Big bang theory shock: time had no beginning and eventually reverses

An alternative to the Big Bang theory is the big bounce – which hypothesises the universe expands until it can expand no more, before crashing back into one infinitesimally small point in a

cycle which repeats for eternity. If the Big Bang is true, it would mean that time as we know it started at a single point 13.8 billion years ago. However, if the Big Bounce theory, which is

a cyclic model meaning it is part of a broader cycle, is correct then it would mean that time did not have a beginning, but rather has the ability to flow in all directions and has been

doing so for eternity. RELATED ARTICLES As the Universe begins to shrink back into itself, some physicists believe time will also run backwards. This ‘twin Universe’, as Louisiana State

University physicist Parampreet Singh puts it, existed before the Big Bang where it was a mirror image of our own cosmos and everything ran in reverse. Mr Singh said: “In the universe before

the bounce, all the general features will be the same. It will follow the same dynamical equations, the Einstein’s equations when the universe is large. “Further, the matter content will be

the same, and it will have the same evolution. Since the pre-bounce universe is contracting, it will look as if we were looking at ours backward in time.” Big Bang Theory shock: Time had no

beginning and eventually reverses towards Big Bounce (Image: GETTY) The Universe exploded into life 13.8 billion years ago (Image: GETTY) In other words, when the Universe expands, time

runs forwards, but when it contracts, time runs backwards. The Universe expands due to dark energy – a mysterious substance in the cosmos which effectively counters the effects of gravity.

However, as the cosmos grows, dark energy will become more sparse, which could theoretically allow gravity to win the battle. At this point the Universe will begin to contract down to an

infinitesimal point. READ MORE: BIG BANG THEORY WRONG? ‘ALIENS CREATED UNIVERSE' "The matter content will be the same, and it will have the same evolution." (Image: GETTY)

RELATED ARTICLES Even if the theory is correct it will take a trillion or so years to contract to the infinitesimal point from where it began. Once the universe is at its most compact point

a Big Bang is triggered and the universe expands once more. Charles Steinhardt, professor of astrophysics at the California Institute of Technology, wrote on Q&A website Quora: “There

are ‘cyclic’ models in which the natural future of the universe is not indefinite expansion, but rather eventual contraction, a bounce, and a new Big Bang. “In such a model, time would not

start at the Big Bang, but rather would be able to continue infinitely in both directions. DON'T MISS Big Bang bombshell: Did dark matter come BEFORE birth of universe? Big Bang theory

wrong? Star older than Universe discovered Multiverse BREAKTHROUGH: Universe is ‘one patch of space and time’ Time could run backwards during the Big Crunch (Image: GETTY) “It’s not clear

how exactly to test either of these scenarios.” The Big Bounce theory was first popularised in 1987 when it appeared in German science journals, with physicists using it as a way to explain

the problems with the Big Bang, such as where it came from or to remove the problematic singularity. The only other time in the Universe where a singularity occurs and the laws of physics

are thrown out of the window is at the event horizon of a black hole, which is also unexplainable by current scientific methods. However, other experts believe the Big Bounce theory does not

stack up, claiming there is little evidence to support his hypothesis. Hubble offers a glimpse of the Universe (Image: EXPRESS) Columbia University theoretical mathematician, Peter Woit

wrote in his Not Even Wrong blog: “To qualify as legitimate science such claims need to be backed up by some conventional sort of evidence. “This might take the form of experimental

predictions, testable either now or in principle in the future. “It might also take the form of a highly constrained and beautiful theory whose success in other realms makes a compelling

case that it could also explain experimentally inaccessible phenomena. “I don’t know of any example of such pre-Big Bang scenarios now being sold to the public that comes even close to

having such backing.”