Science – Page 7 – Me on the net

Trust

English: Feathers and wedges are being used to... — English: Feathers and wedges are being used to split a large slab of sandstone. A three pound sledge hammer is being used to drive the wedges into holes drilled in the stone. The crack is just visible as a ragged line connecting the holes. (Photo credit: Wikipedia)

“Trust me, I know what I’m doing”. Sledge Hammer’s famous line encapsulates many things about trust in its seven words. The ironic twist is that the first iconic series ends with Hammer saying the words as he tries to dismantle an atomic bomb. He is not successful!

Trust is a belief that the person or thing that is trusted can be relied upon to do what is promised. There is trust between you and the bank. You trust them to look after the money that you hand over to them to invest and maybe pay you some interest. You also trust them to give you the money back when you request it. There may be conditions on the investment, such as minimum deposit periods or maximum withdrawals, interest rates and so on, but fundamentally you can get you money back.

California Bank & Trust Building in LA (Photo credit: Wikipedia)

Similarly the bank may loan you money, under conditions, which you can use to purchase a house, or a boat, or for any other reasons. They trust you to pay back the loan sooner or later, together with interest, and have the right to pursue you through the law if you don’t repay it.

The money in your pocket requires you to trust in it. After all the value of ordinary coins and notes in terms of the metal and paper is negligible, although gold sovereigns are nowadays worth much more than their nominal one pound sterling. Every coin or note represents something much more nebulous than the distinct coins and notes. Early notes had a “promise to pay” written on them, with the signature of a financial authority to encourage people to trust in them as money.

Hammer’s exhortation implies that his companions don’t trust him, which is ironic because, in a back-handed, gun-related way, he usually did. As is evidenced by the way that he encouraged a suicidal jumper to abandon his intents by shooting chunks out of the ledge that the jumper was standing on. His companions’ distrust was related to the non-standard way that he approached problems and their prior knowledge of his previous actions in such circumstances.

As in Hammer’s case, when two or more people interact, they need to trust each other in many ways. Threats are promises of harm, and there may be promises of benefits. Two people may form an alliance against a joint threat, and in such a case they need to trust each other. Each one trusts the other to back them up.

Often conditions are written down in the form of a contract. All the things that are expected by both parties, that are promised by both parties, or as many of them as can be, are written down, and both parties make their mark or sign the document. The contract can be authorised by a third-party or each party may merely carry away a copy of the document.

A contract strengthens the trust between two parties. If a contract in place, goes the reasoning, then all parties know exactly what is required of them, and what the consequences are if one party or another doesn’t do what is required. If there is complete trust between two parties, then no contract would be required, of course, but there never is complete trust.



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However we trust other people all the time without contracts or other documentation. In fact we are sometimes too trusting. Sometimes nefarious characters arrive on our doorsteps and we let them in if they, for example, claim to be from the Gas Board. It is recommended that we always ask for proof of identity if someone who we don’t know knocks on the door. Of course we have to trust the proof of identification if any is proffered, and it could conceivably be faked.

This brings up and issue about trust – we can never be absolutely sure that we can trust someone. We could know someone very very well and still not be absolutely sure that we can completely trust them. The extent to which we cannot completely trust them may be very very small of course.

We cannot even completely trust someone when we have a contract with them. Unexpected occurrences may occur which are not covered by the contract, but relate the the matter that the contract covers. If one of the parties to the contract dies then what happens to the provisions of the contract? Well, there are laws, of course, that relate to contractual matters and it may be that lawyers are needed to sort such matters out.

There’s another sort of trust, other than trust between people. We trust the laws of science. If we throw something up into the air we expect it to come down again. We expect and trust that the sun will come up tomorrow, and it appears that we are justified in our trust. Through many millennia we have trusted that the whole is a sensible logical place where everything has a cause and cause and effect go hand in hand.



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There is a dissenting voice and that voice is the voice of religion. Religions espouse the concert of miracles, that is occasions when the laws of nature are violated, as for instance, water is changed to wine, or a flood covers and destroys the whole earth.

We may trust that the world is a logical place, but we cannot prove that it is. If we keep throwing stones into the air, it is conceivable that one might not come down again. While we can verify that throwing stones into the continues to work, we may for some reason experience a case where the stone does not fall to the ground again.



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If the stone doesn’t come down, our instinct is to look for a reason why it did not, rather than suspect that the law of gravity has been repealed. We trust the law of gravity. The stone may have lodged on a roof of course, or been caught by a passing bird. After we have considered all the possibilities then we might suspect that the law of gravity as we know it has failed.

So we pass it over to the physicists to look into the matter, and they would ponder and experiment, and eventually, we hope come up with a modification to the law of gravity to cover our “special case”. And we can trust the law of gravity again. For now.

Animation showing the motion of a small body (... — Animation showing the motion of a small body (green) in an elliptic orbit around a much more massive body (blue). (Photo credit: Wikipedia)

So, the question arises, when we have found out all that there is to know about the Universe and so be able to predict anything with 100% accuracy. Well, suppose our knowledge of the laws of the Universe is 80% accurate. There’s an old adage that says that the first 80% of anything takes 80% of the time, and the remaining 20% also takes 80% of the time. In other words it is feasible that we could know all the laws of the universe and be able to apply them, but there probably isn’t enough time.

In the meantime, I’m going to trust that the sun is going to come up tomorrow, as, after all 80% is still pretty good!

Consciousness continues to amaze and elude



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I make no excuse for returning to the topic of consciousness. It’s a phenomenon that, apparently, everyone experiences, and almost certainly some animals experience it too. However, it is the ultimate in subjectiveness. No one except yourself knows how you experience consciousness.

It can’t currently be measured and we can only detect it by the behaviour of a person. The old chestnut of a comatose patient coming round with hovering relatives and medical staff is familiar to all. “He’s coming round!” says a person at the bedside as the patient’s eyes flicker and his muscles twitch.

English: Man in coma still not responding to s... — English: Man in coma still not responding to stimuli. (Photo credit: Wikipedia)

This is not a reliable way of determining consciousness. People have surfaced from comas or anaesthetics and have reported that contrary to the physical evidence they were in fact conscious for at least some of the time when they were comatose. Also, deep brain scans have shown changes which may indicate that the patient was responding to question in that his brain patterns changed, which has led to a medical furore. There is disagreement as to whether or not the changes in the brain indicate that the patient was in fact conscious.

Definition of “Conscious”

1.

a. Characterized by or having an awareness of one’s environment and one’s own existence, sensations,and thoughts. See Synonyms at aware.

b. Mentally perceptive or alert; awake: The patient remained fully conscious after the local anesthetic was administered.

2. Capable of thought, will, or perception: the development of conscious life on the planet.

The fact that consciousness is an objective phenomenon (so far as we can currently tell) means that we can only subjectively assess if it exists in a person. Even if a person behaves as if he or she were conscious, feeling pain, drinking beer, doing all the things that a conscious person would do, how does one know that this person is actually a conscious person? It is conceivable that what looks like a person is a sort of zombie, programmed to behave exactly like a conscious person would behave.

(These philosophical zombies are not like the usual cinematic concept of a zombie – they look like ordinary people, they have not died and revivified, bits do not fall off them, and they don’t have a hunger for brains. It’s a technical philosophical term).

The short answer is that there is currently no objective was to tell. Everyone except yourself might be a zombie. Erm, although I subjectively know that I am not, which might mean that I am the only conscious person in a world of zombies. It’s probably simplest to argue, that I am conscious, and I appear to be little different to everyone else, so it would be silly to argue that everyone else is a zombie. It’s much more likely that we are all subjectively conscious in our own heads.



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Consciousness appears to be an aspect of the brain/mind. If parts of the brain are destroyed, or momentarily shocked by a blow, consciousness ceases and the person becomes unconscious. As above, though, it is conceivable that a person might not be able to move or respond, but still be conscious in the prison of their skull. It sounds like a particularly unpleasant fate.

Consciousness appears to be an emergent property of the brain/mind, because there does not appear to be a particular part of the brain that is related to consciousness as such. I think that it is fair to say this, though I haven’t delved into the subject much recently, though I do read things as I write these posts. In doing this I read an article on The Time website which hits many of the same high notes as I’ve hit here. It’s nice when I find an article that does that!

An emergent phenomenon is something like a family or a sports team or a termite nest. The emergent phenomenon is not implicit in individual members of the family or the sports team or the termite nest, but all the members make up a new entity which has an identity of its own.

Emergent phenomenon rely on the synergistic effect of all the members working in a concerted way to achieve more than a single individual can achieve by themselves. (Emergent phenomenon are not restricted to social interactions – water is wet, though an individual water molecule cannot really be considered to be wet in itself).

Synergy-reaching-with-kite (Photo credit: Wikipedia)

It follows that, just as the higher animals band together into families, bands and packs, which is an emergent phenomenon seen in humans societies, that the brains/minds of some animals are likely to experience the emergent phenomenon of consciousness, as they behave as if they do. It is highly unlikely that consciousness only evolved in one species, though of course it is possible.

Opponents of the idea that animals may exhibit consciousness suggest that we are anthropomorphising when we detect conscious behaviour in animals, and that they may be be zombies (in the philosophical sense of the word), and that the apparent consciousness is merely behaviours that are instinctive.

Of course, no one knows for sure if animals do experience consciousness or not. I rather feel that it is likely that they do, and the extent to which they do is determined by how sophisticated their minds and brains. Certainly, I feel it is unlikely that consciousness is controlled by a genetic on/off switch and that it evolved in animals in the same way as any other trait, that is gradually, and our near relatives on the genetic tree are to some extent at least conscious.

If this is so, then consciousness in animals other than ourselves inform ethics – we should treat animals as if they are conscious beings, as far as we can. I read a science fiction story once in which every being on the earth got a boost in brain function as a result of the earth leaving any area of space where a brake was put on brain function by some physical field or similar phenomenon.



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The human race immediately became super-intelligent, and apes became at least as intelligent and conscious as we were. Also other animals, which we used as food sources became to some extent aware. As the story ended one of the characters was musing on this fact and suggested that maybe a religion of self-sacrifice could be given to these animals so that we could continue to eat them. I’d suspect that, more likely, the human race would become vegetarian! Or possibly, as suggested in the story, we would employ the apes to do the dirty work for us.

Seeing things



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I sometimes suspect that I return to the same topics time and again. Not too often I hope, because that will put people off reading this blog (in case anyone does!) This is possibly a topic which I may have already addressed, but hopefully this post will be interesting anyway.

It seems obvious to me that we all see things differently, and I’m talking about vision here, not “seeing” as a philosophical point of view. Some are short sighted, some long sighted, and others have impaired vision. I see a colour as a shade of blue, while my wife sees it as a shade of green.

One could argue that the difference is merely where the line is drawn, but I think that it is more than that. Apart from the physical differences in the lenses of our our eyes, we may have differences in the physical structure of the rest of our eyes, perhaps in the rods and the cones, and it is highly likely that the physical structures of our brains are different, and our minds (which I think of as the software that runs of the hardware of the brain) are definitely different.

It’s no surprise then that my wife and I disagree on whether a colour is a shade of blue or of green. (Actually we disagree about a lot of things. I believe that it goes with being married for 40+ years!)

Plymouth Valiant 100 of some 40 years ago seen... — Plymouth Valiant 100 of some 40 years ago seen on street in New Orleans (Photo credit: Wikipedia)

In Googling around as I write this post I found an article about the brain’s colour processor. Interestingly it has a section entitled “Color is Personal” which is a part of my theme for this post. This section, however, is not really relevant to my theme as the author then discusses Achromatopsia, where damage to the colour processor causes all sensation of colour to disappear.

It seems that even in our own brains and thinking processes the idea of colour is not fixed. I read another article which describes our own personal perception of colours as “malleable”. The implication of this is that a person might describe a colour as “a shade of green” one day, and “a shade of blue” on another day. Is there no hope of a definitive answer?

A physicist could help us out, couldn’t he/she? He/she could measure the frequency of the light and say, definitively, that the colour is blue, or it is green, couldn’t he/she? Well, sort of. This would work for very simple colours, but real world colours are rarely made up of just one colour. The scientist’s scope would likely show a range of frequencies resembling a mountain range. That blue/green colour might have traces or red or violet, and is fairly certain to have more than one peak in the blue/green range.

Albert Einstein showed us that if a scientist was moving at a high speed relative to us, he/she would measure the frequencies in the colour differently from a scientist whose spectroscope was alongside us and not moving or moving at the same speed as us.

General Relativity (Photo credit: Wikipedia)

The ambient light has an effect on the colours that we perceive. A red object in red light doesn’t look red. Other objects of different colours look different in a red light. Similarly, it is difficult to determine the colours of cars and other objects under the yellow/orange sodium lights. According to Wikipedia, the colour of a street light has effects other than simple colour perception – it appears to affect peripheral vision. New LED technology may be able to remove some of these deficiencies.

There are innumerable effects which affect or perception of colour. The most recently famous illusion is the dress which appears to people to be either black and blue or white and gold, but there are many such illusions. One which I came across a long time ago is the chessboard illusion. In this illusion, two square appear to be different colours, but are in fact the same colour. This illusion is usually shown in monochrome, but the illusion works in colour too, and depends on the shadow of the cylinder to produce the effect.



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One brain is very like any other brain. When a scientist shows someone a colour on a card, the same areas of the brain show activity in all individuals, if we exclude some cases where brain function is abnormal for some reason. We can’t delve very much deeper into this issue as we don’t know what this activity signifies, beyond the bare fact that the person was shown a card with a colour on it. We certainly can’t tell if they see it as a shade of blue or a shade of green, and we can’t tell what their subjective experience is when the brain activity occurs.

In some individuals a number or letter may invoke a sensation of colour. Such people might have the sensation of seeing something green when they think of or read the number 6. I don’t know if this imprinted behaviour because the person was presented with a green symbol when first learning their numbers or whether or not it was merely a chance association that arose at a different time, or indeed if it was because of some neurological happening or trauma that has allowed the association to happen.

Anyhow, when we see something, there are many stages to the process that starts with light leaving the object, reaching our eyes, being refracted by the lens of the eye to form an image on the retina at the back of the eye, being sensed by the rods and cone cells in the retina, and sending signals to the brain, which then processes the data.

The amazing thing here is that the image sent to the brain is pretty messy. The eye is not a perfect sphere, the retina is curved in three dimensions and the resolution is pretty rubbish. The retina has at least one major gap in it, rods and cones are not evenly distributed across the retina. Our perception however, is smooth and break free. We have our image processing hardware and software in the brain to that for that.

It means we can watch a soccer match, and we can see the black and white panels or the ball rotating as it spins across the television screen, when the unprocessed image that reaches our eyes may be quite blurred. Seeing is believing!



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A Miscellany



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I’m going to try something different in this post. I won’t try to stick to a single theme, but will try to create a miscellany of short themes and see how it goes.

Firstly, a friend of mine is a keen photographer who keeps a blog and for five years he has posted one or more photos to his blog every day. It’s a fantastic achievement, and since I have trouble posting once a week, I can only imagine the persistence, application and diligence needed to post once every day.



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I’ve mentioned before that I have started blogs at various times in the past and have been unable to keep them going. This time around, for reasons that I can’t really fathom, I have managed to keep going for coming up to 150 posts now. If Brian succeeds in reaching 5 years of posting he will have posted over 1,870 times. Which is mind-boggling!!

One of the reasons that he has given for dropping his self-imposed regime of daily posting is that he feels that the quality of his posted pictures is possibly suffering from the requirement to post something every day and that the temptation to post a merely adequate (from his point of view) picture just to keep the chain going is strong.

English: Locomotive in KiwiRail livery (not a ... — English: Locomotive in KiwiRail livery (not a particularly good photo, but perhaps adequate until a better is found) (Photo credit: Wikipedia)

I must say that I have not seen any deterioration in his pictures, but I don’t look at them with his eyes. So I will continue to look forward to his posts, even though he will not be posting daily pictures once he reaches the 5 year target.

Of course, this has made me think about this blog and how long I intend to keep it going. I’ve posted nearly 150 times so far which represents a bit under three years. I’d like to reach at least 5 years too, which will be around 250 posts. That’s the current target, so let’s see if I can reach it.

English: 250 West Pratt Street in Baltimore (Photo credit: Wikipedia)

Next topic. If I was able to ask God a question, I would say “Quantum Physics. What were you thinking!” We like to think that the universe is logical and consistent. If it wasn’t then there would be no guarantee that the sun would not blink out 10 seconds from now. 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0! OK we are fine this time.

I’m told, and I have an inkling about it from my reading and thinking, that Quantum Physics is logical and consistent. However the various popularizations of it appear counter intuitive and paradoxical. How can Schroedinger’s poor cat be both alive and dead? What exactly is a superposition of states? What (if anything) is the “collapse of the wave form”?

Omega-Point-Multiverse (Photo credit: Wikipedia)

General and Special Relativity were considered mysterious and paradoxical when Einstein first published his papers. At the time someone claimed that only three people in the world truly understood it, but it didn’t take long for it to be taught down to college and undergraduate levels. While strange and challenging, it was soon accepted as true by the majority of people who had come across it, although people still create web sites where they try to prove that Einstein was wrong.

Quantum Physics is also taught at undergraduate levels I believe but it remains (or so I get the impression) as a work in progress. The famous Copenhagen Interpretation was formulated around 90 years ago by Niels Bohr and Werner Heisenburg and there is still no accessible standard interpretation that is accepted by the majority.

Niels Bohr once said “Anyone not shocked by quantum mechanics has not yet understood it.” Richard Feynman said “Nobody understands quantum mechanics.” So, God, Quantum Physics. What were you thinking about?

Flags and things. There is a big debate in this country at the moment about whether or not to change the flag. People often refer to the Canadian flag as a case where a new flag was adopted after public discussion. It’s not a good case study though as the actual adoption of the winning flag involved a farcical mistake : “Through a six-week period of study with political manoeuvring, the committee took a vote on the two finalists: the Pearson Pennant (Beddoe’s design) and the current design. Believing the Liberal members would vote for the Prime Minister’s preference, the Conservatives voted for the single leaf design. The Liberals, though, all voted for the same, giving a unanimous, 14 to 0 vote for [it]”. (From Wikipedia).

The process for our new flag was decided on early. Firstly all submissions would be reviewed, and a “top 40” would be selected by a panel composed of, basically, a bunch of celebrities and other. No disrespect to them, but they were not flag experts, and if they were chosen to sort of represent the man/woman in the street that is what they achieved.

Of the top 40, four were “approved” by the ruling National cabinet. It’s not too clear how this was done, but only conspiracy theorists would contend that three out of the four contained the fern emblem that the Prime Minister favoured and that he somehow influenced the selection.

Stjórnarráðið in Reykjavik, the seat of the ex... — Stjórnarráðið in Reykjavik, the seat of the executive branch of Iceland’s government (Photo credit: Wikipedia)

Now we have the top four we are supposed to vote in a referendum to pick one to go up against the current flag in a second referendum. Interestingly a group has been formed to promote a fifth design (originally in the top 40) over the top four. We will see where if anywhere that this movement goes. I’d guess it will eventually fail.

One hundred words to go. Interest is high on the attempt of Jarryd Hayne, a former Australian rugby league player who has secured a spot in San Francisco 49ers NFL team. (That’s what is called “American Football” everywhere except the USA). Good luck to him, I say. I expect to see a surge of popularity for the sport in this part of the world.

He seemed to bring something new to the American game, but time will tell if opposition coaches find ways to nullify his effect or whether other players will adopt some of his style, which to my naive eye seems to be a more fluid running game. Or maybe he really is an exceptional player. Time will tell.

Well, I quite enjoyed jumping around through various topics but I don’t think that I will do it every time. I’ll just take it as it comes.

A show jumping course (Photo credit: Wikipedia)

Cycling through life

I’ve been thinking about cycles. A cycle is something that repeats, like the rotation of a wheel, or the rotation of the earth. A true cycle never has an end until something external affects it, and the same is true for the start of a cycle in that something external to the cycle has to happen to start the cycle off.

Conceptually, a perfect cycle would be something like a sine or cosine wave. It’s called a wave because if plotted (amplitude versus time) it resembles a wave in water, with its peaks and troughs. It’s fundamental constants are the distance between the waves and the amplitude of the maximum of each cycle.



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The sine and cosine waves are derived from a circle – when a radius of the circle rotates at a constant rate, the sine and cosine can be measured off a diagram of the circle and the rotating radius. The point where the radius touches the circle is a certain distance above the horizontal diameter of the circle and is also a certain distance to the right of the vertical diameter of the circle. If the radius of the circle is one unit, then the sine is the height and the cosine is the distance to the right.

As the radius sweeps around the circle the sine of the angle it makes to the horizontal diameter goes from zero when the angle is zero and the radius lies along the horizontal diameter to one unit when it is at 90 degrees to the horizontal diameter. When the angle increases further, the sine decreases until it is again zero at 180 degrees, and as it sweeps into the third quadrant of the circle it goes negative, increasing to one unit again at 270 degrees (but downwards) and finally returning to zero at 360 degrees. 360 degrees is (simplistically) the same as zero degrees and so the cycle repeats.

The cosine starts at one unit at zero degrees, decreases to zero units at 90 degrees, decreases further to one unit downwards (conventionally called minus one) at 180, then increases to zero again at 270 degrees and finally to complete the cycle, it increases to one unit at 360 degrees.

When plotted against the angle, the sine and cosine produce typical wave shapes, but shifted by 90 degrees. If the radius rotates at a constant speed, the sine and cosine can be plotted against time, which produces a curve like the track of a point on a wheel as it is rolled at constant speed.

animation of rolling circle generating a cyclo... — animation of rolling circle generating a cycloid; black and white, anti-aliased (Photo credit: Wikipedia)

While these curves are pleasingly smooth and symmetrical, in the real world we can only get close to these ideals. A wheel will slip on the surface that it is turning on, friction on axles slows a freely spinning wheel, lengthening each “cycle” by small amounts, altering the curves so that they are minutely different at different times.

If an ellipse is drawn inside the circle such that it touches the circle at the points where circle touches the horizontal diameter, the radius will cut the ellipse at some point and it turns out that the curves plotted from the intersection point are still sine and cosine curves. However the heights or amplitudes of the curves are different.

An ellipse is approximately the shape of the orbit of a planet about a sun for reasons that I won’t go into here. It isn’t an exact ellipse, mainly because of the effects of other bodies, though it is accurate enough that things like the length of a planet’s year doesn’t vary significantly over many lifetimes. The most accurate atomic clocks can be used to measure the differences but they only need to be adjusted infrequently by very small to keep in line with astronomical time.

To account for these errors the astronomer Ptolemy devised an ingenious scheme. An ellipse can be looked on as result of imposing a smaller cycle of rotation on a larger one, a bit like having a jointed rod, with the larger part connected to the centre of a circle and the smaller part connected to the end of the larger part. If the smaller rod rotates at a constant speed at the end of the larger rod then the tip of the smaller rod draws out a more complex path. If the correct rotation rate is chosen, as is the correct starting angle between the two rods, then the tip of the smaller rod will draw out an ellipse.

Circles on an old astronomy drawing, by Ibn al... — Circles on an old astronomy drawing, by Ibn al-Shatir (Photo credit: Wikipedia)

Ptolemy suggested that the variations from an ellipse could be modelled by imposing other smaller cycles on the first two cycles, and indeed this does result in more accurate descriptions of the orbits.

Ptolemy got a bad press because he believed that these cycles were real manifestations of reality, and his system of epicycles on epicycles on epicycles was hugely complex, but his system can be extended to model any physical system to any degree of accuracy required. It can be proved mathematically that his process exactly matches any equation if the process is taken to infinity. It’s one method of fitting a curve to arbitrary data.

In particular Ptolemy was able to use his methods to calculate the distance of the planets, which was a singular success for his method. It is the sort of technique which is used today to calculate the orbits of newly discovered comets – when it is discovered the astronomer has only one point of location so he/she cannot predict the orbit. When the comet’s next position is measured, the astronomer can start to predict the orbit. A third observation can vastly improve the accuracy of the calculation of the orbit.

Subsequent observations allow the orbit to be refined even more until the astronomer can accurately predict the complete orbit of the comet and its periodicity using something like Gauss’ method as described in the link. In essence the procedure of observation, calculation and prediction/re-observation is the same as Ptolemy used, even though the underlying physics and philosophy is different. Ptolemy’s ideas may seem quaint to us, but in his time we knew much less about the universe, and, given the era in which he was working his ideas were not that outlandish. He did not even know that the planets revolved around the sun. He didn’t know about gravity as a universal force.

Early television and that mess of metal on the roof

In the beginning the consumer television set was a large box with a small blurry screen. To successfully receive one of the few channels being broadcast one needed an aerial to pick up the broadcasts. They came in two sorts. One was a huge “H” or “X” shape that was located on the roof and aligned with the signal from the broadcaster. The other was a small device consisting of a base made of plastic and two metal prongs, known as “rabbit’s ears“.

Of the two types you will only see the rabbit’s ears aerial still being used today. Since television has moved from the VHF (Very High Frequency) band to the UHF (Ultra High Frequency) band, television aerials have shrunk in size and the technology has now improved so that television aerials have become the compact roof top Yagi style aerials that are common today.

Nederlands: Schets Yagi antenne (Photo credit: Wikipedia)

Although it is obvious from the shape of the Yagi aerials that they receive a directed signal, I suspect that not many people know why they are the shape that they are. There is only one element that picks up the signal and that is one of the cross bars on the main shaft of the aerial. All others elements (including the mesh element at the back if there is one) serve to concentrate and direct the incoming signal towards the main element or dipole.

This means that the aerial can pick out weaker signals from general noise but it does mean that the aerial must be aligned fairly accurately with the transmitters signal.

There is a new type of aerial that has become common in recent years and that is the dish aerial. Dish aerials are generally used to pick up signals from stationary satellites and need to detect weak signals broadcast from space. The actual dipole is in the small plastic box in front of the dish. The dish is a passive reflector and just concentrates the small signal onto the dipole in the box, much like the Yagi aerial does for UHF frequencies. Satellite signals are of even higher frequency than the UHF ones.



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In the early days of broadcasting and with the use of VHF frequencies, ghosting was a problem. Because early aerials (and “the rabbit’s ear” type of aerials) were not particularly directional they could receive signals which had bounced off various obstacles on their way from the transmitter to the receiver. The reflection from obstacles such as hills and large buildings meant that the receiver would collect signals which had travelled by different routes and hence had taken slightly different times to reach it.

The result of this was that the images on the screen either appeared to have shadows or duplicates. This phenomenon was called “ghosting” and in a bad case it might appear that in a broadcast soccer match that the match was being contested by two teams of twenty two players using two balls.



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This phenomenon is not often seen these days as UHF signals and satellite signals are much more directional and hence do not receive signals bounced from obstacles in their line of view which has a much narrower angle.

In the early days of television technology the electronic equipment in the receivers was in its infancy. The circuits leaked signals between their parts, and components were not as stable as they are today. Valves and other components had to “warm up” to operating temperature and often the oscillators and other circuits tended to “drift” away from the nominal operating frequencies.



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In real terms this meant that those watching the program would often find that the picture would appear to roll up or down the screen. Someone would have to leap up and twiddle the controls at the back of the television to try to stop the picture rolling. Very often the twiddler would adjust the control to stop the rolling, only to find that his or her very presence had affected the circuits and the screen would start to roll as soon as he or she moved away.

Other effects would cause other issues. Unstable circuits would cause the image to shake like a jelly, or tear completely in one or more places. It was a true art form to twiddle the available knobs (of which there were many) to produce a decent and more or less stable picture.



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Screens were small. Early sets had dimensions of perhaps 9 inches (23 cms). Today screens of 50 inches or more are common. Each screen had (in the UK at least) 405 lines all of which were scanned in one or more cycles. The early television tubes were not very accurate and each line could be clearly seen, and so sometimes could the “flyback” as the circuitry returned the beam to the top of the screen for the next scan.

The end effect was a small picture blurred by circuitry instabilities, often with artifacts like the “flyback” lines polluting the picture, and plagued by instabilities, but which showed pictures of news around the world, or educational programs or discussion panels, plays or game shows. And they even broadcast cartoons for the kids. Everyone wanted one, of course!



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Obviously things improved very quickly. Television electronics became much better, and the pictures much more stable especially when transistors were introduced. The screen increased in size, and colour television was introduced. Some would argue that the quality of the television content has dropped dramatically, but that doesn’t change the fact that most people have one or more televisions in their house and it has become the central focus of many lounges and living rooms. Many people have them in bedrooms, bathrooms and kitchens these days.



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It is ironic that broadcast television may well have peaked. More and more people use their television sets to show content that has not been broadcast, but which has been obtained over the Internet. It may be that this network distributed content may totally displace the broadcast television service and that people will no longer be tied to a broadcast schedule, picking up content that they want to watch from a myriad of Internet sources.

In the Zone

(Ugh! I forgot to post this last week. My apologies)

Programming, as I’ve probably said before is a strange occupation. You start with a blank sheet, steal bits and pieces from where ever you can find them and glue them together modify them, add some bits of original (to you) code and try to think of all the possible ways your program can go wrong.

Then you try and break your code (and usually succeed at first). Programming is still very much an art form. Of course things have changed a lot over the years, and we are able to use the work of others to help us in our endeavours, but my first paragraph is still true.

In the beginning there was “Hello World”. This is probably the simplest program that does something visible. It doesn’t take any information in and its output, the words “Hello” and “World” are not very useful in themselves. Actually, I’d say that there is an even simpler program that takes no input, produces no output, and in the process changes nothing. A “null” program if you like.

A programmer writing a new program may well jump in and start coding by grabbing some other code that he or she has access to, but that stolen code was developed, ultimately, from “Hello World” or the null program.

Picture of "hello world" in C by Use... — Picture of “hello world” in C by User:aarchiba. (Photo credit: Wikipedia)

A good programmer is one who steals code from elsewhere and modifies it to do what he or she wants. There is no stigma of plagiarism attached to this process, and it is in fact strongly encouraged that programmers share code. A spoof news item that I came across stated that all programming courses would be replaced with a course on how to find code on “Stack Overflow“. I’ve been unable to find the link again, but I believe that the item was on “The Onion“, a well known satirical website.

Of course, such a process may propagate errors or bugs across many programs, but it is such an effective strategy that it is used more often than not. If code exists to solve a problem then it would be silly to pass it by and write it ones self, maybe introducing bugs to the code. The advantage of “borrowing” code is that while errors and bugs may be in the borrowed code, many eyes will have looked at the code and there is nothing more that programmers like than pointing out bugs in the code of other programmers.

Stack Overflow allows anyone to post code and comment (up to a point), so code posted may not be top quality, but other programmers are quick to jump if they see bugs or inefficiencies in code. Contributors will also point out code which doesn’t follow standards or conventions in the programming language being used. This is considered useful, as the code, if modified, can be accessed and understood more easily, and may often be safer and free of more bugs than unconventional code.



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When a program is written it starts out as literally a few lines of code or even an empty file. Any programmer knows that a program grows swiftly and in ways that can’t be foreseen until it may be of enormous size. It won’t be all written in one sitting but is usually written in stages. I personally like to write my programs in very small chunks, building on what has gone before. I think that many programmers use this process, though there may be others who write a sizeable chunk of code before testing it.

Ah, testing! Testing is the less enthralling parts of writing programs. Any program must be tested, to ensure that it does all that is required and nothing else. Generally the program being written doesn’t do all that is required and does things that shouldn’t happen, and initially it is likely to crash or produce cryptic error messages under some conditions.



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Testing is supposed to reduce the number of such unwanted happenings, and the programmer may do some rudimentary testing and may handle at least some errors. However the programmer will realise that users who are unfamiliar with how the program is written may well do something that he has not expected.

So clever people have developed ways of automatically testing programs. To do this they have had to write the programs that are used to test programs. And of course those testing programs may have bugs. You can see where that leads to!

Zebra (programming language) (Photo credit: Wikipedia)

When a programmer knows a programming language really well, he is able to literally think in that language. The word “literally” has been devalued in recent time, but I am using it in the true sense of the word. This is hard for some people to understand as they think of language as something like French or Tagalog, and they can’t understand how one can think in a programming language, which is qualitatively different from a spoken language.

An interesting thing happens when a true programmer is programming something. His thought processes become so involved in the process of programming and in thinking in the programming language that he loses track of the outside world. That’s why programmers are whimsically thought to subsist on fizzy energy drinks and dialled in pizza. It is because those things are easily acquired and the programmer can keep programming.



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A programmer “in the zone” is so embedded in the world of the program that he or she may often be reluctant to leave that world and respond to irritations like bodily needs and colleagues. I doubt that there is a real programmer who has not surfaced from a deep dive into the depths of a programming problem and realised that all his colleagues have left and it is late at night or very early in the morning. That’s the reason programmers stay after all other people have left – they know that they can slay the current bug with just a few more changes and a few more runs of the program.

The zone has similarities to the state of meditation. While meditation is passive though, programming is an active state. In both cases the person basically disconnects from the world, so far as he or she can, and the concentration is directed internally. Now that I think about it, any deep thought, be it meditation, programming, or philosophising, even playing a sport at a very high level, needs such concentration that much of the world is disregarded and the exponent enters the zone.



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Weather, seasons and Christmas

At this time of the year, we are looking forward to spring, even though spring is officially about a month and a half away, which puts us slap in the middle of winter. There are signs, though, that spring is around the corner. Plants which bloom early in the year are starting to show signs of life, and the buds on some trees are showing some green as they prepare to burst into green bunches of leaves.

Every burst of clear weather seems to produce both warmth during the days and frostiness during the night. It seems that each cycle is slightly warmer than the last but that might just be me wishing an end to winter! The wetter times don’t seem to be bringing the freezing cold wintry blasts, though there is the occasional shower of hail or sleet mixed in.

English: Snow pellet/Graupel Français : Grain ... — English: Snow pellet/Graupel Français : Grain de neige roulée (Photo credit: Wikipedia)

The main reason for the hope that winter is drawing to a close is the now noticeable lengthening of the days. The day length is up from 9 hours and 12 minutes or so at the solstice to 10 hours and 12 minutes or so today. The day is lengthening at a rate of more than 2 minutes per day at the moment.

I don’t mind the cold as such. It’s the constant shrugging on and off of clothes as one transitions between indoors and outdoors that bugs me, and the necessity of keeping the house warm, which in itself means going outdoors to fetch fuel, which of course involves donning extra clothing and all the annoyances which go with that.

There is a sort of seasonal drag in the clothing department, incidentally. I’ve noticed that I tend to resist slinging on the extra clothing in autumn and early winter and I’m likewise reluctant to take it off as the weather and temperatures improve.

Of course, July and August are the warmer months in the Northern hemisphere and northerners will be experiencing shorter days and colder weather. As we track in to spring you Northerners will be heading towards autumn and eventually winter. We will be looking forward to spring and summer, which pretty much bracket Christmas for us.



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Of course, since I originate from the Northern hemisphere myself I have had to become accustomed to having Christmas in summer and I personally think it’s great. With Christmas at the start of summer we can enjoy it without the hassle of keeping warm. It does make the traditional northern Christian festival meal seem a bit heavy though and who want to roast a turkey for hours in warm weather?

It does conflate two events however – the Christmas holiday period and the traditional summer holidays which seem to merge seamlessly into one another. One effect of this is that people seem to be unavailable from Christmas Eve through to the beginning of February, which was something that I had trouble adjusting to when I moved here.

Tradesmen tend to be unavailable from the start of the Christmas period well into the New Year and some smaller shops also close for an extra week or two. Obviously this has its advantages for the shop keepers, but I still feel disappointed when my favourite barber is closed until mid-January!

We have a Public Holiday for the Queen’s Birthday in June (June 1 this year) and the next Public Holiday is on October 26, which means that there is almost 5 months of the year without a Public Holiday during the darkest part of the year. One advantage of having Christmas in mid-winter is that it gives one something to look forward to as the days close in.

Winter is cold, obviously, but that in itself is bearable (up to a point). But there’s a phenomenon called the “chill factor” which makes windy winter days seem much colder. My weather app on my phone tells me that the temperature outside is 6.9 degrees centigrade, but the it “feels like: 4 degrees centigrade. It recommends 3 – 4 layers of clothing and a windproof layer. Brrrrr! Fortunately it doesn’t seem too wet out so walking the dog should not be too arduous.

In this season of the year we tend to get low pressure system after low pressure system forming in the Tasman Sea which bring cold fronts across the country with associated fronts bringing storms and rains. Sometimes they come down from the tropics and hit us from the north, usually bringing warmer but wetter weather from the north. We tend to get better more settled weather when a high pressure system comes to us, spun off from a high pressure system over Australia.

(I took a break and walked the dog. While we out we were hit by what you could euphemistically call a “wintry shower”. In other words, wind, hail and rain!)

Many people from the Northern hemisphere tend to find Christmas in summer unsettling, but I quite like it. I’m not a barbecue person, but the occasional meal taken outside is very pleasant, and it is becoming more usual over here to have a barbecue on Christmas Day. Another advantage is that when one is Christmas shopping one doesn’t have to dodge the weather as one dashes between shops and fights one’s way through the crowds of late shoppers, all after that elusive and critical last gift.

However, although I think that mulled wine is an abomination, there is something pleasant about sipping your favourite alcoholic tipple in front of a roaring fire. Maybe while doing something traditional, like listening to a CD of carols carefully enunciated by Korean choirs who have no word of the English language and who have little to no idea about the traditions involved.

One thing about having winter at this time of the year, it means that I can tease relatives who live in the Northern hemisphere as we climb up towards warmer weather while they slide down to autumn and winter. However I have to acknowledge that they can get their revenge in six months later as the cycle of the seasons continues to repeat. I’ll be looking out the thermal undies when they start talking about snowdrops and crocuses.



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Time and time again



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Well, this will be my third post in a row about time. I think I’ll discuss something else next week!

As I’ve said before, the path of a particle as it travels through space in the usual way can be represented as a line in a four-dimensional space-time system. There will be one and one line only that represents the history of the particle from the time it is created until the moment that it is annihilated. If we decide to plot only this particle’s location over time there will be no others lines in this space.

Diagram showing phase space plot of particle u... — Diagram showing phase space plot of particle undergoing betatron motion (Photo credit: Wikipedia)

The path will twist and turn as the particle is affected by fields and other particles. It may take a sudden turn when our particle collides with another particle. This interaction can be visualised by adding the data about the other particle to the same space-time graphs. However, since the particle is constantly jostled by other particles the diagram would quickly become crowded so to keep it simple let’s drop out the lines of all the other particles.

So we are back to the original single line we started out with. If we assume that it can’t time travel, there will be no loops and gaps in the line. In other words, for every time between its creation and destruction there will be one and only one set of three space coordinates. Of course the line will have curves and kinks as the particle interacts with other particles and fields.

English: The Markov chain for the drunkard’s walk (a type of random walk) on the real line starting at 0 with a range of two in both directions. (Photo credit: Wikipedia)

Suppose we allow choice into our system. Suppose we have two choices A and B. At the point that the choice is made (at a macro level), there are two possibilities for the space-time position of the particle. From that point on the particles history could be represented by an A line and a B line, which at first glance appears to contravene the single point rule. However by making a choice we are saying that either A will occur, OR B will occur, but not both, so we really have only one line.

A choice is not the same as travelling in time though, so let’s plot A AND B, and we will get a multiply branching tree of lines as the time line splits on every point where a choice is made.

The question arises as to which of these lines is the “real” life line of the particle. This we don’t know in advance because we don’t know what the choice will be, which leaves us in the uncomfortable situation of having something unpredictable happening and physics deals in things that can be predicted.

When a choice is made by someone, it is highly likely that one option is much more likely than the other. Maybe the probability is 0.8 to 0.2 (80:20 in percentage terms). Another way of looking at it is to say that, all other things being equal, if the choice were to come up 100 times, A would be chosen 80 times and B would be chosen 20 times. Of course in a 100 tests, it could be that the actual figures might be 79 and 21.

It would be highly unlikely that A would be chosen once and B chosen 99 times in 100 trials of course, but it remains possible. (We have to remember that the circumstances of the choice must be identical, that is, all other things being equal)

We could incorporate this into our system by adding a “probability” axis (running from 0 to 1, or equivalently to 0 to 100). A point on this axis would represent the probability of the choice that was made and the whole sheet represents the life of the particle.



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It appears that two points on the line are axis, the ones at 0.8 and 0.2 are “special”. In the stated situation those at two probabilities of the outcomes A and B. The probability of any other outcome say Z are zero and effectively outcome Z does not exist.

All things being equal there appears to be no physical reason why someone would choose one option over another. It may be that, all things being equal, that one option gets chosen more often than the other, but the sum of all the probabilities is one – in other words it is absolutely certain that one of the options is chosen. I find this totally mysterious. A choice is an event where the outcome is not dictated by the prior history of the event and is decided by the person making the choice.

English: Figure 1. Demonstration of the decisi... — English: Figure 1. Demonstration of the decision space (Photo credit: Wikipedia)

However the person’s mind is making the decision, and the person’s mind is equivalent to the state of his/her brain and the state of his/her brain is determined by physics, chemistry and biology. I see no “wriggle room” to allow for a person to make a choice.

Can we solve this dilemma by introspection? Descartes looked within himself and concluded that “I think therefore I am“. I don’t know if Descartes intended or realised it, but the implication is that thinking, which happens in the mind/brain, occurs before consciousness. In other words, consciousness is an epiphenomenon of the mind, just as the mind is an epiphenomenon of the brain.



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Why then do we think that we make choices and decide things? Well, by introspection I can look at any decision that I have made and I can always point at reasons why I made the choice. Well, of course this may be simple rationalisation. We look at the decision that we made we look at the reasons that might explain why we chose that course and we pick and choose the ones that we like.

While that may be the reasons that we give, and some of them may be true, I do believe that we have reasons for what we do, but those reasons are physical – the configuration of our brains, as a result of past events and happenings, results in a foregone conclusion – we perform an action which looks to the outside world like a decision.

For instance, if we are filling in a form and we are required to check a box, we “choose” the box depending completely on what has gone before. If the boxes are “Male” or “Female” we know what sex we are so naturally we would choose the correct box. No real decision is made. If we are annoyed at the form or we are in a joking mood we might tick the wrong box. It depends on our state of mind before making the decision what we do, and it depends only on that.

English: checkbox, check box, tickbox, tick bo... — English: checkbox, check box, tickbox, tick box Italiano: checkbox, check box, tickbox, tick box (Photo credit: Wikipedia)

Time Travelling

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Time stories have been around for years, and yet we have seen no time travellers. If there are time travellers, then they are hiding from us. That would be pretty hard, since society and language are changing all the time, and they would most likely look out of place.

If they came from the past, their mannerisms, clothing and use of language would likely give them away. Imagine someone from the time of Sir Francis Drake appearing in the current era. He would quickly be spotted.



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For someone travelling from the past, the issue is that he or she would not know what to expect as the present is the future of times past, so they would not be able to prepare themselves for the future, as they would consider it.

If a citizen of the future where to travel to the current time, he or she could presumably prepare his/herself for what would be the past to him/her. The time traveller could learn about our era and equip him/herself with clothes, money and other things from our era and would be able to learn the idioms of the language of the current time, as well as the ethics and morals of the era.

There are web sites on the Internet which claim to have proof of time travel (I’m not going to link to one – a Google search will bring up many of them). In most cases the evidence is far from compelling, relying on blurry photographs and dubious eye witness accounts.

I’ve recently been scanning my old photographic slides and in one of them, from the early 1980s or late 1970s, the person in the picture appears to be holding an iPad! What in fact she is holding is a place mat, with a cream coloured border and relatively dark picture on it. This demonstrates how easily “evidence” of time travel can be found if you look hard, and if you strongly believe that time travel is possible.

Every person, every object, even every elementary particle has position which can be measured (leaving aside the issue of Heisenberg’s Uncertainty Principle and Quantum Physics for now) at any moment in time. The four dimensions, three of space and one of time uniquely identify an event in the life of the person, object or particle.

These four coordinates represent a single point in a four dimensional space. Since we find four dimensions hard to visualise, this space/time is usually represent by a depiction of a three dimensional space of two space and one time coordinate axes. The path of a person, object or particle through life consists of a single unbroken line in the four dimensional space.

Note that in time dimension, if time travel is not possible, for every value of the time coordinate there will only be one point of the person’s life line. In other words, while the person could visit and revisit the same three dimension spot in space many time, they will only pass through a particular time once and once only. A person’s now is unique.

Time travel means that a person could pass through the same moment in time multiple times, and the possibility arises of loops in time. It seems obvious that the same event could not appear on the time traveller’s life line. In other words the loops in a life line would not cross.

To get from one event in space/time to an earlier event in space/time, the person could either travel through the intervening times or just jump from the first event to the second. In other words time travel if it is possible would be represented by a line going backwards in time or it could be discontinuous, with a break the in the person’s time line.

From the point of view of an observer, a discontinuous time line for the time traveller would be seen as a sudden appearances from nowhere and a later sudden disappearance. If the time line is contiguous, the observer would again see a sudden appearance of the time traveller, and then two instances of the time traveller both apparently travelling into the future at one second per second.



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One will be the time traveller doing just that, and the other will be the observer’s view of the time traveller as he travels backwards in time. Eventually the observer will see one of the instances (people!) merge with another instance of the time traveller and disappear. Since we don’t normally observe such sudden appearances and disappearances it’s very tempting to say that time travel does not happen.

To see what I mean, take a piece of paper and draw a line from top to bottom with a look in it. Now horizontal lines across the page represent time as seen by the observer. If you move a ruler down the page, at first there is a single line, the time line of time traveller. But at the point that the time travellers has travelled back to, suddenly there are (apparently) three lines travelling down the page. At the point that the time traveller travels from, two of the lines merge and disappear.

English: Meter stamp catalog image, three stac... — English: Meter stamp catalog image, three stacked horizontal lines (Photo credit: Wikipedia)

If time travel is discontinuous the observer would first see one instance of the traveller, and then another instance would pop into existence. The two would coexist for a time, and then one instance (the original one) would disappear, with the second continuing to exist.

As I said, it’s tempting to say that this proves that time travel is not possible. Certainly, a macro level we don’t see people appearing and disappearing so it is definitely very unlikely, though reasons for this not to be noticed can be constructed.

At an atomic level though, we do see spontaneous generation of particles, into a particle and its anti-particle. If the anti-particle the meet another particle and they annihilate one another, this could be construed to be a single particle with the anti-particle being the particle travelling back in time.

This is bad news for time travellers. To travel back in time by this method, the time traveller would have to be zapped into a burst of energy and an anti-traveller who would then travel back in time to the earlier time when a burst of anti-energy would be required to zap the anti-traveller into another instance of the time traveller. These occurrences would be likely to destroy the integrity of the time traveller’s body. That is it would destroy it.