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Author Topic: What is energy?  (Read 8801 times)

Offline SimpleEngineer

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Re: What is energy?
« Reply #25 on: 21/10/2013 15:10:04 »
Maybe the definition of energy having the ability to do work, then contradicts the ideas of zero point energies?

For me.. Energy means its going to do something even if I dont know what that something is.. a potential by all means and purposes..

your zero point mass.. sitting there (or moving there) is going to do something at some point.. so it has/is energy!

if its not going to do anything

a) how do you know its there
b) what is the point of it being there
 

Offline Pmb

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Re: What is energy?
« Reply #26 on: 25/10/2013 04:25:17 »
Quote from: SimpleEngineer
Maybe the definition of energy having the ability to do work, then contradicts the ideas of zero point energies?
I fully agree. E.g. How can an atom in its ground state be said to have energy?

Iíve addressed your concern in the webpage I posted earlier in this thread, i.e.
http://home.comcast.net/~peter.m.brown/mech/what_is_energy.htm

Suppose we were to define energy as the ability to do work and you were asked I have in mind a quantity which has the ability to do work. What is that quantity?  What would your answer be? I addressed this point right above Figure 1.

Quote from: SimpleEngineer
For me.. Energy means its going to do something even if I dont know what that something is.. a potential by all means and purposes..
A rock sits at rest on the top of a hill. It has energy by virtue of its position. Why would you expect it to do something?  A stable particle at rest in an inertial frame has energy by virtue of its mass. Again, why would you expect it to do something?
 

Offline SimpleEngineer

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Re: What is energy?
« Reply #27 on: 29/10/2013 10:09:25 »
that rock IS doing something.. its pushing down on the hill.. it may not look like its doing something but it IS doing something. (and will do other things if interfered with)

And the something may be a reaction to outside forces, without energy there can be no interaction.. (i.e. if something hits it, it will change the velocity/momentum of that something)
 

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Re: What is energy?
« Reply #27 on: 29/10/2013 10:09:25 »

 

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