Do we have a theory as to what energy is?

In summary: This is what we do in physics. Then we can try to understand why it is useful and what makes it unique. Lastly, we can ask questions about it that probe beyond what it is defined as.
  • #1
Larry Farmer
13
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Atoms I know Strings I know. these are the things that energy operates in. If we were to be able to make a atom or a string large enough to hold in our hand and pull it apart to smaller and smaller pieces would we begin to understand what energy really is. We know all the aspects of energy But do we understand what energy is . I read that there are only two things matter and energy. to my understanding that is not true. There is only energy formed or molded in cohesive ways to represent matter. From atoms to strings to the nose on my face there is only energy, is this correct.
 
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  • #2
Energy is not as mysterious or fundamental as you are making it out to be. Energy is just a number you can calculate. It is a useful number because if you calculate the energy of a physical system at two different times, you will get the same number, no matter what has happened to the system in the meantime. Because of this we say that energy is "conserved." We understand the deep reason for this: it is because the laws of physics do not change in time. For any physical system whose governing laws are constant in time, there is a number you can calculate which is conserved and plays the role of energy. The mathematics behind this is called Noether's theorem.

Energy is not a mysterious substance that makes up everything. It is just a number.
 
  • #3
Larry Farmer said:
Atoms I know Strings I know. these are the things that energy operates in. If we were to be able to make a atom or a string large enough to hold in our hand and pull it apart to smaller and smaller pieces would we begin to understand what energy really is. We know all the aspects of energy But do we understand what energy is . I read that there are only two things matter and energy. to my understanding that is not true. There is only energy formed or molded in cohesive ways to represent matter. From atoms to strings to the nose on my face there is only energy, is this correct.

This is rather puzzling and odd.

We can measure energy. We in fact use it every single day. It is an inherent ingredient in our description of our world.

Strings, on the other hand, is still highly hypothetical. It has not experimental evidence, and there isn't a single, agree-upon theory.

Yet, you claim to "know" strings, and don't understand energy. This doesn't make any sense to me. You might as well claim that you know about ghosts, but airplanes are mysterious to you.

Zz.
 
  • #4
I meant to imply string theory is a theory of what is smaller than atoms. In short I know of the string Theory. As to Noether's theorem this is describing the actions of energy not what energy is. Does anyone get the concept of this question. I would like some real feed back. Let's just say vibrating strings are the smallest form of energy of which every thing else is made ,quarks, atoms, us everything. Still the question is what is energy. To tell me Noether's theorem is energy is like looking in a dictionary reading the definition of energy and saying, oh that's what energy is.
 
  • #5
Larry Farmer said:
Does anyone get the concept of this question.
Yes, we get the exact question every few months it seems. So we all get it. The question is a reflection of a discomfort people have with the concept of energy. For whatever reason, people want there to be some deeper meaning to it and just can't accept that it is nothing more than a defined property that people discovered was useful a while back and happens to be conserved in a wide variety of circumstances. Or to put it another way: there doesn't need to be a theory: energy is just defined.

For some strange reason, people never ask the same question about velocity. They just accept what velocity is at face value.

I'm sorry, but unfortunately your choices are to accept what energy is at face value or search endlessly, in vain, for something more that doesn't exist.
Still the question is what is energy. To tell me Noether's theorem is energy is like looking in a dictionary reading the definition of energy and saying, oh that's what energy is.
In general, that's what definitions are for: They are descriptions of what words mean/things are.
 
  • #6
Asking what something "is" in physics (or science) is problematic and not generally insightful. Energy is that which has the units of joules (or kg (m/s)^2). Energy is that which is conserved via time symmetry of physical laws (per noether).

When trying to understand what anything "really is" the only way to do that is with a collection of properties about that thing. What energy "is" is that which has certain properties...

Your comparison to the dictionary is not completely inaccurate. All words are defined by other words and you can only get a sense of the language and meanings of words after relating many of them together. Similarly, all scientific concepts and entities are defined in terms of other scientific concepts and entities. You can only get a sense of their meaning by relating them to each other.
 
  • #7
We have a understanding of what velocity is. Just as we understand what water is. To take it further saying how water acts is not saying what water is. But water is made of atoms and atoms are made of energy which no one knows what it is. I was just wondering If anyone anywhere has a guess as to what energy actually is since it makes up everything.
 
  • #8
The atoms are not made of energy. No more than they are made of velocity, momentum, force, etc.
The atoms and its components may be described by these physical quantities but to say they are made of energy is as saying humans are made of length. Or weight.

But maybe you can explain what velocity really is, if you think this is a well understood point.:smile:
 
  • #9
Larry Farmer said:
We have a understanding of what velocity is. Just as we understand what water is. To take it further saying how water acts is not saying what water is.

Actually, the most accurate way of saying what something is, is to give a complete description of its properties and how it acts.

But water is made of atoms and atoms are made of energy which no one knows what it is. I was just wondering If anyone anywhere has a guess as to what energy actually is since it makes up everything.

I agree with Nasu's post on this. Atoms are not made up of energy. It is true that certain reactions can release energy, but this does not mean that the atoms are made of energy.
 
  • #10
Energy may turn out to be better described as an emergent property of a more fundamental description of nature. It's all very new stuff, but you may wish to learn about the Holographic Principle. The origin of which was from string theories, but could be applicable to other descriptions of quantum gravity.
 
  • #11
Larry Farmer said:
We have a understanding of what velocity is.
We have an understanding of what velocity is, because we defined what velocity is: How to measure / compute it.

The same with energy. Just that energy is more generally applicable, as it comes in different forms and therefore there are multiple definitions.
 
  • #12
Craigi yes I agree . the holographic principle is very interesting as well as the simulation theory of nick bostrom. What if energy itself is intelligent and the only simulator is energy its self. I've not seen any theory that gives energy conscious intelligence but but since everything is energy,it seems this may be plausible. Things like the double slit theory, and others imply that energy reacts to observation and behaves different at those times.
 
  • #13
A.T. its not the same.
 
  • #14
Someone else brought velocity up, I was just responding to them.
 
  • #15
Larry Farmer said:
Craigi yes I agree . the holographic principle is very interesting as well as the simulation theory of nick bostrom. What if energy itself is intelligent and the only simulator is energy its self. I've not seen any theory that gives energy conscious intelligence but but since everything is energy,it seems this may be plausible. Things like the double slit theory, and others imply that energy reacts to observation and behaves different at those times.

[my bolding]

Bostrom's simulation argument is philosophy rather than physics, but does have some grounding in multiverse theories. You would need to find a way to connect the argument physically, to discuss it here. I don't know of any paper that does so, but I wouldn't be suprised to find that Tegmark has published something to that effect. Guth has also explored the theoretical implications of how one might go about creating universes.

You can't just throw in terms like "any theory that gives energy conscious intelligence" then expect people not to object. Firstly, it doesn't have any (obvious) meaning. Secondly it sounds like you're trying to make physics fit a preconcieved notion of reality.
 
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  • #16
Atoms are made of energy and everting below an atom is made of energy.
 
  • #17
Maybe, I was just doing a little SciFi type speculation as to energy and intelligence.
 
  • #18
Physics sprang from philosophy after all. They are not totally different.
 
  • #19
Larry Farmer said:
Atoms are made of energy and everting below an atom is made of energy.

Larry Farmer said:
Maybe, I was just doing a little SciFi type speculation as to energy and intelligence.

Larry Farmer said:
Physics sprang from philosophy after all. They are not totally different.
Have you, perchance, read the forum rules regarding unsupported claims, personal speculation and philosophical discussion?
 
  • #20
Larry Farmer said:
A.T. its not the same.
Of course not. The definitions of velocity and energy differ. But in both cases they are human made definitions, which say what velocity and energy are.
 
  • #21
String theory speculates vibrating strings of energy are what atoms are made of.
If you have philosophy that the Earth revolves around the sun. Then you prove your theory by physics.
But oh please forgive the SciFi energy intelligence reference. Bandersnatch.
 
  • #22
Larry Farmer said:
Physics sprang from philosophy after all. They are not totally different.

Nevetheless, you should read the forum rules.

Under the traditional definition, physics is a subset of philosophy. A more contemporary definition, defining academic disciplines, renders them as distinct subjects. Inevitably, there are areas which do crossover, but the forum is for discussing physics. Bostrom's simulation argument is better described as metaphysics. That isn't to say that we can say with certainty cosmology will never apply it, but without a physical reason to do so, it remains philosophy.
 
  • #23
Larry Farmer said:
We have a understanding of what velocity is.
So, what is velocity?
 
  • #24
russ_watters said:
So, what is velocity?

A seemingly magical quality possessed by objects which causes them to continuously disappear from one location and reappear in another.
 
  • #25
Einstein/Poincare conversation

With respect to everyone involved in the above discussion upon energy.
I add a little light hearted banter with an air of philosophy:

Einstein:
'You know Henri, I once studied mathematics, but I gave it up for physics'.

Poincare:
'Oh, really, Albert, why is that?'

Einstein:
'Because although I could tell the true statements from the false, I just couldn't tell which fact were the important ones.'

Poincare:
'That is very interesting, Albert, because, I originally studied physics, but left the field for mathematics.'

Einstein:
'Really, why?'

Poincare:

'Because I couldn't tell which of the important facts were true.'

The definition of energy has been very well discussed, illuminating(!) and highly enjoyable.

Planck's pivot: hv=E=mc^2 (v=f=frequency).
 
  • #26
We just go over a thread about "What is mass", a week or so ago. Nothing "is anything". We just attribute a regularly observed relationship between other 'things' and give this new 'thing' a name.
If you have a problem with this then consider the whacky ideas (as we would call them) about Science that were bandied about in History. The 'quantities' and 'entities' that were used to describe experiences were just as real to thinking people and were used by them to build models of the World. It's the same with the quantities we use today - only we hope they are a bit more reliable. Time will tell.
 
  • #27
Larry, the ones who answered all want to make a point clear for you, and that is you either already know what is energy, or you know just a little amount of physics and should study more.

I want to extend Modus's good example:
Your comparison to the dictionary is not completely inaccurate. All words are defined by other words and you can only get a sense of the language and meanings of words after relating many of them together. Similarly, all scientific concepts and entities are defined in terms of other scientific concepts and entities. You can only get a sense of their meaning by relating them to each other.
Imagine a baby who still can't talk. S/he starts learning his/her first language by just observing how words are used. S/he gets no definition, no explantion, there is only observation. In this way, S/he gets some feeling for a number of words. Then other words are thought to him/her using the words that S/he has some feeling for.
As Modus said, physical concepts,like any other word are defined in relation to other words. And if you go down the ladder you reach to concepts that you need no definition for understanding them or you just accept them and know them by examples. If there were no such words and everything needed a definition, there would be no end to any logical structure and everything would be useless. You should understand the existence of down-ladder things and energy is one of them.
 
  • #28
I think the moderators ought to close that thread. Clearly the OP didn't come here to learn anything.
 
  • #29
Think you shyan, I agree there is no answer that will satisfy me at this time. So I will move on from this discussion.
 
  • #30
Energy is a calculated value: a number. Not only that, it is a frame-dependent value. In other words, a different number for different observers. It isn't "really" anything else.
 
  • #31
you are taking the topic away of physics by speaking of some selfconsiousness of a quantity.
There are many quantities in physics that we can measure, but asking what they are makes no sense.
If someone asks you what water is, and you reply "atoms" you are just going into a more "fundamental" thing, yet you don't answer what water is.
"Atoms are made of energy and everything below an atom is made of energy"
this again makes no sense. How can you make such a statement if you don't know what energy is?
Energy is a measurable quantity, which happens to be conserved, that's all...

What is for example the charge? (if you get the point)


Also don't say that thing about strings and vibrating energy... It's not so simple... and of course not-verified experimentally ...
 
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  • #32
gmax137 said:
Energy is a calculated value: a number. Not only that, it is a frame-dependent value. In other words, a different number for different observers. It isn't "really" anything else.

I think that I have an idea what you are referencing to when you suggest frame-dragging as the resultant...?
Relativistic energy and (angular) momentum?
Recall the way that space and time become united in relativity theory to become the single entity 'space-time', the time coordinate t being adjoined to the
3-space position vector
x=(x^1,x^2,x^3) to give the 4-vector:
(x^0,x^1,x^2,X^3) = (t,x)
We should then find that momentum and energy become similarity united.
Any finite system in special relativity will have a total energy E and a total momentum 2-vector p.
These unite into what is called the energy-momentum 4-vector, whose spatial components are
(p^1,p^2,p^3) = c^2p,
and whose time component p^0 measures not only the total energy but also, equivalently, the total mass of the system according to
p^0 = mc^2,
which incorporates Einstein's mass-energy relation.
Correct me if I am wrong or on another tac...
 
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  • #33
It seems as if you have never heard of Lagrangian/Hamiltonian mechanics.

Zz.
 
  • #34
Hello ZapperZ,
Yes I have..
But If you would like a discussion on the merits of the Penrosian v L/H approach I would sincerely like to have your opinion.
 
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  • #35
Larry Farmer said:
What if energy itself is intelligent
The substance of your question has been fully and completely answered (even if you choose to ignore it), and further discussion will lead to nothing more than this sort of speculation. Thread closed.
 

1. What is energy?

Energy is the ability to do work or cause change. It is a fundamental concept in physics and is often described as the "currency" of the universe. It comes in many forms, such as kinetic, potential, thermal, electrical, and chemical.

2. How is energy measured?

Energy is measured in joules (J) in the International System of Units (SI). Other common units of energy include calories (cal) and kilowatt-hours (kWh).

3. Do we have a complete theory of energy?

At the moment, there is no single, complete theory of energy. However, there are several well-established theories and laws, such as the law of conservation of energy and the laws of thermodynamics, that help us understand and explain the behavior of energy.

4. Can energy be created or destroyed?

According to the law of conservation of energy, energy cannot be created or destroyed. It can only be transferred from one form to another. This means that the total amount of energy in a closed system remains constant.

5. How does energy relate to mass?

According to Einstein's famous equation, E=mc², energy and mass are equivalent and can be converted into each other. This is known as mass-energy equivalence and is a fundamental concept in modern physics.

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