Life inside a star?

When we imagine other possible forms of life, we may sometimes be a bit carbon chauvinistic. This is understandable because carbon-based chemistry allows for the most complex structures we know of in this universe. But is there some other mechanism that would allow for the chemical diversity required for life? We don't know, but that hasn't stopped some scientists from searching.

One of the most outlandish proposals for life is not one we are familiar with, and it doesn't even use atoms. It proposes that fundamental kinks and defects in the structure of the universe - cosmic strings with magnetic monopoles - could evolve into complex structures and even live inside stars. The idea was even published in a physics journal, and today we will talk about how plausible this idea is.

Cosmic strings and magnetic monopoles

But first, we need to understand some basics, what exactly are cosmic strings and magnetic monopoles? Both are fascinating subjects, so I will briefly introduce them here: cosmic strings and magnetic monopoles are what we call topological defects.

Quantum fields should also be able to produce topological defects. These probably formed shortly after the Big Bang, when massive phase transitions swept through the universe. These transitions are similar to phase transitions between states of matter, such as water freezing into ice. Here, the quantum field itself changed state due to a rapid drop in temperature, termed a "spontaneous symmetry breaking", an event that also led to the emergence of separate forces from the initial unified force.

Now it is important to note that these phase transitions may lead to different types of topological defects, just like in the case of crystal formation. Let's look at the possibilities: 0-dimensional topological defects are magnetic monopoles, 1-dimensional topological defects are cosmic strings, and 2-dimensional defects are called domain walls - they are the boundaries between regions of the universe with different properties.

We are now interested in cosmic strings and monopoles. In some theoretical scenarios, magnetic monopoles can be attached to the ends of cosmic strings, and such magnetic monopoles are called beads, and we can have a string of beads forming a "necklace". Physicists imagine a nuclear life in which these chains form complex structures that can have certain chemical properties and may even evolve into what we call life. The goal of their research is to figure out under what conditions this could happen.

The conditions for life

The researchers listed three conditions of life that they investigated. Condition 1 is the ability to encode information: Our DNA encodes all the instructions our cells need to build the molecular machinery of life. It's hard to imagine a life form without a way to store information. Condition 2 is the ability of information carriers to replicate faster than they can break down: any given chain of molecules holds information, but if it falls apart before it can replicate itself, that's not good. Condition 3 is free energy: we know this is essential for any life, including nuclear life.

Can these magnetic monopole string necklaces store information? There are 4 different base pairs in DNA, and the order of these base pairs is a language that determines the order in which amino acids are transcribed into proteins. For a simple magnetic monopole, the only possible necklace is a series of alternating north and south poles. There is only one possible configuration, so it is not possible to store information in this way. However, it would be nice to add more exotic physics that could form different types of monopolies. For example, after the formation of magnetic monopoles, they split in half and become so-called half-poles, so that we have four coded "letters". In this way, it is possible to develop something like DNA.

The next condition: can these information carriers be replicated faster than they can be broken down? These necklaces may be less stable, but as long as they can be replicated faster than they can be dispersed, that's what the interior of the star does. Some have speculated that cosmic strings may be trapped inside stars during star formation and that these star interiors may provide the mechanism for the necklaces to change or even replicate rapidly.

Depending on the star type and region, stellar interiors can be very turbulent places. The flowing plasma and magnetic fields may stretch and break the necklaces, which may reconfigure them over and over again until they find stability in their environment, developing the ability to replicate faster than they can be torn apart. As for how this replication occurs, this study does not elaborate, except to say that it may be catalyzed by interactions with atomic nuclei in the star.

One last condition: do they have free energy? Energy can only be used to do work if there are differences in the energy in different possible states. If the energy is concentrated in certain places, we call it an ordered low entropy situation. Energy likes to disperse itself as evenly as possible, moving towards the disordered high entropy state. In this process, energy can be used when it flows between states, much like a water wheel placed in a flowing river. For example, life uses energy to flow from the high energy density of the sun to the low energy density of the earth. We talked about all this in our article on the physics of life. We saw that these, represented by life, accelerate the smoothing process of all energy and that low entropy dots like life eventually accelerate the increase of the entropy of the universe.

There must be free energy inside the star, energy flowing from the fusion engine in the core to the surface. It is conceivable that a life form could take advantage of this flow. What would that look like? It would have to accelerate the diffusion of energy, which could be more evenly distributed throughout the electromagnetic spectrum, which causes the star to appear cooler than stars of its class. That is, the star should behave differently from what our stellar physics models predict. Several stars in our modern survey do behave differently than predicted, but there are many other possible explanations, and it may be too early to conclude that a new form of life has been discovered.

In conclusion

We must have a better understanding of cosmic strings and magnetic monopoles, and we must first verify that they exist. Until we can determine whether they can evolve into the complex interactions required for life, the authors of this paper do not pretend that it is all possible; their point is more an indication that there may be other possible bases for life besides the familiar carbon chemistry. So, are stars filled with thriving biological ecosystems made up of broken quantum fields? Unlikely, but not impossible. Who knows what other exotic life forms are waiting to be discovered in distant, unfamiliar space-time?