Time travel: fact or fiction. A study on the scientific, social and historical impacts of time travel.

By Waania Zia


This is an article detailing the different models and theories of time travel, focusing on Einstein’s theory of relativity and Minkowski space-time, which is the combination of the 3 dimensional space with a 4th dimension of time. It delves into the development of time travel within science and fiction as well as comparing the two. Different models of time travel like the wormhole theory and the Tipler cylinder are evaluated along with the possibility of human time travel. This project gives a great insight into time as a 4th dimension, which is vastly overlooked, and curved space-time. One of my greatest realisations during my research was the lack of knowledge surrounding time and I enjoyed exploring time as a social construct. The number of obstacles to successful time travel was also surprising, since we don’t think in our day-to-day about the impact certain events have on our lives. Paradoxes posed a large issue to travelling through time- like the grandfather paradox- but during my research, I found solutions that could avoid these. I also researched the issues that time travel would bring to society and our economy, realising the dangers are countless and could increase corruption amidst our communities.


Time travel – a concept that only used to exist within the realms of science fiction but is now expanding into theoretical physics with scientists all over the world searching for the answer that could change civilisation as we know it, along with our history and future. This is a detailed exploration into the world of time: how it affects all of us, and the possibility of us travelling through it. I have chosen this topic as I enjoy theoretical physics and delving into ideas once thought of as impossible. The idea of time travel challenges our human logic and opens our minds to new philosophies which is what attracts me the most to this topic. Following on from the famous words of Albert Einstein[1]“People like us, who believe in physics, know that the distinction between past, present and future is only a stubbornly persistent illusion.”– I will be shedding light on the mysteries of time travel.

But first to understand the phenomenon time travel, we must have a clear grasp of what time actually is. The notion of time is a mystery stretching back centuries to when cavemen recorded days with little etchings on rocks. Who decided that a day was 24 hours or that an hour was 60 minutes? It was us, humans. We created the measure of time we use, and it only applies to us and our earth. An extraterrestrial consciousness living on a planet 3 million light years away would have a different system for measuring time and thus time means something entirely different for it. Time is a social construct made by humans for humans, it is an idea we plot our lives on to have some sort of order and yet we can’t control it. The most fundamental thing about time – according to Carlo Rovelli[2] is that time is an arrow which is continuously flowing with no end. Unlike other physical laws, time has only one direction-forward. This confirms that no matter how hard we try to ‘live in the present’ we simply can’t because our present is constantly changing. Even as you read this, the time taken for the light from the pages to travel to your eyes means that you are reading this in the past.

This leads clearly into my next point, the uncertainty among scientists about what time actually is. A surprising realisation I made during my research is that we know more about what time isn’t than what it is. One of these discoveries was made by Einstein and published within his book[3] ‘Relativity: the special and general theory’: time passes faster, the higher up an object is because it experiences a weaker gravitational force. This illustrates that time isn’t uniform or absolute, it is relative. We also know that time doesn’t have a direction.

Entropy is the amount of disorder in a system, the measure of the spreading out of the atoms’ energy. What distinguishes the past from the future? There is only one equation within the entirety of physics that does: the 2nd law of thermodynamics[4] published by Clausius in 1854: where ‘’ is the change in entropy(a measurement of disorder).This displays that heat only travels from hot bodies to cold ones- it can only travel in one direction. Heat- the microscopic agitation of molecules- is the only thing that differentiates the past from the future. This leads to a revelation that the only difference between the past and the future is our distorted vision. Our inability to see on a microscopic level could be the reason why we have a past and a future. It may be that if we could see on a microscopic level, we would realise that we have the same amount of knowledge about the future and the past. Time has lost yet another certainty it could have had.

Philosophers older than regulated time have pondered ‘what time is’ like Aristotle who first posed that question. His answer was that time is a measurement of change, therefore if nothing changes then no time has passed. This brings forward the obvious question: ‘what is the period that passes in the silence?’ That is still time because the very measuring of time during no period of change is a change thus resulting in time changing. However, Newton proposes the exact opposite. He calls Aristotle’s version of time ‘Relative time’ and states that ‘true time’ is independent and passes regardless of anything. The question that now lingers is who’s right: Newton or Aristotle? I’ll let you ponder that one.

Now that we have a more rounded understanding of time, we can dive into the realities of time travel and the dangers they pose to us as individuals and as humankind.

Literature Review

The origins and historical development of time travel

The first mention of time travel was its representation within H.G. Wells’ novel[5]: ‘the time machine’. He was the first to merge these two seemingly ordinary words into something extraordinary. Time travel took a fairly long time to be discovered even as a hypothesis and it was only after the industrial revolution that people began speculating the possibilities of travelling through time. This is most likely because the industrial revolution was the first-time technological advancement on that scale, was seen within a lifespan.

Within science, time travel was first given a backbone by Einstein’s theory of relativity which has already been mentioned. This theory links space and time together with one seemingly simple equation: . It shows that mass and energy are the two sides of the same coin. The presence of mass-energy determines the curvature of the spacetime continuum, which again, affects the perception of time in that space. It is based on 2 main assumptions:

➢ the laws of physics are identical for all inertial frames of reference. In other words, these laws remain the same no matter what constant velocity the object is travelling at.

➢ the speed of light in vacuum is the same for all observers, regardless of motion.

The latter of the two is a fundamental constant that our research of time travel and much of modern-day physics depends on. So, to confirm this constant (as nothing can really be determined until you have seen it for yourself), research was conducted into the speed of light (c). For this experiment all that was needed was a bar of chocolate, a microwave and a ruler. With 21st century technology, measuring c has become much easier than when it was originally done in 1676 by Roemer whilst measuring the eclipses of the moons of Jupiter. Now all that needs to be done is placing a bar of chocolate into the microwave until it begins to melt. After this was done, I measured the gap between the 2 miniature craters that had been generated in the chocolate due to more energy being transferred to them. The gap between 2 dots is half a wavelength and is then multiplied by 2 to get a wavelength. The experiment was repeated twice to find a good approximation. The measurements for a wavelength were: 0.16m and 0.12m and the microwave was 2,450,000,000 hertz. Since microwaves are part of the EM spectrum along with light waves, they will both travel at the same speed therefore this equation can be used:. The speed of light is equal to the product of the wavelength and the frequency;. This gave me a value similar to the accepted value.

Continuing, Einstein’s essential discovery was developed by Hermann Minkowski who inserted the concept of a 4th dimension, much like the one which was used in H.G Wells’ piece of fiction. An idea used for entertainment was shockingly becoming more and more a reality. This 4th dimension is known as time and is a mathematical model featuring space-time as a continuum. It allows particles around the universe to move and interact without including gravity as it is still used today as the basis of explaining special relativity. Einstein’s theory of relativity also states how large objects can warp and manipulate the space-time around them creating curves like the Earth’s gravity does. His theory also provides the 1st step in our discovery of time travel since it states that the faster you move the slower time passes. So, if you were traveling at a speed close to the speed of light, time would move relatively much slower for you and you would only notice the consequences when you returned back to those stationary people you left behind. They will have aged significantly more than you have.

In 1949, Kurt Gödel published his solution to Einstein’s field equations known as the Gödel Metric[6]. The Gödel Metric describes a universe that is constantly rotating with a constant angular velocity of:where ‘a’ is a free constant. It also contains closed time-like curves: an idea that if an object travels far enough it will return to its starting point and time will loop back upon itself. It’s space-time coordinates would remain identical, thus giving us a mathematical formula for time travel. However, many scientists argue the real-life implications of Gödel’s solutions are little to none and will not allow time travel to work in reality. One of the main arguments is that his solution relies on our universe having spin which scientists have agreed is likely to be false. Another reason why Gödel’s universe is artificial is due to the value of the cosmological constant(Λ) which must be changed in relation to the density of the dust particles. The Λ refers to the energy density of space and was discovered by Einstein and added to the field equations to balance the effects of gravity and initially to allow for a static universe. The world was warming up to the idea of time travel in the 20th century, despite there being little evidence backing it up. Theoretical physics was not disillusioned by the lack of tangible applications though.

In 1967, scientists brought forward the idea of a particle that could travel at or even faster than the speed of light and contains imaginary mass (i) which is √(-1). Since the Lorentz factor (the factor by which time changes for a moving object) is: γ=1/√(1-v^2/c^2 ), it will only become imaginary if the velocity is larger than the speed of light. Therefore an imaginary mass is required to obtain a real energy because E=γmc^2.This hypothetical particle was given the name: Tachyon[7], and even though it has not been found in any experiments to date, they make the probability of time travel increase tenfold. Research is being continued today to experiment travel as the vehicle of the future.

The current theory of time travel

At the moment time travel relies heavily on 2 different theories, the theory of relativity- which is a recurring theme within this project- and the wormhole theory. The latter was first theorised by Ludwig Flamm[8], whilst he was making solutions for Einstein’s theory. He explained the idea of a ‘white hole’, the opposite of a black hole, an entity which couldn’t be entered from the outside, but energy could escape from. A black hole being a region where the space-time curvature and time dilation are infinite. Flamm also suggested that the entrances to both black and white holes could be connected via ‘space-time conduits’ (much like the ones now used in ‘Doctor Who). Nathan Rosen further developed his theory by introducing the idea of shortcuts through space-time which we now call wormholes. Mathematically, the existence of wormholes was predicted in Einstein’s theory and in 2006 a gamma ray burst with atypical properties was spotted and many believe this to be the first observation of a white hole yet there was not enough substantial evidence to support this claim. Wormholes could allow matter to be transported from one place to another instantaneously. The entrance of a wormhole would be a black hole and the exit therefore a white hole. Although none have been seen to date, many people think that wormholes may work on a subatomic level making it impossible to see them and very difficult to replicate them on a larger scale for human use.

This theory may be useful theoretically but is practically flawed since there are many risks associated with this method of time travelling. Wormholes may never be large enough for humans or even ants to travel through and could lead to certain death for anyone who tries since the conditions required to open a wormhole (great density and energy) will not be endurable by humankind. However, one may argue that the universe is expanding- as proven by Edwin Hubble- and therefore some wormholes may be stretched to larger sizes within the process. Another problem one reaches is that Rosen’s theorised wormholes lack stability and will collapse quite rapidly. The only way to keep these wormholes open for a longer period of time would be with the use of ‘exotic matter’- any non-baryonic matter with unusual properties. Non-baryonic matter is any matter not composed of baryons which is a subatomic particle with an odd number of valence quarks(e.g. protons). This type of matter containing negative energy has never been proven to exist. However, the Casimir effect, a proven phenomenon within physics, may be able to manipulate wormholes. It describes a force that acts between 2 uncharged plates due to the temporary changes in the amount of energy within a point of the electric fields (quantum vacuum fluctuations). But using this effect would also increase the instability of the wormholes and make them even more unpredictable. Particle-antiparticle pair production is a process which creates an electron-positron pair using a photon. It also occurs within a vacuum and uses energy from the photon. Every method of time travel comes built-in with drastic risks that one may expect when trying to defy the laws of physics. However, the wormhole theory in particular is full of assumptions and even the most calculated methods will result in death.

Alternative theories[9] of time travel do exist including the infinite cylinder, also known as the Tipler cylinder[10], which requires rolling a mass much larger than that of our Sun into a cylinder and then rotating it extremely quickly. This could cause a spaceship that was going around the cylinder to be trapped in a closed-time loop thus resulting in time travel. This time machine, proposed by Tipler, unfortunately comes with one major flaw- as suggested in the name- an infinitely long tube is needed. Since infinity is a mystery, the probability of us creating a tube that long is highly impossible at the moment. A similar method can be used, with a black hole instead of a tube. In some ways this may seem more feasible, as black holes do actually exist, but the spaceship would have to travel at around the speed of light. Which as well as being very difficult to do, would most likely cause the spaceship to fall apart before it even reaches that speed (a flaw which was pointed out by Amos Iron). Another theory involves the usage of cosmic strings- hypothetic tubes of energy which stretch out through the universe. They contain large amounts of mass meaning that they can warp the space-time around them thus resulting in time travel. Further research needs to be done within more realistic solutions involving concepts that actually exist like black holes and inventing machinery that can travel fast enough or changing different conditions (density, pressure, energy etc.) so speed no longer remains the limiting factor. At the moment, there is a constant problem with all these theories, they all involve the hypothetical, where nothing is actually near to being practically usable.


Time travel itself is a contradiction, filled with paradoxes which make it seem impossible. Many of these paradoxes are used by scientists to argue against the possibility of time travel. The most famous of the temporal paradoxes is the grandfather paradox. This is a problem which would arise if you travel into the past and kill your grandfather before he has had children, thus resulting in you never being born. You have essentially ended your whole existence and therefore never would’ve travelled back in time to kill your grandfather in the first place. This is known as an inconsistent causal loop. Another way this paradox can be used is when people travel back to kill Hitler, if they are successful then Hitler wouldn’t exist in the future and therefore there would be no reason to go back in time in the first place. As you can tell this creates a rather large issue since time travel can’t exist if it is built-in with these issues. Another paradox is known as the Bootstrap paradox, which is also referred to as the ontological paradox. It is essentially where an object or piece of information is sent back in time thus creating an infinite loop where the origin on the object can no longer be unearthed. The ontological paradox is featured within the terminator films because for Skynet to exist it would have needed the T-800 cybernetic organism that it sent back in time to stop John. It is a type of closed-loop paradox much like the pedestrian paradox which is where cause and effect are repeated in a loop until the point of origin is no longer distinct. Even though the bootstrap paradox is consistent, it defies the natural laws of physics like the law of causality since a cause from the past cannot be used to predict the event from the future as it could be an event from the future which causes the event in the past. The pedestrian paradox is an additional temporal paradox where going into the past causes the object or individual to become involved within the past events that they were most likely going back to stop in the first place. Within this paradox, history must be pre-written and cannot be changed therefore anything that tries to interfere will only help preserve the past events. The final paradox that will be discussed is Polchinski’s paradox. This was founded by Joseph Polchinski through unpublished writing to Kip Thorne. It states that if one sends a billiard ball into the past via a wormhole and it then collides with its previous self, meaning that it doesn’t enter the wormhole in the first place. This paradox is based on science that agrees with Einstein’s theory making it more reliable. Whilst all these paradoxes make time travel seem like nothing more than a dream there are solutions to them. The 2 main methods to counteract these issues are:

  • Multiple universe hypothesis, which states that for every time you commit an action there is a different universe in which you didn’t execute it. So, if you go back in time and successfully kill your grandfather then you have entered a different timeline and if you were to go back to the present within that timeline you wouldn’t exist.
  • Another method to stabilise the paradox is the timeline protection hypothesis theory. In this theory the timeline would prevent actions from taking place which would disrupt it. Therefore, you would never be able to kill your grandfather, e.g.: the gun wouldn’t fire, or your knife would miss the mark.

Both of these methods render the paradoxes futile in acting against time travel but there continue to be new theories arguing that our universe simply was not built for time travel and could not withstand its effects.

One of these individuals is Stephen Hawking, he publishes his Chronology protection conjecture[11] which argues strongly against voyaging through time. It announces that time travel is only possible on a microscopic scale and the laws of the universe prevent all time travel except that. It is because closed time-like curves are prevented from being created thus making time travel substantially more difficult. It is also worth noticing that if time travel was possible, we would be flooded with masses of travellers yet there is little evidence to support this, suggesting that time travel is either only available for the select few or impossible. As well as this the ‘weak energy condition’ also discredits any theories of time travel since it expresses that energy should always be positive and therefore there cannot be any negative mass. The reason this is such a large issue is because for a closed time loop to exist negative mass is required and as of now this doesn’t exist. Science has reached an impediment and for further developments to be made in the exploration of space-time there must be more research into closed time loops. Scientists have also argued against travelling into the future, one of the most notable debaters being Richard Muller[12]. He suggests that as space is expanding- as proved by CMBR (cosmic microwave background radiation)- time is also expanding. The future doesn’t exist, it is being created as we speak, and we live on the cusp of the present. This means that it would be impossible to travel into something that doesn’t exist. Journeying through time is seeming bleaker by the second due to the unbreakable principles of physics.

During my research, I came across the Classical and quantum gravity[13] journal by Mallary, Khanna and Price. This published paper is vital in the search for methods of time travel which do not contradict the laws of physics. It complies with the weak energy condition[14](which states that the local mass-energy density must not be negative to preserve stability of vacuums)- a problem the majority of other theories have not been able to overcome. In their explanation, they made use of naked line singularities (NLS); a location in spacetime, without an event horizon, in which the gravitational field of a body becomes infinite. ’Superluminal travel is possible’ parallel to the NLS so they can be used to shortcut between areas in spacetime and thus create closed time-like curves. Their model consists of 2 cars, with a positive mass, parked parallel to each other. One car accelerates while the other stays still. A time-loop can be created in the gap between the cars. This theory is advantaged by the prospect that it does not breach the weak energy condition because the objects involved have positive mass and suggests that this ‘condition isn’t sufficient enough to prevent superluminal travel’. However, a weakness of this model is that NLS have never been observed in nature but if loop quantum gravity (theory that merges general relativity and quantum field theory) is correct then it can be possible. The unified field theory allows forces and elementary particles to be written in terms of physical and virtual field pairs. This journal has given a new perspective to time travel and more investigation must be done into theories compliant with the weak energy condition.

Impacts of time travel

Regardless of the scientific possibilities of time-traveling, there are many moral, economic and social factors to consider. If one day time travel was practically possible, who could use it? The scientists and rich, or would it be available for everyone? If the answer leans towards the former, then the inequality between the upper and lower classes would exponentially increase. With the rich continuing to go back in time and possibly becoming richer. This divide would lead to higher levels of distrust among the 2 classes and higher levels of violence including gang-related crimes, which are statistically known to be linked to poverty[15]. On the other hand, if time travel became cost effective enough to become a major part of the technology industry, then their economy would thrive, and wages would increase for workers within the time travel industry. This increased salary would add to the extra money of the workers which they would spend and add back into the global economy. Overtime, everything would return to equilibrium as usual. However, there will always be people in the lowest percentile that can’t afford this new mode of transportation- they will get left behind and not be able to exploit time travel like the remainder of the population. Time travel would have major effects on the economy, due to the exploitation of knowledge[16]. People could go back into time and invest in stock-markets since they have seen which ones prosper. Or they could go back and win the lottery; the possibilities are endless, but they share one factor in common. The value of information would greatly decrease because people could go back in time and invent things before the original creator, patent them and earn a great deal of wealth. Also, the uncertainty of the past has become almost nil, since we could go back and check: did Jesus really exist or who was Jack the Ripper? At first glance this may seem great because many of the world’s mysteries are being debunked but knowledge in the wrong hands can be a weapon of great destruction. Terrorists can use time travel to plan out venues for bombings more accurately. Or militaries could take advantage of time travel to win wars and essentially alter the future. The main issue with travelling to the future lies within semantics- once one has travelled to the future it is no longer their future and instead becomes their present. At the moment, we remain stuck cemented in the present- no matter how much time passes we are always in our present. Manipulation of time could result in us entering a parallel universe, instead of the future or even creating more parallel universes.

Assuming that time travel does exist, it comes built in with inherent dangers that are irresolvable. One of them being knowing where you are travelling to. It is known that the Earth rotates on its axis, therefore the place you travel from won’t be the place you arrive. It may be that you find yourself in the middle of the Pacific Ocean or just wandering aimlessly in space. The further you travel in time- back or forwards- the more problems that are likely to arise. Our atmosphere[17] is constantly altering, at the moment due to global warming. Therefore, the increased amounts of CO2 in the future’s atmosphere may be unable to support human life so when you arrive your body will not be used to the atmosphere leading to your most likely death. This also applies whilst travelling a great distance back in time. The Jurassic period had higher levels of carbon dioxide than now therefore we would face the same problems as our body hasn’t evolved to filter out high amounts of CO2. As well as this, the resistance our body has built from bacteria applies only to our generation so time travellers could be adversely affected by different illnesses from the past and future. Generally, time travel has not been thought through well enough and has many implications that may be overlooked. Even within fiction, the majority of problems are neglected, and time travel is portrayed as less problematic than in real life.

Portrayal of time travel within pop culture

Within this article, I researched multiple representations of time travel within science fiction (books, films and TV series) since that is where time travel got its foundations. One of the most popular being ‘Doctor Who[18]’- our resident time lord. Within this series, spacetime is explored by time lords via the ‘TARDIS’, it is essentially a bubble of spacetime that travels in closed time-like curves. Benjamin K. Tippett and David Tsang published a paper[19] detailing the model that the TARDIS could follow to successfully travel through time. Even though Time lords may be a supernatural being, they still have to follow certain regulations[20] to ensure that the universe doesn’t descend into total chaos. They can’t ‘rewrite history’: this rule is useful in reality also because it eliminates the possibility of the grandfather or Hitler paradox occurring and thus keeps the world-line consistent. Each object has its own world-line which represents the path of that object within space-time. Another surprising principle is this idea of ‘fixed points’. They are events that can’t be changed or altered in any way so that the timeline is secure. This is very similar to the timeline protection hypothesis theory mentioned earlier which ensures that the universe will remain consistent. Time travel within ‘Doctor Who’ follows quite a few aspects that scientists require it to and manage to avoid most of the paradoxes. However, they do not explain the closed time-like curves created or avoid the energy conditions- which still lies one of the largest difficulties with time travel in the present.

In addition to this, ‘Harry Potter[21]’ also uses time travel, mainly within the 3rd book in the series, for mundane tasks as well as saving lives. ‘Time turners’ are small devices which allow the user to safely travel up to 5 hours back in time[22]. Travel for any longer, in the wizarding world, would result in cataclysmic effects like the traveller’s body ageing substantially- causing their death as well as many of their family being un-born due to alterations in their timelines. That may be one of the reasons it is only used in everyday problems that would not result in as many issues. Maybe this is the only future of time travel that we would be able to explore because of the lack of dilemmas it poses. This version of time travel has only happened into the past within the books and follows the single-verse theory as there is no universe where the event did not occur. This contradicts the multiverse theory that many scientists believe is necessary for time travel to exist and brings light to a predetermined timeline. In this timeline, nothing is ever altered because it always has been altered, without your knowledge. This type of timeline- although not realistic- removes the grandfather paradox. Conversely, it heightens the ontological paradox as objects lose their origin since they were always supposed to be there. Time travel was also carefully controlled within ‘Harry Potter’ by the government and only given to Hermione for specific purposes. It was also very secretive, with only the teachers and Hermione herself knowing to minimise exploitation.

The final portrayal of time travel that I researched is The Flash[23], within this series time travel is mainly done by running at extreme speeds (usually faster than light) and then choosing a destination to travel to. The universe theory is highly inconsistent within ‘The Flash’ compared to other fictional works I have studied. It tries to follow a vague multiverse theory with an ‘Earth-1 and an Earth-2’, so that the majority of the paradoxes can be ignored. One large difference between time travel within these books, series and reality is that almost everyone who travels in time is not human. They are some form of supernatural species which allows these interpretations to ignore effects time travel has on the human body and mind. In reality this is not the case, because as humans we are a vulnerable species and our bodies cannot withstand much, especially the toll time travelling will have on our body. Out of all the media I studied, Doctor Who’s model of time travel seems the most consistent and feasible due to the laws they must abide with. Along with this, the ‘fixed points’ mentioned enable a more reasonable version that our universe is likely to follow.


Time travel is a complex concept that tests our logic and the very laws of physics that this universe is built upon. Little evidence of time travel exists due to the extreme conditions (speed, etc.) required for it to take place. The main supporter of travelling through time remains through history to be Einstein’s relativity theory. During this project, it was learnt that with drastic changes within our velocity, the laws that dictate our universe begin to change. However, the speeds needed are not achievable even with modern day technology. The most prominent barrier to human travel in space-time is the speed of light, and investment needs to be made in conquering this obstacle so that more technological advancements into building a functioning time-machine can occur. Although it might be that exceeding the speed of light is prohibited by the laws of physics due to needing an infinite mass.

In my opinion, the most realistic model of time travel is black hole theory, which similarly to the Tipler cylinder, requires a ‘ship’ to travel rapidly around a black hole so it is caught within a time loop. This theory appeals the most to me due to the fact that black holes do actually exist unlike the majority of the other theories which requires hypothetical ideas. However, there is little known about what happens after one crosses the event horizon, objects could be destroyed thus removing the usage of black holes in travelling through time.

Personally, I believe that time travel is achievable in theory and occurs on microscopic scales but even the universe has limits that we may never be able to exceed. With our current technology, time travel is more like a dream but with developments over time we may invent objects able to withstand the pressure of superluminal travel. However, it may be for everyone’s best interests that time travel remains a mystery since the danger associated with such travel could be detrimental. With every new innovation one must determine whether the benefits outweigh the risks. And in this, I don’t believe that they do. The powers accompanying time travel give way for chaos to arise and end the universe as we know it. Many will attempt to exploit the possibilities time travel offers for their own personal gain. From Newtonian mechanics to nonlinear dynamics, the journey of physics is amazing, yet who knows what the future has in store for us?


1- ‘Broken limits to life expectancy’ (2002) Available at: Accessed:{07 June 2020}

2- Rovelli C (2017) The order of time. Italy: Penguin books.

3- Einstein A (1916) Relativity: the special and general theory. London: Methuen & Co. Ltd.

4- ‘Universal Laws of thermodynamics’ (2016) Available at: Accessed{10 Nov 2019}

5- Wells HG (1895) The time machine. Signet classics.

6- Gödel K (1949) An example of a new type of cosmological solutions of Einstein’s field equations of gravitation. Rev. Mod. Phys. 21(3) Available at: Accessed{6 Sept 2019}

7- TechRadar. (2017) A history of time travel: the how, the why and the when of turning back the clock. Available at: Accessed {3 Sept 2019}

8- Flamm, L. (1916) Republication of: Contributions to Einstein’s theory of gravitation. Gen Relativ Gravit 47, 72 (2015)

9- Futurism (2013) Four ways time travel might work. Available at: Accessed{30 Sept 2019}

10- Tipler FJ. (1976) Causality violation in general relativity. University of Maryland, College Park

11- Hawking S (1992) Chronology protection conjecture Phys. Rev. D. 46(2) American Physical Society

12- World Economic Forum (2016) Time, space and why we can’t time travel. Available at: Accessed{14 Oct 2019}

13- Mallary C (2018) Classical and quantum gravity.  IOP Publishing Ltd. Available at: Accessed:{12 Nov 2019}

14- Futurism (2018) A new model debunks a popular argument against time travel. Available at: Accessed{30 Sept 2019}

15- (2019) Revealed: full links between poverty and violent crime in London. Available at: Accessed{29 Feb 2020}

16- How stuff works (2010) How would time travel affect life as we know it. Available at: Accessed{11 Nov 2019}

17- Odyssey (2017) The inherent dangers of time travel. Available at: Accessed{11 Nov 2019}

18- Chibnall C (1963) Doctor who.

19- Tippett BK (2019) Traversable Achronal Retrograde Domains In Spacetime. Available at: Accessed {3 March 2020}

20- Digital spy (2018) How does time travel actually work in Doctor Who? Available at: Accessed{4 Nov 2019}

21- Rowling JK (1999) Harry Potter and the prisoner of Azkaban. Bloomsbury Publishing PLC.

22- Wizarding world (2015) Time-turner. Available at: Accessed{3 March 2020}

23- Johns G (1959) The Flash. DC comics.

Figure reference

Figure 1- wormhole(time warp), Shutterstock, Accessed:{ 7 June 2020}

Figure 2- wormhole, Live science ( originally from Shutterstock), Accessed:{ 7 June 2020}

Figure3- Tipler Cylinder, SlidePlayer, Accessed:{7 June 2020}

Figure 4- Tardis, Stockfreeimages, Accessed{7 June 2020}

About the author

Waania is a 17 year old dedicated to making her mark on the world and exploring evolutionary ideas within physics, chemistry and maths. She is an ambitious individual with a passion for scientific ideas which can aid society

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