The wise people, particularly, the aged ones always think of complex metaphysical problems. The youngsters who call themselves rational, scientific, and down-to-earth may even laugh at them! But the wise ones are well experienced! Great thinkers have dealt at length on all these metaphysical problems and, have realized the transitory, spatio-temporal and illusory or the 'make-believe' nature of this universe. We do not understand how our focused adamant mind and its whimsical imagination, dreams, mislead us! We should always remember that whatever is limited or governed by 'Time and Space', or whatever that comes under the grip of causality, duality, limitations (niyati) is not real. The 'Real' is eternal, unchanging and the 'Truth'. It is the one unborn, immortal, and endless. It is called ananta, acyutam. There is nothing that is eternal or enduring, permanent on this earth. The earth is elemental, gross matter, and, it is governed by its own laws. As a part of the solar system the Sun governs its existence and all that is found here on it are also governed by the Sun. The sunrays are the mainstay and support earth and its life-forms; but for this, it has no independent existence. The sunrays produce light, heat, and the life-supporting energy ( actinic rays). The tmosphere on the earththat extends to about 10 kms. approx. has dense air consisting of Nitrogen, Hydrogen, and Oxygen, Argon, Ozone, and a few other gaseous elements (some rare ones, too!). The Sun is made up mostly of Hydrogen and some of it converted into Helium on its surfecae! Thus, we know very little about this mysterious earth. We do not know 'who is who' or 'what is what' and 'whys and hows' that are found here! There is a lot to explore and know about this mysterious living planet earth!
Now, the question arises as to the durability, endurance, sustainability, etc. Nothing is permanent here, for sure! Everything is subject to degeneration, decay, and deterioration. The truth is simple. Nothing i born and nothing dies here. Everything is transitional, just a process of transformation. Hence, one should know and realize the truth behind all that exist here. Everything is mysterious and mesmeriszing! Everything is trans-migratory, including our soul! When the soul leaves the body as pranic energy, it seeks resurrection. It wanders as a ghost, bhoota, preta, pshacha and wanders in search of a physical body! Everything is just a transformation, magical transformation of one into another.
Bhgavan Sri Krishna says, "I Am the myavin, Magician. I wave my magic wand and things appear and disappear. I Am kaal! (kaalo'smiI). "I Create, sustain, and finally, devour all that I Create, and again recreate! So, it is very clear that 'Time' rules the roost!
Those who realize the true nature of this world as explained by the Lord in the Bhagavad-Gita will enjoy the short span of their life bestowed to them by Him.