I don’t know how long this is going to be because it’s a bit of a thought dump, which actually everything on here is supposed to be, so this is actually more in the spirit of the intention of this blog than usual, to some extent. Then again, most of what I put on here is a bit like that – unstructured stream of consciousness stuff with a small readership.
But someone has said something which has made me think, and I was already thinking about this. They were concerned that they might be a figment of the imagination.
Let’s start from the beginning.
Everything used to be in the same place. Then something happened and things started being in different places. Supposèdly, anyway. This was the Big Bang. I’ve just come out of the other side of a phase of not believing in the Big Bang but now I think it probably did happen because it was preceded by a infinitely long period of time going backwards. The reason I didn’t believe in the Big Bang was that given that time is eternal and the conditions of the Big Bang can arise spontaneously by quantum events at any time, very improbably, the chances of being within measurable distance of the beginning of the Universe are zero. This is, incidentally, not the same as impossible. Infinitely improbable events happen all the time. If someone were to flip a coin forever the sequence of heads and tails they produce would have a probability of zero but it would have to be a particular sequence, and the Universe, in some places, does kind of consist of a figurative coin being flipped forever in the sense that there are random quantum fluctuations. However, there are infinitely more of these random fluctuations than the actual event they mimic, so you can be certain that we are not near the beginning of the Universe. However, the idea that we are in a habitable period of the Universe’s history is entirely different. In this case we’re not near the beginning, just near an event following the collapse (backwards expansion actually) of the Universe followed by a Big Bang, which probably happens a lot. This is fine because it eliminates the possibility of us being infinitely special. We’re just living in the period where it’s possible for us to exist instead, and so now I kind of believe in the Big Bang again.
Yesterday I mentioned cosmic strings. Since I’ve only just said what they are, or what I think they are, I’m going to go into that again just briefly this time. Cosmic strings are basically wrinkles or cracks in space which didn’t collapse down to the three dimensions we’re familiar with nowadays but stayed more like the early Universe, and as such are either very massive or very “anti-massive” and tend to warp space. This depends on string “theory” because of the extra dimensions, or rather it’s related to it. This made me wonder if it’s actually more than this. I should point out here that this is now just me, a philosopher and herbalist, thinking and not a physicist.
Up until I was thirteen, I used to believe that fermions were tiny vortices in space time, and that bosons, including light, were gravitational waves. Just to explain that briefly, bosons carry force and fermions are stuff, such as protons, neutrons and electrons. This happens to be similar to a nineteenth century theory of atoms that they were vortices in the æther, which was the medium believed to carry light. At this time, I seemed to have been assuming that space was a thing rather than a relationship, because presumably if something could swirl about it had to be something.
I was at some point disabused of this model by my physics teacher. Incidentally, to get a bit home-eddy (geddit?), this was the same physics teacher who inadvertently killed my interest in physics after an optics lesson about refractive indices, which by that point I’d known about for more than half my life, when I asked him why anything was transparent and he said “you don’t need to know that at O-level”, the problem being that he was of course constrained by time and resources to teach O-level physics and was therefore unable to help me pursue my highly motivated curiosity. Nowadays I still have no idea why some matter is transparent and some opaque. It would make sense to me if everything was opaque or everything transparent, and I can to some extent understand translucency, but I don’t understand why there’s a difference. Also, I only understand structural colour. I get that some atoms absorb or emit certain wavelengths of electromagnetic radiation when their electrons change energy level, but beyond that I get stuck. This has been going on for more than three dozen years now and it really bugs me sometimes.
It’s important to be aware of the patterns one’s mind tends to fall into because of how it’s predisposed to function. For instance, as a child I used to have a habit of trying to imagine two-dimensional phenomena in three or more dimensions. This initially gave me a frisson of intellectual superiority but after a short while I got worried that I was falling into a rigid mental tendency in this area. This, of course, was the mind of a nine year old child, so perhaps it reflects a developing brain rather than some ingrained issue. Nonetheless, it’s helpful to be suspicious of one’s own thought processes and try to step outside them sometimes, although literally speaking that’s impossible as one is still having thoughts about having thoughts. But it’s about self-awareness, and that’s definitely important. I bring this up because what I’m about to say seems quite like my childish vortex notion of matter.
Cosmic strings are supposed to be pinched-up wrinkles in space. They form into loops when they intersect with themselves, so presumably by now there are loads of looped strings around the Universe formed from former strings, and for all I know they also merge and become bigger strings or loops once again. But also, I couldn’t help thinking that these enormous strings, some gigaparsecs long apparently, really sound like superstrings, and that maybe at some other juncture in the early Universe after the Big Bang space was just really scruffed up and wrinkly, and this led to the formation of elementary particles, perhaps as different knots or maybe vibrating at different rates, which were nothing other than really tiny cosmic strings or loops. I would like to believe that this is what string theory is, but to be honest I have no idea at all other than the stuff in my own head, so I dunno, maybe. Little loops of vibrating multidimensional space?
I am purposely avoiding doing any research for this post. I’m as interested in the process giving rise to my thoughts, and therefore those of other people, as I am in the ideas themselves here, and I don’t want to set off the “someone else’s idea” alarm, so I’m not reading up on this right now.
What is the nature of space-time? Space stops everything from being in the same place and time stops everything from happening at once. There are other ways of measuring things based on space and time, such as temperature and weight. The absolute temperature scale begins at the lowest possible temperature, and it works like this. It was discovered that at the freezing point of water a gas had a particular volume, which was 1/273 smaller at -1°C, 2/273 smaller at -2 and so on, so the question arose, what happens at -273? It’s actually -273.15, but that would involve more accurate measurement than was possible at the time. The answer is quite simple. It always takes the same energy to reduce temperature by a certain proportion, or alternatively, the same energy is always lost when temperature goes down by the same proportion, so reducing temperature from 100°C to about -86°C, which is halving the temperature from 373 to 186.5 above absolute zero, takes as much energy as reducing it from -273.14°C to -273.145°C, so absolute zero can never be reached. Hence there are no negative absolute temperatures. Not every quantity measured can be negative. Mass might be an example of this. Nonetheless it makes sense to think of temperatures as located along a line, and the differences between them as measured along this line. After all, that’s what a thermometer is. Likewise with weight and a spring balance, the weight of an object is measured along a line. We abstract these quantities in terms of a dimension.
Now a ruler could be the same kind of device, as could a protractor. They measure something, but that doesn’t make that thing any more of a “thing” than temperature, weight or pressure. Length, width and breadth are quantities along with direction, and from those we abstract the idea that there is a “thing” called space, and likewise from clocks, stopwatches and calendars we abstract the idea of the quantity we measure with those into a “thing” called time, and of course the two are related, and they do exist, but maybe they’re not things.
Why would it be a good idea not to think of space-time as a thing?
There’s a question which seems to betray a misunderstanding of the nature of space and time yet is constantly asked: what is the Universe expanding into? The reason this question gets asked is probably due to the idea of the expanding Universe being illustrated as an inflating balloon, which makes it sound like there is a larger, higher dimensional hyperspace into which the Universe is expanding. I’ve long maintained that this isn’t so. In fact the idea of the expanding Universe is that the maximum possible distance between two points is always increasing, and that beyond a certain distance the direction of an object reverses. This is true on a spherical surface if you think of it as flat, but for different reasons, so for example the maximum possible distance between two locations on Earth is (almost by definition) 20 000 km, and if you are on the equator and someone else near your antipodes is walking West, they will be East of you once they pass it. In the case of the Universe, however, it’s a property of space implied by geometry not being Euclidean and space is not a “thing” in the same way as Earth’s surface is. Consequently, although the Universe seems to have the topology of a hypersphere, there is no geometrical real hypersphere corresponding to that topology.
Or so I thought. I should point out that not everyone thinks this way. There is a thing called “‘brane theory”, where “‘brane” is short for “membrane”. According to this theory, there really is a hyperspace in which this universe and many others are expanding, and when they touch and cross each other new universes are made. Incidentally you should check that – I’m not looking anything up for the purposes of this exercise, but I think that’s what brane theory is. It’s also an amusingly similar word to “brain”, which is an intrinsically funny word. If brane theory is correct, that really is what the Universe is like and space is actually a thing.
Now to get back to superstring theory, which I admit I may have got completely wrong. If particles are superstrings, and superstrings are topological defects in the same way as cosmic strings are, then all matter is, is swirly bits of space, and the problem with that is that if space and time are not really “things”, there’s nothing to swirl and nothing to be anywhere or happen at a particular time, and there just is no time or space. So, huh? Does this mean that space-time is actually a thing, or just that I have misunderstood superstrings? Or, does it mean string theory is flawed? Probably not the last one.
A Box Of Chocolates 