Maths – Page 2 – Me on the net

Choose! Choose now!

Life throws many choices in our way. One view of the world is that it is like a many branched pathway, with our every day choices causing us to thread a particular path though this maze of branches, to reach the ever growing tip of the tree of events that is our past.

The future is yet to come into being but we can see dimly into it, and we use this limited view to inform our choices. The view into the future is like a mist. Things appear dimly for a while only to fade and be hidden from view. Sometime in the future is the instant of our demise. We know it’s coming but we do not usually know how and when.

We try to compensate for our inadequate view of the future by trying to cater for all possibilities, and one way we do this is by making a will, to prescribe how we would like our things, our assets, to be distributed when we are dead.

Some people try to predict the future. Some people gamble, on horses or whatever, trying to guess the winner of a race. There are two sorts of such people, those who estimate the odds and then build in as much of a safety margin as they can. These are usually the ones who run the books, while the other sort take a more optimistic view and gamble that the bookmakers are wrong. The first group is generally happy to make small profits while the second group want high returns. Generally the first group does a lot better than the second group over a reasonably long time frame.

The interesting thing about choice is that it is a discrete thing. We choose from one or more possibilities and the number of those possibilities is an integer. Often it is a choice between option one or option two. Pretty obviously it isn’t option one point five.

If we have two possibilities, call them A and B, then the probability of A occurring might be thirty percent. This means that the probability of B happening is seventy percent. The two must always add up to one hundred per cent.

So there is a mapping here between discrete events and continuous probabilities. Between integers and real numbers. One way of looking at this is that “event A” is a sort of label to the part of the probability curve that represents the event. Or it could be considered that the probability of the event is an attribute of the event.

It could be that when a choice is made and the probability of making that is more probably than making the other choice then that it is similar to making a choice of road. One road is wide and one is narrow. The width of the road could be related to the probability of making that choice.

The width of the road or the probability of the choice may well be subjective of course. I might choose to vote for one political party because I have always voted for that party. The probability of me voting for that party is high. The probability of my voting for another party would be quite low. However for someone who is the supporter of another party, the road widths are the other way around.

Is it true that when I vote for the party that I usually vote for that I exercise a choice? Only in a weak way. Merely doing things the way that one has always done is just taking the easy way and involve little choice. The reason for taking the easy choice may be because one has always done it that way and there is no reason to change. Habit, in other words.

Most choices we make are similar. We have a set of in-built innate or learned reactions to most situations, so that we don’t have to trouble to make a choice. If you make a choice, if you drill down far enough you will find that there are always reasons for a choice that you make. Your father always voted for the party, so you do out of loyalty and shared beliefs.

Every choice, when you examine it, seems to just melt away into a mass of knee jerk reactions and beliefs. When you examine choices you find that there was in fact no other way that we were likely to choose and free choice doesn’t really exist.

We have all been to a fast food restaurant only to find that the person before us is unable to make up their mind. This is probably because they do not have strong preferences so that they don’t have any reason to choose one dish over the other, or they dislike all the dishes equally.

If we put people in a situation where they have no reason to prefer one course of action over another and we force them to make a choice, they will often think up ludicrous reasons for making the choice that they finally make.

For instance on game shows where they have to make a selection from a multiple choice question in a limited amount of time, quite often they will say something like “I haven’t pressed B in a while”, or “I guessed A last time and it worked out for me so I did it again”, even something like “It’s my boyfriends favourite colour.” It’s hard to know if they really used that reasoning or whether they are justifying their choice after the event.

Another way to cause people to make a random choice is to try and remove all distractions. I can envisage an experiment where people are placed in a room with a screen and two buttons. They are then told by a message on the screen to press the correct button within ten seconds and a count down starts. Since they have no knowledge of which is the correct button they will be forced to choose any button to press or to let the timeout expire. Then they will asked why they chose that particular button. The results of such a test would be interesting.

Two Hundred and Fifty

This post will be my 250th. 250 times approximation 1,000 words. A quarter of a million words. Wow. I didn’t think that I could do it. I hit the target. I reached the summit of Everest. I ran a marathon. And other similar metaphors for success.

Of course, I could be posting into a void. I see that I get, usually, a few dozen views for each post and some people are actually “following” me. I even, now and then, get a comment. I’ve done zero in the way of self promotion. I finish each post, figuratively pat it on its back and send it on its way, never to be seen again.

This doesn’t concern me. It seems that, for me, writing this blog is a bit like playing a piano in an empty room, or doing a jigsaw on the Internet. The reward is in the doing. I certainly feel a sense of achievement when I hit the “Publish” button, but I don’t often follow up on the post.

What I found amazing is my ability to ramble on for 1,000 words on any subject. I reckon that I could probably stretch any subject out to 1,000 words. In fact, I usually go over. Around the 300 to 400 word mark I’m wondering if I will reach the 1,000, and then suddenly I’m a couple of dozen words past the mark and wondering how to stop. Many times I will just stop so if you think I dropped a subject abruptly, you are probably right.

Some subjects have come up more than once. If you have been a regular reader you will have noticed themes running through my posts. There’s science, particularly physics and cosmology, there’s philosophy, there’s maths. I’ve tried to steer away from politics, but Trump has crept in there somewhere.

There’s weather, there’s seasons, there’s discussion on society, as I see it, and occasionally I discuss my posts themselves. These things are, obviously, the things that interest me, the things that I tend to think about.

Apparently I have 144 followers. That’s 144 more than I expected. I hope that some of them read my posts on a regular basis, but that’s not necessary. I hope that more dip in from time to time and find some interest nugget.

That sound disparaging to my followers, but that’s not my intent. My intent is to reflect on the realities of blogging. I follow other blogs, but I don’t read all the posts on those blogs. Maybe one or two of them I read pretty much every time the blogger posts a new post.

Someone's blog post — Someone’s blog post

That’s the reality of blogging I think. Millions of blog plots are published every day, and I reckon that very few of them are read by more than one or two people at the most. Some blogs strike the jackpot, though, and have millions of followers.

I’d guess that the big blogs are about politics in some shape or form, or fashion and fashion hints and tips. Maybe cooking? I’ve seen a few cooking blogs and they seem to be quite popular. Some big firms have taken to publishing a blog. Some people blog about their illnesses and their battles with it. The best of the latter can be both sad and uplifting.

You know the sort I mean? You go to the firm’s website and there’s a button or menu item that proudly proclaims “Blog”. When you look at the blog, it’s simply a list of what the CEO and board have been up to, or releases of new products, or sometimes posts about workers at the firm getting involved with the local community. All good earnest stuff, but scarcely riveting. I wonder how many followers they get? Probably about as many as me! I hope so. At least they are trying.

(Approaching 600 words of waffle. I can do it!)

Since I’m not doing a political blog, I don’t think that anything I post is controversial, which is probably reflected in the number of my followers. I don’t stir up any furores with my words on Plato’s Cave analogy, so far as I know. I get no furious comments about my views on Schrodinger’s Cat. “You should see what he says about Plato’s Cave! You must go on there and refute it!” Nah, doesn’t happen!

As I said, the low number of hits doesn’t worry me. It would be a hassle if suddenly my followers shot up to thousands, and I felt obligated to provide all these people an interesting post on a regular basis. As it is I can ramble on about prime numbers or the relationship between the different number sets and potentially only disappoint a few people. If any.

What have I learnt from all this blogging? That it is hard. It’s not just a matter of sitting down and blasting out a 1,000 words. Well sometimes it is, actually, but most times I grind it out in 100 word or so chunks. I aim to write the blog on Sunday and add pictures and publish on Monday.

Sometimes I miss the Monday deadline, out of sheer forgetfulness, mostly and pop it out on Tuesday or even later. Sometimes I forget to write my post until late on Sunday, but it is only rarely that I have to write it on Monday or even later. So far as I can tell, I’ve not completely missed a weekly post since the earliest days.

This is not the first blog I’ve tried to write. I had several goes before this one and I think that maybe this attempt “stuck” because I set out my aim to publish weekly early on. Maybe. It may also be the target of 250 posts that I set myself early on. Now I’ve achieved that goal.

So what next? I’ve not decided. I might stop now, or I might go on to 500. I may not know right up until the last minute. 500 posts is approaching 10 years of posts which seems a phenomenally long time. But then again, 250 posts is around 5 years of posts and I achieved that. We’ll have to see.

(As I sail past 1,000 words, I reflect that I can extract that many words from practically nothing. It seems to be a knack.)

Parallel worlds or a Continuum?

A cursory search on the Internet doesn’t tell me one way or another if Erwin Schrodinger owned a cat. Nevertheless he could have owned a cat, so the existence of Schrodinger’s actual cat is unknown to me. David Deutsch might possible argue that Schrodinger’s decision to own a cat or not own a cat resulted in two parallel worlds.

The above is obviously a play on the original scenario outlined by Schrodinger, the famous Schrodinger’s Cat thought experiment. The cat’s state before the box is opened is a strange state, referred to as a superposition, where the cat is both alive and dead. When the box is opened it is argued that this state is somehow resolved with cat being definitely alive or dead.

Suppose that we install a detector in the box with the cat which determines whether or not the cat is dead and notes the time when it dies. Does this resolve the paradox? After all, if the detector says that the cat died three minutes ago, then we now know exactly when the cat died.

This doesn’t resolve the issue, though, as the detector will also be in a superposition until the box is opened – we don’t know if it has been triggered or not. Of course, some people, including Schrodinger himself, are not happy with this interpretation, and it does seem that, pragmatically, the cat is alive until the device in the box is triggered and is thereafter dead.

However the equation derived by Schrodinger appears to say that the cat exists in both states, so it appears as if Schodinger’s “ridiculous case” (his words) is in fact the case. Somehow the cat does appear to be in the strage state of superposition.

If we look at the experimenter, he (or she) has no clue before opening the box whether the cat is dead or not. Nothing appears to change for him (or her), but in fact it does. He (or she) is unaware of the state of the cat, so he (or she) is in the superimposed state : He (or she) is unaware whether or not the cat is alive or whether it is dead, which is a superposition state.

Yet we don’t find this strange. If we remove the scientific gadgets from the box, this doesn’t really change anything – the cat may drop dead from old ages or disease before the box is open. Once again we cannot know the live/dead status of the cat until we open the box.

So, what is special about opening the box? Well, the “when” is very important if we consider the usual case with the scientific gadgets in the box. If we open the box early we are more likely to find the cat alive. If we open it later it is more likely that the cat will be dead. Extinct. Shuffled the mortal coil.

So it is the probability of atomic decay leading to the cat’s death that is changing. It may be 70% likely that cat is dead, so if we could repeat the experiment 1000s of times 7/10th of the time the cat is dead, and 3/10th of the time the cat is still alive. Yeah, cat!! (There’s also a possibility that the experimenter gets a whiff of cyanide and dies, but let’s ignore that.)

But after the box is opened, the cat is 100% alive or 100% dead. Apparently. How did that happen? Some people claim that something mysterious called “the collapse of the waveform” happened. I don’t think that really explains anything.

The same thing happens in the real world. If I don’t check my lotto tickets I’m in a superposition state of having won a fortune and not having won a fortune. When I check them I find I haven’t won anything. Again! I must stop buying them. They are a waste of money.

The many worlds hypothesis gets around this by postulating the splitting of the world into two worlds whenever a situation like this arises. After I check my lotto ticket there are two worlds, one where I am a winner and one where I am not. How can I move to the world where I’m a millionaire? It doesn’t seem fair that I stuck here with two worthless bits of paper. does it?

And what does the probability mean? In the lotto case it is 1 in an astronomical number that I come out a winner and almost 1 that I get nothing. In the cat case it may be 60/40 or 70/30, and in the cat case it changes over time.

If the world splits every time a probabilistic situation arises, then the probabilities don’t actually mean much. What difference does it make if a situation is “more probable” than another situation if both situations come about in the multiverse regardless? It doesn’t seem that it is a meaningful attribute of the branches. What does it mean, in this model that branch A is three times more likely than branch B? Somehow a continuum (probability) reduces to a binary choice (A or B).

We could consider that the split is not a split at all, but that reality, the universe, whatever, has another dimension, that of probability. Imagine your worldline, a worm travelling through the dimensions of space and the new one of probability. You open the box and lo! Your worldline continues, and the cat is now dead or alive, but not both.

But which way does it go? That is determined purely by the probabilities, by the throw of the cosmic dice, but once it chooses a path, then there is no other possibility. In the space dimensions you can only be in one place at a time. If you are at A you cannot be at B, and similarly in the probability dimension, if you are at P you cannot be at Q.

However any point P (the cat is still alive!) is merely a point on the probability line. There are an uncountable number of points where the cat is alive and also an uncountable number of points where the cat is deceased. But the ratio between the two parts of the line is the probability of the cat’s survival.

What is philosophy for?

English: A cropped version of Antonio Ciseri's... — English: A cropped version of Antonio Ciseri’s depiction of Pontius Pilate presenting a scourged Christ to the people. See: Eccehomo1.jpg for full version. (Photo credit: Wikipedia)

“What is truth?” Pilate asked of Jesus. Jesus had just asserted that he had come into the world to testify to the truth. Pilate used this to close off the conversation, as he knew that truth is exceedingly difficult to define, and that one man’s truth is another man’s falsehood.

We live in a world where politicians cite “alternative facts” to defend themselves when their statements are questioned. Hmm. This seems like a step on the road to fluid “truth” of the authorities in the book “1984”, but is more likely to be a scrambling attempt of the establishment to defend itself.

Philosophy is a means of addressing Pilate’s question and many many others that do not fall into the realm of science or of mathematics. What is real and can we know it? Can we know anything? Is there a God, and if so, why does he permit evil into His universe?

These are questions which fall into the realm of philosophy, as do others about the meaning of science and mathematics, and questions of ethics and morals.

Almost by definition, philosophical questions cannot be answered. The “What is truth?” one is a prime example. Will the sun rise tomorrow morning? Did the sun rise this morning? Is the sun risen at the moment? All of these questions can be pragmatically answered “Yes!” but probe a little deeper and the answer can appear less definite.

After all, we might remember the sun coming up this morning, but what if these are false memories. Or maybe what we see is a mere “virtual reality” fed directly to our brains. And just because the sun rose this morning, and the morning before, and so on, doesn’t mean that it will rise tomorrow. Maybe there is some as yet unknown physical event that will cause it not to rise. Maybe cause and effect are illusions and anything can happen.

We nowadays separate science and philosophy, but this was not always so, and science was once termed “natural philosophy“. The ancient Greeks would have been termed philosophers, but they dealt with such questions as what everything is made of. Some of their suggestions would seem quaint today, but they did suggest the concept of atoms.

At the time there was no way that any of their hypotheses, such as the atomic hypothesis, could be tested and some of them even thought that testing them was a bad idea. They meta-hypothesised that everything could be deduced simply by thought. They needed no experiments!

Atomic theory is now definitely in the realm of science. Biology too, and mathematics, though maths now has its own realm, apart from science. Anything that is in the realms of philosophy may find its way to the realm of science or maths.

What about things like ethics and morality? Surely these won’t ever move to the field of science? Well, maybe. I wouldn’t bet on it, though it may be a long time before there is an ethical Newton, a morality Einstein.

Science has made great grabs in recent times for the fields of behaviourism and in studies of human consciousness. These have been until recently the domain of philosophers alone. In a way, it might be better if we did not understand the way that people and societies and human consciousness work, because understanding things is the first step to control things. Let’s hope that the ethical Newton and the morality Einstein arrive before we know how to scientifically control people and societies.

Philosophic pondering on the way things are tend to be wild and diverse. We tend to think of such hypotheses as the multiple worlds theories as new and cutting edge, but Professor Pangloss in Voltaire’s 1759 book “Candide” proclaims that “all is for the best” in this “best of all possible worlds”, which implies that there are, or could be, other worlds where things might be different.

Of course, since there was no real divide between philosophy and science and maths in the early days, we can’t really say that science has taken over these philosophical topics, more that they have been hived off as science split from philosophy. Nevertheless, science is probing topics, such as the nature of reality, which definitely have a philosophical flavour to them. For instance, is the cat alive or dead, or maybe both?

The philosopher Zeno of Elea introduced some paradoxes which even today exercise the minds of philosophers and mathematicians. Basically, Zeno poses the question : How does one (or an arrow for that matter) move from point A to point B? There’s plenty on the Internet about these paradoxes, so I’m not going into them in detail, but essential the core of the problem is how to sum an infinite number of increasingly small intervals of space or time without the result becoming infinite.

Obviously Achilles does overtake the tortoise, the arrow does reach its target and it is possible to travel from A to B, but some people still think that science and maths have not yet solved these paradoxes, and there’s still a sliver of a problem for the philosophers. Arguments these days resolve more around whether the paradoxes have been resolved and therefore we can move from A to B, or are still in the realm of philosophers and therefore we cannot move from A to B!

When the Greek philosophers were thinking about atoms and what things are made of, there was no way to test the various theories out. When they were developing theories about the stars and other astronomical objects they had no way to test the theories out. However, eventually the “natural philosophers” like Newton, laid the basis for astronomical theories, and early chemists like Lavoisier laid the basis for the science of chemistry, which made use of the theory of atoms.

A scan of the first page of John Dalton's &quo... — A scan of the first page of John Dalton’s “A New System of Chemical Philosophy”, published in 1808. Please do not “update” the list with modern spellings. This is a historic list and the old spellings are intentional. Yes, it’s “carbone”, not “carbon”. (Photo credit: Wikipedia)

Philosophy exists because people like to ask questions like “What is beyond the end of the Universe?” or “If God made everything, who or what made God?” Or “How long is the hypotenuse of a right angled triangle with sides on one cm or one inch?” Or “Why is the ratio of the circumference to the diameter of a circle a fixed number and what is it?”

Philosophy exists to postulate parallel Universes, massive balls of fusing gas, and terrestrial planets complete with humans or maybe little green men. Its job is to wonder what lies beyond the bounds of science and what makes humans behave the way that they do, and whether or not God is dead. It is to ask the impossible questions. It is science’s job to prize these issues from the hands of the philosophers and answer them.



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A Sum of All the Parts

Cover of the Book Conscious Robots (Photo credit: Wikipedia)

Consciousness is fascinating and I keep coming back to it. It is personally verifiable in that a person knows that he or she is conscious, but it is difficult if not impossible to tell if a person is conscious from the outside.

When you talk to someone, you and that person exchange words. You say something, and they respond. Their response is to what you say, and it appears to show that the person is a conscious being.



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It’s not as easy as that, however, because it is conceivable that the person is a zombie (in the philosophical sense) and his or her responses are merely programmed reactions based on your words. In other words he or she is not a conscious being.

It seems to me that the best counter to this suggestion is that I am a conscious being and I am no different in all discernible ways from others. It is unreasonable to suggest I am the only conscious being anywhere and that all others are zombies.



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Of course this leaves open the suggestion that some people may be philosophical zombies, but that then raises the question of what the difference is, and how can one detect it. William of Occam would probably wield his razor and conclude that, if one can’t tell, one might as well assume that there are no zombies, as assuming that there are zombies adds a (probably) unnecessary assumption to the simple theory that all humans are conscious beings.

It follows that consciousness is probably an emergent phenomenon related to the complexity and functioning of the brain. It also follows that lower animals, such as dogs, cats and apes are also probably conscious entities, though maybe to a lesser extent that we are.

The only way we can directly study consciousness is by introspection, which is more than a bit dubious as it is consciousness studying itself. We can indirectly study consciousness by studying others who we assume to be conscious, maybe when they have been rendered unconscious by anaesthetics and are “coming round” from them.

In addition, consciousness can be indirectly studied using mind altering drugs or meditation. However we are mainly dependant on verbal reports from those studied this way, and such reports are, naturally, subjective.

Chemical Structure of LSD (Lysergic acid dieth... — Chemical Structure of LSD (Lysergic acid diethylamide) (Photo credit: Wikipedia)

When we introspect, we are looking inwards, consciously studying our own consciousness. There are therefore limits on what we can find out, as the question arises “How much about itself can a system find out?”

A system that studies itself is limited. It can find out some things, but not all. It’s like a subroutine in a bigger program, in that it knows what to do with inputs and it creates appropriate output for those inputs. Its sphere of influence is limited to those processes written into it, and there is no way for it to know anything about the program that calls it.

A subroutine of a larger program uses the lexical, syntactical and logical rules that apply to the program as a whole, though it may have its own rules too. It shares the concept of strings, number, and other objects with the whole program, but it can add its own rules too.

The Universe is like the subroutine in many ways. The subroutine has inputs and outputs and processes the one into the other. In this Universe we are born and we die. In between we spend our lives.



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An aware or conscious subroutine would know that it processes input and creates outputs, but it would have no idea why. We know that we are born, we live and we die. Apart from that we have no idea why.

This sort of implies that while we may use introspection to investigate some aspects of consciousness we will always fall short of understanding it completely. We may be able to approach an understanding asymptotically however – we might get to understand consciousness to the 90% level, so it would not be a total waste of time to study it.

Consciousness seems to be more than a single state, and the states seem to merge and divert without any actions on our part. For instance, when I am driving there is a part of me that is driving the car and a part of me that is route planning, and maybe a part of me that is musing on the shopping that I intend to do.

The part of me that is driving is definitely aware of what is happening around me. I don’t consciously make the decision to slow down when other traffic gets in the way, but the part of me that is driving does so.

Similarly the part that is route finding is also semi-autonomous – I don’t have to have a map constantly in my mind, and don’t consciously make a decision to turn right, but the navigator part of my consciousness handle that by itself.

Those parts of my mind are definitely conscious of the areas in which they are functioning, because if they were not conscious, they would not be able to do their job alone and would frequently need to move to the front of my consciousness disrupting my musing about my shopping.

It’s like part of my consciousness are carved off and allowed to perform their functions autonomously. However if an emergency should arise, then these parts are quickly jolted back into one.

The parts of my mind are definitely conscious as, at a low level, I am aware of them. I’m aware of the fact that I’m following that blue car, and I’m aware that I have to turn left in 200m or so. I’m also aware of my shopping plans, while I’m aware of the music on the radio.

Deutsch: Servicemenü des Blaupunkt Bremen MP74... — Deutsch: Servicemenü des Blaupunkt Bremen MP74 (Aktivierung: Gerät mit gedrückter “Programm1”- und “Menü”-Taste einschalten). Aktuelle Frequenz: 89,70 MHz (France Musique, Sender Luttange (Metz), PI-Code F203); aktuelle Suchlauffrequenz: 96,80 MHz (bigFM Saarland, Sender Friedrichsthal/Hoferkopf, PI-Code 10B2) (Photo credit: Wikipedia)

While it sounds scary that I’m not totally concentrated on my driving, I believe that this sort of has to happen. If I was totally concentrated on my driving, I would need to stop at every intersection so that I could decide which way to turn.

I would need have my shopping list completely sorted out, to the point of knowing which stores I am going to before even getting the car, and I would have to plan my route precisely. This would not allow for those occasions when passing by something or some shop reminds you that you need something that is not on your shopping list.

This splitting of consciousness allows us to perform efficiently. The only downside is that splitting things too much can result in us becoming distracted. And that is the reason we shouldn’t fiddle with the radio or use cellphones when driving.

The Space Between the Stars

Space is big. The Voyager spacecraft (Voyager I and II) were launched in 1977 and are, forty years later, only just entering interstellar space. Though the exact point at which space becomes “interstellar” is debatable.

The Voyagers will take 40,000 years or so to reach one of the stars in the “local” group. That’s about one fifth of the time that humans have existed as a separate species. Or 400 times as long as the length of time that a human is able to live. If a generation is around 20 years long, that is about 2,000 generations. It is a long, long time, and we may well be extinct as a species by then, for one reason or another.

The “local group” of stars is an arbitrary group of stars which are (relatively) close to the Sun. I’m unsure whether they really constitute a group of bodies bound by gravity or whether they are close to the sun by chance. Of course if any of the stars in the local group are bound by gravity, then the stars would form a binary or multiple star system.

Of course, our star and all the others in the local group are part of our galaxy, the Milky Way. Specifically we are part of one of the arms of the Milky Way, which is a spiral galaxy. All stars in the Milky Way are bound by gravity, with the possible exception of stars which are merely passing through the Milky Way at this time.

Just like stars, galaxies seem to form groups, which then form super-groups and so on. All these structures are several orders of magnitude larger than the prior smaller ones, are more complex and contain more matter.

The majority of space however is just space. The gaps between the bits of matter, stars, systems, galaxies, groups and so on contain almost nothing, or a seething sea of virtual particles depending on how you look at it.

The “almost nothing” consists of a very small number of particles (usually hydrogen atoms or nuclei, protons) in a cubic metre. For comparison the best vacuum that can be created on Earth may contain several million atoms in that volume. This of the same order of magnitude as molecular clouds as observed by astronomers. Molecular clouds are among the densest clouds observed in space.

The stars, planets, asteroids and similar bodies comprise only a very small part of the Universe and the average density of the Universe is much the same as the density of empty space. In other words, the Voyagers are heading into areas where the conditions are more typical of the Universe than those around our star.

Voyager 1 is currently within the heliosheath ... — Voyager 1 is currently within the heliosheath and approaching interstellar space. (Photo credit: Wikipedia)

I mentioned virtual particles earlier. While virtual particles show up as short-lived particles that briefly come into existence in some particle interactions, the virtual particles that I refer to come into existence in a vacuum as pairs and almost immediately mutually annihilate. Though they do not interact with other matter, they do have an effect which can be measured.

Mathematicians have a different concept of space. In mathematics space is a (usually) three dimensional construct that serves merely to separate and give structure to such things as points, lines, planes, volumes and shapes. Point A is distinguished from point B by the distance between them and also the orientation of a line joining them.



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In a simple case every point has (usually) three coordinates which define its position relative to some fixed point or origin and fixed coordinate system. The coordinate system can be any system that locates the point.

For instance, you can describe the point A’s position as “Face along a given axis, rise up until you are level with point A. The distance moved up is one coordinate. Rotate left through an angle until a line parallel to the plane you rose up from passes from you through the point A. The angle you turned through is the second coordinate. The third coordinate is the distance along the line from you to the point.

I’ve described a cylindrical coordinate system, but the coordinate system may be any system that gives three unique (in that system) coordinates for point A. A common system is the Cartesian system of three mutual perpendicular axes. Another is the spherical system, defined by two angles and a distance.

Of course, such systems can be generalised to more dimensions or fewer, depending on the needs of the mathematician. Most people can understand simple two dimensional graphs which are usually drawn using a two dimensional Cartesian coordinate system.

Of course scientists use mathematical models for various purposes. For instance the scientist may wish to know the probability of one hydrogen atom in the interstellar space meeting another such molecule. Since we have only about one such atom in every cubic metre, the probability is going to be small, but, of course, we can assume as lone a time period as we wish.

Gravity has to be figured in, to be sure, but a long time will be required for such atoms to collide. If the atoms are by chance moving slowly relative to each other, they may stick together and form the basis of a particle of matter. Such a clump might attract other atoms and before long (well actually after literally an astronomical length of time) a star will form.

It must have happened otherwise we would not be here. We are the result of matter aggregating and then exploding. All the atoms in our bodies that are not hydrogen were made in the centres of stars. The stars have to have exploded to allow these atoms to end up in our bodies.

A long time has passed since the birth of the Universe. In that time matter has crept together hydrogen atom by hydrogen atom until great collections of atoms have compressed in the centre to the point where nuclear reactions have occurred. Hydrogen fused to helium, then to heavier elements all the way up to Uranium.

Ball-and-stick model of the haem a molecule as... — Ball-and-stick model of the haem a molecule as found in the crystal structure of bovine heart cytochrome c oxidase. Histidine residues coordinating the iron atom are coloured pink to distinguish them from haem a. Colour code: Carbon, C: grey-black Hydrogen, H: white Nitrogen, N: blue Oxygen, O: red Iron, Fe: blue-grey Structure by X-ray crystallography from PDB 1OCR, Science (1998) 280, 1723-1729. Image generated in Accelrys DS Visualizer. (Photo credit: Wikipedia)

At which point the stars have exploded throwing all the elements out into the Universe. These elements then crept together again to produce new stars like our sun and gaseous and rocky planets orbiting them. Prior to this there were no rocky planets and no life. We live in the Universe Mark II.

Simple Arithmetic

There periodically appears on the Internet an arithmetic type of puzzle. Typically it will be a string of small natural numbers and a few arithmetic operations, such as “3 + 7 x 2 – 4” and the task is to work out the result.

The trick here is that people tend to perform such a series of calculations strictly from left to right, so the sequence goes:

3 + 7 = 10, 10 x 2 = 20, 20 – 4 = 16. Bingo!

Most mathematicians, and people who remember maths from school would disagree however. They would calculate as follows:

7 x 2 = 14, 3 + 14 = 17, 17 – 4 = 13. QED!

Why the difference? Well, mathematicians have a rule that states how such calculations are to be performed. Briefly the calculations is performed from left to right, but if a multiplication or division is found between two numbers, that calculation is performed before any additions or subtractions. In fact the rule is more complex than that, and a mnemonic often used to remember it is “BODMAS” or “BEDMAS” (which I’m not going to explain in detail here. See the link above).



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This rule is only a convention and so is not followed everywhere, so there are various “correct” answers to the problem. Also, there are still ambiguities if the conventions are applied which could cause confusion. However, most people with some mathematical training would claim that 13 is the correct answer.

Interestingly, computer programming languages, which are much stricter about such things, codify the precedence of operations in a calculation exactly, so that there can be no ambiguity. It is the programmers task to understand the precedence rules that apply for a particular language.

In most cases the rules are very, very similar, but it is the documentation of the language which describes the rules of precedence, and wise programmers study the section on operator precedence very closely.

There are ways of specifying an arithmetic problem uniquely, and one of those (which is sometimes of interest to programmers) is “Reverse Polish Notation“. Using this my original puzzle becomes “3 7 2 x + 4 -” which looks odd until you understand what is going on here.

Illustration of postfix notation (Photo credit: Wikipedia)

Imagine that you are traversing the above list from left to right. First you find the number “3”. This is not something you have to do, like “+”, “-“, “x” or “/”, so you just start a pile and put it on the bottom. The same goes for “7” and “2”, so the pile now has “3” on the bottom and “2” at the top and “7” in the middle.

Next we come across “x”. This tells us to do something, so we pull the last two things off the pile and multiply them (7 x 2 = 14) and stick the result, “14” back on the stack which now contains “3” and “14”. The next thing we find is “+” so we pluck the last two things off the pile “3” and “14” and add them, putting the result “17” back on the (empty) pile.



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Next up is “4” which we put on the pile, and finally, we have “-“, so we pull the two last elements from the pile (“17” and “4”) and subtract the second from the first, giving “13” (Yay!) and that is the answer which we put back on the stack. The stack now contains nothing but the answer.

This looks confusing, but that may be because we are used to the conventional left to right way of doing things. It is actually easier for a computer to understand the RPN version of the puzzle and there are no ambiguities in it at all. Technically, it’s a lot simpler to parse than the conventional version.

Image for use in basic articles dealing with p... — Image for use in basic articles dealing with parse trees, nodes, branches, X-Bar theory, linguistic theory. (Photo credit: Wikipedia)

Parsing is what happens when you type a command into a computer, or you type something complex, such as a credit card number into the checkout section of a web site. The computer running the web site takes your input and breaks it up if necessary and checks it against rules that the programmer has set up.

So, if you type 15 numbers or 17 numbers into the field for the credit card number, or you type a letter into the field by mistake, the computer will inform you that something is wrong. Infuriatingly, it may be not be specific about what the trouble is!

Español: Un Guru meditation en una amiga (Photo credit: Wikipedia)

Anyway, back to the arithmetic. It grates with me when people make simple arithmetical errors and then excuse themselves with the phrase “I never was much good at maths at school”! That may well be true, but to blame their problems with arithmetic of the whole diverse field of mathematics.

It’s like saying “I can’t add up a few numbers in my head or on paper because I missed the class on elliptic functions“! It’s way over the top. For some reason people (especially those who can’t get their head around algebra) equate the whole of mathematics with the bit that they do, which is the stuff about numbers, which is arithmetic.

As we evolved, we started counting things. It’s important to know if someone has got more beans than you or that you have enough beans to give everyone one of them. We invented names for numbers and names for the things (operations) we did on them.

We did this without much thought about what numbers actually are. We as a species have only relatively thought deeply about numbers fairly recently, and we only discovered such things as real numbers and geometry in the last couple of thousand years so it is not surprising that the average brain has yet to expand to cope with the more advanced mathematical concepts.

Graphic showing the relation between the arith... — Graphic showing the relation between the arithmetic mean and the geometric mean of two real numbers. (Photo credit: Wikipedia)

This could be why so many people these days equate fairly simple arithmetic with mathematics as a whole – our brains are only now coming to grips with the concept that there is more to maths than simply manipulating numbers with a very few simply operations.

It may be that the average human brain never will get to grips with more advanced maths. After all, people can survive and thrive in the modern world with on a rudimentary grasp of mathematics, the arithmetic part.

Some human brains however do proceed further and much of modern society is the result of mathematics in its wider sense applied to the things that we see around us. For instance, we could not have sent men to the moon without advanced mathematics, and technology relies heavily on mathematics to produce all sorts of things. It’s a good things that some brains can tell the difference between the field of arithmetic and mathematics as a whole.

Let’s be Rational – Realer Numbers

Leopold Kronecker said “God made the integers, all else is the work of man”. (“Die ganzen Zahlen hat der liebe Gott gemacht, alles andere ist Menschenwerk”). However man was supposedly made by God, so the distinction is logically irrelevant.

I don’t know whether or not he was serious about the integers, but there is something about them that seems to be fundamental, while rational numbers (fractions) and real numbers (measurement numbers) seem to be derivative.

English: Note: The irrational and rational num... — English: Note: The irrational and rational numbers make the set of real numbers. (Photo credit: Wikipedia)

That may be due to the way that we are taught maths in school. First we are taught to count, then we are taught to subtract, then we are taught to multiply. All this uses integers only, and in most of it we use only the positive integers, the natural numbers.

Then we are taught division, and so we break out of the world of integers and into the much wider world of the rational numbers. We have our attention drawn to one of the important aspects of rational numbers, and that is our ability to express them as decimal fractional numbers, so 3/4 becomes 0.75, and 11/9 becomes 1.2222…

The jump from there to the real numbers is obvious, but I don’t recall this jump being emphasised. It barely (from my memories of decades ago) was hardly mentioned. We were introduced to such numbers as the square root of 2 or pi and ever the exponential number e, but I don’t recall any particular mention that these were irrational numbers and with the rational numbers comprised the real numbers.

Why do I not remember being taught about the real numbers? Maybe it was taught but I don’t remember. Maybe it isn’t taught because most people would not get it. There are large numbers of rational accountants, but not many real mathematicians. (Pun intended).

In any case I don’t believe that it was taught as a big thing, and a big thing it is, mathematically and philosophically. It the divide between the discrete, the things which can be counted, and the continuous, things which can’t be counted but are measured.

The way the divide is usually presented is that the rational numbers (the fractions and the integers) plus the irrational numbers make up the real numbers. Another way to put it, as in the Wikipedia article on real numbers, is that “real numbers can be thought of as points on an infinitely long line called the number line or real line”.

Collatz map fractal in a neighbourhood of the ... — Collatz map fractal in a neighbourhood of the real line (Photo credit: Wikipedia)

Another way to think of it is to consider numbers as labels. When we count we label discrete things with the integers, which also do for the rational numbers. However, to label the points on a line, which is continuous, we need something more, hence the real numbers.

Real numbers contain the transcendental numbers, such as pi and e. These numbers are not algebraic numbers, which are solutions of algebraic equations, so are defined by exclusion from the real numbers. Within the transcendental numbers pi and e and a quite large numbers of other numbers have been shown to be transcendental by construction or argument. I sometimes wonder if there are real numbers which are transcendental, but not algebraic or constructible.

A rather sexy image of Pi from the german wiki... — A rather sexy image of Pi from the german wikipedia. (Photo credit: Wikipedia)

The sort of thing that I am talking about is mentioned in the article on definable real numbers. It seems that the answer is probably, yes, there are real numbers that are not constructible or computable.

Of course, we could list all the constructible real numbers, mapped to the real numbers between 0 and 1. Then we could construct a number which has a different first digit to the first number, a different second digit to the second number and so on, in a similar manner to Cantor’s diagonal proof, and we would end up with a number that is constructed from the constructible real numbers but which is different to all of them.

I’m not sure that the argument holds water but there seems to be a paradox here – the number is not the same as any constructible number, but we just constructed it! This reminds of the “proof” that there are no boring numbers.

So, are numbers, real or rational, just labels that we apply to things and things that we, or mankind as Kronecker says, have invented? Are all the proofs of theorems just inventions of our minds? Well, they are that, but they are much more. They are descriptions of the world as we see it.

Whether or not we invented them, numbers are very good descriptions of the things that we see. The integers describe things which are identifiably separate from other things. Of course, some things are not always obviously separate from other things, but once we have decided that they are separate things we can count them. Is that a separate peak on the mountain, or is it merely a spur, for example.

Other things can be measured. Weights, distances, times, even the intensity of earthquakes can be measured. For that we of course use rational numbers, while conceding that the measurement is an approximation to a real number.

A theorem represents something that we have found out about numbers. That there is no biggest prime number, for example. Or that the ratio of the circumference to the diameter is pi, and is the same for all circles.

We certainly didn’t invent these facts – no one decided that there should be no limit to the primes, or that the ratio of the circumference to the diameter of a circle is pi. We discovered these facts. We also discovered the Mandlebrot Set and fractals, the billionth digit of pi, the bifurcation diagram, and many other mathematical esoteric facts.

It’s like when we say that the sky is blue. To a scientist, the colour of sunlight refracted and filtered by the atmosphere, peaks at the blue wavelength. The scientist uses maths to describe and define the blueness of the sky, and the description doesn’t make the sky any the less blue.

The mathematician uses his tools to analyse the shape of the world. He tries to extract as much of the physical from his description, but when he uses pi it doesn’t make the world any the less round as a result. Mathematics is a description of the world and how it works at the most fundamental level.

English: Adobe photoshop artwork illustrating ... — English: Adobe photoshop artwork illustrating a complex number in mathematics. (Photo credit: Wikipedia)

[I’m aware that I have posted stuff on much the same topic as last time. I will endeavour to address something different next week].

Rational versus real

(My last post was very late because I had taken part in a 10km walk on the Sunday and spent the week recovering.)

There’s a fundamental dichotomy at the heart of our Universe which I believe throws some light on why we see it the way we do. It’s the dichotomy between the discrete and the continuous.

A rock is single distinct thing, but if you look closely, it appears to be made of a smooth continuous material. We know of course that it is not really continuous but is constructed of a mesh of atoms each of which is so small that we cannot distinguish them individually, and which are connected to each other with strong chemical and physical bods.

An early, outdated representation of an atom, ... — An early, outdated representation of an atom, with nucleus and electrons described as well-localized particles on well-localized orbits. (Photo credit: Wikipedia)

If we restrict ourselves to the usual chemical and physical processes we can determine to a large extent determine what the atoms are which comprise the rock, and we can make a fair stab at how they are connected and in what proportions.

We can explain its colour and its weight, strength, and maybe its magnetic properties, even its value to us. (“It’s just a rock!” or “It’s a gold nugget!”) We have a grab bag of atoms and their properties, which come together to form the rock.

English: Gold :: Locality: Alaska, USA (Locali... — English: Gold :: Locality: Alaska, USA (Locality at mindat.org) :: A hefty 63.8-gram gold nugget, shaped like a pancake. Very beautiful and classic locality nugget. 4.5 x 3 x 0.6 cm Deutsch: Gold :: Fundort: Alaska, Vereinigte Staaten (Fundort bei mindat.org) (Photo credit: Wikipedia)

The first view of atoms was that they were indivisible chunks with various geometric shapes. This view quickly gave way to a picture of atoms as being small balls, like very tiny billiard balls. Then the idea of the billiard balls was replaced by the concept of the atom as a very tiny solid nucleus surrounded by a cloud of even tinier electrons.

Of course the nucleus turned out not to be solid, but to be composed of neutrons and protons, and even they have been shown to be made up of smaller particles. Is this the end of the story? Are these smaller particles fundamental, or are they made up of even smaller particles and so on, “ad infinitum”?

It appears that in Quantum Physics that we have at least reached a plateau, if not the bottom of this series of even smaller things. As we descend from the classical rock, through the smaller but still classical atoms, to the very, very small “fundamental” particles, things start to get blurry.

The electron, probably the hardest particle that we know of, in the sense that it is not known to be made up of smaller particles, behaves some of the time as if it was a wave, and sometimes appear more particle like. The double slit experiment shows this facet of its properties.

Diagram of the double-slit experiment (Photo credit: Wikipedia)

The electron is not unique in this respect, and in fact the original experiments were performed with photons, and scientists have performed the experiment even with small molecules, showing that everything has some wave aspects, though the effect can be very small, and is for all normal purposes unnoticeable.

A wave as we normally see it is an apparently continuous thing. As we watch waves rolling in to the beach we don’t generally consider it to consist of a bunch of atoms moving up and down in a loosely connected way that we call “liquid”. We see a wave as distributed over a breadth of ocean and changing in a fairly regular way over time.

At the quantum level particles are similarly seen to be distributed over space and not located at a particular point. An electron has wave like properties and it has particle like properties. Interestingly the sea wave also has particle like properties which can be calculated. Both the sea wave and the electron behave like bundles of energy.

You can’t really say that a wave is at this point or that point. A water may be at both, albeit with different values of height. If the wave is measured at a number of locations, then by extension it has a height in between locations. This is true even if there is no molecule of water at that point. The height is in fact the likely height of a molecule if it were to be found at that location.

By analogy, and by the double slit experiment, it appears that the smallest of particles that we know about have wave properties and these wave properties smear out the location of the particle. It appears that fundamental particles are not particularly localised.

It appears from the above that at the quantum level we move from the discrete view of particles as being individual little “atoms” to a view where the particle is a continuous wave. It points to physics being fundamentally continuous and not discrete.

There’s a mathematical argument that argues against this however. Some things seem to be countable. We have two feet and four limbs. We have a certain discrete number of electrons around the nucleus of an atom. We also have a certain number of quarks making up a hadron particle.

Other things don’t appear to be countable, such as the positions a thrown stone can traverse. Such things are measured in terms of real numbers, though any value assigned to the stone at a particular instance in time is only an approximation and is in fact a rational number only.

At first sight it would appear that all we need to do is measure more accurately, but all that does is move the measurement (a rational number) closer to the actual value (a real number). The rational gets closer and closer to the real, but never reaches it. We can keep increasing the accuracy of our measurement, but that just gives us a better approximation.

It can be seen that the set of rational numbers (or the natural numbers, equivalently) maps to an infinite subset of the real numbers. It is usually stated that the set of real numbers contains the rational numbers. I feel that they should be kept apart though as they refer to different domains of numbers – rational numbers are in the domain of the discrete, while the real numbers are in the domain of the continuous.

Numbers are fascinating

Numbers fascinate me. What the heck are they? They seem to have an intimate relationship with the “real world”, but are they part of it? If I heave a rock at you, I heave a physical object at you. If I heave two rocks at you, I heave real objects at you. It’s a different physical experience for you, though.

If I heave a third rock at you, again, it’s a different qualitative experience. It’s also a different qualitative experience from having one rock or two rocks thrown at you.

Numbers come in three “shapes”. There are cardinal numbers, which answer questions like “How many rocks did I throw at you?” There are ordinal numbers, which answer questions like “Which rock hit you on the shoulder?” Finally there are nominal numbers, which merely label things and answer questions like “What’s you phone number?”

As another example, in the recent 10km walk which I took part in, I came sixth (ordinal) in my age division. That sounds good until I admit that there were only seven (cardinal) entrants in that division. Incidentally, my bib number was 20179 (nominal).



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Cardinal numbers include the natural numbers, the integers and the rational numbers and the real numbers (as well as more esoteric numbers). For instance the cardinal real number π is the answer to the question “How many times would the diameter fit around the circumference of a circle?”

It’s a bit more difficult to relate ordinal numbers with real numbers, but the real numbers can definitely be ordered – in other words a real number ‘x’ is either bigger than another real number ‘y’, or vice versa or they are equal. However, there are, loosely speaking, more real numbers than ordinals, so any relationship between ordinal numbers and real numbers must be a relationship between the ordinal numbers and a subset of the real numbers.

English: Example image of rendering of ordinal... — English: Example image of rendering of ordinal indicator º Italiano: Immagine esemplificativa della resa grafica dell’indicatore ordinale º (Photo credit: Wikipedia)

Subsets of the real numbers can have ordinal numbers associated with them in a simple way. If we have a function which generates real numbers from a parameter, and if we feed the function with a series of other numbers, then the series of other numbers is ordered by the way that we feed them to the function, and the resulting set of real numbers is also ordered.

So, we might have a random number generator from which we extract a number and feed it to the function. That becomes the first real number. Then we extract another number from the generator, feed it to the function and that becomes the second real number, and so on.

The random map generator provides a limitless ... — The random map generator provides a limitless supply of colourful terrains of various themes. Open island maps, like this one, allow players to use airstrikes. Cavern maps have an indestructible roof which cannot be passed. (Photo credit: Wikipedia)

What we end up doing is associating a series of integer ordinal numbers with the generated series of real numbers. These ordinal numbers are associated with the ordered set of real numbers that we create, but the real numbers don’t have to be ordered in terms of their size.

Nominal numbers such as my bib number are merely labels. They may be generated in an ordered way, though, as in the case of my bib number. If I had registered a split second earlier or later I would have received a different number. However, once allocated they only serve to show that I have registered, and they also show which event I registered for.



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On the occasion that I took part there were two other events scheduled : a 6.5km walk and a half marathon. My bib number indicated to the marshals and officials which event I was taking in and which way to direct me to go.

I’m not a mathematician, but it seems to me that ordinal numbers are more closely aligned to the natural numbers, the positive integers, than to any other set of numbers. You don’t think of someone coming 37 and a half position in a race. Indeed if two people come in at the same time they are conventionally given the same position in the race and the next position is not given.

There’s a fundamental difference between natural numbers or the integers, or for that matter the rational numbers and the real numbers. The real numbers are not countable : they can’t be mapped to the natural numbers or the integers. The rational numbers can, so can be considered countable. (Once again, I’m simplifying radically!)

Natural numbers and integers are related to discrete objects and other things. The number of dollars and cents in your bank account is a discrete amount, in spite of the fact that it is used as real number in the bank’s calculations of interest on your balance. If I toss two rocks at you that is a discrete amount.

English: Causal loop diagram (CLD) example: Ba... — English: Causal loop diagram (CLD) example: Bank balance and Earned interest, reinforced loop. Diagram created by contributor, with software TRUE (Temporal Reasoning Universal Elaboration) True-World (Photo credit: Wikipedia)

Even I tip a bucket of water over you, I douse you in a discrete number of water molecules (plus an uncertain number of other molecules, depending on how dirty the water is). However the distance that I have to throw the water is not a discrete number of metres. It’s 1.72142… metres, a real number.

At the level at which we normally measure distances distances don’t appear to be broken down into tiny bits. To cover a distance one first has to cover half the distance. To cover half the distance one must first cover one quarter of the distance. It is evident that this halving process can be continued indefinitely, although the times involved are also halved at each step.



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This seems a little odd to me. Numbers are at the basis of things, and while numbers are not all that there is, as some Greek philosophers held, they are important, and, I think, show the shape of the Universe. If the Universe did not have real numbers, for example, then it would be unchanging or perhaps motion would be a discrete process, like movements on a chess board.

If the Universe did not have any integers, the concept of individual objects would not be possible, since if you could point at an object you would have effectively counted “one”. In other words we need the natural numbers so that we can identify objects and distinguish one from one another, and we need the real numbers so that we can ensure that the objects don’t all exists at the same spot and are, in fact separated from one another.