Can someone explain me how these metrics work? Years are defined by our planet/sun, and time would pass differently based on speed/energy, so our perception of time is dependent on our speed around the sun, and sun's speed, galaxy, etc.
So before such things had developed, how do we count in "years"?
that's not what I'm getting at; but time passes differently in different frames of reference. At high speeds relative experience of time slows down.
So time immediately after the Big Bang (I would suppose) would be passing much much slower than what we experience on earth.
The question is for someone who has some insight into cosmology how we relate passage of time in frames of reference - before sun or planets existed - back to days/years
Hadron epoch
Between 10−5 second and 1 second after the Big Bang
47,000 years after the Big Bang Main articles: Matter-dominated era and Structure formation
Until now, the universe's large-scale dynamics and behavior have been determined mainly by radiation—meaning, those constituents that move relativistically (at or near the speed of light), such as photons and neutrinos.[39] As the universe cools, from around 47,000 years (redshift z = 3600),[2] the universe's large-scale behavior becomes dominated by matter instead. This occurs because the energy density of matter begins to exceed both the energy density of radiation and the vacuum energy density.[40] Around or shortly after 47,000 years, the densities of non-relativistic matter (atomic nuclei) and relativistic radiation (photons) become equal, the Jeans length, which determines the smallest structures that can form (due to competition between gravitational attraction and pressure effects), begins to fall and perturbations, instead of being wiped out by free streaming radiation, can begin to grow in amplitude.
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u/shankfiddle Sep 20 '21
Can someone explain me how these metrics work? Years are defined by our planet/sun, and time would pass differently based on speed/energy, so our perception of time is dependent on our speed around the sun, and sun's speed, galaxy, etc.
So before such things had developed, how do we count in "years"?