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Everyone knows that everything is run by energy…
…and comes in many forms such as electrical energy to power lightbulbs..
… but what is the true pure form of energy.
And if we are energy beings then our conciousness is cumulated energy so as proven by science that energy cant be created nor destroyed but can be converted into another form of energy then an afterlife exists in this form.
But the first question remains, What is energy?
Energy is the potential to do useful work - nothing else.
It is important to realize that in physics today, we have no knowledge of what energy is. We do not have a picture that energy comes in little blobs of a definite amount. It is not that way. However, there are formulas for calculating some numerical quantity, and we add it all together it gives “28” - always the same number. It is an abstract thing in that it does not tell us the mechanism or the reasons for the various formulas.
Of all the physical concepts, that of energy is perhaps the most far-reaching. Everyone, whether a scientist or not, has an awareness of energy and what it means. Energy is what we have to pay for in order to get things done. The word itself may remain in the background, but we recognize that each gallon of gasoline, each Btu of heating gas, each kilowatt-hour of electricity, each car battery, the wherewithal for doing what we call work. We do not think in terms of paying for force, or acceleration, or momentum. Energy is the universal currency that exists in apparently countless denominations. The above remarks do not really define energy. No matter. It is worth recalling once more the opinion that H.A. Krammers expressed: “The most important and fruitful concepts are those to which it is impossible to attach a well-defined meaning.” The clue to the immense value of energy as a concept lies in its transformation. It is conserved – that is the point. Although we may not be able to define energy in general, that does not mean that it is only a vague, qualitative idea. We have set up quantitative measures of various specific kinds of energy: gravitational, electrical, magnetic, elastic, kinetic, and so on. And whenever a situation has arisen in which it seemed that energy disappeared, it has always been possible to recognize and define a new form of energy that permits us to save the conservation law. And conservation laws, as we remarked at the beginning of Chapter 9, represent one of the physicist’s most powerful tools for organizing his description of nature.
Pmb's analogy with a bookeeping scheme is a good one.
It is an abstract thing in that it does not tell us the mechanism or the reasons for the various formulas.
As far as energy not being the ability(capacity) to do work, I found an article online about this at http://www.loreto.unican.es/Carpeta2012/TPT(Lehrman)WorkEnergy.pdfIt seems like a nice article so far. I recommend reading it. It was published in The Physics Teacher under the title Energy is Not the Ability to do Work by Robert Lehrman, Phys. Teach. 11, 15 (1973) This article http://scienceblog.com/16727/is-energy-the-ability-to-do-work/ agrees with me too.
As far as energy not being the ability(capacity) to do work, I found an article online about this at http://www.loreto.unican.es/Carpeta2012/TPT(Lehrman)WorkEnergy.pdf
It seems it's not so much a question of energy being the capability to do work, but more of energy having the capability to do work.
A nicely written article indeed, but a bit confusing when he shows the mass balance of nuclear fission including the "mass of photons produced". Having convinced your students that photons do not have mass (indeed cannot as they travel at c) you could end up with egg on face or a lot of explaining to do here!
Quote from: dlorde on 24/09/2013 15:31:12It seems it's not so much a question of energy being the capability to do work, but more of energy having the capability to do work.I disagree. The problem with that statement is that it can't act as a definition because it doesn't tell you how to obtain any quantity to be called "energy."
Why can't I call p = mv the "energy" of the particle? (and please don't tell me that its because this is momentum. We're assuming that we're starting from scratch and don't know these things yet). Why can't we call E = (1/2)mv^2 the "momentum" of the particle?
Quote from: Pmb on 24/09/2013 17:27:34 Why can't I call p = mv the "energy" of the particle? (and please don't tell me that its because this is momentum. We're assuming that we're starting from scratch and don't know these things yet). Why can't we call E = (1/2)mv^2 the "momentum" of the particle?Quite simply, because I don't. The purpose of language is to communicate, and we do this best if everybody uses the same definition of each word.
(and please don't tell me that its because this is momentum. We're assuming that we're starting from scratch and don't know these things yet).