I googled "the first attosecond after the Big Bang", but didn't get any relevant results. So, I am asking the question here, in hopes of being more successful. What happened during the first attosecond of the universe? What important milestones, from a physics perspective, happened during or around that time?


1 Answer 1


In the timeline of the early Universe the key milestones in the first attosecond ($10^{-18}$ seconds) were:

  • At $10^{-43}$ seconds after the Big Bang gravity separates from the other three fundamental forces
  • At $10^{-36}$ seconds after the Big Bang the strong force separates from the other fundamental forces
  • At $10^{-33}$ seconds after the Big Bang cosmic inflation begins
  • At $10^{-32}$ seconds after the Big Bang cosmic inflation ends

After cosmic inflation ends the universe is filled with a dense, hot quark-gluon plasma. Particle interactions are still energetic enough to create and destroy large numbers of exotic particles, including W and Z bosons and Higgs bosons.

The next milestone after $10^{-18}$ seconds is at $10^{-12}$ seconds when the electromagnetic force separates from the weak force. The four fundamental forces are now separate from one another and particles can acquire mass by interacting with the Higgs field.

  • 1
    $\begingroup$ You should definitely note that all the milestones you list are speculative and are not predictions of our current-best models. You might also discuss which speculative models make these particular predictions. $\endgroup$
    – Xerxes
    Dec 11, 2023 at 15:20
  • 1
    $\begingroup$ @Xerxes These are the milestones described in the linked Wikipedia article and I think the order of events is quite standard. In particular, I believe the existence of an inflationary epoch is accepted by the majority of cosmologists. The timings are obviously approximate and may be out by a few orders of magnitude, but I would not describe them as speculative. However, if you have an alternative timeline then feel free to write your own answer. $\endgroup$
    – gandalf61
    Dec 11, 2023 at 16:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.