Posts Tagged big bang
Back in February, 2017, an interesting article appeared in that month’s issue of Scientific American. Written by Anna Ijjas, Paul J. Steinhardt, and Abraham Loeb, the authors presented some evidence for a “big bounce” in the life of our universe, rather than the much better known “big bang.” The universe as we know it is thought to have started by a rapid inflation of all matter and energy from a point so small it would fit inside an electron with room to spare. Thus the idea of the “big bang” was born, though it was probably a quiet “bang” since there wouldn’t have been any air around to transmit a sound. The authors of the article give some evidence (not overwhelming by any stretch of imagination) that the universe has been alternately expanding from a point, then contracting to another point and expanding again. Ad infinitum.
Well, later several other physicists, thirty-three to be exact, including Stephen Hawking and Alan Guth (who, by the way is the pioneer of the inflation theory) wrote a letter stating their opposition to the evidence in the article, and reaffirming their belief that the universe started with one and only one big bang. Their evidence is that the universe is not only expanding, but is expanding at an ever increasing rate, and either already has or soon will reach a “point of no return” where it can only continue to expand, and never will contract. Too much dark energy pushing the matter in the universe apart. It’ll go on forever.
Two competing theories. I emphasize that the Scientific American article did not state that the authors thought the Big Bang theory was wrong, just that they thought it did not explain everything, and a rebounding universe was a possibility. Okay, so much for that.
My interest in this discussion between the “Uni”-verse theory and the “Multi”-verse theory isn’t to try and distinguish between them, or even try to add my name to one or the other. I’m not a physicist and haven’t got the faintest idea which is correct. I’ll let those more competent than I figure that out. But as I began to think about the concept of a rebounding universe, my thoughts took a philosophical turn, and I began to wonder where we all fit in such a scenario. The universe expands from a point source and grows larger and larger, to eventually result in our galaxy, our solar system, our planet, our cities and towns, and us. It goes on for billions of more years, and reaches a tipping point. It begins to contract and drops back to a point, and the cycle starts all over again. All of that is conceivable by the human mind. But what isn’t conceivable is the idea that this has been going on forever, and will go on into infinity. Back in 2010, I wrote a blog called “Wrap Your Mind Around This…” in which I pointed out a few examples of things that are so out of the ordinary in today’s world that they were impossible for the human mind to comprehend. This rebounding universe is another. (See the earlier blog at https://rogerfloyd.wordpress.com/2010/08/08/wrap-your-mind-around-this/) Although I can see a universe that starts with an inflation and continues on only to dissipate into infinity, I can’t begin to envision a universe that bounds and rebounds, like a tennis ball that will not stop bouncing. Such a universe violates the laws of physics. The most difficult part to envision is that there has never been a beginning, and there will never be an end. How does something never have a beginning?
I wonder, does the universe play the same thing over and over with each rebound? Did we exist in all those past universes? Or, is each universe different?
The universe in which we currently exist is so large, we are almost infinitely tiny in comparison. Our galaxy, which is so much larger than us, is itself only one of billions, even, perhaps, trillions. But to put all that in the context of a universe that rises and falls like a bouncing ball, and has been going on forever—no beginning, no end—just makes the comparison even more difficult to understand.
The title of this post isn’t meant to ask where you are in a spatial location, but in terms of time. Where are you—where are we all, for that matter—in the life of this universe? I’ve been thinking about this for a long time. We all live on a rather attractive blue, white, green and brown planet circling a rather ordinary yellow-white star in a rather ordinary galaxy somewhere in the middle of billions of other galaxies which together constitute what we affectionately refer to as the “universe.” This universe arose from a massive expansion of all matter and energy some thirteen billion years ago, and is rapidly expanding and expanding, apparently to go on forever, driven apart by wild forces within itself. It will go on for time immemorial, never to return to its original state. That’s, at least, the current thinking.
Here we are, sophisticated, sentient human beings, watching this all unfold, trying to make sense of it. I’ve wondered, ever since I heard of the “big bang” hypothesis, which is the current favorite explanation of how we got here, if there isn’t an alternative explanation, that the universe will eventually run out of steam and collapse back onto itself in a sort of “big crunch,” or “big splat,” from which it would rebound into another expansion and another universe, and so on, ad infinitum. That seems to me to be a more logical way for the universe to run than just one “bang” which blows up like a balloon and dissipates out in the nether regions, never to be seen again. The “single bang” theory doesn’t explain what came before the expansion, nor what will come after it. But that may be the way it really is. Dark energy seems to be pushing the galaxies apart faster than dark matter can keep them together.
Philosophically, this is mind boggling. We are the only species on this planet that really understands, to any degree whatsoever, the goings-on out there in space. We’ve been watching the skies for thousands of years. We’ve sent satellites into orbit to observe it. We’ve sent men to the moon. Do you think that cat or dog or goldfish or parakeet in your house cares much about the big bang? Do the deer and the wolves in the forest understand that the little red dot in the sky is a cold, solid planet rather than a blazingly hot star? Or even what a star is in the first place? No, just us. Yet we humans make up such a miniscule percentage of the universe, it’s difficult to estimate how many zeros I’d have to put down to the right of a decimal point to give that percentage. We humans are what I might call “universe sentient.” We know where we are, though we can’t travel very far in it. We’ve seen the stars, the Milky Way, and some of the other galaxies that make up our universe. We have a lot to learn, granted. But we are capable of learning it. We have the mathematical skills and computer skills to master the intricacies of the universe. No dog or cat, or even chimpanzee, has that. Most likely, other civilizations exist in our galaxy with similar skills, perhaps even more advanced. (Maybe they can tell us if dark matter and dark energy really exist.) But philosophically we are alone, and, I suspect, will remain alone for the foreseeable future.