Rock Port, Missouri - The First 100% Wind Powered City

[LMagic007]

Originally Posted by Besoeker

Actually, it does not accord with any equations. Energy can not be instantaneous.

I think maybe therein is the crux of the matter.
Call the period or passage of time p.
For 0<p<1 as you suggest, p is a finite value. It could, for example, 0.5s, that being the passage of time. That isn't instantaneous.

Going back to your comment in post #35
"Fundamentally speaking, a unit of power (Watt) is equivalent to a unit of energy (Joule) over a unit of time (Second)"
That gives us:
W=J/s
And that gives us the more fundamental definition:
Power is the RATE of doing work. It could be Nm/s, ft-lbf/s, kW etc.
(That applies whether it is electrical, mechanical, or fluid power.)
The rate of doing work.
Energy is what you get from that rate of work over a period of time. No time, no energy.
One kWh can be generated in an hour, a week, or 1ms (1ms being 3.6GW)
But not instantaneously.

An analogy that may be helpful......
Suppose that you drive at a rate of 60kph.
Travel for an hour you do 60km
In a minute, 1km
In a second, 17m
In 1ms, 17mm.

In other words, the rate at which you travel (instantaneous speed) tells you nothing about the distance you will cover unless you define time period. You can't instantly cover 50m.

That above description is somewhat misleading. Instantaneous speed is not simply the rate at which you travel. Instantaneous speed is the speed or rate of travel at a given moment or instant in time. The rate at which you travel is simply distance over time.

Getting back to the main point though, if energy cannot be instantaneous, then nor can power, because power without time is meaningless. Power requires time to have meaning. Instantaneous implies in an instant with no intervening time, making time zero and if time is zero then work cant be done and if work cant be done then power does not exist.

Power is a rate at which work is performed or the amount of energy expended over a unit of time. This rate is a ratio, in which two measurements ( 1. unit of energy - joule and 2. time ) are related to each other to derive meaning. If no time passes then this rate cannot exist, yet to be instantaneous requires no passing of time, meaning time is zero, therefore power cannot exist if time is zero. Power W requires 1 joule over 1 second. If time does not pass then power does not exist and thus cannot be derived. If no work is done then power does not exist. For work to be done time must pass. i.e. for 1 unit of work being 1 joule, 1 second must pass. However, to be instantaneous requires no passing of time. We thus have a null contradiction.

However for descriptive purposes in terms of measuring energy over a very short space of time a different interpretation of instantaneous is sometimes given. i.e. without perceptible time. This might explain one reason why in fact the term instantaneous energy is used in areas of science and technology.

It's clearly not pragmatic to have zero time, meaning without passing of time, or no intervening time, because this would mean zero energy, zero work done and zero power. Thus pragmatically speaking, instantaneous time is applied to simply mean, a very short space of time and usually sub-second but greater than zero time. i.e. for pragmatic purposes no perceptible time, being a very short space of time.

Regardless of all this though, it does not change the fact that the intended meaning of the articles is clear.

[Besoeker]

Originally Posted by LMagic007

That above description is somewhat misleading. Instantaneous speed is not simply the rate at which you travel. Instantaneous speed is the speed or rate of travel at a given moment or instant in time.

A pretty fair description of instantaneous speed.

Originally Posted by LMagic007

The rate at which you travel is simply distance over time.

Quite so.

Originally Posted by LMagic007

Getting back to the main point though, if energy cannot be instantaneous, then nor can power, because power without time is meaningless. Power requires time to have meaning.

It doesn't.
Instantaneous implies in an instant with no intervening time, making time zero and if time is zero then work cant be done and if work cant be done then power does not exist.

Originally Posted by LMagic007

Power is a rate at which work is performed or the amount of energy expended over a unit of time. This rate is a ratio, in which two measurements ( 1. unit of energy - joule and 2. time ) are related to each other to derive meaning. If no time passes then this rate cannot exist, yet to be instantaneous requires no passing of time, meaning time is zero, therefore power cannot exist if time is zero. Power W requires 1 joule over 1 second. If time does not pass then power does not exist and thus cannot be derived. If no work is done then power does not exist. For work to be done time must pass. i.e. for 1 unit of work being 1 joule, 1 second must pass. However, to be instantaneous requires no passing of time. We thus have a null contradiction.

However for descriptive purposes in terms of measuring energy over a very short space of time a different interpretation of instantaneous is sometimes given. i.e. without perceptible time. This might explain one reason why in fact the term instantaneous energy is used in areas of science and technology.

It's clearly not pragmatic to have zero time, meaning without passing of time, or no intervening time, because this would mean zero energy, zero work done and zero power. Thus pragmatically speaking, instantaneous time is applied to simply mean, a very short space of time and usually sub-second but greater than zero time. i.e. for pragmatic purposes no perceptible time, being a very short space of time.

Regardless of all this though, it does not change the fact that the intended meaning of the articles is clear.

[Besoeker]

Originally Posted by LMagic007

That above description is somewhat misleading. Instantaneous speed is not simply the rate at which you travel.

It is exactly that.

Originally Posted by LMagic007

Getting back to the main point though, if energy cannot be instantaneous, then nor can power, because power without time is meaningless. Power requires time to have meaning.

Not so. It is a rate of doing work.

Originally Posted by LMagic007

Instantaneous implies in an instant with no intervening time,

Yes, that what it means.

Originally Posted by LMagic007

if time is zero then work cant be done

Exactly so.

Originally Posted by LMagic007

and if work cant be done then power does not exist.

Incorrect at that point. Power is the rate of doing work. If that rate is performed over zero time there is no work.[/quote]

[LMagic007]

Originally Posted by Besoeker

Not so. It is a rate of doing work.

Power is a derived rate of Work / time. If time is zero, you cannot derive a value for power and work cannot be done, except it can be observed for that moment in time, which is implied rather than actual, on the basis that at the next instance of time, work will continue. This gives practical meaning to instantaneous, because in mathematical terms zero time passes at an instant. Work must be done for power to have meaning, but work cannot be done if zero time passes, but it can be observed as having been done, at that moment in time.

Originally Posted by Besoeker

Incorrect at that point. Power is the rate of doing work. If that rate is performed over zero time there is no work.

That's what I indicated. And, if no work is done, power cannot be derived except for the reason I explained above.

If velocity has any meaning, with regard to wind energy, at any instant kinetic energy content per unit area exists. Therefore energy in motion ( wind ) can be instantaneous, when measured at a given moment. In that respect it's no different to power as described above.

Energy is present all the time. Energy does not have to be doing work to exist. Power on the other hand is the rate at which energy is transmitted or work done, but for work to be done, energy has to be transferred. The mere meaning of transferred implies past tense and therefore implies the passing of time and hence past of the current moment. For energy to be transferred, time must pass, yet in an instant, no time passes and we can only observe what has gone before. Thus instantaneous power is more of an observation or measurement of what has occurred, but viewed in an instance or a moment, without passage of time. Energy however is always present and instantaneous and in some ways more so than power.

[Besoeker]

Originally Posted by LMagic007

Power is a derived rate of Work / time. If time is zero, you cannot derive a value for power and work cannot be done,

Corect. WORK cannot be done in zero time. But you CAN derive a value for power.
As δt → 0 you get dw/dt for rate of work. The equations deal with the concept of zero time very nicely, (thanks Mr Newton. )
QED. Power does not imply or require the passage of time.

Power is an instantaneous value. No ifs, no buts.
If you can't understand that, just accept it.

[LMagic007]

Originally Posted by Besoeker

Corect. WORK cannot be done in zero time. But you CAN derive a value for power.
As δt → 0 you get dw/dt for rate of work. The equations deal with the concept of zero time very nicely, (thanks Mr Newton. )
QED. Power does not imply or require the passage of time.

Power is an instantaneous value. No ifs, no buts.
If you can't understand that, just accept it.

Power is a derivation of time and work and to exist ( have a value > 0 ) requires time. Your argument though, was that energy cannot be instantaneous. I claimed and demonstrated that it can. No ifs, no buts. If you can't understand that, just accept it. More importantly though, none of this changes the fact that the articles intended meanings are clear.


Also; you claim energy can't be instantaneous when time = 0 because value is zero when t = 0

i.e. with; E = P x t; so if t = 0 E = 0

But also one can say a similar thing about power;

P=w/t; thus; P x t = w; thus if t = 0 then P x 0 = 0 thus P= 0 w= 0 t = 0

Thus when t = 0 w = p = 0 Thus with your logic appears inconsistent.

Instantaneous is in the observation of the moment the frame of reference, be you observing power or energy or anything else. Power is just a rate of work over time and further more average rate of power can be applied over time.

The articles are clearly understandable and correct.

[Besoeker]

Originally Posted by LMagic007

Power is a derivation of time and work and to exist ( have a value > 0 ) requires time.

I clearly demonstrated in post #424 that it does not.

Originally Posted by LMagic007

Your argument though, was that energy cannot be instantaneous.
I claimed and demonstrated that it can.

It can't.
Energy = power x time.
Zero time, zero energy.
It's as simple as that.

[LMagic007]

Originally Posted by Besoeker

I clearly demonstrated in post #424 that it does not.

It can't.
Energy = power x time.
Zero time, zero energy.
It's as simple as that.

Electrical Energy expressed in kwh = Power x Time. Power = W/t. being the rate at which work is done. Power cannot be observed greater than zero without time. Work must be done for power to be observed greater than zero. For work to be done, time must pass. Energy of varying kinds exist irrespective of power. Energy cannot be created or destroyed. Energy is ever present. Energy when observed at any moment is instantaneous. Power requires work to be done to be observed being greater than zero. Simple as that.

Overridingly though, the intended meaning of the articles is clear.

[Besoeker]

Originally Posted by LMagic007

Electrical Energy expressed in kwh = Power x Time.

Exactly. No time equals no energy.

Originally Posted by LMagic007

Power = W/t. being the rate at which work is done. Power cannot be observed greater than zero without time.

It can. And that seems to be the point with which you have difficulty.

[LMagic007]

Originally Posted by Besoeker

Exactly. No time equals no energy.


It can. And that seems to be the point with which you have difficulty.

There is no difficulty. Power is a rate measurement that requires work to be done to derive useful meaning. Work requires time. It's implied even though you may observe it in an instant, it implies the passing of time to give it contextual meaning. Energy however is ever present and instantaneous when observed and even when not observed. Energy is more fundamental than power.