Can Energy Be Converted to Mass?

[hanii]

It was one of Einsteins favourite illustrations to state that an object when hot is more massive than the same object when cold.

but hot water is lighter than cold water...!

 

[Dadface]

but hot water is lighter than cold water...!

Are you confusing mass with density?

 

[treehouse]

Mass and energy are just metrics applied to systems; unlike Transformers they are not actual objects. E=mc^2 says that the energy in a system is equal to the mass of a system times the speed of light in a vacuum. This implies that adding energy to a system increases its mass; its 'rest mass' is the mass it has when it has no energy. Sometimes rest mass is created by particle accelerators or positron emission; because of the law of conversation of mass, it is assumed that the rest mass created is equal to the mass of the energy that is consumed by its creation.

The nuclear reactions inside stars cause them to emit cosmic rays including protons. Those protons (hydrogen nuclei) can be used as fuel for nuclear fusion. The fused nuclei (or just the protons emitted by stars) can drift into a forming star, becoming fuel for that star's nuclear reactions.

 

[Drakkith]

Mass and energy are just metrics applied to systems; unlike Transformers they are not actual objects. E=mc^2 says that the energy in a system is equal to the mass of a system times the speed of light in a vacuum.

Mass is a fundamental property while energy is a description of the interaction of systems via work. While i agree that mass and energy themselves are not "objects", all objects have mass and energy.

The nuclear reactions inside stars cause them to emit cosmic rays including protons. Those protons (hydrogen nuclei) can be used as fuel for nuclear fusion. The fused nuclei (or just the protons emitted by stars) can drift into a forming star, becoming fuel for that star's nuclear reactions.

This is...kind of correct? The nuclear reactions inside stars release energy and neutrinos, but the reactions themselves do not release "cosmic rays" in the form of protons or electrons. The solor wind is composed of charged particles such as electrons and protons, but these are ejected from the outer atmosphere of the sun, not the core where the fusion is taking place. Also, the unused Hydrogen can indeed form other stars, and it is our current view that the Sun was created when a nebula, composed of hydrogen and other elements from previous stars, collapsed in on itself.