Science

Life on Earth may have arrived very early on the cosmic timeline

Life on Earth may have arrived...
Our attempts to make contact with ET may be a little premature
Our attempts to make contact with ET may be a little premature
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Our attempts to make contact with ET may be a little premature
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Our attempts to make contact with ET may be a little premature

At this moment, two Voyager probes are speeding out into the unknown each carrying a "golden record" with information about our planet, our many different languages, our sciences and arts. The thinking was that those records could tell other civilizations in the cosmos about ourselves when they encounter the probes. But if a new theory about life in the universe is correct, those records may never find an audience.

The new theoretical study comes from scientists from Oxford and Harvard and suggests that life on Earth may have arrived early cosmically speaking, so the advanced civilization we're always combing the galaxy for might actually be us.

The general assumption that other civilizations older than our own exist in the universe seems well-founded. After all, the logic goes, the universe is 13.8 billion years old, while the Earth is a relative spring chicken of only 4.5 billion years young. Therefore there's been plenty of time for life on other planets to outstrip us.

But the new research study, led by Professor Avi Loeb of Harvard University, suggests that life in the universe is statistically much more likely in the future than it is now.

That's partly down to the preponderance of red dwarves.

Although medium-mass stars like our sun seem to offer the best conditions for orbiting planets to host life, lower-mass stars such as red dwarfs are almost as adequate; their "goldilocks zone" is narrower, but not by that much.

And the good news for red dwarf fans is that lower-mass stars have a much longer lifespan than medium-mass stars – in fact, they can glow for trillions of years longer. This means that ultimately, these long-lived, lower-mass stars offer much more time for life to evolve in the eons to come as the universe matures and our Sun eventually burns out.

The master equation that the team came up with factored in the number of habitable planets around stars, the number of stars in the universe at a given time (including their lifespan and birth rate), and the typical mass of newly-born stars.

Dr Rafael Alves Batista of Oxford's Department of Physics, one of the study's authors, says the main result of the research is that life seems more likely to evolve in the future than it does now. That doesn't necessarily mean we're currently all alone in the universe. But if there were 1,000 planets with life on them today, there's likely to be 1,000,000 in the future he says.

"We folded in some extra information, such as the time it takes for life to evolve on a planet, and for that we can only use what we know about life on Earth," says Dr Batista. "That limits the mass of stars that can host life, as high-mass stars don't live long enough for that. So unless there are hazards associated with low-mass red dwarf stars that prevent life springing up around them – such as high levels of radiation – then a typical civilization would likely find itself living at some point in the future. We may be too early."

It's an interesting idea to ponder. It's pretty clear that a lot of us hope to make contact with civilizations beyond our planet. If we discover that we're living in an era when life is emerging, but still relatively rare, will it change the way we approach this theoretical contact?

The research has been published in the Journal of Cosmology and Astroparticle Physics.

Source: University of Oxford

4 comments
Growling_M.A.D+Dirty
Life does not have to equate carbon life forms.
Life could have existed as carbon life forms before our universe was created. Our universe could just be a growing embryo in a bigger universe. The universal geneticists infused carbon based genome into this fractally small universe which earlier scientists called pan spermia. If these scientists are billion times larger than our universe, it is possible form them to insert a probe into the growing universe and put certain code strands into the mix creating their desired prototype of a life form.
All this is speculation, just as the science behind our current understanding is. Men in Black could have had it right. The giant foot in the Monty Python series could be true. Radical, dude.
VincentWolf
The timeline is something so many people can't fathom and fail to recognize as the PRIME reason why we haven't found ET yet. Not only does it take hundreds of millions of years to evolve intelligent life--if not billions--but the chances of two such life forms existing on nearby sun systems along the same timeline is extremely small. Keep in mind we have only been able to produce radio waves for a little over a century now. And that means our 'communications' have only reached out for a little more than a 100 light years. What is the chances of another intelligent species being within 100 light years that is INSIDE that same small time window (100 years)? It's very small--hence no ET yet.
Augure
Finally some sense into the "Dyson Sphere" "Advanced Civilisation E.T. signal" science-fiction fantasies. It is philosophically, SPECIFICALLY philosophically unlikely that there are any intelligent civilisation that that much more advanced as to travel because it doesn't just take cosmological, geological, biological evolution but also intellectual evolution, and such a combination that would lead to inter-galaxy travel or light-years signal broadcast are unlikely so soon in the cosmic timeline.
Elaxicom
Humans, as a species, are extremely young and I would think, very naive and narrow minded. Our planet is about 4 billion years old, the universe we can measure is close to 14 billion; so for about 10 billion years this universe was just chugging along, without us, doing nada regarding the formation and evolution of life; I mean 10 billion years and we are early? I don't care how many "theories" are formulated using what ever "human" physics we develop and/or use to conclude that this very young planer is ahead of its time, evolutionarily speaking, literally boggles my mind. Here is a theory I've developed, using simple math; 14-10 = 4 so 10- 4=6. 6 is the goldilocks period where most intelligent species developed and evolved and may have even visited our developing solar system about 3 billion years ago and again say about 65 million years ago to witness the devastation earth's life would suffer and maybe again to check the progress of life's return on earth. I don't know; I think my math and my theory is just as plausible as this one. I just can't dismiss 10 billion years based on any theory, not even mine.