Backwards in time

A way to illustrate the evolution of the universe, by starting at the present day and running time in reverse...

Step	Time since big bang	Time since today	Status
1	13.8 billion years	0	46 billion light years of space is observable in all directions, expanding ever faster and cooling, containing about two trillion galaxies being swept away from each other by expanding space.   A region of unknown size, perhaps infinite, lies beyond our observation as it is expanding away from us faster than speed of light.  The trillions of galaxies we observe contain billions of trillions of stars.

For the purpose of this exercise, we now put time into reverse and imagine we are able to observe the backward chain of events. Before we do that, click here to see what we mean by the Big Bang. 

Step

Time since big bang

Time since today

Status

2	13.798 billion years	2.5 million years	No human life remains on earth
3	13.6 billion years	200 million years	No mammals remain on earth
4	13.3 billion years	470 million years	No plants remain on earth
5	13.1 billion years	700 million years	No animals remain on earth
6	12.7 billion years	1.1 billion years	No complex organisms remain on earth
7	10 billion years	3.8 billion years	No life of any kind remains on earth
8	9.9 billion years	3.9 billion years	There are no organic molecules on earth - planet is now a lifeless globe of rock, chemicals and water
9	9.3 billion years	4.5 billion years	The earth, moon and nearby planets starts to break up into lumps of rock and asteroids
10	9.2 billion years	4.6 billion years	What was the solar system is now just a swirling cloud of elements in the form of dust and gas with a young sun shining in the centre and gas giant planets in the outer regions (Jupiter, Saturn, etc.)
11	9.1 billion years	4.7 billion years	The sun stops shining
12	9 billion years	4.8 billion years	The elements in the dark, swirling cloud of dust and gas disappear gradually, becoming simpler, until there is no trace of the solar system. The other stars in our galaxy gradually fade away
13	10 billion years	5.8 billion years	Many galaxies including our own Milky Way, are gone but many remain so to a casual, interstellar observer, the universe looks similar to today's version.  However, space is shrinking ever faster and the galaxies are travelling towards each other, and beginning to dissipate into dust and gas
14	300 million years	13.5 billion years	All galaxies have now dissipated into gas and dust.
15	200 million years	13.6 billion years	No stars or planets, no environment for life anywhere in the universe.  Clouds of gas glowing with ultra violet light, are barely visible as the universe goes dark.  Spacetime itself continues to shrink
16	380,000 years	13.7996 billion years	The universe stops shining and the cosmic background radiation becomes invisible. Universe is now an  opaque plasma and shrinking ever faster.
17	1 year	13.8 billion years	The universe has shrunk to 100,000 light years in diameter.  All complex elements have broken down into helium and hydrogen. Mean temperature 2 million degrees
18	3 minutes	13.8 billion years	The temperature reaches 1 billion degrees. The only remaining element - hydrogen - breaks down so that protons, electrons, photons and neutrons remain in isolation
19	1 second	13.8 billion years	The universe is now just 20 light years in diameter
20	1 billion trillion trillionth of a second	13.8 billion years	The universe is now as big as a grain of sand. The particle fields are gradually disappearing, only the quarks are left.
21	100 billion trillion trillion trillionth of a second	13.8 billion years	All particle fields have gone and the four fundamental forces (electromagnetism, weak nuclear, strong nuclear and gravity) merge into one force (one unified field). The only activity is tiny density fluctuations.  Temperature is 100 million trillion trillion degrees.
22	100 billion trillion trillion trillionth of a second	13.8 billion years	The entire universe is compressed into a space the size of a proton. There is no matter, no radiation, no antimatter, no neutrinos, and no particles at all. All the energy that was present in the Universe is bound up in the fabric ofspace itself: a form of vacuum energy. All we can observe (if it were possible) are quantum fluctuations.
23	0	13.8 billion years	A singularity?
24	Before 0		Nothing. But nothingness is impossible, hence an infinite ocean of quantum fluctuations in a vacuum field?