The TARDIS or Time And Relative Dimensions In Space, is a time machine developed by the Time Lords from the planet Gallifrey from the popular science fiction television show Doctor Who. It is know to be a blue 1960's police box and one of it's most well known features is how the TARDIS is "bigger on the inside". But is it really 'bigger on the inside? In this post I will explain how the TARDIS can be "bigger on the inside" and how it can travel through time and space. Allons-y!! How is Time Travel Possible?Before we begin I would like to say that everything on here is probably theoretical (as of 2019 Earth year, Stardate 2019.32) and this is NOT a guide on how to build your own TARDIS. Anyway before we start looking at the inner workings of the TARDIS we must first understand time travel. So, how does time travel work? Is it actually possible? Usually on a normal day we only experience time moving forward. To travel backwards in time or retrograde time travel you will need to travel faster than light. This is because of light cones. Lightcones mark the boundaries in spacetime in which an object a reach without going at superluminal or faster than light speeds. The future lightcone marks the future and every single event that would happen from now that a light originating from that point will be able to reach whereas the past lightcone contains every single event that has ever happened that the light present at that point in time and space have ever been.These lightcones are marked by plotting the path of the photons or light that is radiated to all possible directions from 1 point. This means that if you manage to travel at speeds faster than light you will be able to travel either backwards in time or forwards in time but in a faster rate than you are now. Time is a relative construct as it depends on the observer. According to Einstein’s theory of relativity the faster the observer is moving, the slower they experience time passing. This is because the person who is moving faster will feel a stronger gravitational force. But in this case gravity is not just a force but a curvature in the fabric of spacetime. Say you got K-9 to run along a curved surface. You plot out a path that seems straight but in reality K-9 isn’t moving in a straight line. This is similar to the planets,stars or any of the massive celestial objects in the sky. Since the star which has a huge gravitational force bends spacetime the planets what would move in a straight line in a uncurved “flat” spacetime would move in a curved path as the trajectory of the planet would curve and bend around the star. This curve is why time slows down at the event horizon of a black hole.Technically time does not seem to slow down for the person at the event horizon but to the observer it would look as if time is slowing down. The speed of light is a constant in the universe (approx 300,000 km per seconds) . If the speed of light is a constant throughout the universe it would mean that it would take longer for the light to reach the person at the event horizon due to the curvature in it’s path from the massive gravitational “force” from the black hole. This is called time dilation. Another way time dilation can be achieved is though traveling at a faster rate relative to the observer. This again has something to do with the speed of light. As mentioned before the speed of light is a constant throughout the universe. It can not speed up nor slow down. This means that if an object or person moves light will have to travel further to reach them but it would not speed up therefore it would take the light longer to reach the person or object. A famous example of this is the twin paradox where one of the twins travel into space at a speed near the speed of light while the other stays on earth. To the twin in space time would move slower relative to the twin on earth. This would mean that when the space twin goes back to earth they would be younger than the earth twin. How does the TARDIS travel through time and space?One of the things the TARDIS is famous for is her ability to travel through time and space. It's even in her name Time And Relative Dimensions In Space. But how exactly does the TARDIS do that? Space as we know it ,takes up 3 dimensions, with (x) , length (y) and height (z). Now let’s add another dimension. A 4th dimension called time. The fabric of spacetime is the fabric of the entire universe. It shows everything that has happened, is happening right now and will ever happen. Now spacetime geometry is when this spacetime is arranged into a specific shape. There are a lot of different spacetime geometries that are proposed to as they try to find a mathematical model or setting that take in account the different scientific theories such as general relativity. The some of the most well known proposed spacetime geometry being the Euclidean (mathematical setting for general relativity) and Minkowski (mathematical setting for special relativity) space. If a person wants to travel back in time they would have to have a spacetime geometry where the 4th dimension (time) curves and folds back onto itself. A bit like a doughnut. When spacetime is manipulated in the way mentioned above it is called as Closed Timelike Curve or CTC. A CTC can theoretically allow a time traveler to travel through time and space by allowing them to “hop” from their current point in space and time to another point in space and time. Benjamin Tippett and David Tsang proposed a spacetime geometry called TARDIS. The acronym TARDIS doesn't stand for Time And Relative Dimensions In Space but instead stands for Transversable Achronal Retrograde Domains In Spacetime. This TARDIS bubble consists of a closed timelike curve. Using this closed timelike curve or CTC the Doctor and their companion can travel through time and space. In this TARDIS geometry the person will be able to travel backwards, forwards or sideways in time due to the lightcones being tipped and turned in the bubble. From the perspective of the person in the TARDIS bubble and traveling init, it would seen that the room they are in is constantly accelerating forwards. Whereas to the person outside the bubble they would observe a bubble appearing then eventually splitting into 2. The bubble will then start to travel at faster than light or superluminal speeds eventually deccelerating to a halt.The 2 boxes then eventually begin accelerating towards each other, eventually reaching superluminal speeds, merging then disappearing. One of the boxes will then weirdly look as if it’s traveling or evolving back in time whereas the other box will seem as if it is travelling or evolving forwards in time. All of the events that occur in this box or room must also adhere to the Novikov’s self consistency principle. This principle states that the past events cannot be changed as the time travel was part of the past in the first place anyway. This principle was created to fix paradoxes. Using this TARDIS geometry we will be able to travel through time and space by cutting and sticking different bubbles together and creating something called a novel composite geometry,as if we just have 1 bubble it would just be a circle and nothing much could be done in there. This could be used to get from point A to point B by cutting and sticking a series of sections of different TARDIS bubbles together. Another way this could be achieved is by cutting the TARDIS bubble in half into an U shape. By using this the time travellers can enter one end and exit the other end moving backwards in time and their directions of left and right would also switch at the same time. This of course means that there will be a chance for the time traveller to end up in an universe made up of anti-matter due to the factor that our physical law of the universe is time symmetric in a certain way or CPT symmetry ( each letter standing for Change, Parity and Time). What is a Closed Timelike Curve?I mentioned something about a Closes Timelike Curve or a CTC to put it short but what exactly is a CTC? Some whovian scientists believe that the place that the TARDIS travels through referred by the time lords as the time vortex may in fact be a closed timelike curve. A closed timelike curve is a path through spacetime which eventually returns you to the exact same position in space-time as you were before. You are logically moving forward in time yet you somehow manage to get back to the same place and time that you were before. The closed timelike curve theory was first proposed by Willem Jacob van Stockum then later confirmed and elaborated on by Kurt Godel. This can theoretically allow one to travel or hop through time and space. The CTC can theoretically be used to get a time traveler to the past as the theory does not prohibit the time traveller to travel to the past. According to Einstein’s theory of relativity when an powerful gravitational field such as one from a spinning black hole could in fact distort and warp the fabric of spacetime causing it to bend over it self thus creating a CTC. This of course raises some questions such as how the time traveller can travel back in time with no consequences as just the presence of the time traveller in that moment of time or the time traveller interfering could cause catastrophic events and would break the laws of time and cause a paradox . A CTC can be created by something called a tipler cylinder. Imagine you have a cup of water and you stir it with a spoon. You should see the water swirling in the direction of the spoon’s rotation. Now replace the spoon with a infinitely massive and long rod and the cup of water with the fabric of spacetime. This effect is called frame dragging and can be used to tip lightcones either slightly such as in the case of earth (as the effect is reliant on the object's proximity and it’s angular momentum) or completely in the case of the tipler cylinder. When the lightcone completely tips it allows one’s self to travel back in time by going around the tipler cylinder. When the TARDIS travels to the past we can observe that the time vortex is blue whereas when the TARDIS travels to the future the time vortex looks red. This may be because of the doppler effect which states that when an object moves closer or away from an observer a shift/ change of frequency or wavelength can be observed. When the object moves closer the wavelength or frequency appear shorter but when the object moves further away the wavelength/ frequency of the object will appear longer. What are the Laws of Time Travel?Now you know how to travel through time and space but you have to know the laws of time travel so you don't get in trouble with the Time Lords or the Time agency. Now what are the Laws of time? The 1st rule of time travel is as the Time Lords say to not interfere. This is because interfering with the past or future can have dire consequences. Take the grandfather paradox for example. A person goes back in time killing their grandfather before their father was born thus causing them to never be born which would lead them to not killing their grandfather and so on and so on going in a loop. This is a famous paradox looking at the dire consequences of travelling backwards in time and interfering with the past events. Interfering with future events can also be dangerous as changing the future is speculated to change the past due to something called retrocausality which states that an event that occurs later in the timeline can affect an event that happened earlier in the timeline. How is the TARDIS powered?The TARDIS is great and all but what good would it be if you don't know the power source and how to charge it? The TARDIS is powered by an ever collapsing star called the eye of Harmony. The Eye of Harmony is constantly exploding and is suspended in a constant state of collapse and turning in to a black hole. The TARDIS is somehow harnessing this energy. Now is star is in the constant state of turning into a black hole. So what if the thing that is powering the TARDIS is actually the famous Hawking Radiation? There has already been research proving that the positive energy produced by Hawking radiation cannot be harnessed as power. But what if the TARDIS can snatch up the negative energy particles before it gets across the event horizon of the black hole. If this could be achieved while the particles are still accelerating in the direction of the black hole it is theoretically possible that a large amount of negative energy could be harvested, thus powering the TARDIS. How is the TARDIS bigger on the inside?The insides of the TARDIS could be condensed and coiled so a large volume can be contained inside a smaller surface area. In fact we actually see this happening in our day to day lives such as our lungs which if stretched out would measure 75 m^2 . Now for the TARDIS this may be exactly what is happening but in a transdimensional sense. As mentioned before TARDIS stands for Time and Relative Dimensions in Space, the key words being dimensions. This suggests that the TARDIS is operating in a dimension higher than ours. To explain how the TARDIS is bigger on the inside I will need to first introduce something called flatland which is a 2 dimensional universe. This needs to be done as humans cannot imagine dimensions higher than 3 as that is how the human brains have evolved. Now in this flatland say you pass a 3 dimensional object such as a sphere through it. In the 2 dimensional universe it would look as if the sphere is a circle and as it goes through the circle gets bigger or smaller depending on what part of the sphere is passing through. Now imagine this happening with the TARDIS. When you enter the TARDIS you are transported to a dimension higher than ours but said dimension is curved. That curved dimension would cause you to think that you are still in the 3rd dimension as you will see no difference as you will not know that the 3 dimensional world is curved in a higher dimension. ConclusionSo now you are ready to travel through time and space in your very own TARDIS. If you get one that is.You know how the TARDIS works and the basic laws of time. Don't forget the jelly babies and remember rule #1. The Doctor lies. May you live longer and prosper and may the force be with you. Citation
1 Comment
Emil hung
20/3/2019 10:23:15
it was very goood
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