Are There Other Massless Objects Besides Gluons and Photons?

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Discussion Overview

The discussion revolves around the question of whether there are other massless objects in the universe besides gluons and photons. Participants explore various interpretations of masslessness, the relationship between mass and energy, and the nature of physical objects.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that energy is massless but argue it is more a property than a physical object.
  • Others assert that energy has mass, suggesting that increasing energy in a system results in an increase in mass.
  • Mass and energy are described as equivalent, with massless particles typically defined as having zero rest mass, applicable to photons and gluons, and potentially gravitons.
  • The existence of gravitons is questioned, with some participants expressing uncertainty about their existence.
  • Weyl fermions are mentioned as another potential massless entity.
  • Some participants introduce non-physical concepts like shadows and digital information, which are challenged as not being physical objects.
  • The definition of a "thing" or "object" is debated, with suggestions that macro-sized objects could consist of massless particles, such as a laser beam.
  • There is contention regarding the mass of laser beams, with some claiming they have mass due to the photons they contain, while others clarify that individual photons have zero mass.
  • Participants discuss the relationship between mass, energy, and momentum, with a focus on the equations governing these concepts, particularly in relation to photons.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the nature of massless objects, the relationship between mass and energy, and the definitions of physical objects. The discussion remains unresolved with no consensus reached.

Contextual Notes

There are limitations in the definitions of massless objects and the assumptions regarding the nature of energy and mass. The discussion also reflects varying interpretations of physical versus non-physical entities.

Bradfordly1
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Are there any other things/objects in our universe that are massless other than Gluons and Photons? I guess energy is massless, but it's not so much a thing, more-so a property.
 
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Bradfordly1 said:
I guess energy is massless, but it's not so much a thing, more-so a property.

Indeed, energy is a property of objects and systems of objects, it is not something in and of itself. But it does have mass. Or, rather, arranging a system such that it has more energy than before will mean it has more mass as well.
 
Mass and energy are equivalent. When you say something is mass-less, it usually means that the rest mass is zero. This applies to photons and gluons and gravitons (if they exist).
 
Graviton, if it exists at all.
 
Don't forget Weyl fermions.
 
What about a shadow, or digital information?
 
Last edited:
Those aren't physical objects.
 
The OP didn't really qualify what a Thing or an Object was. If you want a macro-sized object, it would have to be an object made of massless particles, like a laser beam.
 
Laser is an acronym for light amplification by stimulated emission of radiation. It is made of photons of a specific wavelength, but photons none the less and it does have mass just as all photons do, however small it is.
 
  • #10
Austin Z W said:
but photons none the less and it does have mass just as all photons do, however small it is.

The mass of the beam is non-zero, but the mass of each photon is zero.
 
  • #11
Each photon has energy which means it has mass. The mass is usually said to be zero in most cases and equations because it is such a small amount of mass.
 
  • #12
Austin Z W said:
Each photon has energy which means it has mass. The mass is usually said to be zero in most cases and equations because it is such a small amount of mass.
That is not correct. The mass, energy, and momentum of a particle are related by ##E^2=(mc^2)^2+(pc)^2##. For a photon we have ##E=pc## so a bit of algebra will quickly show that the mass of a photon is precisely exactly zero.
 

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