The First Particles After the Big Bang: What Do We Know?

  • Context: Graduate 
  • Thread starter Thread starter cbd1
  • Start date Start date
  • Tags Tags
    Big bang Particles
Click For Summary

Discussion Overview

The discussion revolves around the nature and formation of the first particles after the Big Bang, exploring theoretical frameworks and the conditions necessary for particle existence. Participants express interest in distinguishing between real particles and virtual particle-antiparticle pairs, as well as the implications of CP symmetry violations in explaining matter-antimatter asymmetry.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants question whether a single particle could have been the first to arise after the Big Bang, emphasizing the need for real particles to exist beyond virtual pairs.
  • There is mention of a slight difference in decay properties between particles and antiparticles as a potential explanation for the existence of particles, though details remain incomplete.
  • One participant suggests that a slight excess of neutrons may have existed shortly after the Big Bang, but the stability of neutrons at earlier times is questioned due to high photon energy.
  • Another participant highlights the necessity of significant violations of CP symmetry to explain the observed asymmetry of matter and antimatter, referencing known small violations through the weak nuclear force.
  • A timeline of particle formation is presented, detailing the sequence from quark and neutrino creation to the formation of neutral atoms and the evolution of stars and galaxies.

Areas of Agreement / Disagreement

Participants express various hypotheses and uncertainties regarding the formation of particles after the Big Bang, with no consensus reached on the specifics of particle creation or the implications of CP symmetry violations.

Contextual Notes

Limitations include the incomplete understanding of particle decay properties and the unclear distinction between virtual and real particles in the context of early universe conditions.

cbd1
Messages
123
Reaction score
1
I have read "The First Three Minutes" and all of the information about the Big Bang on Wikipedia, but I cannot find through either of these sources the newest theory of the first particles to arise after the Big Bang. Is it possible that one particle may have been first? Also, I am interested in real particles, as opposed to virtual particle-antiparticle pairs, which would all destroy and leave nothing behind. There must have been particles made that were not in such virtual particle pairs in order for there to be any particles remaining today.. What do we know about this?
 
Space news on Phys.org
There must have been particles made that were not in such virtual particle pairs in order for there to be any particles remaining today.. What do we know about this?
This is one of the puzzles of the big bang, since current theory does not have any excess of particles at the big bang. The general theory about why we have particles is that there is a slight difference in decay properties between particles and antiparticles. However, the details are incomplete.
 
Although how they came into being is not known, there is a reasonable chance that a slight excess of neutrons (one neutron per 1.7 x 109 photons) existed just after 10-6 sec. At earlier times, the photon energy was too high for neutrons to be stable for any significant fraction of the age at the time.
 
cbd1 said:
I have read "The First Three Minutes" and all of the information about the Big Bang on Wikipedia, but I cannot find through either of these sources the newest theory of the first particles to arise after the Big Bang. Is it possible that one particle may have been first? Also, I am interested in real particles, as opposed to virtual particle-antiparticle pairs, which would all destroy and leave nothing behind. There must have been particles made that were not in such virtual particle pairs in order for there to be any particles remaining today.. What do we know about this?
Basically you need a significant violation of what is known as the CP symmetry: charge plus parity. We already know of some very small violations of CP symmetry through the weak nuclear force, but those violations aren't large enough to explain the asymmetry of matter/anti-matter in the early universe. For more on this, you may want to take a look at the Wikipedia article:
http://en.wikipedia.org/wiki/CP_violation

Note that this really isn't an issue of distinction between virtual and real particles, because there is no clear distinction between them.
 
Ok here is the load down on the big bang:

1. Between [tex]10^{-43}[/tex] s and [tex]10^{-32}[/tex] s quarks, neutrinos are created.
2. Between [tex]10^{-6}[/tex] s and [tex]255[/tex] s nucleons are formed: neutrons and protons.
3. Between [tex]10^{3}[/tex] s and [tex]10^{13}[/tex] s basic ions are formed : Hydrogen and Helium.
4. Between [tex]10^{13}[/tex] s and [tex]10^{15}[/tex] s neutral atoms form.
5. Between [tex]10^{15}[/tex] s and the present day: stars and galaxies are formed and evolving.

Just to put a scale on this a billion years is [tex]10^{16}[/tex] s so it has taken just under 100 million years for atoms to form.
References: pp1542-1543 University Physics, Young & Freedman.
 
Last edited:

Similar threads

  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 43 ·
2
Replies
43
Views
5K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 25 ·
Replies
25
Views
4K
  • · Replies 27 ·
Replies
27
Views
6K
  • · Replies 56 ·
2
Replies
56
Views
8K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K