Archive for category Science
I am a political scientist, but often in my spare time I prefer to think about science and philosophy rather than politics. So I’m not an expert on the material I’m writing about today, and welcome any corrections or modifications!
Today, while digging mini-trenches in our never-ending yard project, I tried to get my mind around the question of what makes up the universe. There is a delightful irony in thinking of these things while struggling to shovel rocky dirt in rainy cool weather with an aching back and painful fingers. Because as starkly real as that work and those pains are, reality itself almost seems unreal.
The average distance between the nucleus of an atom and the electrons “orbiting” it is about 100,000 times the diameter of the nucleus. That means that even every day solid objects are almost all comprised of empty space. Moreover, the electrons themselves are tiny point particles, existing as part of a probability wave until detected and forced to occupy a single position.
The nucleus of most large particles (hadrons) is made up of quarks — almost all of reality that we experience consists of up and down quarks, and electrons. Electrons have electrical charge, while quarks have color charge (nothing to do with color, that’s the name given to this ‘strong force’ of nature). Particles are also posited as carrying the force that keeps reality together. For electrons this particle is a photon (which we experience as light), and for quarks it is a gluon. These “force carriers” have the attributes of being both a particle and wave, existing in a field. All the stuff of reality — light, particles, even macro objects like human beings — exist as both a particles and waves.
So the universe is made up of electrons and quarks, and most of what we experience are up and down quarks. There also exists strange, charmed, top and bottom quarks, as well as numerous other particles that are made up of different combination of quarks with different color charge and spin — and every particle has an anti-particle — but that’s not the stuff that makes up most of what we experience. These other particles exist in cosmic rays, perhaps stars, and in tiny amounts in nature (thanks to quantum probabilities everything that can exist or happen does — at the quantum level). Humans have seen the impact of these particles in what is created in particle accelerators, but in general our universe seems composed of very basic particles.
Of course, “particle” may be the wrong term. Certainly things like photons are only ripples in fields. Traveling at the speed of light they have no mass and experience no time. That doesn’t sound like anything “real,” even if we experience photons on our space time. The photon seems to be some kind of particle that we experience in space time, but may also exist outside space-time.
So think about it – space and time is an entity that was created at the big bang (what came before may not be sensical within a space-time framework). When physicists came up with quantum electro dynamics, they did to do so with a method called “renormalization.” They measured the the mass and charge of existing particles, and did the calculations backwards, getting rather absurd starting energies/masses for those particles. They had to incorporate a vast number of vacuum fluctuations in order to account for the predictions of the Heisenberg uncertainty principle that now and then for a brief period of time particles will appear out of nowhere. It works in measurements as precise as we can measure, and is universally accepted due to that fact.
Beyond that, to explain the weak force of nature in the same way the strong force was explained (the strong force is through quantum chromo dynamics, analogous to quantum electro dynamics, but involving quarks rather than electrons), a new particle has been theorized (and no science has had more success in correctly predicting new phenomena of nature than particle physics) called the Higgs boson. This particle is essentially thought to be everywhere – it’s really a field, particles are disturbances in fields. The higgs field is what gives particles mass, just as color and electro-magnetic fields give color and charge.
The difficulty in connecting quantum theory with relativity in a complete manner suggests that quantum theory, in all its mathematical complexity, may be hinting at a border between space-time and whatever is outside space-time. The hints seem to be that there is intense energy available to space-time at the quantum level, with reality itself perhaps more ripples in the stream (or disturbances in fields) than solid and absolute. It may well be that the hard and fast nature of space-time that we experience is an illusion based on how our senses operate. Indeed, think of insects who have no clue about the worlds of politics, religion, marriage, social custom, etc, that go on all over their world. That is something outside their capacity to perceive. While their limits may be biological within space-time, ours could be the result of the need to operate effectively in space-time.
So what makes up the universe? Mostly empty space (again, even within the most solid of objects), forces (gravity, the electro-magnetic weak force, and the strong nuclear force), and at a fundamental level, quarks, electrons, photons and gluons. But since these particles are a weird particle/wave mix, they aren’t so much “things” as disturbances in fields. One theory puts forth tiny ‘strings’ with different vibrations as the fundamental stuff of the universe. The forces themselves and the nature of how they interact seems to come from quantum fields and probabilities that require measurement (or consciousness) in order to actualize one of a myriad of probable realities.
Add to that quantum tunneling (the idea particles can be actualized outside the confines of where they should be — the equivalent of a person falling through a solid wall) exists and our sun’s capacity to produce energy requires it, and non-locality (a change in a particle can impact another distant particle immediately, violating the laws of Newtonian physics which would require some kind of communication, which would take time,) and its clear we know little about the true nature of reality. In fact, there are so many paradoxes and apparent contradictions in modern physics that the whole theory might get thrown out as weird and impossible were it not for the reality that these models work in the real world to achieve practical results.
I remain struck by the “non-reality” of reality. Atoms that are 99.999% empty space. The forces that put the world in motion seem to come from nowhere. They include things like photons that experience no time or space, but we experience them in time and space (and they, like neutrinos which zip through our body by the hundreds of trillions every second, have no mass.) Particles and forces that are ripples in probability fields (as Max Born called early quantum field theory) which seem themselves to have no certain form. I mean, if one were inside a video game as a character, this is how it might look. Or, ideas and spirit could be more the stuff of reality than matter. At a fundamental level, we just don’t know those things. That’s what makes learning about and thinking about this kind of question fun!
For years now I’ve been awaiting yesterday morning’s big event: the large hadron collidor at CERN (on the border of France and Switzerland) was turned on, with the goal of recreating conditions just after the big bang (as in a millionth of a second after). It’s not clear what will be found, but given the puzzles and uncertainties in existing particle physics, it’s virtually certain that we’ll discover a lot about the nature of our reality.
I’ve had a fascination with modern physics, in particular particle physics, for quite some time. I don’t understand the math, and the concepts are often really tricky. From renormalization to quantum chromo dynamics and the electro-weak theory (including quantum electro-dynamics) trying to figure out what is going on and what it means is difficult, especially for us lay people on the outside. Yet it is important for anyone truly curious about what this world is all about, what is the nature of reality.
It appears that ‘matter,’ or ‘particles’ are actually just ripples in fields. Moreover, these ripples are probabilistic, meaning that they don’t have any particular fixed state. Somehow they seem to fix in our experience of reality, but we’re not really sure why. Also, they have mass — some are quite massive (relatively speaking), others have no mass (like a photon or electron). Moreover, photons traveling at the speed of light do not experience time or space. Is a photon ‘everywhere all the time’ or ‘nowhere none of the time’? Our language can’t really capture the state of affairs.
One theory on why there is mass is that while we know about electro-magnetic fields and in fact a variety of different fields, there could be a field we don’t know about, called the Higgs field. The Higgs field would permeate all of reality (i.e., the space-time reality we experience) and mass would come basically because things are slowed down by that field, much as how moving through air is easier than moving through molasses. If the field exists, a particle called the Higgs particle should be produced at the energies the new accelerator can achieve.
Since I’m not a physicist, I don’t want to get too deep into the science here. Rather, for me the interesting thing it to reflect on what all this means for understanding our world. First, the more I learn about modern physics and particle physics, the more I realize that the world we experience of solid objects that operate according to precise laws is more or less an illusion. Solid matter is almost completely made up of empty space, and all laws are probabilistic. There are other weird things such as non-locality (a particle can affect another particle a long distance away instantaneously, apparently sending information faster than the speed of light, something which should be impossible) and quantum tunneling. There is a absurdly low probability my computer could suddenly tunnel through my desk — that would require the zillions of particles to all at once do the improbable thing of tunneling simultaneously. But some tunneling does occur, our sun depends on it.
So what does this all mean? Back in 1991 I bought the book The Holographic Universe by Michael Talbot, and after having read it once I put it aside. Last spring I was talking to a friend, a former student here who transferred down to Georgetown, and she noted how she took a course with Karl Pribram, the 90 year old neurosurgeon who developed the idea of seeing the brain as a hologram. That caused me to recall the book (which discusses the ideas of Pribram and physicist David Bohm extensively), and start re-reading.
I’ve never felt comfortable with the notion that “things” are “out there” as separate objects from myself. First of all, experience itself is very subjective. It is a series of sensations which I interpret into pictures, sounds, smells, tastes and touches. The only reason we believe there is something external to ourselves is because of causality and lack of volitional control over our reality. I cannot choose to fly or stay young, aging and gravity will always pull me down. If I jump out my window, the fall will cause me injury or death. Therefore, how can there not be something external to myself which limits what my mind can experience, or what I can or cannot do?
From quantum physics, however, it seems that almost everything is possible, you simply have different probabilities. Moreover, the observer seems to matter. While some hold on to the interpretation that says everything is in a state of flux until it is observed, that seems a pretty weak assumption. What is meant by observe? Why is human observation/measurement so important? While one can simply accept it and do the calculations (well, I can’t do that kind of calculation!), it’s more plausible to believe that all exists in every probability at the same time. Probabilities may depend upon the way the universe is being looked at. And that’s where the hologram theory comes in.
Like a holographic image, you can get a lot from a little, and angles matter. Pribram looked at memory, and notes that memory doesn’t seem to be located within any particular place in a brain (coincidentally, I heard a story on NPR about how catepillars retain memories when they become moths, despite having their entire system, including the brain, essentially disintegrated during metamorphisis). Bohm saw the universe as much like an information stream, which we interpret, presumably from a particular angle or perspective.
What I like about all of this is how it meshes with the kind of philosophy I’ve been leaning towards: the absolute idealism of someone like Berkeley (for whom the ‘hologram’ is projected from the mind of God), and unity of all by people like Plotinus, or the eastern philosophies. Now, believing a controversial scientific theory because it complements my pre-existing philosophical biases isn’t likely to persuade others who hold different beliefs. Yet there is something about how this kind of image conforms to my experience of reality — not just the physical experience, but my subjective/intuitional experience — that is compelling. It also is far better able to deal with things like how photons do not experience time or distance, how subatomic particles seem to break down to being nothing more than ripples in fields. All of this, combined with quantum puzzles, the space-time continuum as an entity that is unified, etc., push towards a radically different view of reality than we’ve had before.
And, if ideas are the stuff of the universe, if our material reality is a kind of illusion that at some level we create, and if there is an interconnected unity to all of existence, what does that mean for our experience of life? I know for many that’s just an irrelevant tangent, a meaningless contemplation in a world where bills must be paid, people fight wars, and it’s obvious other people are different and there are a variety of things and elements in this world which we cannot control. I’m compelled to read more, think about these issues, and try to find their relevance to my life. After all, what’s the point in living if you don’t try to contemplate what this life is all about?! And it seems to me the more I think about these things and try to learn more about them, the easier it is to find some kind of satisfaction and happiness in my day to day routine. I’m not really sure why, but looking at the world this way works for me. But I’ll keep trying to learn, and eagerly await the new insights the LHC at CERN will present.