Energy Explained

[arkain101]

Obviously there's energy in both cases, but whether you say a photon is "made" out of energy is moot.

Allow us to call a photon or anything with velocity C to be flowing at the same velocity as time.

If time is nothing, then energy is nothing. Then you must consider relative to what, is either of these concepts real.

[sebbysteiny]

I can see people have moved on from my post which was only half written.

So I'll delete my original post and replace it here.

I'm sorry if much of what I say is simply a repeat of yours, Arkain.

But instead, I'll suggest a less mathematical explanation.

I am highly sceptical of calling energy 'a thing, like red' (or perception). I think it is a real property (or underlying property) of matter.

It can't just be a description attached to mass since there are massless particles that are entirely made of energy [Note these particles DO also have a momentum].

Yet you have pointed out difficulties in which the meaning of Kinetic energy appears meaningless depending on the frame. The question is, can this be resolved without giving up on the idea that energy is a property of the Universe and exists.

You also mentioned how energy, like money, can be recycled into another form which I think is only a half truth.

There are 3 topics that seemed to arise: relitivistic and non-relativistic treatment of Kinetic energy and momentum; and entropy.

Non-relativistic treatment of energy

Even under non-relativsitic velocities, the link between energy and momentum is unmistakable, as you pointed out popular. By simply changing the frame of reference, the energies and velocities of the particles completely changes. But at the non-relativistic level, there is no universal underlying property of matter that equates the two so one cannot say they are both descriptions of the same more fundamental thing as far as I'm aware. So we must put up with the notion that energy and momentum, though linked, are not fundamental properties. However, this changed after Einstein.

Nevertheless, from Newton's third law, momentum is always conserved, and from Newton's second law, energy must always be conserved. So in all frames, both are conserved making both together very useful albeit not a fundamental property.

Relativistic treatment of energy and momentum

In relativity, like that there is no such thing as time and space, only space-time, there is no such thing as energy and momentum, only momenergy. Momentum is three coordinates (Px, Py, Pz) and Energy is one cooridinate (E) in a four dimensional thing called momenergy. Thus, MOMENTUM AND ENERGY ARE ONE AND THE SAME. And the only conservation law now is conservation of momenergy.

With the simple formula, dt^2 = dPx^2 + dPy^2 + dPz^2 - dE^2 [units of c=1], all momentum - energy calculations in all frames can be made. This is because the proper time (ie the time measured by an observer in the moving frame, dt, is constant in all frames of reference.

So essentially momenergy does not vary in all frames and so I say it IS a fundamental property of matter even if it's co-ordinates (energy, momentum) are not. Momenergy exists, and it is conserved.

As a side issue, if mass = 0 then the proper time of the particle = 0. Here, Energy = Momentum. A massless particle must have both momentum and energy.

Entropy

Originally Posted by Popular

Another illustration is money. You can spend money just like you can expend energy. But the money doesn’t disappear, just as the energy doesn’t disappear. Somebody else now has your money, just as some other thing now has your energy.

The problem with your analogy that I can see is that money, once spent, can be spent again. However, there is no conceivable way of using the energy wasted into the environment again to create usable work. Once energy is used, it is used for now and forever.

Why can't we?

It's all about entropy. Entropy can be viewed as the amount of order in the Universe. Energy [or at least, momenergy] is a property of matter. That is always conserved. But whenever energy changes form, it creates a state of greater disorder.

Eg, heat can flow from a hot iron bar into a cold one making both bars medium heat. Energy is conserved. But we cannot bring the heat from the now warmed up bar back into the now cooled down bar. The reason is that before one heated up the other, there was order. All the energetic particles were in one bar, and all the cooler ones were in another. After, this order was gone and can never return. The energy used to heat the cooler bar can now never be used as usable work again.

This is what is meant by 'we are using up our energy resourses'. Technically, we are actually just using up our entropy resourses. And entropy is, again, a fundamental property of matter just like energy.

A qualitive and quantitive discussion of this is at about 2nd year University level.

[arkain101]

Good post.

If you keep taking half the entropy out of a hot bar (presuming half is lost) can you ever reach zero entropy? (energy), presuming we keep using bars from space that are nearly zero kelvin.

Obviously the energy becomes less each time and significantly useless. But mathamatically, if an object was at zero kelvin, what would occur if we took transfered the heat from the hot to the cold, then the two less hot, to a new cold, and the now 3 warms, to a cold.

This sounds like a stupid question, to me for some reason but, universally I thought it might matter.

[sebbysteiny]

Originally Posted by arkain101

Good post.

If you keep taking half the entropy out of a hot bar (presuming half is lost) can you ever reach zero entropy? (energy), presuming we keep using bars from space that are nearly zero kelvin.

Obviously the energy becomes less each time and significantly useless. But mathamatically, if an object was at zero kelvin, what would occur if we took transfered the heat from the hot to the cold, then the two less hot, to a new cold, and the now 3 warms, to a cold.

This sounds like a stupid question, to me for some reason but, universally I thought it might matter.

If you have a bar of temperature 100K, and you put it in contact with an identical bar at 0K, with perfect insulation, you would get two bars at 50K. Next bar would give 3 bars at 33K. But the heat from one can never be used to heat up the bars again.

At absolute zero, every molecule / atom / particle is in its lowest possible energy state. That's the definition.

Okay, I'm going to be bold and give some formula. Boltzman tried to calculate the value of the entropy from the number of available state. He came up with the famous Boltzman equation, S = Kb ln (Z) where S = entropy, Kb = Bolstzman's constant and Z = the total number of available states. One cannot overstate the utility of this equation in thermodynamics and statistical mechanics.

So if every particle is in it's lowest possible energy state, there is only 1 possible way to arrange the molecules / atoms / particles. It has a perfect order and therefore an entropy of zero. Or, mathematically, S = Kb ln 1 = Kb * 0 = 0.

So in your example, the entropy will continue to drop exponentially until the limit of zero. The temparature will drop expanentially until the limit of zero. But the overall energy will remain constant, but just spread out over more bars.

[Farsight]

Sebby:

I am highly sceptical of calling energy 'a thing, like red' (or perception). I think it is a real property (or underlying property) of matter...

Is there some confusion here? I think "red" is just perception, because the underlying property is wavelength. I don't think energy is just perception. Heat burns, cannonballs take your head off.

It can't just be a description attached to mass since there are massless particles that are entirely made of energy [Note these particles DO also have a momentum].

I'm sure everybody agrees that energy isn't uniquely tied to mass, but whether massless particles are entirely made of energy is moot.

Yet you have pointed out difficulties in which the meaning of Kinetic energy appears meaningless depending on the frame. The question is, can this be resolved without giving up on the idea that energy is a property of the Universe and exists.

Am I getting mixed up with something arkain said? I do think energy is a property of the Universe and exists.

You also mentioned how energy, like money, can be recycled into another form which I think is only a half truth.

Sure, the parallels between Money and Energy are interesting rather than total. See MONEY EXPLAINED.

In relativity, like that there is no such thing as time and space, only space-time...

I beg to differ. Seriously, I think SR says time is not fundamental. It's a strange concept I know, but I'm perfectly serious about it. See TIME EXPLAINED.

I'm ashamed to say I've never heard of momenergy. On a side note, I think mathematics should support an explanation in English that offers "grasp" of the subject. All too often it doesn't.

The problem with your analogy that I can see is that money, once spent, can be spent again. However, there is no conceivable way of using the energy wasted into the environment again to create usable work. Once energy is used, it is used for now and forever... It's all about entropy... and entropy is, again, a fundamental property of matter just like energy.

Think perfectly elastic collisions for an example of repeated energy expenditure. Sure there are practical problems with our energy consumption and the environment, but the energy has dissipated, not disappeared. Energy reuse depends on your "sink" level.

Entropy is not a fundamental property of matter, it's a statistical property of systems. Maybe that was just a slip of the tongue. Anyhow, I was reading about Boltzmann the other day, he had problems with Poincare:

http://www.math.umd.edu/~lvrmr/History/Recurrence.html

[sebbysteiny]

Originally Posted by Popular

Is there some confusion here? I think "red" is just perception, because the underlying property is wavelength. I don't think energy is just perception. Heat burns, cannonballs take your head off.

Appologies. I must have misunderstood what your thesis is.

Perhaps you can explain what conclusion you were trying to reach in this paragraph.

My objection is based on the last sentence, which seems to me to be the main thesis of what you were saying.

Let’s start by saying that energy is the property of a thing. It is not a thing in its own right. To illustrate this, I can talk about a red bus, or a red red ruby. All these things have the property that we call red. A thing can be red, but you cannot remove this red and hold it in your hand. You can remove the paint or the dye and hold that in the palm of your hand, but you are still holding a thing that is red. You cannot remove the red from the dye to hold the red in the palm of your hand. Even when you imagine red, the image in your mind’s eye is a thing. You always need a thing to be red. There is no such thing as “raw red”. In similar vein there is no such thing as “raw energy”.

Originally Posted by Popular

whether massless particles are entirely made of energy is moot.

I think that depends what you mean by 'made'. A photon is made of 1) energy, 2) momentum and 3) electro magnetic forces that take the form of a wave travelling at speed c. Is this moot?

Originally Posted by Popular

Sure, the parallels between Money and Energy are interesting rather than total. See MONEY EXPLAINED.

I'm not saying you're definately wrong. But since energy in the form of usable work cannot be 'recylced' into another form of usable work (ie capable of respending) as a consequence of entropy, I'm not sure how the money analogy helps in any way.

Originally Posted by Popular

I beg to differ. Seriously, I think SR says time is not fundamental.

What I mean is that time and space are both coordinates of the more fundamental property of space-time. Space time is a 4 vector that contains all 4 coordinates (x,y,z,t). Time is thus not a separate entity any more than x is from y.

Originally Posted by Popular

Think perfectly elastic collisions for an example of repeated energy expenditure. Sure there are practical problems with our energy consumption and the environment, but the energy has dissipated, not disappeared. Energy reuse depends on your "sink" level.

Lets consider the following. Fossil fuel burns to turn turbines. Almost 60% of the energy is lost in heat (and thus cannot be recycled). 40% becomes electricity. That is then used to power a moter at a home with about 10% wasted leaving about 36% recycled into useable work. the moter powers a pendulum with about 1% loss leaving still about 36% recycled. That pendulum can turn a spring etc.

So what's going on?

Yes, some energy is recylced, but the more one wastes, the more becomes unusable for work. So i take your point. It's like exchanging money, but a bit of it is burnt or taken in tax (never to be returned) every time it is spent.

So I'm not disagreeing with your analogy, but I do think that you may need a discussion of entropy as well.

Originally Posted by Popular

Entropy is not a fundamental property of matter, it's a statistical property of systems. Maybe that was just a slip of the tongue.

1) fundamental property. 2) statistical property. Why are the two mutually exclusive? My understanding is that it is both.

Originally Posted by Popular

Anyhow, I was reading about Boltzmann the other day, he had problems with Poincare:

If Boltzmann had problems, then I won't pretent to find a solution. From what I can see, Poincare just suggests that, every now and then, a system should gain entropy for a short period. Nevertheless, entropy in the universe will fall vastely more than it gains.

[Farsight]

sebby: No probs, I think we've been talking at cross purposes on some of this stuff.

Basically what I want to say is Energy is Tension, but I can't quite say that because tension is defined to be negative pressure, and to get the dimensionality right I have to chuck in volume too.

I'm not quite sure which last sentence you mean. It's quite hard to say what a photon is. We know it's an electromagnetic "wave" thingy, and we know it's got momentum and energy, but is it "made" out of the things its got? Is a bus in any sense made out of red, or more properly, wavelength? This stuff gets real tricky. I think we need a separate essay for it. Fair dinkum if you don't think the money helps. I understand what you mean about spacetime, perhaps we can discuss that elsewhere? And I do take your fossil fuel point about the energy becoming unavailable, I just wanted to stress that it's still there but dispersed. Hmmn, maybe I do need to talk about entropy. Noted.

1) fundamental property. 2) statistical property. Why are the two mutually exclusive? My understanding is that it is both.

I take an ontological view, and say a fundamental property is something that a subatomic "particle" has got. It hasn't got colour, sound, heat, smell, or taste. It's got mass, charge, velocity, spin, and other stuff like wavelength, depending on what sort of "particle" it is. It doesn't have entropy. It's only when you look at some large collection of particles that you can talk about the entropy, of the system. But it's a derived property, a little like "sameness".

The thing about entropy and Boltzmann is that you get this "Heat Death of the Universe", then nothing much happens for a very, very, very long time. The thing is that if nothing much happens there isn't much time, so it's academic really. Then something "much" happens, and by chance (or otherwise) you find you've dealt the perfect hand of bridge, and you've got another big bang or something. There's this great little Science-Fiction story by Isaac Asimov that really brought it home to me years back, and while I'm not at all religious, I confess it brought a tear to my eye:

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

[arkain101]

So in your example, the entropy will continue to drop exponentially until the limit of zero. The temparature will drop expanentially until the limit of zero. But the overall energy will remain constant, but just spread out over more bars.

So I wonder, would we end up with infinite bars? or a number of bars so great it would require more than we could muster? The point of this question and sorry for placing it in this thread, is that, what this number comes to, would directly apply to explaining the universes size.

[Farsight]

I am wondering whether photons kind of "make" the space they travel through.

[arkain101]

I am wondering whether photons kind of "make" the space they travel through.

In relation to my theory of relativity popular, a photon does make space. Infact it is space.

As space contracts for a frame, let us use the frame of an electron, it must use up energy, that is because velocity nearing C requires energy and compresses space relative to the frames observation.

From an outside measurement we would observe the electron to expand dimensionally. When the electron is observed to fall back down, the reverse would occur. Its view is that its space has expanded, dimensionally. This requires just as much energy to do than it does to contract it. So, energy in the form of spacial contraction is released from the atom, via mechanics that I am not confident to presume. The energy or spacial contraction is in the form of a masseless wave-particle. Or let us say an observation of space changing. (however the logic might actually be in the reverse process, that is viewing expansion makes the energy...)

The more matter that does this action of spacial change, the greater the intensity it can create. Wwhen you observe space contracting relative to your oservation you are infact moving towards it. So the frequency of spacial contraction from a large body of mass goes out from the body sphere-like, and loses intesity as pulses outwards. Any observatoin frame that comes in the vacinity of these passing contractions of space, will keep on seeing space contract, bit by bit.. thus they keep on getting closer, or aka gravity.

So if we take earth for example and a person. The person emmits spacial contraction all the time, and infact the earth itself observes the person getting closer/time it is in the vacinity. However, the intesity of the persons contraction is so minimal to the earths that relative to eachother, the person observes MORE contraction, so their frame accelerates more quickly. This would be mass. The difference between frames, and how the accelerate relative to eachother in many forms of interaction.

To help with this concept;


All things are frames. All frames observe the present, they have no dimension. So everything is respectivly a frame of no dimension.
There is nowhere you can go where you are not a frame. Everything is a frame (and frame of observation). A) it must have constant speed of light B) the laws of physics remain the same.



Try to think of all the places you could observe from; an electron, or an atom as a whole, or whatever.
In your frame as in all frames, all obseravations are inside your present moment. Thus you are frame of zero dimension. Distance is your future, your future is distance. What you see happen is what happens. Or that is, what happens, like spacial contraction, is what will effect that frame.

It is impossible to not be in a frame of observation. Everytime you see an object you are viewing from a frame. And if you imagine to view from that object you are becoming a new frame, and if you want to imagine observations from atoms with in that object you are only becoming another frame. It is the conclusion to all things, and everything a frame observes happen happens to its frame.

Regardless of what you want to lable or title something, such as; matter, or electron, or proton, or anything you can think of, in general you are refering to a frame. In that frame, is no dimension and the same laws of physics apply, C, and consistant physics.

Anything that is a dimension is what is observed and it is your present moment. By this, You can only conclude that everything you see is your present, which is zero distance.

If you fall to earth did you fall? Or did you observe the space shrinking between you and the earth.
If you said fall you claim there is real space.
If you said, you observed space to contract between you and earth you claim there is no space but only observations in zero dimension.

Adding dimension only adds new form of restrictions.
Removing dimension opens up infinity and boundlessness.