(ORDO NEWS) — Life in space is a rarity: only a small part of matter exists in its living form, writes The Atlantic. Life is also fast-paced in terms of time. Recent scientific studies have shown that our existence is just an accident, one roll of the cosmic dice.
Like many other inhabitants of planet Earth, I looked with bated breath at the first images taken by the James Webb Space Telescope: lacy curls of galaxies, apricot-colored filaments of nebulae, the remains of exploded stars.
Less picturesque, but still completely revolutionary, part of the Webb’s mission is to look for signs of life on other planets in the universe. The space telescope methodically performs this most important task, analyzing the light of stars, which is refracted, passing through the atmospheres of distant planets.
Each molecule leaves its own unique mark on a beam of light, and some molecules, such as oxygen, carbon dioxide, and methane, may be evidence of the presence of some form of life on a planet through which the light of distant stars streams through the atmosphere. “Webb”
Given that there are billions of planets in our galaxy, and billions of such galaxies in the visible part of the Universe, few scientists believe that only our planet is inhabited.
However, the discovery of compelling evidence for the existence of living beings elsewhere in space would have a profound emotional and psychological impact and would have philosophical and theological implications.
Such a discovery would force us humans to reconsider some of our fundamental beliefs: How do we define “life”? What are the possible varieties of life? Where did we living beings come from? Is there some kind of space community?
In fact, recent scientific studies show that life in the universe is very rare. A few years ago, using data from the Kepler satellite to estimate the number of stars with potentially habitable planets, I calculated that even if all the potentially habitable planets do have life, the proportion of living matter in the universe is extremely small – about one billionth one billionth.
It’s like a few grains of sand in the Gobi Desert. That is, we, living beings, are the result of a very special organization of atoms and molecules.
Life may be even rarer. In the mid-1970s, Australian physicist Brandon Carter pointed out that our universe is fine-tuned enough for life to form. For example, if the force of atomic bonding, which holds the nuclei of atoms together, were slightly weaker, then the complex atoms necessary for the emergence of life would not appear at all.
If this attraction were a little stronger, all the hydrogen in the newly born universe would shrink and turn into helium. Without hydrogen, there would be no water, and most biologists believe that water is essential for life.
Another example of fine tuning: if the observed “dark energy” that fills the cosmos (it was discovered in 1998) was a little more than it really is, the universe would expand so quickly, that matter could never come together to form stars, the ultimate source of all the complex atoms thought to be necessary for life.
But with slightly less dark energy, the universe would expand and contract again so fast that stars wouldn’t even have time to form.
Carter’s idea that our universe is finely tuned so that life can originate in it is called the anthropic principle. The most important question this principle raises is why. Why should the Universe care if there is living matter in it?
The theological answer to this question is a cosmic form of intelligent design: our universe was created by an omnipotent creator who wanted life to exist in it.
Another, more scientific explanation is that our universe is just one of a huge number of universes called multiverses, which have a wide range of atomic strength, dark energy, and many other fundamental parameters.
In most of these universes, the values of these parameters do not fall within the narrow ranges that give rise to life. And we live in one of these “friendly life” universes, because otherwise we would simply not exist and we would not ask this question. Our existence and our universe itself is just an accident, one roll of the cosmic dice.
The same logic could explain why conditions favorable for life have formed on the planet Earth – water in its liquid state, moderate temperatures (at least for now), a large amount of oxygen necessary for high-order metabolism.
The obvious explanation is that there are many planets, even in our solar system, where there is no water, no oxygen in the atmosphere, and where temperatures are not so favorable. And there is no life on these planets.
Meanwhile, we live on Earth, building houses, writing novels and wondering about our existence, because we are on one of the very few planets where conditions are favorable for life. In short, living matter is not only rare in our own universe, but does not seem to exist at all in most possible universes.
At the time Carter published his article, I had just completed my graduate work and was doing research in astrophysics at Cornell University.
During the two years I spent at Cornell, I lived in an apartment with a large picture window overlooking Cayuga Lake. Every day the lake looked different, as if it had been painted by a new artist. I often spent the hours I should have spent thinking about equations, looking at the lake, its changing colors and textures.
At Cornell University, I met several titans of science such as Edwin Salpeter, Thomas Gold, and Hans Bethe. Gold, a theoretical astrophysicist and biophysicist, born in Vienna in 1920, I got to know quite well. Tommy was not particularly good at mathematical calculations, but he was a brilliant and courageous intuitionist.
Chubby, ruddy, with a wide smile, he had his own strong opinion about almost everything and did not hesitate to challenge the scientific establishment. He was able to throw new ideas quickly, like darts at a target. Most of them flew past the target, but not all.
In 1948, Gold teamed up with other astrophysicists to challenge the Big Bang theory. They put forward their own counter-theory, called the cosmological “stationary state theory”. According to this hypothesis, the universe never had a beginning.
It does not change over time, although it expands due to the constant formation of new matter. The steady state theory eventually turned out to be wrong. In 1968, Gold correctly suggested that the newly discovered pulsating radio waves from space were the result of the rapid rotation of neutron stars.
In the 1970s, Gold argued that the oil on planet Earth did not originate from the decomposition of organic material, as most geologists believe, but was already deep below the surface when the planet first formed.
He even convinced the Swedish National Energy Company to drill a deep exploration hole in the meteorite crater. The analysis of the extracted rocks gave very controversial results,
and the company went bankrupt.
I remember very well standing in Tommy’s office trying to solve a problem with the equations written on the blackboard, when he angrily pushed me away and said the correct answer – just visualizing the problem in his head.
Most scientists also have this “physical intuition,” but the extent of Tommy’s intuition was truly staggering.
Tommy also had golden hands. One day he showed me a beautiful three-legged chair that he designed and made himself and explained that all chairs should be like this. Even if the three legs are of different lengths, the chair will still stand firmly on the floor because the three points (the ends of the chair legs) always form a unique plane (the floor).
Add a fourth leg – a fourth point – and if it’s not cut to exactly the right length, its end won’t lie in the same plane as the first three.
As a result, the chair will rock back and forth between its four legs, because the ends of any three of them will lie in the plane of the floor, but the fourth will not. In other words, three legs allow only one position of the chair, and four allow several such options.
Thinking back to Tommy’s three-legged chair, I realize that it was the perfect metaphor for the one and only universe that most scientists dreamed of.
Physicists, especially theoretical physicists, would like to think that there is only one possible universe, consistent with the fundamental laws of nature – as the only possible solution to a crossword puzzle or a chair with three legs. If so, we can figure out why our universe has to be the way it is.
The possibility that there are many other universes with different properties, many other options for the same fundamental laws of nature, causes deep concern to many scientists. It’s like walking into a shoe store and discovering that you are equally good in size 3, size 6, and even size 11.
Modern physicists pride themselves on being able to calculate anything based on “first principles”, that is, on just a few fundamental laws.
For example, a physicist can calculate how fast a ball will hit the floor if it is thrown from a height of three feet using the law of conservation of energy: the total energy in a closed system is constant, although this energy can change shape.
The law of conservation of energy, in turn, follows from an even deeper principle called “stationarity” – the laws of nature do not change over time.
With the help of basic laws, physicists were able to calculate the color of the sky, the exact orbits of the planets, the strength of magnetism in an electron, and many other phenomena.
But, if there are many different universes that obey the same initial principles and laws, then the fundamental nature of our universe is incalculable. Some basic properties of our universe must be random. Physicists really don’t like randomness.
If there are too many chances, it means that nothing can be predicted. Wheelchairs will suddenly start flying up into the air. On some days the sun may rise and on others it may not. The world will become a frightening place.
There is another disturbing aspect to the idea of a multiverse. Even if this set of universes really exists, it may well turn out that there are simply no ways to prove or disprove their existence. By definition, the universe is a closed region of space and time that cannot send a signal to another such region, even in the infinite future.
That is, one universe cannot communicate with another universe. A hypothetical set of universes must be accepted or rejected on the basis of faith alone.
Just as scientists don’t like chance, they don’t like being made to believe something they can’t prove. But the multiverse and other aspects of this strange space in which we find ourselves may not only be unknown to us at the moment, but also fundamentally unknowable.
Not all scientists accept the multiverse hypothesis. But one thing is certain: life in our universe is extremely rare. I have already explained that life in space is a rarity: only a small part of matter exists in its living form.
Life is also rare in time, in the long history of the universe. At some point in the future, perhaps a few hundred billion years from now, after all the stars have burned out and all sources of energy have been exhausted, life in our universe will cease – not just life like Earth, but life in all its forms. The “age of life” will pass.
What conclusion are we to draw from this thought? Personally, it gives me a feeling of closeness with all living beings. We living beings are just a mechanism by which the universe can observe itself. We living beings are just a few grains of sand in a vast desert.
We are the result of a special arrangement of atoms and molecules, and we can try to understand and capture this dazzling picture of existence. To some extent, we living beings give meaning to the universe. Without us, space would just be space.
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