We might feel insignificant compared to the large scale of the cosmos, but according to a new study the laws that regulate the expansion of the universe might have influenced the formation of life.
An international team of researchers focused on gamma-ray bursts (GRBs), creating a computer model where they could simulate how quickly the universe needs to expand to make sure the density of GRBs doesn’t sterilize the whole cosmos. According to the paper, the universe seems to expand at the right rate to guarantee the evolution of intelligent life.
“In dense environments, you have many explosions, and you’re too close to them,” cosmologist and theoretical physicist Raul Jimenez of the University of Barcelona in Spain, and an author on the new study, told Science. “It’s best to be in the outskirts [of a galaxy], or in regions that have not been highly populated by small galaxies – and that’s exactly where the Milky Way is.”
This investigation, published in Physical Review Letters, explores the universal qualities of the anthropic principle, which states that the universe must be compatible with the intelligent life we observe. Life can obviously evolve in our universe, but how fine-tuned must its parameters be for life to thrive?
This is not the first investigation by Jimenez and colleagues on the effect of GRBs. They have previously shown that GRBs could be responsible for mass extinction events, even from one galaxy to another. GRBs are powerful enough to disrupt the ozone layer, dosing planets with deadly levels of radiation. They are thought to originate in extremely powerful explosions, such as a supernova, but other mechanisms can produce them. GRBs are thought to have been more common in the early universe, so it’s important to understand how quickly galaxies moved away from each other.
In their model, they show that a fine balance is possible and it looks very similar to our universe. The ideal universe is one which minimizes the exposure to cataclysmic cosmic explosions like GRBs, and yet maximizes the formation of hydrogen burning stars like our Sun. This approach is obviously limited to our understanding of life.
“Is this going to be catastrophic to life?” Jimenez added. “I think so, but it may be that life is more resilient than we think.”