It is not always easy remembering what we know, or don’t know. Even in science. Sometimes just one new decision or assumption causes all our problems to seemingly vanish in a glorious wave of insight; profound in its simplicity and all the more plausible because of that simplicity. How can something so elegantly simple, so seemingly obvious, that fits so perfectly, be anything but true?
It seems inherent within our nature that aesthetics lends itself to trust and belief. We like simple things — beautiful things. We like easy, convenient things. What is aesthetically appealing to us often carries greater weight, even in terms of knowledge, than what might actually be. It is a strong temptation to embrace that which is beautiful and easily available. And, much like the company we keep, over time we may become blind to the perspectives we once inhabited, having shed them in increments along an aesthetic trail that may, or may not, represent an actual, or real, situation.
In other words, though it can often be prudent to follow the aesthetic, aesthetics alone do not determine actuality. Aesthetics can be a short-hand; conveniently embraced, which can just as easily obscure a more fundamental and meaningful issue. An issue that, perhaps, is messy-er (not to be confused with Messier). And when aesthetic determinations build upon other aesthetic determinations it is more than just conceivable that error results. And these types of errors can be excruciatingly difficult to find your way back from. An aesthetic foundation can often support an incredibly elaborate, hefty and lofty structure, but this building method is constantly in peril of collapse, with much effort and resources lost.
I was reminded of this two days ago, in a few different ways, when talking with a man at a store. He liked how the full moon was so much larger when it was low on the horizon. After wrestling with myself over aesthetics for a moment, I asked him if he knew this was really an optical illusion, and that the moon wasn’t any bigger when it was lower on the horizon. He answered that he knew the moon wasn’t really bigger, but that the earth’s atmosphere acted like a lens, magnifying it so that it looked bigger, and that’s what he liked.
Looking at him, and wrestling a little more with aesthetics, I told him, that was an answer I knew was out there, and many people believe it, but it isn’t true. The moon only looks bigger when it is next to objects on the Earth and you can see its relative size. If you were to hold a ruler out and measure it on the horizon or straight up in the air, you would find it is the same size.
In him, the large, romantic moon, rising on the horizon, had given way to a “scientific” explanation of atmospheric lensing. Now, without measuring for himself, his scientific explanation is proven erroneous, being replaced by another. I did, at least, offer that optical illusions seemed far more romantic to me than lensing effects. But it didn’t matter. Something had crumbled and a pissing match ensued. He asked me if I knew that the moon orbits the Earth because the Earth warps the space around it. I answered that I had heard something to that effect.
Then I might have cheated: I asked him if Earth is warping space, then what exactly is getting warped? He looked at me like I was an idiot. Space is getting warped, he answered. Yes, but what is Space, to be warped? Space is nothing — it’s the empty space that everything in the universe is floating around in. Well, how can something that’s nothing get warped? I asked. I don’t know, he said. And with that, he was a bigger man than many. I don’t know what space is either. And nobody does.
Regardless of this inconvenience, much science has been done about the universe, and with some spectacular results. The largest body of Einstein’s work dealt with the nature of space, or space-time, and how things behaved within it — but without being able to say what space actually was. This is, in many ways, a problem similar to Newton’s laws of gravity, which predicts a good many things that have withstood the tests of time. But strangely, Newton had no idea what gravity was. Instead, he was happy enough to predict gravity’s effects on things. Much the same can be said about Einstein and space — and gravity, too. Yes, we have no idea what space is, nor do we have any idea what gravity is. We’re just happy we can predict some things within it. Well, that’s not entirely true. We have some ideas. Some are aesthetically pleasing. Some are not. I leave it to you to imagine what the majority of our modern science is based upon.
It was a very long time ago that we humans began imagining that the substance of all matter around us might be made of smaller things that we could not see. The Greek philosopher Leucippus (through his student Democritus) suggested something called atoms exist which are very tiny, invisible components that give all the matter we see its properties by their arrangement. Even the soul was made of atoms, which were a little like fire, that float out and around while our body atoms followed along. I imagine he was dreamy. Atoms were mathematical: geometric — round or sharp or square, depending on what they made. For example, water was made of rounder geometric shapes, while stone had more solidly square atoms.
The Greek word atomos means uncuttable. That is, if you started slicing away at something, you can only divide it so far before you cannot cut it any smaller. It is there you reach the indivisible atom. Another peculiarity within this ancient idea is the concept of a vacuum. What this vacuum was, was a matter for debate. As it still is. Some held that a vacuum was nothingness. Others held that a vacuum was not nothingness, but was instead a vacuum, devoid of stuff. Aristotle, being a natural philosopher, just threw up his hands and said “nature abhors a vacuum”.
The believers in atomism needed a vacuum. The vacuum was the empty space in which atoms could move about. We had two main concepts: a vacuum, and atoms. This sounds familiar. Aristotle said this was wrong, mainly because atoms in a vacuum could move without any hindrance, and therefore at infinite speeds, which was counterintuitive. The aesthetic of Aristotle prevailed and it was well over 1,000 years before we returned to the notion of atoms and found it valid. And shortly, relatively speaking, after doing so, we discovered that these uncuttable particles were, in fact, made of other things, namely electrons, protons and neutrons.
To a naturalist like Aristotle, if he were still alive, this was troubling. If we are composed of all these atoms, and they are what is real, what about the aggregate of these atoms — our minds and bodies? Are they unreal? Are we unreal? Most modern philosophers have come to terms with the implications of atomism through mechanisms akin to plurality, where atoms can be fine and real, while what they make, like a tree, or us, are equally fine and real. Yes, it does soothe our aesthetic sensibilities, allowing us to re-focus back upon the atomic.
But then we discover that even protons, neutrons and electrons are not what they seem to be. By smashing them together really hard while we watch, we can see other things flying out from the debris. This leads us into the realm of the quanta, which, like atoms, we also claim are indivisible. The quantum realm operates down at the unimaginably small Planck length. I’m not certain if using the width of the human hair comparison is useful for us to get an idea of these relative sizes, but if we looked at how many Planck distances there are in a human hair, and stacked that many hairs side by side, we would have a table full of hair that stretched approximately 20 billion light years across space. That’s a lot of hair, and would span a good chunk of the entire universe.
So as you might imagine, the Planck length is quite small. However, the warping of space by objects with mass happens on a much larger scale. We assume that the Planck length is within or comprises space, however small it is. But, if gravity is the warping of space, how do you warp something at that small, immutable quantum level? Well, apparently you can’t. Instead, you must say that another particle exists down there, and we’ll call that particle a graviton. And this particle “communicates” gravity between other particles with mass, which somehow warps whatever space happens to be, only on larger scales.
Another troublesome aspect we face is this concept of mass. What is it? Well, we know what mass is, because we’ve defined it. In several different ways. For example, you can say that mass is measured by how strong a gravitational field is produced from it. Or, in a more classical sense, you can talk about how resistant a thing is to a change in its motion. But some particles have no mass. These are often the speedy ones. Like light. But if light has no mass, how can gravity change its course, as demonstrated again and again? Well, ask Einstein and you will see that gravity does not effect this mass-less light — instead gravity warps space, which in turn changes the path that light must travel. So again, it’s just an optical illusion of sorts, that gravity bends light. Really, it’s space itself that is bent, and light is traveling in a sensibly straight line, unaffected by gravity. The tiny quantum realm has no such definitive reasoning, however. But they are working on defining what quantum gravity might be. One of the biggest problems they face leads us back to our original question: what is space? Well, the answer depends upon who you ask. And they may change their minds at any moment. Interestingly, I don’t think you’ll find anyone who is willing to say they don’t know.
It is all well and good, if you want to make predictions, to say that space and time are analogous to a big sheet that gets warped by things put upon it. It is another thing altogether, when working at the tiny quantum scale. What is this sheet? How is it made, and the fabric, threads and strings all hooked together? Traditional quantum field theory cheats a bit, perhaps, as does string theory. They locked themselves, for the most part, into a given space-time plane. As such, these perspective really can’t say much about the actual structure of space-time, because space-time is an aesthetic-like thang built into the foundation. It is only when you venture into background-independent theories, like loop quantum gravity, that you really have any chance to determine the structure or nature of space itself.
So maybe once we figure out what space is made of, we might be able to explain how quanta, like gravitons, can seemingly “warp” space on a larger scale. In that case, I am left wondering, do the gravitons then communicate gravity between objects, or only to this space substance, whatever it is, between those objects?
It may well turn out that space (and matter) is actually a vast network of tiny, discreet “containers” at the Planck lengths that hold semi-indeterminate and probabilistic information. Much like a professor’s chalk scribbling an equation on a blackboard, or memory addresses accessed by a computer program. These “containers” can change their quantum arrangements or states only in increments of Planck time, which you would be correct in imagining is a very tiny, also irreducible, chunk of time.
If this is the case then everything in the universe truly is interconnected, and we inhabit, in our most fundamental components, a few globs within a vast network far beyond ourselves. Loop quantum gravity is most interesting, at least to me, in that space and time are derived qualities of the theory, and so the theory itself exists independent of space and time. Perhaps this can help explain observed anomalies such as quantum entanglement, where objects can effect one another, regardless of their distance apart, instantaneously.
But loop quantum gravity makes some aesthetic assumptions, too, as surely as string theory does. Oh, and they love to bicker. Generally, string theorists accuse loop quantum gravity (LQG) people of being old-fashioned (where quantum particles must be incorporated into the theory by hand instead of predicting them), while LQG people accuse string theorists of making wild assumptions (such as a flat, fixed space-time which is not even relativistic, or the addition of 7 or so extra dimensions that we cannot observe).
But that isn’t the beginning, nor the end of their problems. Despite all the complexity, the mathematical beauty, and verifiable predictions emerging from quantum mechanics, there are still more assumptions. Going back to this notion of mass — what gives something mass? We can say that particles or groups of particles have mass, but what is it about those particles that cause them to spontaneously “create” a gravitational field, or resist change in their momentum? Well, much like, “it must be a graviton”, we have, “it must be a Higgs boson”.
Now this, at least, we might be able to test when Europe’s Large Hadron Collider comes online shortly. The collider will allow us to smash things together harder than we ever have before. Those particles will blow up real good! As an aside, it is far from certain that the LHC is powerful enough to reveal Higgs boson if they exist. However, there is little doubt that the US Superconducting Supercollider would have been powerful enough. Unfortunately, that project was canceled years ago when the cost estimate reached $12 billion. And that cost isn’t even a month’s worth of war.
This “Higgs field” supposedly permeates all of space as a quantum fluid and carries various quantum information. Discovery of the Higgs boson will apparently confirm that this Higgs syrup exists, and that certain subatomic particles get bogged down by it, resulting in what we call mass for them. If this proves to be the case, then the particle physicist’s Standard Model will get a big crowing gold star, since the Higgs is the last particle yet to be observed.
I didn’t say any of this to the guy at the store, though. I saved it for you. I just told him that I didn’t know what space was, either. I suppose I could have written here, “I don’t know!”. Instead, I thought I would share some of the neurosis going on, in case you might be curious, and didn’t already know or suspect.
There are many people who claim that our scientific approach to understanding existence will always result in an infinite regress. That is, our definitions, knowledge and current understanding used to formulate our questions, will always lead to us having to redefine them after we achieve our result. I would say these people are probably right. But that is, by no means, a reason to abandon a scientific approach. To my mind, all knowledge is good, even if it is somewhat askew or sends us down rabbit holes — as long as we were trying, in good faith.
We must ask questions, of everything, as surely as we must take our time to enjoy our simple existence along the way. Scientific inquiry, and even mathematical models, are ways we can ask questions and discover things with some reasonably definitive results. However, I am not entirely convinced that all valid answers come through science alone, or ever will. It is adorable watching so many scientists behaving like philosophers. And at least the Philosophy of Science offers some employment opportunities for modern philosophers.
And in our keen information age, we can sit back and watch the discourse and discoveries unfold. We can even have little mini-debates at the local supermarket. Ah, it’s good to part of the Empire. Well, except for the burdensome Philosophy of Ethics. I just thought I would un-bog myself from it for a few moments, so that I might share our better selves. Our selves that deserve our greatest attention and support. Those selves that want to do better for all of humanity. Just because. Or, if you must, because it’s aesthetically pleasing.