How will it all end? In fire or ice? With a bang or a whimper? For our little world that we live on, the answer is fire, definitely fire. As our sun continues its inevitable progression towards the red giant phase of a star, it will become hotter. The earth will eventually be charred into a lifeless cinder and spiral into our fiery sun and into oblivion.
But what about the whole shebang, the universe itself, will it too end someday? Physicists and cosmologists are of the opinion that it will. Things with a beginning have an end. Eschatologists, those who study the end of things, have come up with some interesting ideas about how it all comes to a close.
Probably, those who think about such things tell us, the universe will end in a scenario known as heat death. Think of it as the death of heat, not death by heat. Stars eventually run out of gas, literally, hydrogen gas. With nothing left to power them they inevitably go dark. The amount of gas in the universe is finite and that supply too will be exhausted someday. If we were around to see it, which we won’t, the sky would go dark. Galaxies, once lit by the brilliance of hundreds of billions of stars, will be reduced to dim ghostly skeletons of their former selves.
Heat death, the ultimate whimper, is probably not something you have to worry about when you wake up in the middle of the night and can’t get back to sleep. We are talking about the distant future, trillions of years from now. Neither of our two political parties will include it on their platforms to run on for the next election.
About that vacuum
But what if there was something lurking out of sight just around the corner? Something that could catch up with us at any time? Even before you finished reading this newspaper. What if our universe has an inherent fatal instability, a planned obsolescence so to speak?
Physicists have thought up just such an end, unlikely to be sure, but they cannot rule it out altogether either. Imagine that our universe is like a delicate vase precariously balanced on the edge of a table, and just the slightest nudge could send it crashing down shattering into a thousand pieces.
Scientists have given it an ominous sounding name, vacuum decay, and it is much worse than it sounds. Suddenly all the forces of physics, which we never think about but on which our very existence depends, would forever disappear. Stars would explode and atoms would instantly disintegrate. How would this affect us? Our bodies are made of atoms, well, you get the idea. Nothing, absolutely nothing that we are familiar with would survive this total and irrevocable annihilation.
Even worse, this wave of death would spread through the universe at the speed of light. It could have already started somewhere and is headed for us at this very moment ready to engulf us at any time.
Not to worry
Is there anything we can do about vacuum decay? No, not a thing. Would we have any warning? Not even a nanosecond. Would it hurt? Not a bit. Would it even matter? There would not be anyone else around to miss us when we are gone, so maybe it does not matter. For these reasons eschatologists tell us not to worry about it, but I will let you decide that for yourself.
Closer to home, Venus is crawling higher into the western twilight sky and is easier to spot. Look for her shining brightly just above where the sun went down about 30 or 40 minutes after sunset before it gets completely dark. Saturn and Jupiter can be seen in the southeast late at night. First, dimmer Saturn makes an appearance followed by much-brighter Jupiter.
If this whole decay business is not scary enough to keep you awake in the middle of the night, don’t worry. I will come up with something even scarier another time.