms do not collapse, not even Bohr himself had any idea why.  As Sir James Jeans remarked, the only justification for Bohr's theory was "the very weighty one of success".<ref name="VA">http://galileo.phys.virginia.edu/classes/252/Bohr_to_Waves/Bohr_to_Waves.html</ref>

In 1915, [[Niels Bohr]] applied this to the electron problem by proposing that [[angular momentum]] is also quantized - electrons can only orbit at certain locations, so they cannot spiral into the nucleus.  While this model explained how atoms do not collapse, not even Bohr himself had any idea why.  As Sir James Jeans remarked, the only justification for Bohr's theory was "the very weighty one of success".<ref name="VA">http://galileo.phys.virginia.edu/classes/252/Bohr_to_Waves/Bohr_to_Waves.html</ref>

It was Prince Louis de Broglie who explained Bohr's theory in 1924 by describing the electron as a wave with wavelength λ=[[Planck's Constant|h]]/[[momentum|p]].  Therefore, it would be logical that it could only orbit in orbits whose circumference is equal to an integer number of wavelengths.  Thus, angular momentum is quantized as Bohr predicted, and atoms do not self-destruct. <ref name="VA" />

It was Prince Louis de Broglie who explained Bohr's theory in 1924 by describing the electron as a wave with wavelength λ=[[Planck's Constant|h]]/[[momentum|p]].  Therefore, it would be logical that it could only orbit in orbits whose circumference is equal to an integer number of wavelengths.  Thus, angular momentum is quantized as Bohr predicted, and atoms do not self-destruct.<ref name="VA" />

Eventually, the mathematical formalism that became known as quantum mechanics was developed in the 1920s and 1930s by [[John von Neumann]], [[Hermann Weyl]], and others, after [[Erwin Schrodinger]]'s discovery of wave mechanics and [[Werner Heisenberg]]'s discovery of matrix mechanics.

Eventually, the mathematical formalism that became known as quantum mechanics was developed in the 1920s and 1930s by [[John von Neumann]], [[Hermann Weyl]], and others, after [[Erwin Schrodinger]]'s discovery of wave mechanics and [[Werner Heisenberg]]'s discovery of matrix mechanics.

===The uncertainty principle===

===The uncertainty principle===

As a result of the wave nature of a particle, neither position nor [[momentum]] of a particle can never be precisely known.  Whenever its position is measured more accurately (beyond a certain limit), its momentum becomes less certain, and visa versa.  Hence, there is an inherent uncertainty that prevents precisely measuring both the position and the momentum simultaneously. This is known as the [[Heisenberg Uncertainty Principle]]<ref>http://hyperphysics.phy-astr.gsu.edu/Hbase/uncer.html</ref>:

As a result of the wave nature of a particle, neither position nor [[momentum]] of a particle can never be precisely known.  Whenever its position is measured more accurately (beyond a certain limit), its momentum becomes less certain, and visa versa.  Hence, there is an inherent uncertainty that prevents precisely measuring both the position and the momentum simultaneously. This is known as the [[Heisenberg Uncertainty Principle]]:<ref>http://hyperphysics.phy-astr.gsu.edu/Hbase/uncer.html</ref>

:<math> Dx \times Dp \ge \frac{h}{4\pi}</math>

:<math> Dx \times Dp \ge \frac{h}{4\pi}</math>

*[[Max Planck]]

*[[Max Planck]]

==External Links==

==External links==

{{reflist}}

{{reflist}}

For an excellent discussion of quantum mechanics, see:

For an excellent discussion of quantum mechanics, see:

http://www.chemistry.ohio-state.edu/betha/qm/

* http://www.chemistry.ohio-state.edu/betha/qm/

*[http://www.relativitycalculator.com/compton_effect.shtml The Compton Effect]

*[http://www.relativitycalculator.com/compton_effect.shtml The Compton Effect]