Does antimatter (negative matter) have negative mass ?

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Discussion Overview

The discussion revolves around the concept of whether antimatter possesses negative mass, exploring theoretical implications and distinctions between antimatter and hypothetical negative matter. It includes considerations of mass, energy, and gravitational effects.

Discussion Character

  • Debate/contested

Main Points Raised

  • Some participants assert that antimatter has opposite charge but not negative mass, emphasizing that mass is guaranteed to be non-negative.
  • One participant proposes that negative rest mass would imply negative rest energy, leading to complex implications for velocity and gravitational interaction.
  • Another participant distinguishes between antimatter, which is known to exist with positive mass and reversed charges, and negative matter, which is only hypothesized to have negative mass but the same charges.

Areas of Agreement / Disagreement

Participants generally agree that antimatter has positive mass, but there is disagreement regarding the existence and implications of negative mass, with some proposing theoretical scenarios while others maintain that negative mass is not supported by current understanding.

Contextual Notes

Limitations include the dependence on definitions of mass and energy, as well as unresolved theoretical implications regarding the behavior of negative mass under gravitational influence.

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Does antimatter (negative matter) have "negative mass"?

If not, why is this so suspected? And could anything theoretically have negative mass?
 
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Welcome to PF, easyconcepts! :smile:

Antimatter has opposite charge, not negative mass.
Indeed mass is guaranteed to be non-negative.
And the only particle to have "rest-mass" zero is the photon.
 


Theoretically for something to have negative rest mass must mean it has negative rest energy.

E0=M0*v^2

Therefore when rest mass of M0 < 0, any value for velocity v squared is greater than or equal to 0, since √ -1 = i where i ≠ ℝ.


Anyway, negative mass means in my mind that the mass dimension is negative, thus when affected by gravity (if it would be), since F = ma and F = mg when free-falling under gravity, it would have negative acceleration (deceleration) or negative force (or positive relative to direction). Gravity would seemingly repel rather than absorb the object to the centre of the object.
 


Antimatter has a positive mass, but reversed charges. Negative matter has a negative mass, but the same charges. Antimatter is known to exist, but negative matter is only hypothesized to exist.
 

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