Chapter 23 Universe Constant
The next day, Lin Xian and CC were sitting in the living room eating breakfast, with the black and white television broadcasting the morning news.

"Your voice seems to be much better," CC said, looking at Lin Xian as she forked a sandwich. "It doesn't feel so hoarse anymore, basically back to my old voice. I'm really glad this cold didn't last too long."

Lin Xian nodded. "Yes, I'm also very happy that your health has recovered so quickly. We were talking about the universe constant yesterday. Is there anything else you'd like to add?"

CC thought for a moment, and then said, "The concept of the universe constant is indeed very interesting. Einstein initially proposed this concept in order to make his theory of general relativity consistent with the then observed fact that the universe was static. But later, Hubble's observations revealed that the universe was actually expanding, so Einstein had to abandon the hypothesis of the universe constant."

"Yes, Einstein later called the universe constant the biggest mistake he had ever made in his life. However, even after abandoning the universe constant, the theory of general relativity itself is still very successful, and it explains many astronomical observation phenomena very well," Lin Xian added.

"That's right. General relativity has achieved great success in explaining gravity and spacetime curvature. However, the concept of the universe constant was later reintroduced to explain the phenomenon of the accelerated expansion of the universe," CC said.

"Yes, that's the so-called dark energy. According to observations, there is an unknown energy in the universe that has a negative pressure intensity, which causes the universe to expand at an accelerated rate. This unknown energy is called dark energy, and it accounts for about 70% of the total energy of the universe," Lin Xian explained.

"This is indeed a very mysterious existence. We know very little about the nature of dark energy, only that it has a negative pressure intensity, but scientists are still exploring what specific substance or field it is," CC said thoughtfully.

"Yes, the nature of dark energy has always been an important issue in cosmological research. Some people think it may be the energy of the vacuum itself, while others think it may be a new basic field. However, these are just guesses and need more observation and theoretical research to verify," Lin Xian said.

"Then, if dark energy really exists, what impact will it have on the future of the universe?" CC asked curiously.

"According to current observations and theoretical models, dark energy dominates the future evolution of the universe. If the density of dark energy remains constant, then the universe will expand forever at an accelerated rate, eventually entering a cold, dark state," Lin Xian explained.

"That sounds like a very pessimistic prospect. The universe will expand forever until everything disappears into the darkness," CC said with some worry.

"Yes, this is the so-called 'heat death' doomsday prophecy of the universe. However, there are other possibilities, such as the density of dark energy not being completely constant, but changing with time. If the density of dark energy changes or even disappears at some point in the future, then the evolution of the universe may undergo fundamental changes," Lin Xian said.

"What kind of change would that be?" CC asked curiously.

"According to different hypotheses, there may be several possibilities for the future of the universe. For example, if the density of dark energy gradually decreases, the expansion rate of the universe will gradually slow down, and it may eventually begin to contract again, eventually forming a new Big Bang. This is the so-called 'Big Crunch' universe model," Lin Xian explained.

"That sounds interesting too. The universe expands and contracts, and then undergoes another Big Bang, what would that look like?" CC's eyes sparkled with curiosity.

"This is indeed a very magical possibility. If this is the case, then the universe is no longer a single life cycle, but an eternal cycle. Each Big Bang may produce a completely new universe, bringing new possibilities," Lin Xian said excitedly.

"Then, are there any other possibilities besides the Big Crunch model?" CC continued to ask.

"Another possibility is that if the density of dark energy suddenly disappears at some point in the future, then the expansion rate of the universe will suddenly slow down, and there may even be a Big Collapse, eventually forming a black hole. This is the so-called 'Big Rip' universe model," Lin Xian explained.

"Wow, that sounds scary too. The universe suddenly collapses into a huge black hole, what would that look like?" CC asked with some worry.

"This is indeed a very scary prospect. If this really happens, all the galaxies, stars, and even planets in the universe will be swallowed by this huge black hole. The entire universe will instantly fall into darkness and destruction," Lin Xian said.

"Then, do we have any other possibilities? Isn't there a more positive and optimistic future?" CC asked with some disappointment.

"Of course, there are other possibilities. For example, if the density of dark energy remains stable in the future, then the expansion rate of the universe will also remain stable, and it may eventually reach a state of equilibrium, forming an eternal universe. This is the so-called 'static universe' model," Lin Xian said.

"That sounds more optimistic. It's good that the universe can exist forever," CC nodded, revealing a smile.

"Yes, the static universe model gives a more positive and optimistic future expectation. However, these are just theoretical possibilities, and we need more observation and research to verify which model is closer to reality," Lin Xian said.

"Okay, I am looking forward to future scientists being able to further explore and unravel the mysteries of the universe. But no matter what the future of the universe will be, as a part of the universe, we should cherish the present and live well," CC said.

Lin Xian nodded. "Yes, although we are insignificant existences in the universe, we are also the most special existences in the universe. We have the ability to think and explore the mysteries of the universe, which is a unique value in itself."

"You're right. Although we are small, we should cherish our lives and live well. No matter what the future of the universe will be, we should do our best to create our own wonderful lives," CC said.

The two were silent for a moment, both immersed in thinking about the universe and life. After a long time, Lin Xian opened his mouth and said, "You know, I've been thinking about a question, that is, how did life forms like us come into being?"

"You mean the origin of life?" CC asked.

"Yes, the origin of life. We know that the universe originated from the Big Bang, but how did life come from nothing? This question has been bothering scientists," Lin Xian said.

"This is indeed a very mysterious question. We know that life needs certain chemical conditions, such as the combination of carbon, hydrogen, oxygen, nitrogen and other elements. But how exactly did inorganic matter evolve into organic matter and then form the first life forms? This process is still a mystery," CC said thoughtfully.

"Yes, this is the so-called 'origin of life' problem. Different theorists have proposed various hypotheses, such as the chemical evolution theory, the RNA world hypothesis, and so on. But it is still very difficult to find conclusive evidence," Lin Xian said.

"Then, do you have any of your own ideas?" CC asked curiously.

"I personally prefer a more mysterious possibility. Maybe the origin of life is not entirely a random chemical process, but the universe itself contains some kind of essence of life. Just like there is dark matter and dark energy in the universe, maybe life is also an essential attribute of the universe," Lin Xian said.

"That sounds interesting. You mean life is not produced by accident, but the universe itself has the potential for life?" CC said thoughtfully.

"Yes, maybe life is not an accidental product, but an inherent attribute of the universe itself. Just like there are various basic particles and fields in the universe, life may also be a basic form of the universe," Lin Xian said.

"If that's the case, what kind of impact will it have on our understanding of life?" CC asked.

"If life is indeed an essential attribute of the universe, then our understanding of life will undergo a fundamental change. We are no longer existences that appear accidentally in the universe, but a part of the universe itself. This may give us a new understanding of our own existence," Lin Xian said.

"Is this really a possibility?"