Contents: Definition(s), basic forces, Laws of Thermodynamics (include Zeroeth Law).
Primary Sources: Feynman Lectures, Wikipedia
Energy is tricky.
Science has a pretty good handle on it, but - as a fundamental term - its exact definition tends to be contextual and inferential. Many work with energy every day without appearing to have a clear understanding of fundamental definitions, a situation exacerbated by specialization. The very deepest thinkers in the field tend to sound like mystics!
Here, I'll be trying to present the simple, practical definition, but also approach through some of the 'laws' revolving around the broader concept of energy.
Basic formulations:
Definition of Energy:
"Measure of the ability of a body or system to do work or produce a change, expressed usually in joules or kilowatt hours (kWh). No activity is possible without energy and its total amount in the universe is fixed. In other words, it cannot be created or destroyed but can only be changed from one type to another. The two basic types of energy are (1) Potential: energy associated with the nature, position, or state (such as chemical energy, electrical energy, nuclear energy). (2) Kinetic: energy associated with motion (such as a moving car or a spinning wheel)."
-- from Business Dictionary (of all places!)
Conservation of Energy:
"...there is a certain quantity, which we call energy, that does not change in the manifold changes which nature undergoes." -- from The Feynman Lectures on Physics
Laws of Thermodynamics quoted from Wikipedia (references removed):
The four laws of thermodynamics are:
- Zeroth law of thermodynamics: If two systems are in thermal equilibrium independently with a third system, they must be in thermal equilibrium with each other. This law helps define the notion of temperature.
- First law of thermodynamics: When energy passes, as work, as heat, or with matter, into or out from a system, its internal energy changes in accord with the law of conservation of energy. Equivalently, perpetual motion machines of the first kind are impossible.
- Second law of thermodynamics: In a natural thermodynamic process, the sum of the entropies of the interacting thermodynamic systems increases. Equivalently, perpetual motion machines of the second kind are impossible.
- Third law of thermodynamics: The entropy of a system approaches a constant value as the temperature approaches absolute zero.[2] With the exception of non-crystalline solids (glasses) the entropy of a system at absolute zero is typically close to zero, and is equal to the logarithm of the multiplicity of the quantum ground states.
The four, fundamental forces:
(Consider these under KERNAL Forces with Newton's Laws of Motion?)
- Gravitational
- Electromagnetic
- Strong nuclear
- Weak nuclear
Reformulation:
Energy is the capacity of a body or system to do work or produce a change, or the measure thereof.
Law of Conservtion of Energy:
Energy cannot be created or destroyed, only transformed and transferred.
Radiant Energy propagates through empty space in wave/particle duality.
Potential Energy is associated with position or state of matter.
Kinetic Energy is associated with motion of matter.
Thermal Energy is the kinetic energy of atoms in motion.
Entropy is the universal tendency toward random distribution, or the measure thereof.
Random distribution, equilibrium and incapacity for work are similar.
0 Law of Thermodynamics:
When two systems are in equilibrium with a third system, they are in thermal equilibrium with each other.
1 Law of Thermodynamics:
When energy transfers into or out from a system as work, as heat, or with matter, its internal energy changes in accordance with the Law of Conservation of Energy (no energy is lost or destroyed).
2 Law of Thermodynamics:
A system can not convert all of its energy to working energy; some is always transformed to heat (total entropy always increases).
3 Law of Thermodynamics:
No system can be brought to zero degrees Kelvin (a state of no thermal energy).
Rendition:
Pending.
No comments:
Post a Comment