The Laws of Physics? Episode 1

 

Many cosmologists believe that the Universe may be part of a more extended cosmos, a multiverse

We cannot observe or see across the entirety of the Universe that has grown since the Big Bang because insufficient time has passed for light from the first fractions of a second to reach us. Some argue that we therefore cannot be sure whether the laws of physics could be broken in other cosmic regions – perhaps they are just local, accidental laws. And that leads us on to something even bigger than the Universe.

The multiverse

Many cosmologists believe that the Universe may be part of a more extended cosmos, a multiverse, where many different universes co-exist but don’t interact. The idea of the multiverse is backed by the theory of inflation – the idea that the universe expanded hugely before it was 10^-32 seconds old. Inflation is an important theory because it can explain why the Universe has the shape and structure that we see around us.

But if inflation could happen once, why not many times? We know from experiments that quantum fluctuations can give rise to pairs of particles suddenly coming into existence, only to disappear moments later. And if such fluctuations can produce particles, why not entire atoms or universes? It’s been suggested that, during the period of chaotic inflation, not everything was happening at the same rate – quantum fluctuations in the expansion could have produced bubbles that blew up to become universes in their own right.

But how does God fit into the multiverse? One headache for cosmologists has been the fact that our Universe seems fine-tuned for life to exist. The fundamental particles created in the Big Bang had the correct properties to enable the formation of hydrogen and deuterium – substances which produced the first stars.

The physical laws governing nuclear reactions in these stars then produced the stuff that life’s made of – carbon, nitrogen and oxygen. How come all the physical laws and parameters in the universe happen to have the values that allowed stars, planets and ultimately life to develop?

Some argue it’s just a lucky coincidence. Others say we shouldn’t be surprised to see biofriendly physical laws – they after all produced us, so what else would we see? Some theists, however, argue it points to the existence of a God creating favourable conditions.

But God isn’t a valid scientific explanation. The theory of the multiverse, instead, solves the mystery because it allows different universes to have different physical laws. So, it’s not surprising that we should happen to see ourselves in one of the few universes that could support life. Of course, you can’t disprove the idea that a God may have created the multiverse.

If two particles are entangled, you automatically manipulate its partner when you manipulate it

This is all very hypothetical, and one of the biggest criticisms of theories of the multiverse is that because there seem to have been no interactions between our Universe and other universes, then the notion of the multiverse cannot be directly tested.