Exploring The 'Multiverse' Could Be Key to Finding The Best Conditions For Life

Is there anything else out there, or is our universe all there is? Is the multiverse, which includes all possible universes, just one big collection of them?

What would they be like if there are other universes? Could they support life?

Although it may seem like conjecture on top of theory, this is not as absurd as you might believe.

My coworkers and I have been investigating the potential existence of additional regions of the multiverse, as well as what these fictitious adjacent universes might have to teach us about the prerequisites for life and how they form.

What-if scenarios

Some scientists assert that the existence of a multiverse is inescapable because of inflation, a burst of fast expansion that occurred at the cosmological beginning. In reality, our universe would only be one of many.

According to this theory, every new universe emerges from the roiling inflationary backdrop bearing a distinct set of physical rules.

We can understand these other worlds if they follow physical rules comparable to our own. At the very least in principle.

Physics in our universe is controlled by laws that specify how things should interact with one another and laws of nature that specify the intensity of interactions, such as the speed of light.

We can therefore create hypothetical "what-if" worlds in which we alter these characteristics and investigate the results using mathematical equations.

Although it may seem straightforward, the universe is fundamentally composed of the principles we play with. What would happen to stars, planets, and even life if we imagined a world where, say, the atom is a hundred times heavier than in our universe?

What is required for life?

In a recent set of articles, we addressed this issue by looking at habitability across the multiverse. Of course, habitability is a complicated idea, but we believe that for life to begin, a few prime components are needed.

One of those elements is complexity. The intricacy of life on Earth is derived from the periodic table's elements, which can be combined and organized to form a wide variety of molecules. We are chemical engines that are alive.

However, a steady atmosphere and an uninterrupted supply of electricity are also necessary. It is not surprising that the origin of life on Earth occurred on a rocky world with a rich chemical composition and in the light of a long-lived steady star.

modifying the underlying factors

Do comparable environments persist throughout the multiverse's full extent? We began our theory investigation by taking the wealth of chemical components into account.

Except for the initial hydrogen and helium created during the Big Bang, all elements in our universe are created during the lifetimes of stars. They are either produced by nuclear fusion in stellar centers or by the most violent explosions known as supernovae, which occur when a massive star rips itself apart at the end of its existence.

The four fundamental forces of the cosmos control each of these activities. The stellar center is squeezed by gravity, which raises its warmth and density to incredible levels. Atomic nuclei are attempted to be forced apart by electromagnetic forces, but if they can get near enough, the powerful nuclear force can bind them together to form a new element. The star fire is ignited by the weak nuclear force, which has the power to change a proton into a neutron.

The masses of the basic elements, like quarks and electrons, can also be extremely important.

We can turn a lot of knobs in order to investigate these hypothetical worlds. The remainder of physics is affected by the modifications to the fundamental world.

Carbon-oxygen equilibrium

We divided the different physics components—stars and atmospheres, planets and plate tectonics, the origins of life, and more—into manageable parts in order to address the enormous intricacy of this issue. Then, using the individual pieces, we pieced together a larger narrative about habitability in the universe.

Emerging is a complicated image. The habitability of a world can be significantly influenced by a few variables.

For instance, the ratio of carbon to oxygen, which is determined by a specific series of nuclear processes in the star's core, seems to be especially significant.

It would be very difficult for life to appear and flourish in settings that stray too far from the balance in our universe, where there are approximately equal quantities of the two elements.

However, it seems that the excess of other elements is less significant. They can be important building elements for existence as long as they are secure, which depends on the harmony of the basic factors.

discover more complexity

We have only been able to sample the space of options in very small, discrete stages in order to uncover habitability across the universe.

Furthermore, we had to use a number of theoretical heuristics and estimates in order to handle the issue. As a result, our knowledge of the prerequisites for existence throughout the universe is still in its infancy.

The complete complexity of alternate physics in other worlds needs to be taken into account in the following stages. It will be necessary to extrapolate from our understanding of the small-scale effects of the basic forces to the formation of stars and ultimately planets on a larger scale.

One piece of advice

The concept of a multiverse is still just a conjecture that hasn't been put to the test. Actually, we're not sure if it's a hypothesis that can be evaluated just yet.

And if the physical rules are distinct across the multiverse, we don't know how much different they might be.

We may be embarking on a voyage that will eventually disclose where we ultimately belong within infinity, or we may be moving in the wrong direction in terms of science.

Geraint Lewis, Professor of Astrophysics, University of Sydney