can energy exist without matter

[sushi]

can pure energy exist in massless state?

mass and energy are interconnected, but what if mass=0 or there is no mass, like a pure vacuum, does energy still exist

some people say there are quantum fields which generate energy, but i doubt energy can exist without mass.

 

[sushi]

if energy exist without mass, that means energy can come from nothing. that would be free energy from nothingness.

 

[elliptoid]

EMR is energy in a pure massless state ... and when you get into the higher frequencies such as UV or Gamma you discover that it has quite a lot of energy indeed.

E=hf

Observe how there is no mass.

 

[elliptoid]

Part II:

As for calling it free energy, you must consider that radiation and emission of light still observe the laws of entropy the only difference is that the amount of space and time involved in these equations is universal in magnitude.

 

[Yellow]

Microwaves, radiowaves, lightwaves -- they're all energy forms that don't involve mass, in space.

Your second part suggests you were really asking "can energy exist without ever involving matter?", and the answer is, "maybe, probably, as far as we know".

Boson particles, for example, are non-matter, mass-less particles that contain energy.

The rest of your questioning seems to be edging into the big question, "if nothing can come from nothing, why is there anything?" All this energy and matter had to come out of nothing at some point, right?. Unless it's all eternal? What even is "eternal"?

Fucked if we know. Based on what we've learned to date, we no evidence that something can come from nothing.

 

[Ex-User (14663)]

What about E = mc^2. Wouldn't it imply that if there is no mass then there is no energy?

 

[Yellow]

That equation alone doesn't apply to photons. You have to use the equations for total energy, which my phone is unequipped to post.... Or find, apparently.

 

[redbaron]

Energy is just a configuration of matter.

 

[Haim]

What about E = mc^2. Wouldn't it imply that if there is no mass then there is no energy?

The full equation is E^2=(p^2)*(c^2)+(m^2)*c^4
Where p is momentum, which massless particles have.

 

[elliptoid]

What about E = mc^2. Wouldn't it imply that if there is no mass then there is no energy?

E=hf (quantum of light)
E=mc^2

Seems like it. Here's a good post on a physics board about why they denote different types of energy.

Haim's answer just above me is very useful as well and helps one understand that relativistic mass in the case of special relativity equations is actually the quantity of momentum which is also a scalar like mass. This way (momentum) the atomic mass of nuclei and mass in general are preserved independent of speed.

Edit - Here is another link that brings you directly to a wall of text about relativistic mass, in which basically the author says E=mc^2 refers to relativistic mass and not rest mass. Since relativistic mass is actually momentum, we quickly discover the importance of using more elaborate equations.

 

[Ex-User (14663)]

I see, so E=mc^2 is only for mass at rest.

Pretty good explanation of how particles without mass can have momentum:
https://physics.stackexchange.com/questions/2229/if-photons-have-no-mass-how-can-they-have-momentum

 

[elliptoid]

I see, so E=mc^2 is only for mass at rest

E = mc^2 has at least two majorly fundamental, important implications:

1. Mass Energy Equivalence

Mass and energy are equivalent. The more massive something is, the more energetic it is. Mass is energy.

2. Special Relativity

Almost not quite the opposite face of the same coin. The more energetic something is, the more massive it becomes.


**

Obviously some issues here. We clearly have at least two different types of mass. E = mc^2 pertains to relativistic mass insofar as relativistic mass directly pertains to mass-energy equivalence, and furthermore energy requires momentum.

So in equations where you see mass, and you aren't sure what it means, then you have to look at momentum.

 

[sushi]

but it seems the energy flow of a system depends on mass

imagine any system (like the wheel or the earth) for it to move continuously


energy+heat
energy+work
energy+ space
energy+ mass
energy+ acceleration

can energy flow in a system wthout mass?

i am not delving into quantum mechanics yet, just basic thermodynamics

 

[Grayman]

but it seems the energy flow of a system depends on mass

imagine any system (like the wheel or the earth) for it to move continuously


energy+heat
energy+work
energy+ space
energy+ mass
energy+ acceleration

can energy flow in a system wthout mass?

i am not delving into quantum mechanics yet, just basic thermodynamics

Energy may or may not be confined to space or time but it is basically only measurable while it interacts with matter which has mass.

Light is massless energy and it does not appear to interact with itself so it would seem that mass is essential for energy to 'work' within a system.

 

[Grayman]

i am not delving into quantum mechanics yet, just basic thermodynamics

Energy in standard physics has to travel through a medium or through direct interaction of matter. In quantum mechanics energy particles can travel through empty space without need for a medium.

 

[sushi]

maybewhat i want to say is 0 matter energy, not 0 mass energy, because that would be easier to clarify

energy without matter to be concise.

 

[sushi]

Energy in standard physics has to travel through a medium or through direct interaction of matter. In quantum mechanics energy particles can travel through empty space without need for a medium.

empty space is still a medium?

 

[Ex-User (8886)]

gravitational waves?