The Notion of Nothingness—Part 3: What is Nothing?

Any analysis of a question such as: Why is there something, rather than nothing? must be clear about the definition it’s using. So, turning to the dictionary for some clarity, the definition of nothing has a variety of meanings. It is, for example: “Not anything; no single thing; a thing that does not exist; something of no importance; and something of no amount—zero.”

From these definitions we get several interesting expressions: “Nothing could be further from the truth.” “Nothing is simple.” “Nothing is easy.” “Working for nothing.” “Nothing but the best will do.” “Nothing doing!” “Nothing of importance.” “Whispering sweet nothings in her ear.” “You ain't seen nothing yet!” Nothing is certainly a far-flung concept, so we must be careful how we use it.

The mathematical definition of nothing is another interesting angle to consider. The concept of zero was conceived of by mathematicians in India, well over a millennium ago. Up to that time many cultures struggled with counting beyond just a few items. The Sanskrit word for zero (or void) is sunya. Arab scholars introduced the concept of zero to the West, calling it sifr, from which we get “zero.”

Zero is nothing, no quantity. In contrast, “one” (or any other number such as “seven”) is something. So consider the equation 0 = 1 – 1. It says that the addition of something (some number, in this case “one”) with its negative is zero... or nothing. Or, we could consider the equation from a different perspective: telling us that zero (nothing) splits in two identical “somethings,” one positive and one negative.

In fact, another reason that many astronomers wonder why the universe contains anything at all, is because theory suggests that, in the immediate wake of the Big Bang, equal amounts of matter and antimatter should have been created. Had this been so, those opposites would have met and annihilated each other... resulting in zero… nothing. (Such as in the equation above.) Yet our universe has something. Another puzzle.

In a similar vein, some people suggest that we can point to an example of nothing right here in our universe. The vast spaces between galaxies and stars consist of close to nothing, which we call a vacuum. It's space, which by definition is “entirely devoid of matter.” The root of the word vacuum is the Latin vacuus, “empty.” So the universe—which is almost entirely space—is essentially nothing, right? Well, not quite. Quantum mechanics tells us that even a perfect vacuum is not nothing. Subatomic particles are constantly popping into and out of existence there. Thus empty space—which some of us might consider to be nothing—is replete with matter and antimatter, dancing in and out and around each other. The most vacuous space is something!

This little adventure into the definition of nothing has probably not shed much light on the question of, Why is there something, rather than nothing? If anything, it has demonstrated the difficulty of understanding how different people conceive of nothing, and thus it illustrates the challenge of answering our question. Can we even comprehend what nothing is? Living in a universe of “somethings,” nothing may simply be unimaginable for us.

Next time: Some deeper responses to the question.

Ultimately Untestable?

Contemporary physics is facing a problem—some physicists would even describe it as a crisis. And as is true for most crises, controversy erupts. Factions appear and engage in debate. Emotions bubble up. Yes, even staid physicists can become emotional, and a few of them even become impassioned.

The cause of this particular crisis is the shortcomings of what has come to be known as the “standard model” of physics. It describes the fundamental behavior of matter—which is essentially the core of physics. But the standard model, although it has been very successful in describing most of the behavior of aggregate matter, does not explain the behavior of elementary particles. The model does very well at the macro level, but is quite useless at the micro level.

Beginning about 100 years ago, a few physicists developed a new micro-matter theory that's come to be called quantum mechanics. It does a very nice job of describing the behavior of subatomic particles—such as electrons, protons, and neutrons. The problem—the crisis—lies in physicists being unable to reconcile the two theories.

What's worse, while the standard model has been verified by countless experiments, that's not true for several aspects of quantum theory. While many predictions of quantum mechanics have been verified by tests, there are some aspects of the theory that seem to be beyond experimental investigation. And that really bothers some physicists. The time-tested scientific principle is that scientific theories must be proven by experiment. So what do you do, when you can't put your theory to the test?

A rough parallel is the theory that was put forth by the Ptolemaic model for the universe—the nearly 2,000-year-old idea that placed the Earth at the center of the universe. Ptolemy's model was very cumbersome and complex, but it explained various phenomena for centuries. It was finally replaced by the far simpler Copernican (sun-centered) model in the 17^th century by Kepler, but his model's proof had to wait until science had the tools to do the experiment and irrefutably demonstrate that the new model was correct. The crucial tool that did the job: the telescope.

Quantum physics today is in a rather similar place. It could be that we may someday have the tools to run the experiments and confirm the correct theory (or correct theories). Yet some physicists are convinced we may never be able to do the experiments. If so, do we abandon the venerable rule that all theories must be testable, or just abandon those theories that can't be tested? The debate continues. Emotions are roiling.

Universes: Parallel or Unique? (Part 2)

There's a second way in which the concept of parallel universes comes up in modern physics: Not so long ago our understanding of the cosmos was far more limited than today. It was literally a smaller universe. The more we learn, however, the bigger it all appears to be. In fact, some scientists pose the possibility that the universe is unimaginably huge; even infinite. There is currently no known reason why it couldn't be. If so, it opens up the possibility for something very weird: If the universe is actually infinite, there may be an infinite number universes contained within it. No limit.

Since there are only a finite number of elements that make up everything, an infinite universe offers the chance of an infinite number of ways that things can arrange themselves. Sooner or later, you and I will find ourselves being duplicated. It's like giving 100 monkeys 100 typewriters to play with (OK, today, it'd be 100 PCs). Given enough time (infinite), they would write all of Shakespeare's plays. It's a crazy thought... but it's theoretically possible.

And finally, there's a third way that parallel universes come up: via string theory. There are currently three contrasting ways that physicists model our universe: (1) classical mechanics (Newton's baby), (2) relativity (Einstein's baby), and (3) quantum mechanics. Each one uses a type of mathematics that works quite well within its domain—either large and slow, very fast, or at atomic scales. But when two of these domains intersect or overlap, they clash in their predictions of how things behave. These three approaches disagree with one another in that overlapping zone—something that causes the stomachs of physicists to wildly churn, or creates painful scientific headaches.

A few decades ago a novel theory came into existence to deal with this disagreement: string theory. It irons out a lot of overlapping wrinkles in the old theories—providing a seamless description of our world; big, small, fast, slow, etc. String theory has introduced a few wrinkles of its own, however. One is that science may never be able to come up with experiments to test its validity. That's a bummer in the eyes of physicists who know they'll eventually have to have experimental verification of their theories. So string theory, although attractive, awaits (maybe forever) some kind of proof. (Interestingly, Einstein's theory of relativity remained an abstract curiosity for a couple of decades until an experiment in 1919 proved it true, and Albert became an overnight sensation.)

A particular aspect of string theory also suggests the possibility of parallel universes. So science now has at least three ways to suggest the possibility of parallel universes: quantum mechanics, the realization that the universe may be infinite, and string theory. As a result, other universes are coming into vogue and several new terms have entered the discussion: parallel worlds, the multiverse, the metaverse, the megaverse, alternative universes, etc. The imaginations of science fiction writers have been stimulated by all these developments. The possibilities are endless.

As yet, however, the evidence for parallel universes is only conceptually possible. There is no proof. There may never be. That's disturbing for some physicists and has others toying with the many potential implications. Nobody yet knows. So expect ongoing speculation for some time yet... and maybe the dilemma will foster a bunch more great science fiction stories and movies.

Universes: Parallel or Unique? (Part 1)

People have enjoyed playing with the notion of parallel universes for many years. Science fiction stories have featured myriad possibilities of the existence of them, and often describe a hero accidentally being dumped into one of them, followed by harrowing and strange adventures. Our hero will discover the weird characteristics of the new universe, become trapped within it, finally escape, and return safely home, back to our unique universe. It's been a rich topic to explore.

One of the more modern fictional depictions of parallel universes is the notion that multiple, split-off copies of each of us exists in these countless other universes. How does this happen? At each moment, we are presented with multiple choices; the road branches again and again. We choose one path, but other copies of us (in other universes) make other choices, each time creating endless copies of ourselves that do their own thing in their own universe. These replicas of us carry on in their lives pretty much as we do, but pursue an infinite number of alternative possibilities.

After each moment's decision that we make, we sometimes wonder: What if I were to have chosen another path? (The fun part of the fiction is that another “me” did so, in another parallel universe.) What would my life be like today? If only I could peer into one of those alternative worlds. These fanciful questions often occur to us, and we can get into daydreams about another path that we might have taken. Another playground for science fiction.

Once the sole realm of science fiction, the possibility of the existence of parallel universes has entered mainstream science in recent years. Parallel universes pop up in physics and cosmology in several ways. One of the ways is via the field of quantum mechanics. Its predecessor, classical mechanics (the result of Isaac Newton's insights), described an exact, unique universe—in which the laws of physics allowed us to make precise predictions of the future behavior of things such as planets and billiard balls. Given enough information, one could describe precisely where that planet would be in a hundred million years, or in which pocket a billiard ball would eventually drop. Classical mechanics offered a certainty that we humans like to have.

But then quantum mechanics entered the picture and introduced the fact that chance, instead, may rule our beloved universe. Physics was transformed from an exact science to a probabilistic one. (This irked the hell out of some scientists... Einstein was one of them.) Quantum mechanics tells us that an event, rather than being unique, may have any number of outcomes—each with a given probability of happening. We won't know what outcome actually will occur, until we run the experiment. Afterwards, we may wonder why that particular result occurred. Another outcome theoretically could have happened. This probabilistic nature of the quantum world posits the possibility of multiply-different outcomes in multiply-different universes—each outcome equally likely to have occurred in its own universe. Weird!

More on alternative universes next time...

Brouhaha Brewing—Part 1

Physicists in recent years have been confronted with a number of intractable problems that just keep mocking their attempts to resolve them. Some of the brightest researchers (count Albert Einstein and Stephen Hawking among them) have unsuccessfully banged their heads against a brick wall of seemingly insoluble problems for much of their careers.

Here are a few examples: Why can't scientists get Einstein's theory of relativity and quantum mechanics to agree? What the hell is all the mysterious “dark matter” and “dark energy” that constitutes some 96% of the universe, and why can't we find it? Why can't a single unified theory describing and relating all the fundamental forces of the universe be found? How can the confusing soup of fundamental particles be sorted out and finalized? Why is it that string theory—which appears to be an elegant “theory of everything”—started out so promising a few decades ago, but has gotten bogged down in the last few years, such that all attempts to resolve it have either led to a dead end or even more puzzling mysteries? What is the nature of the bizarre mechanism that causes “quantum entanglement,” in which information seems to travel faster than light—in fact, instantaneously? (That last one really bugged Einstein.)

Now comes a mathematician who claims to have solved all these quandaries (and more) by taking a completely new approach. His theory, which he's dubbed “Geometric Unity,” is a work that he's devoted his last 20 years to developing. This remarkable announcement has been issued by one Eric Weinstein. He has a PhD in mathematical physics, but dropped out of academia 20 years ago to pursue his dream as a lone wolf.

It's both a startling and a romantic story: an unknown genius toiling away for two decades in the shadows, eclipsing what legions of physicists and mathematicians have failed to do for a couple of generations. Weinstein was invited this past May to give a lecture at Oxford University, to describe his theory and its implications. He says there is no missing dark matter in his calculations; it's all present and accounted for. His model is apparently straightforward and elegant, and it makes many new predictions about particle physics.

This is an amazing development—one fit for sensational press headlines; and it's gotten a few, though the topic is a bit too complicated for your typical tabloid sound bite shrieks. Has Dr. Weinstein truly made the work of countless scientists futile? Some non-scientists may jump on this announcement and get carried away with its implications, but let's hold on a minute here.

This situation is reminiscent of the sensational news a year or so ago, that Italian experimentalists had measured neutrinos exceeding the speed of light. Gracious! Einstein was wrong! The speed of light is not an absolute limit, after all! What furious sound-bite reporting zinged around the world's cyber lanes at the time! A few months later, however, further investigation showed that they had made an experimental error. So Einstein was right after all! I doubt that even one of all those newspapers and TV “news” shows—those that had earlier trumpeted the amazing “discovery”—even noticed the retraction. If they did, they'd certainly not regard it as news worthy.

More on the brouhaha next time...