Eishun Doji
This is Kawaguchi Hidetoshi. This is my humble answer to the question.
In Buddhism, a unit of time called a long period of time is treated, but according to one theory, a disaster is the length of time from birth to the end of one universe. If that were the case, would it be about 20 billion years?
In the sutras, expressions such as “100 trillion nayuta asogi” and “100 trillion yuan heist” appear, but in other words, 100 x 1,000 x 10,000 x 100 million times 1 heist (120 billion if you think about it above)... Well, I think you can see that it's a huge amount of time.
For example, it will be explained that over a huge period of time, we have continued to reincarnate in this world of confusion and suffering due to ignorance (fundamental ignorance).
When you think about it, well, 5 billion years, would you say an instant or a blink of an eye, it's like that.
Also, sentient beings do not exist only on Earth, and there are many other planets, or other universes, and even worlds that we can't imagine today, the color world, the colorless world, of course, the Pure Land, etc., and even hell as the six ways, etc., and it is a place where they have continued to reincarnate in countless worlds due to ignorance and karma.
Therefore, I hope you can think that unless we get out of this reincarnation, even if the Sun and Earth disappear, we will lose our way and suffer for a long time in another world, such as another planet, another universe, etc.
Of course, Buddhism is the teaching for getting out of that reincarnation of hesitation and suffering.
If I can do something about it, in my next life, I want to be a better place than the human world, and if possible, a world where there is Buddhism, a world where Buddha is present, in other words, the Pure Land, etc., with the aim of being born in a situation where Buddhism can be practiced, and I would like to firmly combat ignorance and bad work in this life.
Kawaguchi Hidetoshi Gassho