FUTURE SCIENCE: The universe and beyond

Young stars from the outer reaches of our own universe.

A top physicist has claimed that the world we know could be just a holographic projection of another universe. It sounds mad – but in the strange world of ‘multiverse theory,’ anything goes.

The development

Once upon a time, ‘the universe’ meant everything that existed. That is already big enough to make anybody’s mind reel: there are around 300 billion stars in our galaxy; billions of galaxies in our universe.

But according to many scientists, our universe may be just one among infinitely many. This is ‘multiverse theory,’ the most radical and disconcerting idea that physicists have ever explored.

Recently, a scientist made headlines by arguing that our entire world may be merely a hologram – a three-dimensional projection of a universe that really exists somewhere else altogether.

Other implications of multiverse theory are equally bizarre. In one version, there is a universe for every reality that obeys our laws of physics. If we could travel far enough, we would find other planets identical to Earth, with exact copies of every inhabitant.

Another version suggests that fundamental laws vary from one universe to another. In that case, other universes would be so totally different that they are unimaginable. Not only would life as we know it be impossible; but stars and even atoms may not exist.

Then there is a third possibility, perhaps the most dizzying of all: each time a random event occurs, a universe is created for every possible outcome. The multiverse is like a sprawling tree, with countless new branches forming every second.

How it works

A ‘random event’ does not mean the same to theoretical physicists as it does to you and me. Events that we call ‘random’ only seem so because we do not have enough relevant information to predict their outcome. But on the most minuscule level, randomness does appear to exist.

True randomness has some surprising consequences, which can be demonstrated by a famous thought experiment called ‘Schrödinger’s Cat.’ Austrian physicist Erwin Schrödinger sadistically imagined putting a cat in a box in which it had a random fifty percent chance of surviving an hour.

While the box is closed, asked Schrödinger, is the cat dead or alive? His answer sounds absurd: it is both. Yet this is widely accepted as a fact of modern physics.

Some physicists believe that the cat settles into one constant state when the box is opened. But increasingly the ‘many worlds’ interpretation takes things one step further: once the box is opened, the theory goes, the experimenter continues to exist in two separate universes. They are identical in every way but one: in the first, the cat is alive; in the second, it is dead.

Where this might lead

If this is true, we are living alongside countless other universes. They are not separated from us by physical distance, but by a strange gap unlike anything we understand. Could this gap ever be bridged?

Probably not. But not all scientists have given up hope.

If such travel is possible, the opportunities are literally endless. We could meet up with dead relatives in worlds where they still live; we could find our perfect reality and move there.

We could even move through time. The paradoxical possibility of killing your mother would not be an issue: it would simply create other universes where you do not exist.

Fantasy or nightmare?

Some of the implications of multiverse theory are so strange that they challenge our most basic assumptions. Quantum physicists are thrilled by this. Science is at its best, they say, when it lets us glimpse just how bewilderingly complex the universe can be.

But many find these discussions deeply unsettling. How can we find any meaning in our life, they ask, if everything we know is random or false? Scientists should further our understanding of the reality we live in, they say – not try to find alternative ones.

You Decide

  1. If you could travel to any parallel universe, where would you go and why?
  2. If parallel universes can never have an impact on our lives, is there any point in scientists studying them?

Activities

  1. Write a fantasy or science fiction story in which somebody travels to a parallel universe.
  2. Draw a diagram explaining how the Schrödinger’s Cat thought experiment works.

Some People Say...

“There’s no such thing as chance.”

What do you think?

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