Time Travelling

Embed from Getty Images

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.

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.

Bruntons Traveller
Bruntons Traveller (Photo credit: Wikipedia)

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.

English: Front of black iPad 2.
English: Front of black iPad 2. (Photo credit: Wikipedia)

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.

Figure showing light crossing the x1 axis and ...
Figure showing light crossing the x1 axis and corresponding representation in optical phase space (Photo credit: Wikipedia)

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.

Spiral loop
Spiral loop (Photo credit: Wikipedia)

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.

Embed from Getty Images

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.

Intended for inclusion in Wikisource article f...
Intended for inclusion in Wikisource article for Flatland (Photo credit: Wikipedia)

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.

Burst Apart
Burst Apart (Photo credit: Wikipedia)


Dwelling in the past

Merlin, from the Nuremberg Chronicle (1493).
Merlin, from the Nuremberg Chronicle (1493). (Photo credit: Wikipedia)

Some accounts have the wizard Merlin living his life from future to past, in the opposite direction to the rest of us. This meant that to him, what would a final farewell to us would be a joyous first meeting for him, and a first meeting would a sad goodbye. He remembered the future, but the past was a complete mystery to him.

Troll becoming a mountain ill jnl
Troll becoming a mountain ill jnl (Photo credit: Wikipedia)

The trolls in Terry Pratchett’s Diskworld had similar ideas. They considered that they travelled through time from past to future, as is normally understood, but they also considered that we were facing backwards in time as we travelled through it. This was conjectured by the trolls, to explain the fact that we can see where we are going when we travel in whatever direction we choose but we cannot see where we are going in time. Similarly we can’t see where we have been when walking from one place to another, but we can see where we have been in time.

discworld town lancre terry pratchett
discworld town lancre terry pratchett (Photo credit: Wikipedia)

Scientists have no difficulties with direction in time. In an equation with a time variable in it, one can trace the changes to other variables from the nominal zero point to see what would occur in the future, merely by incrementing the time variable. A scientist can predict the trajectory of a thrown item (a parabola) merely by substituting later times into the time variable in the equation.

y =ax² + bx + c

The scientist should compare these results to experiment and find, that this more or less works. Lets say though, that the scientist is an astrophysicist investigating an asteroid or other object on a parabolic trajectory around a larger object, like a moon or planet. (A parabolic trajectory is the trajectory which divides objects in hyperbolic trajectories which are not bound by the larger body’s gravity, from those in elliptical trajectories where the object is bound by the larger body’s gravity).

English: Parabola showing relation between the...
English: Parabola showing relation between the focus, directrix, and a point on the curve. (Photo credit: Wikipedia)

The astrophysicist would be able to track the trajectory of the body backwards in time, simply by substituting negative values for time into his equations. He would be able to see where it had been. However this process of substituting negative time values into the equations only works so far. At some point the body will feel the influence of other objects and the retrograde trajectory will deviate from the values predicted by the parabolic equation.

Embed from Getty Images

Of course, if the trajectory is projected forwards far enough similar considerations arise. Eventually some other body will divert the body away from the parabolic trajectory. However in the region in which the parabola  applies, the behaviour is symmetrical with respect to time. From a film of the event one could not tell whether or not the film was being run forwards or backwards.

Of course, if a film is run backwards for any length of time, it becomes obvious that something is wrong. Things fall upwards, and broken crockery comes back together again. People walk backwards.

Embed from Getty Images

On a closer look, people can intentionally walk backwards and it is possible that a spring or other mechanism could be used to shoot things upwards, but it is a lot harder to imagine a way of reversing the breakage of the crockery. It implies that some process involved in the breaking of crockery is not reversible at a macro level.

It is likely that the process in question is at the molecular level or slightly above. To rejoin two broken surfaces spontaneously would presumably require that the molecules be in the correct positions and that a little burst of energy (equivalent to the little burst of energy that comprises the sound that the crockery makes in breaking and any heat release) be supplied at an instant in time. The weak bonds between the parts of crockery would need to be created, and that is really difficult.

Embed from Getty Images

There’s therefore a discrepancy between the scientist’s view of the world, through his equation which time-symmetrical, and the man in the street’s view of the world, which is asymmetrical with respect to time. In fiction this asymmetry is used to good effect, when the protagonist may “wind back time”, to write a wrong or divert history to an alternate course.

When we consider space we usually imagine a three dimensional space. Events happen at locations in this space and three coordinates are enough to locate an event in space. Every possible point in space has its set of unique coordinates. It is common to add an extra dimension for time, making the space four dimension and consequently difficult to imagine successfully.

English: Coordinates as distances from coordin...
English: Coordinates as distances from coordinate planes in 3 space. (Photo credit: Wikipedia)

All events in space and time have a location and time and are represented by a point in the four dimensional space. The path of a particle is a line within this space, and any point on the line represents the position of the particle at a particular time. Positions on the line are either before or after this point, so it constitutes a “now” point for the particle. There is no actual motion over the line, since in the 4-D space all points represent the past and the future of the particle. They are already there.

The Klein bottle immersed in three-dimensional...
The Klein bottle immersed in three-dimensional space. (Photo credit: Wikipedia)

To move to an earlier time, all we need to do is move to an earlier spot on the line. We would need to either travel back along the line at a speed of so many seconds per seconds where the first “seconds” is seconds measured in the space and the second “seconds” is some other time scale or we could jump out of the space-time completely and return to the requisite point earlier in time. We’d need to do the latter in some other space-time that embeds the original space-time, adding a number of extra dimensions to the mix.

Both options require the addition of extra dimensions, which while possible complicates the situation unacceptably to my mind. The process of adding extra dimensions could be repeated and go on forever, so we end up with infinite dimensions. I believe that it is correct to employ Occam’s razor at this point and declare that it appears unlikely that we could either roll back time or jump to an earlier point in time because of the implication that we would needs infinite dimensions as a result.

English: The Church at Ockham William of Occam...
English: The Church at Ockham William of Occam, died 1285 is commemorated in the church in a stained glass window. He gave his name to ‘Occam’s Razor’, whereby in any investigation: follow the obvious path first – it’s likely to be correct. (Photo credit: Wikipedia)



thermographic of a tarantula
thermographic of a tarantula (Photo credit: Wikipedia)

At the time that I write this the temperature at this desk is 12.7 degrees Centigrade. Of course it will warm up soon, but overnight the temperature drops dramatically at this time of year. I hate the cold. As the saying goes it makes your bones ache.

The climate here is “cool to warm temperate”. This means that places in the south see low temperatures which drop to zero degrees Centigrade or a few degrees below, with occasional falls to lower temperatures in some places. Snow rarely lasts long except of course in the mountains and hills.

A powder snow avalanche
A powder snow avalanche (Photo credit: Wikipedia)

In the north, places like Auckland rarely drop to zero, remaining a few degrees above zero in most winters. Auckland and further north rarely experience snow, and a flurry of sleet in Auckland would usually gets a mention on the television news.

While snow rarely lasts long at low altitudes, it tends to come in quantity when it does, closing hill roads and even sometimes brings southern cities to a halt. Dumps at higher altitudes can of course cause severe issues to farmers. The farmers’ worst nightmare is a dry summer and autumn resulting in low yields from pastures followed by an early heavy fall of snow.

English: Entrance to Pike Hall Farm in the snow
English: Entrance to Pike Hall Farm in the snow (Photo credit: Wikipedia)

Of course the skiers rejoice when there is a snow dump and they head for the many ski fields in their hundreds sometimes causing traffic jams on the access roads! Snow for skiing can be undependable so most major ski fields have snow generating machinery as a backup.

When the snow melts the rivers rise of course. New Zealand rivers can be chillingly cold as a result. Many parts of the country have what is know as braided rivers, which appear to be mostly boulder filled for much of the time. Sometimes during a dry spell it may be possible to cross the river from bank to bank without getting one’s feet wet, while a surprising amount of water travels below the surfaces between the boulders.

English: Waimakariri River, Canterbury, New Ze...
English: Waimakariri River, Canterbury, New Zealand. (Photo credit: Wikipedia)

When there is a thaw or after heavy rain such rivers rapidly fill and the water rises to the surface, creating a broad and sometimes heavy flow filling the river bed from bank to bank. The flow can be impressive, carrying large trees and other debris from the higher altitudes down to the lower altitudes.

Consequently there are long bridges on these braided rivers that seem to mostly traverse an expanse of rocks and boulders with maybe a relatively small looking river, possibly split into several channels.

Macquarie River in flood at Bathurst.
Macquarie River in flood at Bathurst. (Photo credit: Wikipedia)

Sometimes the boulder banks are populated by Russell lupins, which can block and change the nature of these braided rivers. While picturesque, the lupins are an introduced species and can damage the river’s ecosystem.

The water in the rivers is cold and can be bone-achingly cold as the water is mainly melted snow from the Southern Alps and other mountain ranges. Consequently swimming in such rivers can be challenging. I have swum in a river in the United Kingdom, wearing a wetsuit, with chunk of ice floating down the river, and that was an experience that I will not forget. The rivers here are likely to be at least as cold.

English: Ice circles in the river Llugwy at Be...
English: Ice circles in the river Llugwy at Betws-y-coed, 31.12.08. There had been no rain for two weeks, so water levels were low, and after a week of sub-zero temperatures, there was ice on the river’s edge in places. (Photo credit: Wikipedia)

Ice is a strange substance. Well, perhaps that should be water is a strange substance. As water is cooled its volume reduces, like other substances. When it reaches four degrees Centigrade however it reaches a maximum density and then starts to expand again, which is counter intuitive. The reason for this behaviour is related to the way that water molecules link weakly to one another, as a result of the polar nature of the water molecule.

So water at 3 degrees Centigrade is lighter than water at 4 degrees Centigrade and so tends to move to the surface of the water. At 0 degrees Centigrade the water turns to ice, which floats on top of the liquid. This allows all sorts of things and protects fish and other aquatic organisms from the elements and from freezing solid, up to a point. It also allows us to skate on the surface of frozen bodies of water since the slight pressure of the blades causes the ice to temporarily melt.

English: A monk ice skating on a frozen river.
English: A monk ice skating on a frozen river. (Photo credit: Wikipedia)

When a human body gets cold, the body has various defences. As warm blooded animals we need to maintain our body temperature and if we don’t we die. So, when we get cold, blood flows to the centres of our bodies to maintain our core temperature, which means that our hands and feet become significantly colder than the rest of our bodies.

If the cold reaches into our core bodies, things start to shut down and hypothermia sets in. Brain function is hit hard and we start to behave irrationally and we would be in danger of dying. Fortunately as humans we have invented things like fire, houses, and clothing to keep us warm when the weather is cold. I personally have problems with maintaining heat as I do not like to wear gloves and I don’t like any form of headgear!

English: W. Stanley Moss behind Fuchs, Hillary...
English: W. Stanley Moss behind Fuchs, Hillary and others, Scott Base, Antarctica, 1958. Commonwealth Trans-Antarctic Expedition. (Photo credit: Wikipedia)

Another thing that I find in cold weather is that my breath passes over my moustache and beard so in colder weather the moisture in my breath condenses on my moustache and beard making them wet, and if it is cold enough the condensed moisture will freeze. My moustache and beard develop icicles.

On cold days everyone likes to sit beside the fire. An open fire, though, is horrendously inefficient! Even a free-standing stove, which radiates heat into the room, sends much of the heat directly up the chimney or flue. Even the radiant heat quickly rises to warm the air in the ceiling of the room. To add insult to injury, the air that keeps the fire burning is drawn from other places in the house, and has to be replaced by cold, cold air drawn into the house making these other places even colder.

English: A fire burning in a fireplace.
English: A fire burning in a fireplace. (Photo credit: Wikipedia)

I’ll conclude by noting that the days are becoming longer and while we are still in the depths of winter, spring is around the corner. Indeed, some early blooming plants are already showing signs of life, although they won’t amount to much until later in the year. The day length here will increase by one minute and 11 seconds tomorrow, and this rate of increase will grow rapidly until the equinox (around 21 September) by which time we should be much more cosy. However due to seasonal lag, we may still have the coldest times for this year ahead of us.

Garden with some tulips and narcissus
Garden with some tulips and narcissus (Photo credit: Wikipedia)

Teamwork and sport

First soccer team of Bagé, called Sport Club B...
First soccer team of Bagé, called Sport Club Bagé, in 1906. (Photo credit: Wikipedia)

A team is an interesting thing – a group of people all with the same aim, working together to some sort of objective. Individually each person knows his role in the team and relies on others in the team to achieve the desired objective. There is a great deal of trust in such a group relationship, as one under performing member can result in the team as a whole reaching their goal.

This interdependence of the team members can lead to strong bonds outside of the group project – the members of a successful team are frequently close friends outside of the team environment. This can make it difficult for a new team member to fit in initially.

English: Ryan Valentine scores the goal that k...
English: Ryan Valentine scores the goal that keeps Wrexham in the Football League. Français : Ryan Valentine marque le but qui permet au club de Wrexham de se maintenir dans la ligue de football. Italiano: Ryan Valentine segna il gol che mantiene il Wrexham nella Football League Deutsch: Ryan Valentine schießt das Tor das Wrexham den Klassenerhalt in der “Football League Two” sichert (Photo credit: Wikipedia)

There may be personality clashes within a team, leading perhaps to physical interactions between team players. The scuffles and fights may well “clear the air”, and allow the team to function better in the team environment with most of the interpersonal tensions resolved or reduced. A divided team will never perform as well as a united team.

English: Kitting up One of the few people to b...
English: Kitting up One of the few people to be happy having his nuts squeezed tight. Helmet mounted torch on the left of the picture and video camera on the right. The diver is reliant on his support team when kitting up. They can’t help with an itchy nose though. (Photo credit: Wikipedia)

A team will have its support staff – in a sports context it will have the manager, the coach, the medical staff, the team drivers and so on. They are so important that they could be considered to be a part of the team, even though they don’t actually play the games themselves in the most part.

This inclusiveness can of course be expanded out as far as the supporters of the team, but this is not usually done. In amateur sport there is more reason to include the supporters as they are usually mothers or fathers of team player and often fill the roles of coaches and managers and provide transport to match for the players.

Embed from Getty Images

Supporters of a professional sports team do have a large role to fulfil though, that of providing the revenue for the team, the support staff, the stadium, and other ongoing expenses.

They also provide support on the game day, but I wonder how much that has an effect. Obviously the crowd will make a noise when the teams first come out onto the field, but when the game is being played it is likely that the players will be concentrating on the game and the crowd noise will just be a background noise.

Embed from Getty Images

Nevertheless, the crowd does have an effect. When the teams come on to the field the players have the leisure to hear them and respond to them and when the team is pressing for a score, the sound level from the supporters is going to increase and be noticeable to the players. However the intensity of play of the attacking team is liable to be higher at those times anyway.

There have been times when matches have been played to empty stadiums, either for safety reasons or if it is expected that friction between the fans would cause violence. Sometimes I, seem to remember, teams can be penalised for some off field offence committed by the fans, the management or the players.

The referee signals that a foul has been commi...
The referee signals that a foul has been committed. (Photo credit: Wikipedia)

It would be interesting to get the teams view of what it is like to play to an empty stadium, but I don’t know if the players have been seriously asked to report what it is like. It’s unlikely to have no effect!

In sport at the grass roots level players are unlikely to specialise over much. They all may take turns at being goalie for example and every kid wants to score goals or touchdowns. Coaches at this level often enforce substitutions and switches so that every kid gets a go and enjoys himself/herself. That’s what sport is about at that level.

Embed from Getty Images

But even at a quite low level player start to specialise, fulfilling a specialist role in the team as defender, or attacker, or bowler or batsman. One player will also be called on to be captain, and read the run of the game and set the strategy. Sometimes the strategic role will not be on the field as in American Football where the coach may make the strategic calls. In this case the captain’s role is much reduced.

Sports, especially the contact sports, can be considered to be ritualised warfare or at least ritualised conflict. It can possibly reduce tensions between different nations or rival groups, but is rarely specifically undertaken to do so, and indeed supporters sometimes come to blows during tense matches. Sportsmen who through personality or skill have an impact on the course of the game are treated like heroes.

English: Jack Williams, a player on the Denver...
English: Jack Williams, a player on the Denver Broncos American football team. (Photo credit: Wikipedia)

Sport sometimes makes the players very rich. At the top levels of basketball and in English soccer, for example, players may make millions of dollars or pounds during a relatively short career. Other may only earn relatively little. In order to try to prevent this becoming out of hand some sports use a “salary cap” to restrict excessive salaries and allow relatively poor clubs to compete on a more level basis with the richer clubs.

Fairness is considered to be obligatory in sport, at all levels. If a player is considered to have behaved unfairly he or she will be punished according to the laws of the sport. He or she may be ejected from the field of play or even the game. His or her team may have points deducted or the other team may be given a temporary advantage. The overall intent is to allow the team who are best on merit to win the match.

Free Kick
Free Kick (Photo credit: Wikipedia)

It is a fact of life that, especially in contact sports, that players get injured. This may be in accidental incidents on the field of play, such as a collision between two players or they may occur as a result of stress as the player exerts himself or herself in playing the game.

New players may temporarily or permanently replace injured players, and old players may “retire” from the game. The team will be constantly changing and the skill of the captain and the other players in supporting players leaving or joining the team can go along way to ensuring that the team relationships are harmonious and the team melds into an efficient unit.

Embed from Getty Images