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jbartos
Electrical
- Jan 15, 2000
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Suggestion: There appear to be different views on energy nature. One view substantiates electric current as a flow of material energy, e.g. energy suppliers, electrical energy generation, electrical energy load flow (e.g. programs modeling electrical energy load flow.)
The other view indicated that the energy is not a material it is an effect.
What about mechanical energy:
F = m x a
Where
F is force
m is mass
a is acceleration
Work = F x s
s is distance
Energy = Work x time = F x s x time = m x a x s x time
where mass "m" substantiates material nature of energy.
The other view indicated that the energy is not a material it is an effect.
What about mechanical energy:
F = m x a
Where
F is force
m is mass
a is acceleration
Work = F x s
s is distance
Energy = Work x time = F x s x time = m x a x s x time
where mass "m" substantiates material nature of energy.
Skogsgurra
Electrical
I am reading this, too. No comments.
SidiropoulosM
Electrical
Suggestion to Jbartos: your argument that you can block energy with material layers doesn't mean anything. Energy is carried by material particles and surely can be blocked if you block the particles. This doesn't mean that energy itself is material.
imok:
Lets take a step back and take a deep breath! Clear your preconceived thoughts, right or wrong. This is not as complicated as it is made out to be otherwise there won't be many electrical engineering graduates or only geniuses would be electrical engineers.
Also draw a boundary to limit our discussion in order to understand the basics. So we will not go beyond Newtonian physics, still valid for our day-to-day life. (Imagine if we try to explain all knowledge in one class! No one will learn a thing.)
If you re-write your original statements as "Electrical current is established when electrical energy flows. 'Electrical' energy is same thing as electricity" Then they would be more accurate. Read this a few times.
Also when you say electricity moves back and forth, you are thinking electrons or electrical charge as electricity that is not accurate. Electricity is the ‘name’ given to electrical form of energy, same as ‘heat’ is for thermal energy.
You can think of movement of electrons under the influence of electrical pressure/field same as vibration of atoms under influence of thermal gradient. More the ‘vibration’, more elevated is the temperature; we say more ‘heat’ is there. You don’t call those molecules ‘heat’. Heat ‘transfers’ or moves; molecules don’t.
As for AC and DC it gets little complicated but I will try to explain with ‘heat’ analogy.
Imagine a piece of pipe with water flowing through it. The friction will cause the pipe temp to go up. This is equivalent to a resistor connected in an electrical circuit, AC or DC. Now this pipe don’t care as to which direction water is flowing inside. The water can be flowing in one direction constantly and create X amount of heat. (Equivalent of DC). Moving the water back and forth through the pipe can create the same effect, which is equivalent of AC. (Side note: The AC value which creates the same effect in a resistor as DC is termed as rms value of AC). It is incidental that in one case it is the mechanical energy and in other it is electrical but both produce the same effect ‘heat’, just a conversion of ‘form’ of the energy! Hail Newton! The water is just a medium; so do not confuse the flow of water with flow of electricity, the energy.
This discussion can go on and on, but I think I did my best to explain. You will do well to remember that ‘energy’ by itself is not visible, it does not have mass, only its effect can be felt or ‘seen’ by change in the characteristics of a visible object.
Also based on its form, it may or may not need a medium to travel. In poor form it requires a medium, such as heat or certain range of frequency and DC in electrical form, but can also travel through space in it much purer from, such as light or electromagnetic waves and cosmic radiations. By Einstein’s theory, which is not contradictory at all, energy in its purest form will have no mass! All of mass m is converted to E then. But as long as we are not converting mass into energy or energy into mass (a feat not achieved yet by man), both can be treated independently.
Material carrying energy is not same as energy! Moving car has kinetic and inertial energy but car is not the energy! Energy does not have a Car, but car does have energyJ.
Let me also clarify the mechanical/hydraulic analogy. Water distribution network and electrical power distribution network is a famous and well established analogy, so much so that the same form of equations could be used to solve either network problem.
There quantity of water equals ‘electrical energy’ only from modeling point of view, the difference being electricity is not a material or mass like water.
Lets take a step back and take a deep breath! Clear your preconceived thoughts, right or wrong. This is not as complicated as it is made out to be otherwise there won't be many electrical engineering graduates or only geniuses would be electrical engineers.
Also draw a boundary to limit our discussion in order to understand the basics. So we will not go beyond Newtonian physics, still valid for our day-to-day life. (Imagine if we try to explain all knowledge in one class! No one will learn a thing.)
If you re-write your original statements as "Electrical current is established when electrical energy flows. 'Electrical' energy is same thing as electricity" Then they would be more accurate. Read this a few times.
Also when you say electricity moves back and forth, you are thinking electrons or electrical charge as electricity that is not accurate. Electricity is the ‘name’ given to electrical form of energy, same as ‘heat’ is for thermal energy.
You can think of movement of electrons under the influence of electrical pressure/field same as vibration of atoms under influence of thermal gradient. More the ‘vibration’, more elevated is the temperature; we say more ‘heat’ is there. You don’t call those molecules ‘heat’. Heat ‘transfers’ or moves; molecules don’t.
As for AC and DC it gets little complicated but I will try to explain with ‘heat’ analogy.
Imagine a piece of pipe with water flowing through it. The friction will cause the pipe temp to go up. This is equivalent to a resistor connected in an electrical circuit, AC or DC. Now this pipe don’t care as to which direction water is flowing inside. The water can be flowing in one direction constantly and create X amount of heat. (Equivalent of DC). Moving the water back and forth through the pipe can create the same effect, which is equivalent of AC. (Side note: The AC value which creates the same effect in a resistor as DC is termed as rms value of AC). It is incidental that in one case it is the mechanical energy and in other it is electrical but both produce the same effect ‘heat’, just a conversion of ‘form’ of the energy! Hail Newton! The water is just a medium; so do not confuse the flow of water with flow of electricity, the energy.
This discussion can go on and on, but I think I did my best to explain. You will do well to remember that ‘energy’ by itself is not visible, it does not have mass, only its effect can be felt or ‘seen’ by change in the characteristics of a visible object.
Also based on its form, it may or may not need a medium to travel. In poor form it requires a medium, such as heat or certain range of frequency and DC in electrical form, but can also travel through space in it much purer from, such as light or electromagnetic waves and cosmic radiations. By Einstein’s theory, which is not contradictory at all, energy in its purest form will have no mass! All of mass m is converted to E then. But as long as we are not converting mass into energy or energy into mass (a feat not achieved yet by man), both can be treated independently.
Material carrying energy is not same as energy! Moving car has kinetic and inertial energy but car is not the energy! Energy does not have a Car, but car does have energyJ.
Let me also clarify the mechanical/hydraulic analogy. Water distribution network and electrical power distribution network is a famous and well established analogy, so much so that the same form of equations could be used to solve either network problem.
There quantity of water equals ‘electrical energy’ only from modeling point of view, the difference being electricity is not a material or mass like water.
- Thread starter
- #25
Then would you agree that in any electric circuit, the smallest particle of electrical energy is NOT the electron. The smallest particle of energy is the unit quantum of electromagnetic energy: it is the photon. Electrons are not particles of EM energy. Electricity is made of electrons, while electrical energy is electromagnetism and is made of photons.
imok:
Now you are entering a subject beyond this forum and even beyond anyone on earth have understood. No one really knows answer to some of your question in your last post as to what the ‘energy’ is or what it is like in its purest form. There are a bunch of theories and that is pretty much that, theories. Some may be relevant, some not. But we do know ‘effects’ of energy to some extent. (Here ‘some’ is a relative term J)
I am not a physicist, but photon is a unit of light, not electricity. Light is not the electricity, as we know it. Electromagnetic energy is only a ‘form’ of energy, not the only or all of the energy. Or all electricity is energy but all energy if not electricity. The same apply to all ‘forms’ of energy. Electricity is NOT made of electrons or photons. Electrons help carry electrical charge.
What we do know is the ‘effect’ of electricity and how to maneuver it in a limited fashion to our advantage.
Electricity is a creation of Nature and not of humans. It is a discovery, not an invention. We do know that moving a conductor in electrical field creates the current but not necessarily know why does it happen.
We, mankind, collectively have yet not resolved the mystery of this universe. Existence and origin of energy is one key part of it. According to our known basis of science something has to come from something, so where does the last thing comes from? This is where faith in GOD and science meet, someday hopefully mankind will advance enough to know that, not likely anytime soon when we are still fighting over petty things and relying on fossil fuelJ).
Sorry, I an unable to agree to some of your statements, but this has been a good discussion, I think. I will stay tuned for any expert physicist's posts!
Now you are entering a subject beyond this forum and even beyond anyone on earth have understood. No one really knows answer to some of your question in your last post as to what the ‘energy’ is or what it is like in its purest form. There are a bunch of theories and that is pretty much that, theories. Some may be relevant, some not. But we do know ‘effects’ of energy to some extent. (Here ‘some’ is a relative term J)
I am not a physicist, but photon is a unit of light, not electricity. Light is not the electricity, as we know it. Electromagnetic energy is only a ‘form’ of energy, not the only or all of the energy. Or all electricity is energy but all energy if not electricity. The same apply to all ‘forms’ of energy. Electricity is NOT made of electrons or photons. Electrons help carry electrical charge.
What we do know is the ‘effect’ of electricity and how to maneuver it in a limited fashion to our advantage.
Electricity is a creation of Nature and not of humans. It is a discovery, not an invention. We do know that moving a conductor in electrical field creates the current but not necessarily know why does it happen.
We, mankind, collectively have yet not resolved the mystery of this universe. Existence and origin of energy is one key part of it. According to our known basis of science something has to come from something, so where does the last thing comes from? This is where faith in GOD and science meet, someday hopefully mankind will advance enough to know that, not likely anytime soon when we are still fighting over petty things and relying on fossil fuelJ).
Sorry, I an unable to agree to some of your statements, but this has been a good discussion, I think. I will stay tuned for any expert physicist's posts!
jbartos
Electrical
- Jan 15, 2000
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Suggestion to SidiropoulosM (Electrical) Oct 25, 2003 marked ///\\Suggestion to Jbartos: your argument that you can block energy with material layers doesn't mean anything.
///Really?\\ Energy is carried by material particles and surely can be blocked if you block the particles. This doesn't mean that energy itself is material.
///I am not writing that the energy is material only. My claim is that without material there is not energy, e.g. bullet has to have mass and speed to have energy to impact the target. If the speed subsides, energy subsides and the bullet stops without doing any harm. E.g. bullet shot upward stops at some height, experiences mass and zero speed and zero energy. Also, one cannot have nothing with speed. That does not make any sense. Therefore, without mass there cannot be energy. So, the energy is mass plus speed, for example. The mathematical equations must hold. Else, they would be meaningless.\\
///Really?\\ Energy is carried by material particles and surely can be blocked if you block the particles. This doesn't mean that energy itself is material.
///I am not writing that the energy is material only. My claim is that without material there is not energy, e.g. bullet has to have mass and speed to have energy to impact the target. If the speed subsides, energy subsides and the bullet stops without doing any harm. E.g. bullet shot upward stops at some height, experiences mass and zero speed and zero energy. Also, one cannot have nothing with speed. That does not make any sense. Therefore, without mass there cannot be energy. So, the energy is mass plus speed, for example. The mathematical equations must hold. Else, they would be meaningless.\\
jbartos
Electrical
- Jan 15, 2000
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- 0
Suggestion to rbulsara (Electrical) Oct 25, 2003 marked ///\\This discussion can go on and on, but I think I did my best to explain.
///That is great.\\ You will do well to remember that ‘energy’ by itself is not visible, it does not have mass,
///If one writes a mathematical relationship, e.g. for Energy=mxaxsxt
then, there is "m" which stands for mass. Therefore, the energy must have mass "m" else the equation would not be valid.
To put it some other way, say, my account accrued $12000 during year by saving $1000 a month or
$12000=$1000/month x 12 month.
If one says the account does not have $ value just its form, then I guess every banker would like one very much.\\ only its effect can be felt or ‘seen’ by change in the characteristics of a visible object.
///That is great.\\ You will do well to remember that ‘energy’ by itself is not visible, it does not have mass,
///If one writes a mathematical relationship, e.g. for Energy=mxaxsxt
then, there is "m" which stands for mass. Therefore, the energy must have mass "m" else the equation would not be valid.
To put it some other way, say, my account accrued $12000 during year by saving $1000 a month or
$12000=$1000/month x 12 month.
If one says the account does not have $ value just its form, then I guess every banker would like one very much.\\ only its effect can be felt or ‘seen’ by change in the characteristics of a visible object.
jbartos:
With all due respect, you are caught in a web of your own miscoception. Please take a step back.
Energy has 'effect' on mass or material, but its not the mass. (except as noted further down)
In the equations you referred to, F=ma and Work= F.s, all it indicates that a certain amount of energy will have the effect on mass m to gain certain speed or acceleration. It does not add or dedcut the mass! The mass remains the same before during and after the effect of the energy is over.
Mass to energy covnersion only takes place in nuclear reactions or when mass approches speed of light (an un-understood part of Einstein theory, I have no intention to discuss that here as I have very little idea about that).
Another example, when the electro-magnetic energy transforms into mechanical energy through an air gap in a motor making the rotor turn, no 'mass' transfers through the air gap! Upon removal of the electric energy no phycial or chemical change in the material is detectable (ignoring hystersis).
Only poorer forms of energy need medium or mass to propagate and we on this mortal earth deal mostly with poor forms of energy except for light so it appears that energy always need a medium.
As for your dollar value example, try this, an ounce of gold is worth, say $100.
You may write $100=1 oz Gold, but that does not make gold the dollar, the bill! Although it has a dollar value. And both can exist independetly. Even though ultimately both may have came from a common source! (like mass and energy.)
With all due respect, you are caught in a web of your own miscoception. Please take a step back.
Energy has 'effect' on mass or material, but its not the mass. (except as noted further down)
In the equations you referred to, F=ma and Work= F.s, all it indicates that a certain amount of energy will have the effect on mass m to gain certain speed or acceleration. It does not add or dedcut the mass! The mass remains the same before during and after the effect of the energy is over.
Mass to energy covnersion only takes place in nuclear reactions or when mass approches speed of light (an un-understood part of Einstein theory, I have no intention to discuss that here as I have very little idea about that).
Another example, when the electro-magnetic energy transforms into mechanical energy through an air gap in a motor making the rotor turn, no 'mass' transfers through the air gap! Upon removal of the electric energy no phycial or chemical change in the material is detectable (ignoring hystersis).
Only poorer forms of energy need medium or mass to propagate and we on this mortal earth deal mostly with poor forms of energy except for light so it appears that energy always need a medium.
As for your dollar value example, try this, an ounce of gold is worth, say $100.
You may write $100=1 oz Gold, but that does not make gold the dollar, the bill! Although it has a dollar value. And both can exist independetly. Even though ultimately both may have came from a common source! (like mass and energy.)
jbartos
Electrical
- Jan 15, 2000
- 6,440
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Suggestion: I see that the perception of Energy as an effect of the mass is very widespread. In one of my posting above, I indicated the bullet shot upward. It will stop at some point. The kinetic energy will be depleted. However, the bullet will have its original mass and potential energy with respect to the earth surface. Again, the potential energy depends on the mass of the bullet, and the energy encompasses the bullet mass and bullet height above the ground. Mass is the fundamental aspect of energy, an attribute of energy. The effect of energy would more on a side of energy consequence.
in reply to Imok:
/// In an AC system, the electricity moves back and forth. In other words, it sits inside the wires and vibrates. The electricity does not move forward at all (if it did, that would be a direct current or "DC."
At the same time, the electrical energy moves forward rapidly. Only the electricity "alternates." The electrical energy does not, the energy flows continuously forwards. ///
I hesitate to plunge into this debate but thought I 'd comment on the above...
Although electrons (and other components) within conductors may oscillate when an AC 'current' passes through this is not the 'electricity' as such - the energy is within the electromagnetic wave and the conductor is merely an effective waveguide for the sort of wavelengths used in normal electricity networks. The first transfer of energy in an electrical power system is aross a machine air gap with no 'conductors' as such and there is no interruption to energy flow when the magnetic paths of power transformers replace the electrical conductors as the conduit...
I suppose my point is that electricity is just one way of using electromagnetic radiation to get energy from A to B. We can also use radio waves, microwaves and various others to transmit energy (although these are of lower power due to limits in our understanding and technology). Its easy to focus on conductors when discussing electricity but they are not the underlying physics.
/// In an AC system, the electricity moves back and forth. In other words, it sits inside the wires and vibrates. The electricity does not move forward at all (if it did, that would be a direct current or "DC."
At the same time, the electrical energy moves forward rapidly. Only the electricity "alternates." The electrical energy does not, the energy flows continuously forwards. ///I hesitate to plunge into this debate but thought I 'd comment on the above...
Although electrons (and other components) within conductors may oscillate when an AC 'current' passes through this is not the 'electricity' as such - the energy is within the electromagnetic wave and the conductor is merely an effective waveguide for the sort of wavelengths used in normal electricity networks. The first transfer of energy in an electrical power system is aross a machine air gap with no 'conductors' as such and there is no interruption to energy flow when the magnetic paths of power transformers replace the electrical conductors as the conduit...
I suppose my point is that electricity is just one way of using electromagnetic radiation to get energy from A to B. We can also use radio waves, microwaves and various others to transmit energy (although these are of lower power due to limits in our understanding and technology). Its easy to focus on conductors when discussing electricity but they are not the underlying physics.
- Thread starter
- #33
rbulsara
I am not a physicist, but photon is a unit of light, not electricity. Light is not the electricity, as we know it.
imok2
Light is energy. I never said that it was electricity.The smallest particle of energy is the unit quantum of electromagnetic energy: it is the photon. So should we no longer say that electric current is "a flow of electricity." Instead, call it a "flow of charge" or a flow of electromagnitic photons? Also that electrons are "charge carriers" rather than "particles of electricity." Should Faraday's Law be changed, so that scientists today can speak of "quantities of charge" rather than the "quantities of electricity" discussed in the traditional definition of the Faraday Electrolysis Law.
I am not a physicist, but photon is a unit of light, not electricity. Light is not the electricity, as we know it.
imok2
Light is energy. I never said that it was electricity.The smallest particle of energy is the unit quantum of electromagnetic energy: it is the photon. So should we no longer say that electric current is "a flow of electricity." Instead, call it a "flow of charge" or a flow of electromagnitic photons? Also that electrons are "charge carriers" rather than "particles of electricity." Should Faraday's Law be changed, so that scientists today can speak of "quantities of charge" rather than the "quantities of electricity" discussed in the traditional definition of the Faraday Electrolysis Law.
- Thread starter
- #34
imok:
Perhaps you should all of my posts over again and also the last post of rsherry.
Elecricity DOES flow, expcet electricity is not electrons and electrons do not move same as electricity! Electricity is the 'name' given to electrical energy which does flow!
Electrons themselves do not move at the same speed at the electricity (electomagnetic wave). Same as when a wave in a body of water propagtes, the water molecules do not travel as as the wave and the enegrgy associated with the wave! I am not sure why you have such a difficulty correlating to this 'mechanical' anaology.
You can say the disturbance (wave) of the electrical charge passes through a condcutor by exhanging the 'charge' like a batton in a athletic relay race at the speed of the propagation of electiricity, but a physical electron barely moves.
You need to give up imagining electrical current as a physical (material) entity, it is not.
May be the follwing example will help. Say a pipe is used to empty all water from a tank. Upon releasing of all water, there is no physical water particles left. While in electricity, if you consider the condcutor a pipe, all of the electrons remain there, before, during and after the electrical current and the energy has passed through it! You are not injecting any electrons nor are you removing any ewlectrons when you apply or remove electrical current through a conductor.
I will not be offended if anyone else wants to jump in with any opinions.
Perhaps you should all of my posts over again and also the last post of rsherry.
Elecricity DOES flow, expcet electricity is not electrons and electrons do not move same as electricity! Electricity is the 'name' given to electrical energy which does flow!
Electrons themselves do not move at the same speed at the electricity (electomagnetic wave). Same as when a wave in a body of water propagtes, the water molecules do not travel as as the wave and the enegrgy associated with the wave! I am not sure why you have such a difficulty correlating to this 'mechanical' anaology.
You can say the disturbance (wave) of the electrical charge passes through a condcutor by exhanging the 'charge' like a batton in a athletic relay race at the speed of the propagation of electiricity, but a physical electron barely moves.
You need to give up imagining electrical current as a physical (material) entity, it is not.
May be the follwing example will help. Say a pipe is used to empty all water from a tank. Upon releasing of all water, there is no physical water particles left. While in electricity, if you consider the condcutor a pipe, all of the electrons remain there, before, during and after the electrical current and the energy has passed through it! You are not injecting any electrons nor are you removing any ewlectrons when you apply or remove electrical current through a conductor.
I will not be offended if anyone else wants to jump in with any opinions.
jbartos
Electrical
- Jan 15, 2000
- 6,440
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- 0
Comment: Engineering is always concerned with dimensions of variables and constants. E.g.
Quantity Unit Unit Symbol Dimensions
==========================================================
Energy Joule J kg m**2 s**-2
Power Watt W kg m**2 s**-3=J s**-1
Voltage Volt V kg m**2 s**-3 A**-1
Voltage Volt V J s**-1 A**-1
Etc.
It is clearly seen that the energy has the mass in its dimension
Then, for example the time rate of change of energy within a given volume is determined by the power flow through the surface A of the volume as:
P=dW/dt=integral over the area A of (S x dA)
where S=ExH
is the Poynting Vector pointing in the direction of the per unit area power flow
Since the Energy dimension includes kg of mass, the radiated energy characterized by the Poynting Vector has a material or kg of mass in its dimension.
Therefore, the mass is tied to energy even though it is not apparent, and the mass is hidden by different units, e.g. J
Quantity Unit Unit Symbol Dimensions
==========================================================
Energy Joule J kg m**2 s**-2
Power Watt W kg m**2 s**-3=J s**-1
Voltage Volt V kg m**2 s**-3 A**-1
Voltage Volt V J s**-1 A**-1
Etc.
It is clearly seen that the energy has the mass in its dimension
Then, for example the time rate of change of energy within a given volume is determined by the power flow through the surface A of the volume as:
P=dW/dt=integral over the area A of (S x dA)
where S=ExH
is the Poynting Vector pointing in the direction of the per unit area power flow
Since the Energy dimension includes kg of mass, the radiated energy characterized by the Poynting Vector has a material or kg of mass in its dimension.
Therefore, the mass is tied to energy even though it is not apparent, and the mass is hidden by different units, e.g. J
SidiropoulosM
Electrical
peebee, yes we ARE funny.....You know, I did my first year in physics before switching to engineering. The reason I switched is because my girlfriend at the time told me that engineers are more fun than physicists. I haven't regretted my switch one bit.
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