There are many New Age websites claiming Everything is energy. Does this even make sense in philosophy of physics and metaphysics?
How can something be "made out of energy"? As far as I understood it energy is not a substance.
At the same time this Substance Monism idea in which everything is "Energy" is very appealing to me so I wonder if there some grain of truth in it.
Memorably, Feynman in his Lectures on Physics states:
It is important to realize that in physics today, we have no knowledge of what energy is.
Energy, the Subtle Concept. The discovery of Feynman’s blocks, from Leibniz to Einstein by Jennifer Coopersmith (Oxford UP, 2010) is a book that substantiates Feynman's claim. It begins by recalling the context, how speaking of simple blocks can be illuminating and ends by ruminating:
The concept of energy is here to stay. It is not sufficient for a concept just to be mathematically defined, measurable,and leading to consistent results—it must also get used. There is no doubt that ‘energy’ meets these requirements. We have shown that the physics and the mathematics move forward together, but it is impossible to tell where the mathematics ends and the physics begins, and vice versa. This is the real message of Feynman’s allegory and the reason why energy is such a slippery concept: the ‘blocks’ are the real thing, energy, and can be measured (in Joules); and they are also nothing more than the mathematical formulae ½ mv 2 , ∫ F . d r , mgh , ½ kT , ½ CV 2 , qV, mc 2 , and so on.
There are a number of quantities that physics has found to be conserved.
"Conserved" means that if you take a situation, and you measure what is in it, then something happens in it (where you measure all inputs and outputs), the measure of those quantities doesn't change.
These include:
No experiment has proven that any one of the above is not conserved in any examined situation.
Under Noether's Theorem (proven by Emmy Noether, one of the most important mathematicians in history in my opinion), each of these conservation laws lines up with a symmetry in the mathematics of physics. Mass-Energy conservation, for example, can be shown to be mathematically equivalent to suitably constructed laws of physics not caring what time it is when it makes predictions.
The kind of "symmetry" Noether is talking about is a generalization of the symmetry you are used to. Some of the symmetries are exotic compared to what you might be used to.
The thing about Mass-Energy conservation is it means that it sort of implies that the two (mass and energy) are somehow the same thing. You can convert one to the other (with effort) and back again.
If you actually start looking really deeply into "solid matter", it ain't very solid. Much of what you consider "solid" is due to Pauli exclusion principle and the lowest energy states for Fermions crowding alternatives out, and increasingly high amounts of pressure being required to shove more Fermions into the matter.
Going deeper, electrons don't have much mass-energy; most of the mass-energy of "solid" matter comes from Neutrons and Protons. They, in turn, are made out of Quarks; most of their mass-energy isn't from the Quarks they are made out of, but rather the potential energy in the binding of the Quarks to each other. (There remains a very small "rest" mass that isn't produced by such binding)
It turns out that if you make a perfectly insulated box, and you heat it up, the box gets heavier. If you build a really powerful spring inside of it and you squeeze it shut, the box gets heavier. The degree that this adds weight and mass is tiny in most practical situations.
Atomic nuclei are basically tiny nearly weightless stuff that has a ridiculously powerful spring tightly coiled in it, and almost all of the mass of "stuff" comes from the tension on the spring, not the things that the springs are attached to.
And this doesn't mean that the things the spring is attached to -- the quarks -- are somehow not also energy. If you take a bunch of quarks and slam them into each other really really hard, you get a LOT more quarks appearing. They spew off in every direction.
The conservation laws above all hold in this collision, but we don't conserve "number of quarks". We conserve difference of quarks and antiquarks, we conserve color numbers, we conserve mass-energy, etc.
In that way, everything is energy. Also, in a similar way, everything is angular momentum. But the second statement is sort of less believable than the first.
Now, most conserved things are signed values or vectors. Mass-energy tends to be denoted as a positive value (but see stuff like the Casmir effect; the zero point of mass-energy is nearly arbitrary). Conservation laws care about the change in Energy in the system, not the total.
Strange things are predicted to occur at the limits of this. If you take a complete vacuum, you'll see one thing. If you start accelerating fast enough in that vacuum, the math predicts that you'll experience a "heat bath" of energy being emitted from the vacuum. Such a "heat bath" includes particles that you won't experience if you where not accelerating.
So, it is plausible that "everything is energy" doesn't go far enough.
In a nuclear explosion, we might say, "matter is converted into energy." But you can't exactly see energy or hold a piece of energy in your hand. It's not "glowy stuff" (as often depicted in fiction and new-age media), and it's not the same as photons. Rather than a "thing," it's better to think of energy as an attribute that things - or arrangements of things - can have, which is conserved among interactions between things.
More specifically, in a nuclear explosion, mass energy is converted into a variety of other forms, including:
The energy that was in the mass is now energy in other forms.
Note that momentum is another quantity that is conserved among interactions between things. If you hit a billiard ball with another billiard ball, momentum has been transferred from one ball to the other. Do we say that billiard balls are therefore made out of momentum, or that momentum is a "thing" separate from the billiard balls? See conservation laws.
The statement is made in the context of the belief that one can effect change or exert control over things that are otherwise out of one's control (like The Secret and its ilk). Energy is thought to be able to be controlled or manipulated in a way that matter is not. Because everything is either matter or energy, and energy and matter are the same, hence everything is energy and everything is potentially subject to control or manipulation.
Energy as a concept, is the result of the journey of unification that the subject of physics has been on. Before Newton 'the heavens' were simply a separate domain with different rules. Physics was full of many such partitions, like the idea temperature was a special substance (choleric, a legacy of the theory of four elements) which got unified with macroscopic kinematics through Boltzman's thermodynamics. Magnetic & electric phenomena were similarly partitioned, then unified into a picture with energy, and fields.
Mass was historically used as synonym for substance. It was viewed as constituting the things that had energy, with fields transmitting changes. Relativity brought a further unification, revealing that mass can be created by energy. Cosmic rays illustrate why we say energy - wherever the kinetic energy of a cosmic ray, whether a photon or electron or helium nucleus or something more exotic, if the kinetic energy is over a threshold a collusion can create an electron-positron pair.
Saying 'energy' is a way of saying this, that there is a language which we can use to talk about all these situations, kinetics, thermodynamics, fields, and particle creation and decay. I'd say it's more accurate to call energy a unifying language, than a substance. Very general ideas like the principle of least action and stable and unstable stationary energy levels allow prediction of very diverse terms.
So, the question that should be asked is, can the language of energy discuss all phenomena? And the answer, is no. We need another language, that of information theory. Entropy is in that language, and was recognised early on in thermodynamics to be as important as energy. Entropy came to be regarded as a secondary property of the fundamental substance, mass, like energy. But unlike mass, it cannot be absorbed into the energy picture.
The historic perspective of science has been of substance monism, in the sense that every 'thing' can in principle be converted into every other thing (within constraints like conservation laws). The journey of unification has been to the current situation of four fundamental fields, with local quantum-number properties associated with particles within them - the 'substances' that have properties, are quantifiable in those four fields; with the expectation of a future unification of those fields, at least in the very early universe.
And information, as a secondary property of those. But information is proving to be a crucial bridging concept between relativity & QM, both being fundamentally about constraints on information flow. There is even Verlinde's theory that gravity is caused by information. Loop Quantum Gravity aims to find gravity, time & space from a more fundamental 'spin network'. And there is an increasing focus on information-as-fundamental approaches, like Wheeler's 'It From Bit' doctrine, also called the Participatory Anthropic Principle. As I say, I think the proper way to regard this is not as a universal substance, but a universal language. Currently though science relies in a property dualism of energy & information, with the unproven assumption of substance monism.
Sometimes the apparently metaphysical claims of contemplative and New Age people need to be interpreted differently from how we would normally interpret those types of claim.
For example, it is a common contemplative claim that "there is no such thing as the self". As a straightforward truth claim, this is clearly (or at least, most likely) false. What they usually mean - but often fail to say - is to add a prefix: "From the subjective point of view, there is no such thing as the self". That is still open to debate of course, but has a greater possibility of being true.
I suspect that the claims about everything being energy are similar: "From the subjective point of view, everything appears as a pattern of energy."
To be honest, even here the word energy should really be in scare-quotes, as it does not mean what physicists would mean by the word.
Unfortunately, I think that although many New Age people base their beliefs on this sort of introspective / subjective perspective, they do then make genuine metaphysical assertions based on them. ie, they would really claim that everything is energy (regardless of the subjective caveat / prefix). If this is what they are claiming, then they are likely wrong - or if correct, only by accident - and have no real basis for the claim.
e=mc^2imply that anything that is not currently energy (and therefore is mass) could be converted to energy under the right conditions? So the idea might be coherent, in the same way that "time is money" is coherent; not that they are the same thing, but that each is readily convertible to the other.