The law of conservation of energy vs. Perpetual Motion

[satanspawn]

The law of conservation of energy states that the total amount of energy in an isolated system remains constant, although it may change forms, into heat or kinetic energy for example.

In short, the law states that energy cannot be created or destroyed.

Denying its validity would undermine not just little bits of science - the whole edifice would be no more. All of the technology on which we built the modern world would lie in ruins.

There is no flexibility in the acceptance of the law as true - at all times, and in all circumstances. Perpetual motion, if possible, would invalidate all scientific laws that we know of.

http://en.wikipedia.org/wiki/Conservation_of_energy

[ovyyus]

Duh

[murilo]

ovyyus said:
Duh...
DITTO!
(I just can't wait for this moment!)

[getterdone]

Gee Satan, I just spent most of my day in the shop working on getting my test wheel reasembled so that I could punch some holes in Newton's law.
I don't want to wreck all of science.We have people in space that need to come home and I don't want to make buildings crumble.
I'm starting to hope I don't succeed

[jim_mich]

The law of conservation of energy is an empirical law of physics.

Meaning of EMPIRICAL
[adj] derived from experiment and observation rather than theory

A key stage in the development of the modern conservation principle was the demonstration of the mechanical equivalent of heat.

The first law of thermodynamics is an expression of the principle of conservation of energy.

The first law of thermodynamics says that energy is conserved in any process involving a thermodynamic system and its surroundings.

The classical statement of the first law of thermodynamics is induced from empirical evidence. It can be observed that given a system in an initial state, if work is exerted on the system in an adiabatic (i.e. thermally insulated) way, the final state is the same for a given amount of work, irrespective of how this work is performed.

Note carefully the wording. This law pertains to thermal to work conversions and work to thermal conversions. A PM wheel that manipulates inertial momentum and kinetic energy is NOT a thermodynamic process. It is a purely dynamic process.

The kinetic energy of an object is the energy which it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.

Kinetic Energy = 1/2 × m × v^2

Since the kinetic energy increases with the square of the speed, an object doubling its speed has four times as much kinetic energy.

Kinetic energy is a measurement of the energy of motion. Motion is always relative. Motion is a measurement between two objects. One object (usually the Earth) is assumed to be stationary while the other object is moving.

Kinetic energy is NOT some substance or force that resides within an object. Rather it is a force that develops spontaneously between two objects moving at different speeds as a result of some force being exerted between the said two objects. Thus kinetic energy is not something that can be "conserved" or stored within an object. An object moving at some given speed will be considered to have a certain amount of kinetic energy relative to stationary Earth or whatever. The same object hitting another object moving at the same speed but in the opposite direction and thus having the same kinetic energy will result in four times as much KE being released with four times as much damage to the objects. From this it can be seen that there is no such thing as conservation of kinetic energy.

The Conservation of Energy Law should be called the Law of Conservation Between Heat and Motion for it is based upon heat engines.

Thermodynamics is the science of energy conversion involving heat and other forms of energy, most notably mechanical work. It studies and interrelates the macroscopic variables, such as temperature, volume and pressure, which describe physical, thermodynamic systems.

Historically, thermodynamics developed out of a desire to increase the efficiency of early steam engines.

Momentum is sometimes referred to as linear momentum to distinguish it from the related subject of angular momentum. Linear momentum is a vector quantity, since it has a direction as well as a magnitude. Angular momentum is a pseudovector quantity because it gains an additional sign flip under an improper rotation.

Meaning of PSEUDO
[adj] (often used in combination) not genuine but having the appearance of;

Meaning of VECTOR
[n] a straight line segment whose length is magnitude and whose orientation in space is direction

Linear momentum of a particle
If an object is moving in any reference frame, then it has momentum in that frame. It is important to note that momentum is frame dependent. That is, the same object may have a certain momentum in one frame of reference, but a different amount in another frame. For example, a moving object has momentum in a reference frame fixed to a spot on the ground, while at the same time having 0 momentum in a reference frame attached to the object's center of mass.

The amount of momentum that an object has depends on two physical quantities: the mass and the velocity of the moving object in the frame of reference.

The second law of thermodynamics is an expression of the tendency that over time, differences in temperature, pressure, and chemical potential equilibrate in an isolated physical system. From the state of thermodynamic equilibrium, the law deduced the principle of the increase of entropy and explains the phenomenon of irreversibility in nature. The second law declares the impossibility of machines that generate usable energy from the abundant internal energy of nature by processes called perpetual motion of the second kind.

This is Hogwash! Go back and read the first part of this quote.

No process is possible whose sole result is the transfer of heat from a body of lower temperature to a body of higher temperature.

The second law is simply a statement that it is impossible for heat to move spontaneously from a cold body to a hot body with no other result. When stated this way the Second Law is a true statement.

But it is Hogwash when extended to all situations and used to declare perpetual motion imposible.

In the philosophy of thermal and statistical physics, Maxwell's demon is a thought experiment created by the Scottish physicist James Clerk Maxwell to "show that the Second Law of Thermodynamics has only a statistical certainty." The thought experiment demonstrates Maxwell's point by describing how to violate the Second Law.

Heat is kinetic energy.
Motion is kinetic energy.
Heat can be converted to motion.
Motion can be converted to heat.
Such conversions obey the Law of Conservation Between Heat and Motion

KE as heat never flows spontaneously from a colder object having less KE heat to an warmer object having greater KE heat.
KE as motion most certainly can flow spontaneously from a slower object having less KE motion to a faster object having greater KE motion, but AFAIK it can only happen in a rotating frame of reference and only by the action of a particular mechanical arrangement method.

Such a flow of mechanical KE motion breaks the spirit of the Law of Conservation Between Heat and Motion but does not actually break said Law because the mechanism is NOT a heat engine. The mechanism is a motion engine governed in part by Momentum = m × v and in part by Kinetic Energy = 1/2 × m × v^2

Of course this is just my opinion. I could be wrong. But I doubt it. ;)

[Trevor Lyn Whatford]

Hi all,

The Contradiction

The Energy Laws are supposed to be the natural laws of physics, but the empirical experiment and observations where conducted while we live on a PM orbiting planet so how can these laws be natural laws when we live on a natural PM system that defy these Laws.

Gravity is needed to keep a PM system in its PM state as shown to us by our planet, the Laws state for PM to be possible it would need to defy these Laws but here we are living on our PM system!

I think what as happened is that a teaching model was needed so these Man Made Laws where constructed, for the best part the laws have been a good teaching model but are not absolute, they should have never been made a Law, they should have been the Energy Conservation Guide.

Regards Trevor

Edit, missed words.

[nicbordeaux]

Thanks Jim, remarkably thought through and clearly put into words. I'll just disagree with the "only in a certain mechaical arrangement" part ;)

[KAS]

The problem with proclaiming physical laws is that you must ensure that there is no chance of a loop hole being discovered in the future.

And its the human trait of being able to see ways around things that keeps me going.
The Gravitational Conservation of Energy law can be and will be re-written in the future; I am confident of it.

Here's an example of a loop hole that may not have been considered.

Einstein said that mass and energy are one of the same thing. Then consider this:

It is generally understood that the Conservation of energy law ensures that any energy gained from mass in a gravity field will lead to a loss in height of that mass. and that height cannot be regained utilising the energy of the mass alone.

Well, That depends on the mass is IMO.

If we hold an apple weighing say, 4 oz in the air 7 feet from the ground and release it; catching it at 3 feet from the ground, then that mass as fallen 4 feet.
The law states that I cannot return it to its to 7 feet position with the energy generated.

But a 4 oz apple contains around 100 calories. If I eat the apple after it had fallen, 100 calories (energy of the mass) will enable me to lift a whole basket of apples 7 feet in the air.

Ingenuity is the key.

Something to think about

Kas

[Grimer]

The second law is simply a statement that it is impossible for heat to move spontaneously from a cold body to a hot body with no other result. When stated this way the Second Law is a true statement.

It's not impossible - just highly unlikely. A bit like winning the lottery only more so.