Patchen Barss: What if the Universe has no end?
The usual story of the
Universe has a beginning, middle, and an end. It began with the Big
Bang 13.8 billion years ago when the Universe was tiny, hot, and dense. In less
than a billionth of a billionth of a second, that pinpoint of a universe
expanded to more than a billion, billion times its original size through a
process called “cosmological inflation”.
Next came “the graceful exit”, when
inflation stopped. The universe carried on expanding and cooling, but at a
fraction of the initial rate. For the next 380,000 years, the Universe wa so
dense that not even light could move through it – the cosmos was an opaque,
superhot plasma of scattered particles. When things finally cooled enough for
the first hydrogen atoms to form, the Universe swiftly became transparent.
Radiation burst out in every direction, and the Universe was on its way to
becoming the lumpy entity we see today, with vast swaths of empty space
punctuated by clumps of particles, dust, stars, black holes, galaxies, radiation,
and other forms of matter and energy.
But what if the Big
Bang wasn’t actually the start of it all? Perhaps the Big Bang
was more of a “Big Bounce”, a turning point in an ongoing cycle of contraction
and expansion. Or, it could be more like a point of reflection, with a mirror
image of our universe expanding out the “other side”, where antimatter replaces
matter, and time itself flows backwards. (There might even be a “mirror you”
pondering what life looks like on this side.)
Or, the Big Bang might
be a transition point in a universe that has always been – and always will be –
expanding. All of these theories sit outside mainstream cosmology, but all are
supported by influential scientists....
https://www.bbc.com/future/article/20200117-what-if-the-universe-has-no-end
