Matter and Antimatter - Gravity

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Discussion Overview

The discussion revolves around the gravitational implications of matter and antimatter annihilation, particularly in the context of the Big Bang and the subsequent gravitational fields. Participants explore theoretical scenarios regarding the gravitational effects of annihilated matter and antimatter and their potential residuals in the universe.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant suggests that matter and antimatter behave similarly in terms of gravitational attraction, implying that antimatter would fall toward Earth like matter.
  • Another participant questions whether there was a gravitational field from the annihilation of matter and antimatter, proposing two possibilities: either no residual gravitational field exists or gravitational waves from the annihilation could still be detectable.
  • A different participant references the equivalence of mass and energy (E=mc²) to argue that gravitational effects would be the same whether considering particles or free energy.
  • One participant posits that the mass of visible matter (stars, galaxies, dust) accounts for only a small fraction of the gravitational field, suggesting that the cosmic microwave background (CMB) radiation has a much stronger gravitational effect.
  • Another participant links the current discussion to a previous thread that touches on similar questions regarding gravity and cosmology.

Areas of Agreement / Disagreement

Participants express differing views on the gravitational implications of matter-antimatter annihilation, with no consensus reached on whether residual gravitational fields or waves exist post-annihilation.

Contextual Notes

The discussion includes assumptions about the nature of gravitational fields and the behavior of matter and antimatter, which may not be fully resolved. The relationship between gravitational effects and the cosmic microwave background is also under examination but lacks definitive conclusions.

Keijo
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Matter and Antimatter,

I have always wondered what happens with regard to the gravitational field when matter and antimatter annihilate each other.
Consensus among physicists is that matter and antimatter behave the same as far as gravitational potential is concerned, i.e., both will attract matter and antimatter, so that a particle of antimatter would fall toward the Earth and not fly off to space.
According to the currently accepted cosmological theory, essentially equal amounts of matter and antimatter were initially created in the big bang.
Matter and antimatter promptly annihilated each other but there was an imbalance in favor of matter by about one part in a billion. This imbalance is what was left and now constitutes all the matter in our universe.
The radiation that resulted from the annihilation is now dissipated with the expanding universe, and is now seen as the cosmic microwave background (CMB) radiation.

But what about the gravity?
In the Big Bang, was there briefly the gravitational field of a billion additional universes before the annihilation took place?

The possibilities seem to be:
No there was not. This means that after annihilation there was also no residual gravitational field, in which case, contrary to what we currently believe, maybe matter and antimatter do in fact have opposite gravitational potentials.
Yes there was. This would mean that after the annihilation the naked gravitational field was radiated away as gravity waves. Maybe those gravitational waves, fields/potentials are still out there somewhere and can be detected or measured similar to the CMB
The question is, what would this residue look like today and how would we go about looking for it?

Any clarifications from you physicists or cosmologists?

Thanks and cheers,
Keijo
 
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Keijo said:
But what about the gravity?
In the Big Bang, was there briefly the gravitational field of a billion additional universes before the annihilation took place?

By E=mc^2, the two (free energy and mass) are equivalent so the same gravitational effects would be observed regardless of whether or not it was particles or free energy.
 
Thanks Nabeshin.
I take it then, that the observed mass of stars,galaxies and dust, accounts for only a tiny fraction of the gravitational field holding back the expansion of the universe.
By far the strongest effect (by nine orders of magnitude) is the gravitational effect of the residual CMB radiation.
Is this what current accepted cosmolgical theory contends?
 

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