Pointing the Camera at the Monitor – An Answer

Here are my answers to the puzzle about what happens when we point a camera at its monitor. The problem has a flavour of infinite regress about it, and sounds a little like a Buddhist koan – a question designed to make us realise (amongst other things) the limitations of logic. But whereas a ‘correct’ answer to a koan is usually something bizarre like barking like a dog, or hitting the questioner with a stick, the four questions I posed do actually have perfectly logical answers. And I find them quite interesting.

Let’s kick things off by showing a picture of what one might see when one looks into the webcam that is perched on top of the monitor, looking outwards. This is a screenshot of what my monitor showed when I did that (Figure 1).

figure-01-q0a-screenshot-cheese-bear-non-max

The image is framed within the window labelled ‘Cheese’ – which is the name of the webcam program I was using. That’s me wearing the red cravat.

Question 1

When we turn the camera around and point it at the monitor, we will see an infinite regress of windows within windows, as the whole picture will be reduced and fitted into the image area where I am above. Then that reduce-and-insert step will be repeated as many times as it takes until the reduced image gets down to a single pixel and can contain no more strip-images. Here’s an image I made of what it should look like (Figure 2):

figure-02-q1_image

In every window, the green desktop background, the desktop icons and the file explorer window to the left are reproduced, and the series shrinks off into the distance. I can tell you it was pretty fiddly putting the tiniest innermost parts into that picture. Infinitely small objects are notoriously difficult to manipulate.

The picture looks a little like a classical picture that uses perspective to show a long, straight road disappearing into the distance, with the point of disappearance at which all the lines converge being in the top-right quadrant of the screen.

But there’s an important and fascinating difference: the dimension along which the images disappear here is of time, not distance. That’s because each nested window is an image captured by the camera’s sensor a short interval earlier than the window that contains it. That interval will vary slightly as we move through the nested sequence, based on the relationship between the rate at which the monitor screen is redrawn (the ‘refresh rate’) and the number of snapshot images captured per second by the camera sensor (the ‘frame rate’). But it will always be more than some minimum value that depends on how long the information takes to travel along the wire from the sensor, through any processor chips in the camera, along another wire to the computer, through any processing algorithms in the computer, and then through the video cable to the monitor. Even without knowing anything about the computer, we know that that time – called the ‘lag’ – will be greater than the lengths of the wires involved, divided by the speed of light (because electrical signals cannot travel faster than light).

So each nested window is earlier than the one outside it, and as we look through the sequence of windows towards the point of convergence at infinity, we are looking back through time!

Question 2

Now we maximise the Cheese window. First let’s see what it looks like with the camera the correct way around, pointing at me (Figure 3):

figure-03-q0b-screenshot-bear-maximised

You can tell from my expression that I’m quite enjoying this little exercise, can’t you?

Here there is nothing outside the Cheese frame, but the Cheese frame still has a broad, non-image bar at the bottom, a narrower bar at the top, and black vertical bars at either side, which are needed to preserve the image’s ‘aspect ratio’ – the ratio of its width to its height.

With that setting, we turn the camera on the monitor, and this is what we would see (Figure 4):

figure-04-q2_image

The lower, upper, left and right bars are reproduced as a series of receding frames, and there is nothing in view other than the receding frames. There is no room left for an actual image of anything other than frames.

Figure 4 gives an even better sense of the ‘time tunnel’ that we mentioned in the previous section. Those white borders really do regress away in a spooky way. It looks like something out of Doctor Who.

The ratio of the height of one window to the height of the window immediately inside it is 1/(1-p) where p is the sum of the heights of the upper and lower margins of the outermost window divided by the total height of the outermost window. The ratios of the widths is the same. In this case it looks like p is around 1/5, so each window will be about 4/5 of the height of the window that contains it.

I used my webcam and shaky hands to try an empirical verification of this. I maximised the Cheese window and, pointed the hand-held webcam at the monitor, centering it as closely as I could. Then I asked my partner to press the Screenshot button on the keyboard to record what the monitor was showing. Below is what we got (Figure 5).

figure-05-q2-empirical-non-full-screen

It’s a bit rough, but you can see it does the same sort of thing as Figure 4.

When one is holding the camera like this, the little involuntary movements one makes cause the trail of receding frames to wobble left and right in waves, that remind me of the effects used in 1970s television to produce a psychedelic impression – particularly prevalent in rock music film clips.

Here’s a link to a video I captured of this effect.

Question 3

Question 3 asks what we will see on the monitor after we click the full-screen icon.

When we click the full-screen icon, we have no borders, so there can be no infinite, reducing regress of nested borders. How can we work out what is shown, assuming that we started in non-full-screen mode with a maximised window, so that the monitor was showing Figure 4?

The answer turns out to be remarkably simple. We just note that, when the full-screen icon is clicked, the computer will do some computing and then redraw the screen using the whole monitor area for the image from the camera. When it has finished the computing it will draw the screen using the image received most recently from the sensor and, since that image was captured before the screen redraw, it will be the same as whatever the screen was showing previously. This assumes that the previous image is left in place on the monitor until the computer is ready to draw the new one. We consider later on what happens if that is not the case.

That re-drawn screen will then be captured again by the camera sensor, sent to the computer and then drawn again on the monitor, and so on. So the image will remain exactly as it was before the full-screen icon was clicked! In this case, since the Cheese window was previously maximised, it will continue to show something like Figure 4.

The image remains static until either the camera is pointed away or the computer is switched out of full-screen mode, using the keyboard or mouse. Barring earthquakes, electricity blackouts and such-like, we would expect the monitor to still be displaying Figure 4 if we locked the room it was in, went away and returned to inspect it ten years later.

We can understand this a different way by considering the time tunnel we talked about in the responses to questions 2 and 3. In those cases, as we travel inwards through the tunnel to successively smaller windows, each window’s image was captured a short while earlier than the image of the window around it. The interval between the capture time of those windows will be much less than a second, typically 1/24 seconds. In Figure 4 each window’s height is about 4/5 of the height of the window that contains it. So to see what the monitor was showing t seconds ago we have to go to the nth window in the sequence, counting from the outside, where n=24t. The height of that window, assuming the height of the monitor’s display area is 300mm, is 300 x 0.8-24t mm. The window size reduces rapidly as we go back through time. A little calculation shows that the 26th window in the sequence is the first to have height less than 1mm, and that window shows what the monitor was showing just over one second earlier.

Without constraint, that time tunnel would continue to go back, getting smaller at an increasing rate, window by nested window (like Russian dolls, or the cats in the Cat in the Hat’s hat), until we got to the time before the camera program window was opened on the computer, and that image would show whatever was on the monitor before the window was opened. But it would be indescribably tiny. If we opened the window – in maximised form – five minutes ago, the height of the window that now showed that image from back then would be 300mm x 0.8–7200, which is approximately 10-688 mm. This is indescribably smaller than the smallest atom (Hydrogen, with diameter 10-7 mm) or even just a proton (diameter 10-11 mm).

I expect our eyes probably could discern no more than the first twenty windows in the sequence. Further, since my screen has about three pixels per mm, the windows would reach the size of a single pixel by the 31st window in the sequence, and the regress would stop there. Hence the sequence would look back in time no more than 1.3 seconds.

When we move to full screen mode, we still have a time tunnel of nested windows, but each one is exactly the same size as the one before it – the height ratio is 1, rather than 0.8. That means that how far we look back in time is no longer limited by shrinking to the size of a pixel, and the sequence will go all the way back to the last image the monitor showed before drawing its first screen in full-screen mode – which will be Figure 4.

In practice, as my friend Moonbi points out, the slight distortions in the image arising from imperfections in the camera lenses, although they may be imperceptible at first, will compound on each other with each layer of nesting so that what is actually shown will be a distorted mess. Like a secret whispered from one person to another around a large circle, or a notice copied from copies of itself dozens of times recursively, the distortions – however tiny they may be at first – will grow exponentially to eventually dominate and destroy the image. One minute after full-screen mode has been commenced, the monitor will be showing a 600 times recopied image of Figure 4, which will be more than enough to obliterate the image.

But this is a thought experiment, so we allow ourselves the luxury of assuming that are lenses are somehow perfect, that there is zero distortion, and each copy is indistinguishable from the original.

What if the screen blacks out?

Above we assumed that the display does not change until the computer is ready to redraw the full-screen image. If you go to YouTube, start playing a video and then click the full-screen icon (at bottom right of the image area) you will see that is not what it does. It actually makes the whole screen go black for a considerable portion of a second, and only then redraws the screen. If the camera program we are using does that then the screen will go black and remain black indefinitely.

If the black-out is shorter than YouTube’s, different behaviour may arise. It depends on four things:

  • the time from image capture to display, which we call the lag and denote by L,
  • the interval between image captures, which we call the frame period and denote by T, and
  • the time the blackout period commences and the time it ends, both measured in milliseconds from the last image capture before the blackout. We’ll denote these by t1 and t2.

If no image capture occurs during the blackout, which will happen if t2<T, the blackout will have no effect on the final image and we can ignore it. The eventual image will still be Figure 4.

If images are captured during the blackout, and the first image shown on the monitor after the blackout was captured during the blackout, the screen will thereafter remain black indefinitely. This will be the case if both L and T are less than t2.

The other possibility is that T<t2 and L>t2. In this case the first image shown after the blackout will be a picture of the pre-blackout monitor, ie Figure 4, but it will be followed sooner or later by one or more black images captured during the blackout.  What will follow then will be an alternation between images showing Figure 4 and black images. It will look like a stroboscopic Figure 4. The strobe cycle will have period approximately equal to L, and the dark period will have approximately the same length as the blackout, ie  t2t1. In essence, the monitor will indefinitely replay what it showed in the period of length L ending at the end of the blackout.

This black-screen issue will also arise if the monitor is an old-style, boxy, CRT (Cathode Ray Tube) rather than a LCD, Plasma or LED device. CRT screens typically draw around 75 images per second, made up of bright dots on a photo-sensitive screen, by shooting electrons at it. In between those drawings, the screen is black. That’s why those screens sometimes appear to flicker, especially viewed through a video camera.

For a CRT screen, the image captured immediately before the redraw may be Figure 4 or black, or something in-between – a partial Figure 4, with a complex dependency based on four parameters: the length of exposure used by the sensor (shutter speed), the length of time taken for a single redraw of the CRT screen and the refresh rate and frame rate. Unless there were a particularly unusual and fortuitous relationship between those four numbers, the image on the monitor would not be Figure 4. I think instead it would either be just black or an unpredictable mess. But one would need more knowledge of CRT technology than I have, to predict that.

Anyway, we don’t want to get bogged down in practical technology. This is principally a thought experiment. And for that ideal situation, we assume an LCD monitor with a computer that, upon receiving a full-screen-mode command, leaves the prior image in place until it is ready to redraw the image on the full screen. And the answer in that situation is Figure 4.

Doing a careful experimental verification of this is beyond me because, amongst other things, I don’t have a camera program that has a full-screen mode. But just for fun, I made a video like the one above under Question 4, where I focused the camera on the area of the monitor that displayed the image, trying to exclude the borders. It wobbles about, partly because of my shaky hands. It is mostly black, but there’s a blue smudge that appears in the lower half and wobbles around. I think that is a degraded version of the regressing images of the lower border. But under such uncontrolled conditions, who knows?

Here’s the video.

Question 4

We are now in a position to work out the answer to question 4, which is ‘what will we see after we point the camera to the right of the monitor and then pan left until it exactly points at the monitor, and stop there?

To start with, we know that, once the camera has panned to the final position of exactly capturing the image of the entire monitor, it will hold that image indefinitely, and that image will be whatever the monitor was showing immediately before the camera finished panning.

We’ll be a little more precise. A video camera captures a number f of images (‘frames’) per second, typically 24. The final image shown by the camera will be whatever the camera captured in the last frame it shot before completing the pan. The nature of that image depends on relationships between the pan speed, the frame rate and the width of the monitor screen, which we will explore shortly. But, to avoid suspense, let’s assume a frame rate of 24, that 32 frames are shot while performing the pan, and that the view to the right of the monitor display area, including the black right-hand frame of the monitor itself, being this (Figure 6):

pan_image_1

Then, on completion of the pan, the camera will show, and continue to show indefinitely thereafter, the following image (Figure 7 – note that the image was made by editing, not shot through a camera. My equipment is nowhere near precise enough to do this accurately):

pan_image_32

C’est bizarre, non?

Those of you that enjoy exploring intricate patterns may wish to read on, to see the explanation of this phenomenon. I will not be offended if most don’t.

The answer depends on the ratio of the speed at which the camera pans left, to the width of the screen. If we want to be precise, these speeds and widths must be measured in  degrees (angles) rather than millimetres. But millimetres are easier to understand so we’ll use them and ignore the slight inaccuracy it introduces (otherwise I’d need to start using words like ‘subtend’, and we wouldn’t want that would we?).

Say the camera rotates at a speed of s mm per second, and that it shoots f frames per second. Hence it shifts view leftwards by s/f mm per frame. So, if the width of the monitor’s display area is w mm, it shoots N=wf/s frames between when the camera first captures part of the monitor’s display area (on the monitor’s right side) and when the camera is in the final position where it exactly captures the view of the whole monitor display area, not counting the last frame. We label the positions of the camera at each of those frames as 1 to N, going from earliest to latest. We omit the last frame because we know that, once the camera is pointing exactly at the monitor, the image will remain fixed on whatever the monitor is showing at that time, which will be what the camera saw in position N.

By the way, we assume that N is an integer even though in practice it won’t be, because it will have a fractional part. It doesn’t make the calculation significantly more difficult if it’s a non-integer, but it is messier, longer, and the differences are not terribly interesting, so we’ll assume it’s an integer.

Divide the view to the right of the monitor’s display area, as shown in Figure 6 above, into N vertical strips of equal width. Number those strips 1 to N from left to right. We will call these ‘strip-images‘, as each is a tall, thin picture. Next, number the positions the camera has when each frame is shot as follows:

  • Frame 0 is when the left-hand edge of the image captured by the camera coincides with the right-hand edge of the monitor display area, so that the camera captures exactly the image of Figure 6, ie strip-images 1 to N. At that time the monitor will be showing what the camera captured one frame earlier, which will be an image made up of strip-images 2 to N+1 (strip-image N+1 is what we can see in an area the same size as the opther strip-images, immediately to the right of Figure 6)
  • The frames shot after that are labelled 1, 2, etc.

Label the times when the camera is in position 0, 1, 2 etc as ‘time 0’, ‘time 1’, ‘time 2’ etc.

With this scheme, Frame N will be the one that is shot when the camera is in the final position, when it exactly captures what is on the monitor, so that that image remains on the monitor indefinitely thereafter.

The following table depicts what is shown by the monitor and what is captured by the camera at each position, in the situation we used to produce Figure 7, which has N=32.

The rows are labelled by the camera positions/times. The first 32 columns (the ‘left panel’) correspond to the 32 vertical, rectangular strips of the monitor display area, numbered from left to right. The next 32 columns (the ‘right panel’) correspond to the strips of what can be seen to the right of the monitor. The number in each cell shows which strip-image can be seen by looking in that direction. The yellow shading in each row shows what images are captured by the camera at that time, to be shown on the monitor in the next row. (Figure 8):

figure-08-pan-table-fullA few key points of interest are:

  • The numbers in the right panel do not change from one row to the next, because rotating the camera does not change what can be seen to the right of the monitor.
  • The numbers in the left panel change with each row, to reflect that what was captured by the camera at the previous camera position was different from what was captured at the one before that, because of the camera’s movement.
  • The yellow area denoting what the camera captures moves to the left as we go down the table, reflecting the camera’s panning to the left.

There are lots of lovely number patterns in the left panel, which I will leave the reader to explore.

Here is a zoomed-in image of just the left panel for those whose eyes, like mine, have trouble making out small numbers (Figure 9):

figure-09-pan-table-left-panel

Referring back to Figure 7 we see that, as we move from the right to the left side, it has a series of eight vertical images of increasing width. The first one is just the monitor’s right-hand frame – a black plastic strip. The next is twice as wide and has the monitor frame plus the strip-image to its right. The one after than is three times the width and so on. This corresponds to the last row of Figure 9:

5 6 7 8, 1 2 3 4 5 6 7, 1 2 3 4 5 6, 1 2 3 4 5, 1 2 3 4, 1 2 3, 1 2, 1

I have put commas between each contiguous set of strip-images. I call each such contiguous set a ‘sub-image‘. The first sub-image is incomplete – being 5 6 7 8 instead of 1 2 3 4 5 6 7 8 – because N is not a triangular number.

The time tunnel applies here, with a slightly different flavour. The newest sub-image is the one on the far right, composed solely of strip-image 1. This was captured from the world outside the monitor one frame period ago. The next, the ‘1 2’, was shot from the monitor last time, and came from the real world outsider the monitor two frame periods ago. The oldest sub-image is the one on the left, which has been through the camera-monitor loop seven times, having first been captured from the real world eight frame periods ago.

It’s quite fun to trace the path of these images as they repeatedly traverse the camera-monitor loop, by the numbers in the above table. Here’s the lower part of the table showing how the first, third and sixth sub-images from the left (using blue, grey and pink shading respectively), make their way from the real world (to the right of the vertical dividing line), into the camera-monitor loop (to the left of that line), around that loop as many times as needed, and finally to the ultimate static image (Figure 10):

figure-10-pan-table-with-locii

My example with N=32 involves a high panning speed. Shooting 24 frames per second, the pan would need to to completed in 32/24 = 1.33 seconds. One would need extremely good equipment to accomplish that without getting a bounce or wobble when the camera stops at the end of the pan – and avoiding wobble is critical to getting the indefinite static picture we have discussed.

It may be that in order to avoid camera bounce one would need a slower pan, giving us a (perhaps much) higher N. What would be the outcome of that? Well, the right-most sub-image contains only one strip-image and, as we move left, each image contains one more strip-image than the one to its right. So, if the number of sub-images is r, then N will be greater than the sum of the numbers from 1 to r-1 (the (r-1)th triangular number) and not exceeding the sum from 1 to r (the rth triangular number). A little maths tells us that this is from (r-1)r/2 to r(r+1)/2. For large N this means that there will be approximately √(2N) sub-images and the largest will be comprised of about √(2N) strip-images. Since for a display width of w the width of a strip-image is w/N, that means the widest sub-image will have width about w√(2N)/N=w√(2/N), which will get smaller as N increases. If N=2048, corresponding to a very slow pan time of about 85 seconds, the widest sub-image would be narrower than the frame of my monitor, so all we would see in the final static image would be black plastic monitor frame, something like this (Figure 11):

figure-11-final2048_smaller

The bars of light are from the screen reflecting on the shiny monitor frame. Because I couldn’t hold the camera straight, they are bigger at the bottom than at the top.

I will leave you with my synthesis of the sequence of 32 images that would be seen, given near-perfect equipment, in the 32-step pan that ends with Figure 7 above. They are simply a realisation in pictures of the patterns shown in figure 9, when applied to the image Figure 6. The sequence is in a pdf at this address. If you go to page 1 and then repeatedly hit Page Down rapidly, you will see a slow-motion video representation of what it would look like as the camera panned. You may need to download it first in order to be able to view it in single-page view, which is necessary in order to achieve a video-like effect. Alternatively, it is represented below, albeit somewhat more crudely, as a pretend film strip.

Andrew Kirk

Bondi Junction, February 2017

strip01-08strip09-16strip17-24strip25-32


Pointing the Camera at the Monitor – A Puzzle

I was listening to a talk by Alan Watts about some aspect of Eastern mysticism. I can’t remember the exact context. I think he was describing the impossibility of truly understanding the nature of one’s own mind. He said that trying to use one’s mind to understand one’s own mind was ‘like pointing the camera at the monitor’.

I was immediately struck by this. Partly I was surprised at his using such a simile, which involves common enough concepts in 2017, in a talk that he gave in the sixties, when computers only existed in large research establishments and occupied enormous rooms. There was certainly no such thing as a webcam back then. I realised later that he probably had in mind a closed-circuit television arrangement, which they did have in the sixties.

But beyond that, I was struck by the fact that it’s actually a very interesting question – what does happen when one points the camera at the monitor? It’s a classically self-referential problem. But unlike some self-referential problems, like the question of the truth of the statement ‘This sentence is false’, it must have a precise answer, because we can point a camera at a monitor, and when we do that the monitor must show something. But what will it show?

There are a number of practical considerations that can lead us towards different types of answers. While each of those considerations leads to an interesting problem in its own right, I tried to remove as many of them as possible to make the problem as close to ‘ideal’ as I could. So here it is.

Imagine we have a computer connected to a monitor and a digital video camera. A webcam is a digital video camera but, since the camera we are imagining here needs to be extremely accurate, a high-quality professional video camera would be more suitable. The monitor uses a rectangular array of display pixels to display an image and the camera uses a sensor that is a rectangular array of light-sensitive pixels, and the dimensions of the display and the sensor, in pixels (not in millimetres) are identical.i

On the computer we run a program that shows the image recorded by the camera. The telecommunication program Skype is a well-known such program that can do that, amongst other things. There are also dedicated camera-only programs, which webcam manufacturers typically include on a CD bundled with the webcams they sell. Let’s call our program CamView (not a real program name). We start up CamView on the computer in a non-maximised window, which we’ll call the ‘CamView window’. Then we turn the camera on and point it at the monitor. We aim and focus the camera so precisely that an image of the display area of the monitor fills the image-display area of the CamView window. Ideally this would mean that each pixel on the camera’s sensor is recording an image of the corresponding pixel on the monitor screen. In practice there will be some distortion, but we’ll ignore that for now.

Question 1: what does the monitor show?

Question 2: Next we maximise the CamView window. What does the monitor show now?

Those questions are easy enough to answer, when we remember that the window for any computer program, in default mode, typically has an upper border with tool icons on it, a lower border with status info on it, and sometimes left or right borders as well.

These questions are fairly similar to the question of what one sees when one stands between two parallel, opposing mirrors, as is the case in some lifts (elevators).

Now comes the hard one. In most video-viewing computer programs there is an icon that, upon clicking, maximises the window and removes all borders so that the image-display area occupies the entire display area of the monitor. Call it the ‘full screen icon’ and say that we are in ‘full screen mode’ after it is clicked – until a command is given that terminates that mode and returns to the default mode – ie restores the borders etc. In full screen mode the display area of the monitor corresponds exactly to the images recorded by the camera’s sensor.

Question 3: We now click the full screen icon. Describe what appears on the monitor, and how it changes, from the instant before the icon is clicked, until ten minutes after clicking it – assuming the program remains in full screen mode for that entire time.

That is the difficult one. It took me a while to figure it out, and I was surprised by the answer. It is possible that what I worked out was wrong. If so, I hope that someone will point that out to me.

I have one more question, and it has an even more peculiar answer – one that I found quite charming.

Question 4: Assume the camera is mounted on a very stable tripod. Still in full-screen mode, we pan the camera to the right until it no longer shows any of the monitor. Then we pan the camera back at a constant speed until it again sees only the display area of the monitor, and we stop the panning at that point. What is visible on the monitor after the camera has panned back to the original position? Does that change subsequently? What does it look like ten minutes later? Does the monitor image depend on the panning speed, or on the number of frames per second the camera shoots? If so, how?

In order to avoid spoiling anybody’s fun in trying to work out the answers to these puzzles for themself, I will not post answers now. I will post them a little later on. It will also take me a little while to make some nice pictures to help explain what I am talking about.

Andrew Kirk

Bondi Junction, February 2017

Footnotes

i Although most camera sensors have a 3:2 aspect ratio, which is different from the 16:9 aspect ratio of most modern computer monitors, it is possible on a sophisticated camera to alter the aspect ratio to 16:9, which is achieved by deactivating the sensor pixels in an upper and lower band of the sensor, so that the area used to record an image has the required aspect ratio. We’ll assume that is done and that the number of pixels in the active sensor area equals that on the monitor.


Hypotheticals, counterfactuals and probability

This essay considers the notion of events occurring that we do not know to either have occurred, or to be almost certain to occur in the future. Imagination of such events is everywhere in everyday speech, but we rarely stop to consider what we mean by it, or what effect imagining such things has on us.

It is dotted with numbered questions, so it can be used as a basis for a discussion.

Counterfactuals

A counterfactual is where we imagine something happening that we know did not happen.

This is fertile ground for fiction. Philip K Dick’s acclaimed novel ‘The Man in the High Castle’, written in 1962, depicts events in a world in which the Axis powers won World War II, and the USA has been divided into parts occupied by Japan and Germany. The movie ‘Sliding Doors’ is another well-known example, that imagines what ‘might have happened’ if Gwyneth Paltrow’s hadn’t missed a train by a second as the sliding doors closed in front of her..

When something terrible happens, many people torment themselves by considering what would have happened if they, or somebody else, had done something differently:

  • What if I had been breathing out rather than in when the airborne polio germ floated by? (from Alan Marshall’s ‘I can jump puddles’)
  • If she hadn’t missed her flight and had to catch the next one (doomed to crash), she’d still be alive now.
  • What would life have been like if I hadn’t broken up with Sylvie / Serge?

We can also consider counterfactuals where the outcome would have been worse than what really happened, such as ‘What would my life have been like if I hadn’t met that inspirational person that helped me kick my heroin habit‘. But for some reason – so it appears to me – most counterfactuals that we entertain are where the real events are worse than the imagined ones. We could call these ‘regretful counterfactuals‘ and the other ones ‘thankful counterfactuals‘.

Then there are the really illogical-seeming ones, like the not-uncommon musing: ‘Who would I be [or what would I be like] if my parents were somebody else?‘ which makes about as much sense as ‘what would black look like if it were a lightish colour?

Here are some questions:

  1. why do we entertain counterfactuals? What, if any, benefits are there from considering regretful counterfactuals? What about thankful ones?
  2. given that for many counterfactuals, consideration of them just makes us feel bad, could we avoid entertaining them, or is it too instinctive an urge to be avoidable?
  3. Do counterfactuals have any meaning? Given that Alan Marshall did breathe in, and did contract polio, what does it mean to ask ‘If he had been breathing out instead, would he have become a top-level athlete rather than an author?‘ Are we in that case talking about a person – real or imaginary – other than Alan Marshall, since part of what made him who he is, was his polio?

That last question can lead in some very odd directions. My pragmatic approach is that counterfactuals are made-up stories about an imaginary universe that is very similar to this one, but in which slightly different things happen. Just as we make up stories about non-existent lands, princesses and far away galaxies, we can make up stories about imaginary worlds that are very similar to this one except in a handful of crucial respects.

Some philosophers insist that counterfactuals are not about imaginary people and worlds but about the real people we know. My objection to that is that, for example, the Marshall counterfactual cannot be about the Alan Marshall, because he had polio. It can only be about an imaginary boy whose life was almost identical to Marshall’s up the point when the real one contracted polio. My opponents (who would include Saul Kripke, that we mention later) would counter that polio is not what defines Alan Marshall, that it is an ‘inessential’ aka ‘accidental’ property of that person, and changing it would not change his being that person. Which begs the question of what, if any, properties are essential, such that changing them would make the subject a different person. Old Aristotle believed that objects, including people, have essential and inessential properties, and wrote reams about that. In the Middle Ages Thomas Aquinas picked up on that and wrote many more reams about it. The ‘essential properties’ of an object are called its ‘essence’, and believing in such things is called ‘Essentialism’. That is how certain RC theologians are able to claim that an object that looks, feels, smells, sounds, tastes and behaves like a small, round, white wafer is actually the body of Jesus of Nazareth – apparently because, although every property we can discern is that of a wafer, the ‘essential’ properties (which we cannot perceive) are those of Jesus, thus its essence is that of Jesus. I tried for years to make sense of that and believe it, but all it succeeded in doing was giving me a headache and making me sad. For me, essentialism is bunk.

  1. Can you make any sense of Essentialism? If so can you help those of us who can’t, to understand it?

I can’t help but muse that maybe thankful counterfactuals have some practical value, as they can enable us to put our current sorrows into perspective. They are a very real way of Operationalizing (I know, right?) what Garrison Keillor suggests is the Minnesotan state motto – ‘It could be worse‘.

Maybe regretful counterfactuals sometimes have a role too, when they encourage us to learn from our mistakes and be more careful in the future. But they are of no use in the three examples given above. What are we going to learn from them: Never breathe in? Never fly on an aeroplane? Never break up with a romantic partner (no matter how unsuitable the match turns out to be)?

If we do something that leads to somebody else suffering harm, considering the regretful counterfactual can be useful. If I hadn’t done that, they wouldn’t be so sad. How can I make it up to them? I know, I’ll do such-and-such. That won’t fix it completely, but it’s all I can think of and at least it’ll make them feel somewhat better.

But once we’ve done all we can along those lines, the counterfactual has outlived its usefulness and is best dismissed. Otherwise we end up punishing ourselves with pointless guilt, which benefits nobody. Yet we so often do this anyway, perhaps because we can’t help it, as speculated in question 2.

I am completely useless at banishing guilt. But the techniques I have, feeble as they are, revolve around reminding myself that the universe is as it is, and cannot be otherwise. The past cannot be changed. If I had not done that hurtful thing I would not have been who I am, and the universe would be a different one, not this one. I am sorry I did it, and will do my best to make restitution, and to avoid causing harm in that way again. But the counterfactual of my not doing it is just an imaginary story about a different universe, that is (once I’ve covered the restitution and self-improvement aspects) of no use to anybody, and not even a good story. Better to read about Harry Potter’s imaginary universe instead.

This universe-could-not-have-been-otherwise approach is currently working moderately well in helping me cope with the recent Fascist ascendancy in the US. There are so many ‘if only…’ situations we could torture ourselves with: ‘If only the Democrats had picked Bernie Sanders’, ‘If only Ms Clinton hadn’t made the offhand comment about the basket of deplorables’, ‘If only the Republicans had picked John Kasich’. Those ‘If only’s are about a different universe, not this one. They could not happen in this universe, because in this universe they didn’t happen.

Counterfactuals also come into Quantum Mechanics. Arguably the most profound and shocking finding of quantum mechanics is Bell’s Theorem which, together with the results of a series of experiments that physicists did after the theorem was published, implies that either influences can travel faster than light – which appears to destroy the theory of relativity that is the basis of much modern physics – or Counterfactual Definiteness is not true. Counterfactual Definiteness states that we can validly and meaningfully reason about what would have been the result if, in a given experiment, a scientist had made a different type of measurement from the one she actually made – eg if she had pointed a particular measuring device in a different direction. Many find it ridiculous that we cannot validly consider what would have happened in such an alternative experiment, but that (or the seemingly equally ridiculous alternative of faster-than-light influences) is what Bell’s Theorem tells us, and the maths has been checked exhaustively.

Hypotheticals

A counterfactual deals with the case where something happens that we know did not happen. What about when we don’t know? I use the word hypothetical or possibility to refer to where we consider events which we do not know whether or not they occur in the history of the universe. These events may be past or future:

  • a past hypothetical is that Lee Harvey Oswald shot JFK from the book depository window. Some people believe he did. Others think the shot came from the ‘grassy knoll’.
  • a future hypothetical is that the USA will have a trade war against China

What do we mean when we say those events are ‘possible’ or, putting it differently, that they ‘could have happened‘ (for past hypotheticals) or that they ‘could happen‘ (for future hypotheticals)? I suggest that we are simply indicating our lack of knowledge. That is, we are saying that we cannot be certain whether, in a theoretical Complete History of the Earth, written by omniscient aliens after the Earth has been engulfed by the Sun and vaporised, those events would be included.

Some people would insist that the future type is different from the past type – that while a past hypothetical is indeed just about a lack of knowledge about what actually happened, a future hypothetical is about something more fundamental and concrete than just knowledge. This leads me to ask:

  1. Does saying that a certain event is ‘possible’ in the future indicate anything more than a lack of certainty on the part of the speaker as to whether it will occur? If so, what?

I incline to the view that it indicates nothing other than the speaker’s current the state of knowledge. What some people find uncomfortable about that is that it makes the notion of possibility depend on who is speaking. For a medieval peasant it is impossible that an enormous metal device could fly. For a 21st century person it is not only possible but commonplace. As Arthur C Clarke said ‘Any sufficiently advanced technology is indistinguishable from magic.’ To us, mind-reading is impossible, but maybe in five hundred years we will be able to buy a device at the chemist for five dollars that reads people’s minds by measuring the electrical fields emitted by their brain.

Under this view, the notion of possibility is mind-dependent. What would a mind-independent notion of possibility be?

There is a whole branch of philosophy called ‘Modal Logic’, and an associated theory of language – from the brilliant logician Saul Kripke – that is based on the notion that possibility means something deep and fundamental that is not just about knowledge, or minds. To me the whole thing seems as meaningful as debates over how many angels can dance on the head of a pin, but maybe one day I will meet somebody that can demonstrate a meaning to such word games.

Sometimes counterfactuals sound like past possibilities. That happens when we say that something which didn’t happen, could have happened. Marlon Brando’s character Terry in ‘On the Waterfront‘ complains ‘I coulda been a contender … instead of a bum, which is what I am‘. As I said above, I don’t think it makes literal sense to say it could have happened, since it didn’t. But if we didn’t know whether it had happened or not, we wouldn’t have been surprised to find out that it did happen. So in a sense we are saying that a person in the past, prior to when the event did or didn’t occur, evaluating it from that perspective, would regard it as possible. Brando’s Terry was saying that, back in the early days of his boxing career, he would not have been at all surprised if he had become a star. But he didn’t, and now it was too late.

What would happen / have happened next?

With both counterfactuals and hypotheticals, we often ask whether some other thing would have happened if the first thing had happened differently from how it did. For instance:

  • [counterfactual] If the FBI director had not announced an inquiry into Hilary Clinton’s emails days before the 2016 US presidential election, would she have won?
  • [past hypothetical] If Henry V really did give a stirring speech like the ‘band of brothers’ one in Shakespeare’s play, exhorting his men to fight just for the glory of having represented England, God and Henry, were any of the men cynical about his asking them to risk death just in order to increase Henry’s personal power?
  • [future hypothetical] If Australia’s Turnbull government continues with its current anti-environment policies, will it be trounced at the next election?

Which leads to another question:

  1. What exactly do these questions mean?

The first relates to something that we know did not happen and the other two relate to what is currently unknowable.

My opinion is that, like with counterfactuals, they are about making up stories. In the US election case we are imagining a story in which certain events in the election were different, and we are free, within the bounds of the constraints imposed by what we know of the laws of nature, to imagine what happened next. Perhaps in the story Ms Clinton wins. Perhaps she then goes on to become the most beloved and successful president the country has ever had, overseeing a resurgence of employment, creativity, and brotherly and sisterly love never before encountered. Or perhaps she declares martial law, suspends the constitution and becomes dictator for life, building coliseums around the country where Christians and men are regularly fed to lions. Within the bounds of the laws of nature we are free to make up whatever story we like.

The same goes for the past hypothetical of Henry’s speech. We can imagine the men swooning in awe and devotion, murmuring Amen after every sentence, or we can imagine them rolling their eyes and making bawdy, cynical quips to one another – but nevertheless eventually going in to battle because otherwise they won’t be paid and their families will starve.

However, the future hypothetical seems to be about more than a made-up story. If the first thing happens – continued anti-environmentalism – then we will definitely know after the next election whether the second thing has also happened. At that point it becomes a matter of fact rather than imagination.

To which I say, so what? Until it happens, or else it becomes clear that it will not happen, it is a matter of future possibilities and can be covered by any of the scientifically-valid imaginative scenarios we can dream up. It is only if the scientific constraint massively narrows down those scenarios that it has significance. If, for instance, we could be sure that any government that fails to make a credible attempt to protect the environment will be booted out office, our future possibility would become a certainty: If the government doesn’t change its track then it will be ejected. But in politics nothing is ever that certain. Other issues come up and change the agenda, scandals happen, natural and man-made disasters, personal retirements and deaths of key politicians. At best we can talk about whether maintaining the anti-environment stance makes it more probable that the government will lose office. Which leads on to the next thorny issue.

Probability

Probability, aka chance, aka risk, aka likelihood and many other synonyms and partial synonyms, is a word that most people feel they know what it means, but nobody can explain what that is.

What do we mean when we say that the probability of a tossed coin giving heads is 0.5? Introductory probability courses often explain this by saying that if we did a very large number of tosses we would expect about half of them to be heads. But if we ask what ‘expect’ means we find ourselves stuck in a circular definition. Why? Because what we ‘expect’ is what we consider most ‘likely’, which is the outcome that has the highest ‘probability’. We cannot define ‘probability’ without first defining ‘expect’, and we cannot define ‘expect’ without first defining ‘probability’ or one of its synonyms.

We could try to escape by saying that what we ‘expect’ is what we think will happen, only that would be wrong. The word ‘will’ is too definite here, implying certainty. When we say we expect a die will roll a number less than five, we are not saying that we are certain that will be the case. If it were, and we rolled the die one hundred times in succession, we would have that expectation before each roll, so we would be certain that no fives or sixes occurred in the hundred rolls. Yet the probability of getting no fives or sixes in a hundred rolls is about two in a billion billion, which is not very likely at all. We could dispense with the ‘certainty’ and instead say that we think a one, two, three or four is the ‘most probable’ outcome for the next roll. But then we’re back in the vicious circle, as we need to know what ‘probable’ means.

  1. What does ‘expected’ mean?

There is a formal mathematical definition of probability, that removes all vagueness from a mathematical point of view, and enables us to get on with any calculation, however complex. Essentially it says that ‘probability’ is any scheme for assigning a number between 0 and 1 to every imaginable outcome (note how I carefully avoid using the word ‘possible’ here), in such a way that the sum of the numbers for all the different imaginable outcomes is 1.

But that definition tells us nothing about how we assign numbers to outcomes. It would be just as valid to assign 0.9 to heads and 0.1 to tails as it would to assign 0.5 to both of them. Indeed, advanced probability of the kind used in pricing financial instruments involves using more than one different scheme at the same time, which assign different numbers (probabilities) to the same outcome.

This brings us no closer to understanding why we assign 0.5 to heads.

Another approach is to say that we divide up the set of all potential outcomes as finely as we can, so that every outcome is equally likely. Then if the number of ‘equally likely’ outcomes is N, we assign the probability 1/N to each one.

That seems great until we ask what ‘equally likely’ means, and then realise (with a sickening thud) that ‘equally likely’ means ‘has the same probability as’, which means we’re stuck in a circular definition again.

  1. What does ‘equally likely’ mean?

After much running around in metaphorical circles, I have come to the tentative conclusion that ‘likely’ is a concept that is fundamental to how we interpret the world, so fundamental that it transcends language. It cannot be defined. There are other words like this, but not many. Most words are defined in terms of other words, but in order to avoid the whole system becoming circular, there must be some words that are taken as understood without definition – language has to start somewhere. Other examples might be ‘feel’, ‘think’ and ‘happy’. We assume that others know what is meant by each of these words, or a synonym thereof, and if they don’t then communication is simply impossible on any subject that touches on the concept.

Or perhaps ‘likely’ and ‘expect’ may be best related to a (perhaps) more fundamental concept, which is that of ‘confidence’, and its almost-antonym ‘surprise’. Something is ‘likely’ if we are confident – but not necessarily certain – that it will happen, which is that we would be somewhat surprised – but not necessarily dumbfounded – if it did not happen. I think the twin notions of confidence and surprise may be fundamental because even weeks-old babies seem to understand surprise. The game of peek-a-boo relies on it entirely.

Once we have these concepts, I think we may be able to bootstrap the entire probability project. The six imaginable dice roll numbers will be equally likely if we would be very surprised if out of six million rolls, any of the numbers occurred more than two million times, or not at all.

There are various frameworks for assigning probabilities to events that are discussed by philosophers thinking about probability. The most popular are

  • the Frequentist framework, which bases the probability of an event on the number of times it has been observed to occur in the past;
  • the Bayesian approach, which starts with an intuitively sensed prior probability, and then adjusts to take account of subsequent observations that using Bayes’ Law; and
  • the Symmetry approach, which argues that events that are similar to one another via some symmetry should have the same probability.

It would make this essay much too long to go into any of these in greater detail. But none of them lay out a complete method. I suspect they all have a role to play in how we intuitively sense probabilities of certain simple events. But I feel that there is still some fundamental, unanalysable concept of confidence vs surprise that is needed to cover the gaps left by the large vague areas in each framework.

Here is one last question to consider:

  1. A surgeon tells a parent that their three-year old daughter, who is in a coma with internal abdominal bleeding following a car accident, has a 98% chance of a successful outcome of the operation, with complete recovery of health. In the light of the above discussion, it seems that nobody can explain what that 98% means. Yet despite the lack of any explicable meaning, the parent is so relieved that they dissolve in tears. Why?

Andrew Kirk

Bondi Junction, January 2017


Mastering maths monsters

‘Partial differentiation’ is an important mathematical technique which, although I have used it for decades, always confused me until a few years ago. When I finally had the blinding insight that de-confused me, I vowed to share that insight so that others could be spared the same trouble (or was it just me that was confused?). It took a while to get around to it, but here it is:

https://www.physicsforums.com/insights/partial-differentiation-without-tears/

My daughter Eleanor make a drawing for it, of a maths monster (or partial differentiation monster, to be specific) terrorising a hapless student. The picture only displays in a small frame at the linked site, so I’m reproducing it in all its glory here.

Andrew Kirk

Bondi Junction, October 2016


Too many words!

Books are too long. People talk for too long. Academic papers are too long. Almost everything is too long.

Why? Partly, because to be concise is very difficult. Urban legend has it that Blaise Pascal once wrote at the end of a letter to a friend: ‘I’m sorry this letter is so long. I didn’t have time to write a short one’.

I struggle with conciseness. Part of the problem is that, when I am trying to explain something, I worry about whether what I have said is clear enough, so I keep on saying it over, in a slightly different way each time, in the vague hope that one of the attempts will make the connection.

I think a better strategy might be to make one brief attempt at an explanation and then wait for a response. If more is needed, I imagine my interlocutor will tell me. If they do, the particular nature of their response will better enable me to tailor my next statement to fill in the information that was missing in my first.

But that requires discipline, and nerves of steel. It is like being silent in an interview after giving a short reply to a question – forcing the interviewer (or interrogator) to make the next move. Few people can carry that off, and I suspect I am not one of them.

Academic papers can be particularly irritating, droning on about all the references and who has written what, so that by the time one gets to the bit about what the authors have done that’s actually new, one is exhausted and wants to retire for a tea break. It’s not clear to me whether this is a stylistic practice, imposed by the producers and reviewers of journals, or whether it reflects insecurity on the part of the authors, who may feel that they need to mention some minimum number of other papers in order to be taken seriously.

Arthur Schopenhauer railed against this sort of writing in a series of essays collected under the title ‘The Art of Literature’. He opens with an unrestrained broadside ‘There are, first of all, two kinds of authors: those who write for the subject’s sake, and those who write for writing’s sake.‘ Schopenhauer loved the first (and of course considered himself to be one of them) and loathed the second.

If someone really has something important to say, it usually doesn’t take very long. When Neville Chamberlain announced the grim news to the British people in 1939 that Britain had declared war on Germany, the message had been delivered by the end of the 67th word. I did a test reading just now and it took about 26 seconds, including pauses for effect.

Einstein’s legendary 1905 paper that presented his special theory of relativity to the world, ending decades of confusion amongst physicists, is only 24 pages, and the key part that resolves the paradoxes by which physics was previously beset is complete by the end of page 12! John Bell’s paper that turned the world of Quantum Mechanics upside down in 1964 is only six pages. Bell cited only five references. Einstein cited none.

In general communication, most people use too many words. I do too, but I am trying to correct that. I feel that, where possible, I would like to conduct a post-mortem on every sentence I utter and work out whether that sentence has added any new information. If it hasn’t, then it was probably a waste of everybody’s time.

Politicians exploit this deliberately. They are trained to, when asked a difficult question by a journalist, give a long-winded, emphatic speech about something only tangentially related, thereby avoiding the issue and (they hope) making the journalist despair of persisting with the question because of the pressure of time. Even better, if the politician sounds confident in their ‘answer’, the less analytic watchers will form the impression that the politician is competent and frank. The more analytic types just shrug their shoulders in disgust and turn the telly off.

A sentence can be very long and yet not reveal what information it contains until late in the sentence. Sometimes there is a key word that makes it all fall into place, The words before that one stack up like the numbers in a long calculation on a Reverse Polish calculator, impotent while they wait for release. Then the key word comes and it all falls into place. It attains a meaning. The wait for that word can sometimes be prolonged, like in this:

Though they all came from different social strata, sub-cultures and occupations, crammed together against their will in the prison cell from which they wondered if there would ever be any release, though none of them had known each other – or even known of each other – in their previous lives, though they squabbled and quarrelled over the tiniest of things, the one thing that bound them together despite the rivalries and petty jealousies, the perceived slights and reconciliations, the development, disintegration and reformation of cliques, was a single shared emotion, an emotion so powerful that they could feel it oozing out of one anothers’ pores, smell it on their breath and discern it in the tones of voice – the emotion of fear.

In some cases, the key word never comes. Perhaps the writer or speaker confuses themselves by their excessive verbiage and ends the sentence with an admission of defeat.

Books are too long as well! Novels are generally OK, as it takes time to get to know and care about the characters. But I have a strong sense that non-fiction books are often padded to reach whatever is considered a minimum page count for a book – usually at least 200. There isn’t really a strong market for writings that are halfway between essay and book length. In many cases a book really only has one idea, which could make a decent essay, but doesn’t justify a book. But essays don’t get to be put on a prominent shelf that catches your eye as you enter the bookshop, nor do they get listed on the New York Times best sellers’ list.

Nassim Taleb’s famous book ‘The Black Swan’ is like that. It really only contains one idea, which is that investors, bankers and other financiers have for decades been making crucial financial decisions based on theories in which they assume that the future will be like the past, and that all occurrences of randomness must follow the Normal Distribution (the nice friendly old ‘Bell Curve’). Decisions based on that erroneous, oversimplified assumption have repeatedly led to disasters, because events tend to be more extreme than is predicted by the Bell Curve. Taleb’s is a good insight, and definitely worth saying, but probably not worth stringing out to book length.

And then, if the book sells well, they write it again, ever so slightly differently, and pretend it’s a new book, with new ideas. Taleb did that. Self-help authors do it all the time – which raises the question ‘If your first book about how to live a better life was so incomplete that it needs to be supplemented by a second, why did I waste my time reading it?‘ I suspect Richard Dawkins may do it too. As far as I can tell he has written at least four popular explanations of evolution. I read The Blind Watchmaker and thought it was great (but too long, of course!). But I didn’t read The Selfish Gene, The Ancestors’ Tale or The Greatest Show on Earth because I couldn’t see any indicators that they would contain much substance that hadn’t already been covered in the one I had read. I imagine there is some new material in each of them, but I would guess it’s more likely to be a dozen pages’ worth rather than 200+.

Fiction authors and other creative artists do this too. Stravinsky acidly observed that Vivaldi wrote the same marvellous concerto five hundred times. Bach shamelessly reused his work (goodness knows he was paid little enough for it!) and Enid Blyton invented maybe a dozen adventure and fantasy stories, which she recycled into what seems like hundreds of similar tales (surely I’m not the only one that’s noticed the remarkable similarity between Dame Slap’s School for Bad Pixies and Mr Grim’s School for Mischievous Brownies?). And let’s not even mention Mills and Boon. But somehow I don’t mind that so much. We humans are story-telling animals, and telling the same story repeatedly, changing it just a little every time, is what we have always done. I find myself able to smile indulgently on the prolixity of Enid and Antonio and Mills (?), but alas not on that of Nassim or Richard, or Deepak Chopra.

I think I’ve ranted for long enough now about how We All (including me) need to work on being more concise with our communication. It’s time to relent a little.

Not all language is just about conveying information, so the efficiency with which the information is conveyed is not always the best test. In comforting a frightened child, information communication is not the purpose of our speech. I will restrain myself from objecting that the second half of the soothing phrase ‘There, there‘ is informationally redundant. In fact, I think I could even stretch to approving of its repetition, if its first invocation was insufficient to assuage the poor mite’s distress.

Declarations of love, expressions of support, telling jokes, goodbyes, hellos and well-wishes are all ‘speech acts’ that have important non-informational components. It seems appropriate to apply different expectations to those speech acts from those we apply to informational speech. Even there, there are limits though. Many’s the operatic love aria I’ve sat through where after a while I just feel like screaming ‘OK, you love him, we get it, can we move on with the plot now please?’ And waiting for Mimi to die in La Boheme (of consumption, what else?) in between faint protestations of her love for Rodolfo, can become a little trying on one’s patience after the first ten minutes of the death scene.

But communication of information is the purpose of much of the language we use, especially in our work lives. It is a pity that so much of it is ill-considered.

Hmmm. 1,742 words. I wonder if I could turn this into a book.

Andrew Kirk

Bondi Junction, November 2015


Helping People on the Internet

I like helping people with their homework on the internet. I do this when I can on physicsforums.com, which is a forum for discussing physics, and philosophyforums.com, which is for discussing philosophy. Both have sections where people can ask questions about problems they are having trouble understanding – usually for homework in a degree course. The physics forum has Help sections covering physics, mathematics and chemistry. The philosophy forum’s Help section is focused on symbolic logic, which is a branch of maths closely related to set theory.

There’s an art to both asking and answering questions on such forums. It is not acceptable to just post a question straight out of an assignment and hope somebody solves it for you. That would be lazy, and possibly also cheating. Equally, it is not the done thing to just post a solution to somebody’s problem, even though that would often be the easiest thing to do. The paradigm of quality advice on the internet seems to be to give carefully chosen hints that will lead the student towards being able to solve the problem by themself. It is quite challenging to choose one’s hints to be not so obvious that they give the game away, and not so obscure that the student remains helplessly lost.

Now you might expect there to be an imbalance between people needing advice and people offering it, so that many people remain unhelped. Well there is an imbalance, but it’s the other way around. There are far more willing advisers than there are people wanting to be advised! How does such an odd situation arise? I can only guess at it based on my own attitude to internet advice – which is that I love giving it. I think there is a deep-seated need in most humans to feel useful. In some it is stronger than others, and in me it is quite strong. In some professions, like being a doctor, one has frequent opportunities to provide advice to one’s acquaintances. People seem to have an inexhaustible appetite for free medical advice. But the knowledge of art critics, journalists, electricians and accountants is drawn upon far less frequently in private life. Of course people would be very happy to draw upon the skills of an electrician without cost, for instance to get them to fix some circuits in one’s house. But that is very different from asking for advice. Spending an hour alone in a dusty roof cavity fiddling with dangerous wires is far less fun than dispensing advice to an agog and appreciative audience. A notable example of this difference is the poor old professional photographer. Goodness knows how many times they get asked by friends, relatives and acquaintances to come to a wedding and take some photos – for no fee, of course. And like the electrician in the attic, it is solitary work, with little appreciation except at the time when one actually delivers the photos.

The few professional photographers I have known have had policies of not doing photography for anybody’s wedding except as a fully professional, paid gig. I thought that policy a bit harsh when I first came across it. But after reflection I realised it was the only way to end up avoiding spending countless hours doing work for free, as well as missing out on being able to enjoy one’s friends’ weddings. Life is hard enough for photographers these days, with news organisations slashing their headcounts of journalists and photographers – preferring to just get stock clips from Getty images. It adds to the woe to be be constantly asked to work for nothing.

On the other hand, if people were to gather around them in adoring circles at parties, asking their advice on shutter speeds, apertures, lenses and filters, that would be a different thing altogether. So far as I can tell, that doesn’t happen very often.

My areas of expertise are not under such hard times as photographers, but neither are they as socially sought-after as those of doctors. They include finance, music, bicycles and fitness, philosophy, physics and mathematics. Once or twice a year I get asked for advice on bicycles, fitness or investment. I don’t think I’ve ever been asked about physics, philosophy, music or maths, unless we count my children asking for homework help when they were little.

So, to fulfil my need to feel useful, I go to the internet to see who needs help integrating x sin x, working out whether a pendulum has enough energy to swing right over the top of its arc, working out whether ‘Dark Energy’ would break a wire stretched between two galaxies, or understanding the significance of the Bell Inequality or Godel’s First Incompleteness Theorem.

And what do I find when I go there? Any question that is expressed even moderately clearly has received three or more responses within half an hour of being posted. It’s almost as though people are falling over one another to be the first to respond. You might think that one response is all that’s needed. But it’s not. There is often room to contribute even when there have already been two or three responses to the request. Remember that answers are supposed to be hints, not answers to the homework problem. The best answers are often in the form of questions to the original poster, like ‘what is the component of the gravitational force that points diagonally down the banked track?‘ They serve just to get the student thinking in the right direction, or even in just a more productive manner. Often responders need to ask questions to clarify the problem because the student has not explained it well enough. In logic, the standard question is ‘what tools are you allowed to use?‘ because the typical problem is to prove a statement, given a number of premises and a set of deduction rules, and there are many different logical systems, with different ‘toolboxes’ of deduction rules. Most students just post ‘how do I prove such-and-such, given the following premises’, without specifying what tools are available to them.

So I still sometimes find questions to which I can helpfully respond. Some questions are expressed so unclearly that nobody wants to touch them. I quite enjoy the forensic work of trying to work out what the communicationally-challenged student was trying to say. In other cases, the question may be clear enough but the responders may have gone off on a false trail, or been insufficiently clear, leaving room for me to contribute. But it’s only the occasional question that I find has received little enough helpful attention for me to respond without giving too much of the answer away.

I have said that I get enjoyment from answering questions. And maybe I am a little more than averagely susceptible to enjoying the fulfilment that comes from that. But there are many people that seem to have a much stronger desire for that fulfilment than I. Many of the responders have made tens of thousands of posts to the forums, and their presence can be seen in most of the questions ever asked. Those that have responded to very large numbers of questions have little electronic trophy icons below their on-line avatar, saying things like ‘Homework Helper’. It reminds me of the Fat Controller, who would occasionally, when Thomas or one of his friends had done especially well, reward them by proclaiming that they were a Really Useful Engine – the ultimate accolade!

Why do people like helping so much on the internet? This wish to be useful is so widespread, and so strong. And it isn’t mirrored in off-line life – or is it? Perhaps it is. Most doctors appear to enjoy being consulted by family and friends on the selection of a surgeon for Tristram’s grommets, and I’m sure the electrician would revel in the opportunity to dispense wisdom on the difference between the connections of a Neutral and an Earth wire, as long as they weren’t then dispatched to the attic to do some free clipping and splicing. I once consulted an electrician on just this topic and, as far as I could tell, they enjoyed providing the information.

Is it possible to harness this human tendency? There are so many people in the world that need help and don’t get it. Maybe it is. But on the other hand maybe the seeming disconnect between the large number of willing advisers on the internet and the large number of people in real life desperately needing help can be explained by the above-mentioned difference between advice and work. Giving advice is often easy, takes little time, costs nothing and is a social activity, as one does it in conversation with the advisee. Work, on the other hand, whether it be fixing wires, taking photos, preparing a pathology slide, or constructing a Monte Carlo model to measure financial risk is time-consuming, usually solitary and often frustrating.

There are exceptions. I’ve always liked the idea of raising a barn, like the Amish do in Pennsylvania, because it seems such an enjoyable, social, neighbourly form of work. Sadly, not many barn raisings happen in my neighbourhood.

Andrew Kirk

Bondi Junction, August 2015


Metaphysics as a creative craft

In my writings I have not infrequently been dismissive of metaphysics, arguing that most metaphysical claims are meaningless, unfalsifiable, and of no consequence to people’s lives (leaving aside the unfortunate historical fact that many people have been burned at the stake for believing metaphysical claims that others disliked).

Perhaps it is time to relent a little – to give the metaphysicians a little praise. At least I will try. The basis for this attempt is a re-framing of what metaphysics is about. Instead of thinking of it as a quasi-scientific activity of trying to work out ‘what the world is like’, perhaps we could instead think of it as a creative, artistic activity, of inventing new ways of thinking and feeling about the world. Metaphysics as a craft, as delightful and uncontentious as quilting.

Why would anybody want to do that? Well I can think of a couple of reasons, and here they are (except that, like the chief weapons of Python’s Spanish Inquisitor, the number of reasons may turn out to be either more or less than two).

We know that there is a very wide range of human temperaments, longings, fears and attachments. A perspective that is inspiring to one person may be terrifying to another, and morbidly depressing to a third. For instance some people long to believe in a personal God that oversees the universe, and would feel their life to be empty and meaningless without it. Others regard the idea with horror. Some people are very attached to the idea that matter – atoms, quarks and the like – really, truly exists rather than just being a conceptual model we use to make sense of our experiences. Philosophical Idealists (more accurately referred to as Immaterialists) have no emotional need for such beliefs, and accordingly deny the existence of matter, saying that only minds and ideas are real. Indeed some, such as George Berkeley, regard belief in matter as tantamount to heresy, which is why the subtitle of his tract ‘Three dialogues between Hylas and Philonous‘, which promoted his Immaterialist hypothesis, was ‘In opposition to sceptics and atheists‘.

So the wider the range of available metaphysical hypotheses, the more chance that any given person will be able to find one that satisfies her, and hence be able to live a life of satisfaction, free of existential terror. Unless of course what they really long for is existential terror, in which case Kierkegaard may have a metaphysical hypothesis that they would love.

One might wonder – ‘why do we need metaphysical hypotheses, when we have science?‘ The plain answer to this is ‘we don’t‘. But although we do not need them, it is human nature to seek out and adopt them. That’s because, correctly considered, science tells us not ‘the way the world is‘, but rather, what we may expect from the world. A scientific theory is a model that enables us to make predictions about what we will experience in the future – for instance whether we will feel the warmth of the sun tomorrow, and whether if we drop an apple we will see it fall. Scientific theories may seem to say that the world is made of quarks, or spacetime, or wave functions, but they actually say no such thing. What they say is, if you imagine a system that behaves according to the following rules – which might be rules about subatomic particles like quarks – and you observe certain phenomena (such as my letting go of the apple), then the behaviour of that imaginary system can guide you as to what you will see next (such as the apple falling to the ground).

It’s just as well that scientific theories say nothing about ‘the way the world is’, because they get discarded every few decades and replaced by new ones. The system described by the new theory may be completely different from that described by the previous one. For instance the new one may be all about waves while the previous one was all about tiny particles like billiard balls (electrons, protons and neutrons in the Rutherford model of the atom). But most of the predictions of the two theories will be identical. Indeed, if the old theory was a good one, it will only be in very unusual conditions that it makes different predictions from those of the new theory (eg if the things being considered are very small, very heavy or very fast). So by recognising that scientific theories are descriptions of imaginary systems that allow us to make predictions, rather than statements about the way the world is, we get much greater continuity in our understanding of the world, because not much changes when a theory is replaced.

I think of metaphysics as the activity of constructing models of the world (‘worldviews’) that contain more detail and structure than there is in the models of science. We do not need the more detailed models of metaphysics for our everyday life. Science gives us everything we need to survive. But, being naturally curious creatures, we tend to want to know what lies behind the observations we make, including the observations of scientific ‘laws’. So we speculate – that the world is made of atoms like billiard balls, or strings, or (mem’)branes, or a wave function, or a squishy-wishy four-dimensional block of ‘spacetime’, or quantum foam, or ideas, or noumena, or angels, demons, djinn and deities. This speculation leads to different mental models of the world.

So metaphysics adds additional detail to our picture of the world. Some suggest that it also adds an answer to the ‘why?’ question that science ignores (focusing only on ‘how?’). I reject that suggestion. As anybody knows that has ever as a child tried to rile a parent with the ‘but why?’ game, and as anybody that has been thus riled by a child knows, any explanation at all can be questioned with a ‘but why?’ question. No matter how many layers of complexity we add to our model, each layer explaining the layer above it, we can always ask about the lowest layer – ‘but why?’ Whether that last layer is God, or quarks, or strings, or the Great Green Arkleseizure, or even Max Tegmark’s Mathematical Universe, one can still demand an explanation of that layer. By the way, my favourite answers to the ‘But why?’ question are (1) Just because, (2) Nobody knows and (3) Why not? They’re all equally valid but I like (3) the best.

Some of these mental models have strong emotional significance, despite having no physical significance. For instance strong solipsism – the belief that I am the only conscious being – tends to frighten people and make them feel lonely. So most people, including me, reject it, even though it is perfectly consistent with science. Some people get great comfort from metaphysical models containing a god. Others find metaphysical models without gods much more pleasant.

So I would say that metaphysics, while physically unnecessary, is something that most people cannot help doing to some extent, and that people often develop emotional attachments to particular metaphysical models.

Good metaphysics is a creative activity. It is the craft of inventing new models. The more models there are, the more people have to choose from. Since there are such great psychological and emotional differences between people, one needs a great variety of models if everybody that wants a model is to be able to find a model with which they can be comfortable.

Bad metaphysics (of which there is a great deal in the world of philosophy) is trying to prove that one’s model is the correct one. I call this bad because there is no reason to believe that there is such a thing as ‘the correct model’ and even if there was one, we’d have no way of finding out what it is. There can be ‘wrong’ models, in the sense that most people would consider a model wrong if it is logically inconsistent (ie generates contradictions). But there are a myriad of non-contradictory models, so there is no evidence that there is such a thing as ‘the right model’. Unfortunately, it appears that most published metaphysics is of this sort, rather than the good stuff.

It’s worth noting that speculative science is also metaphysics. By ‘speculative science’ I mean activities like string theory or interpretations of quantum mechanics. I favour Karl Popper’s test for whether a model is (non-speculative) science, which is whether it can make predictions that will falsify the model if they do not come true. A model that is metaphysical can move into the domain of science if somebody invents a way of using it to make falsifiable predictions. Metaphysical models have done this in the past. A famous example is the ‘luminiferous aether’ theory, which was finally tested and falsified in the Michelson-Morley experiment of 1887. Maybe one day string theorists will be able to develop some falsifiable predictions from the over-arching string theory modeli that will move it from the realm of metaphysics to either accepted (if the prediction succeeds) or discarded (if the prediction fails) science. However some metaphysical models seem unlikely to ever become science, as one cannot imagine how they could ever be tested. The debate of Idealism vs Materialism (George Berkeley vs GE Moore) is an example of this.

So I hereby give my applause to (some) metaphysicians. Some people look at philosophy and say it has failed because it has not whittled down worldviews to a single accepted possibility. They say that after three millenia it still has not ‘reached a conclusion’ about which is the correct worldview. I ask ‘why do you desire a conclusion?‘ My contrary position is to regard the proliferation of possibilities, the generation of countless new worldviews, as the true value of metaphysics. The more worldviews the better. Philosophy academics working in metaphysics should have their performance assessed based not on papers published but on how many new worldviews they have invented, and how evocatively they have described them to a thirsty and variety-seeking public. Theologians could get in on the act too, and some of the good ones (a minority) do. Rather than trotting out dreary, flawed proofs of the existence of God. the historicity of the resurrection, or why God really does get very cross if consenting grown-ups play with one another’s private parts, they could be generating creative, inspiring narratives about what God might be like and what our relationship to the God might be. They could manufacture a panoply of God mythologies, one to appeal to every single, unique one of us seven billion citizens of this planet. Some of us prefer a metaphysical worldview without a God, but that’s OK, because if the philosopher metaphysicians do their job properly, there will be millions of those to choose from as well. Nihilists can abstain from all worldviews, and flibbertigibbets like me can hop promiscuously from one worldview to another as the mood takes them.

We need more creative, nutty, imaginative, inspiring metaphysicians like Nietzsche, Sartre, Simone Weil and Soren Kierkegaard, not more dry, dogmatic dons that seek to evangelise their own pet worldview to the point of its becoming as ubiquitous as soccer.

Andrew Kirk

Bondi Junction, January 2015

i. Not just a prediction of one of the thousands of sub-models. Falsifying a sub-model of string theory is useless, as there will always be thousands more candidates.