Up to so far, we came to know about the universe, its age, and expansion, even the time-space. But when we thought about life in the universe, our mind just goes blank, and even we are not able to imagine because we all know, the universe is created by three gases only hydrogen, helium, and lithium.
Generally, we know that about 4.6% of the mass and energy of the universe are contained in atoms. All of life which is created however is from this 4.6% only. As we discussed above the only three elements at the beginning of our universe are the lightest atoms in the periodic table and these were formed throughout the universe as a hot gas. It’s up to impossible to think of developing a life with the heavier elements than the lithium.
We all are humans, we are carbon-based life forms. We are made of and drink water and we breathe oxygen. So, carbon dioxide and oxygen cannot be created in the Universe but rather much in stars. All of carbon and oxygen in all living things are made in the nuclear fusion reactors and that we call the stars.
All the early stars are massive and short-lived and because of that they consume their hydrogen, helium, lithium, and emerges heavier elements. When these stars die with a bang they spread the elements of life, carbon, and oxygen throughout the universe.
New stars condense and new planets form from these heavier elements. As now we can say, the stage is set for life to begin. If we talk about life, how much longer is life left in the universe? then the answer is, it took 13.8 billion years to know this fact that, how life developed and the age of universe is governed by basic rules govern by matter, energy, and time. how long the universe lasts and how it evolved is dependent totally on the energy and matter content.
As we know that enormously our most matter gets collapsed under its own gravity and much more mass required for stars to make universe long-lived, which is not available at this time. But there is dark energy also available that acts like anti-gravity, and drive the universe to accelerate its expansion. So, we can say that our universe is not too large and not too small, all we need only enough mass and energy for the development of life.