Dark Matter

      For years the physicists struggled for creating an image of the outer space through computers but failed to develop a stable model. The model was being developed in order to see whether the data that we collected is accurate or not. Also the purpose was to discover a black hole. A Black Hole cannot be detected by using instruments in space. Every time the outer space was simulated, every time it fell apart. There was something that was missing, but what was that ? The answer was The Dark Matter.

     What is this new thing? Is it an element or planet or a star? This new thing has been defined as matter but its type is still undefined. A matter is defined to have mass and volume; so does dark matter. Dark Matter constitutes a large amount of the total mass of the universe. This matter cannot be seen, then how can it be detected? The only known way today is by weighing the matter. When values were substituted with dark matter in mind, it gave astonishing result, a stable space. But what was in this matter that we were not able to achieve a stable universe? Using the laws of conservation, the mass of celestial bodies was calculated and equated for analysis, but due to lack of sufficient strength to hold the bodies together in the system, the space was tearing apart again and again which is not true. To resolve this missing mass, the concept of dark matter was introduced.

Teleportation

             Ever since the invention of wheel more than 5000 years ago, human desire to reach a place faster has lead to numerous inventions. From chariot to bicycle to automobile to airplane and rocket, all have been created with a single motive to travel faster. But all these inventions share the same flaw; it requires us to travel the physical distance. With development in the field of paranormal physics, scientists have been trying to combine the properties of telecommunication and transportation to achieve “teleportation”.

         Teleportation involves transfer of matter from one place to another without physical traversing the space between them. It deals with dematerializing an object at one point, sending the details of the precise atomic configuration at another location where it will be reconstructed. With the tremendous potential being embedded on this invention it would explore the possibilities of travelling without physically crossing the space. The idea of teleportation moved out of the realm of science fiction into the world of theoretical possibility in 1933. Physicist Charles Bennett with a team of researchers at IBM confirmed that quantum teleportation is possible, but only if the object being transported was destroyed. Since then, experiments using photons has proven that quantum teleportation is in fact possible.

          In 1998, physicists at Caltech successfully teleported a photon by reading its exact atomic structure, sending the information across 1 meter of coaxial cable and creating a replica of photon.  As predicted, the original photon was destroyed once the replica was made. In the event of teleporting objects larger than photon the main hurdle in the path is “Heisenberg Uncertainty Principle”. The principle states that determining the momentum and location of a particle simultaneously is not possible. If you cannot determine the location of a particle then how can you teleport it? The photon experiment was carried out by using a phenomenon called entanglement. For a person to be transported, a machine would have to be built that can pinpoint and analyze all of the  atoms that make up the human body. That's more than a trillion trillion atoms. The machine would then have to send this information to another location, where the person's body would be reconstructed with exact precision. Molecules couldn't be even a millimeter out of place, lest the person arrive with some severe neurological or physiological defect. The laws of physics may even make it impossible to create a transporter that enables a person to be sent instantaneously to another location, which would require travel at the speed of light. The availability of this technology tough looks bleak in the near future.

           But like all technologies, scientists are sure to continue to improve upon the ideas of teleportation to the point that we may one day be able to avoid such harsh methods. One day, one of your descendants could finish up a work day at a space office above some far away planet in a galaxy many light years from Earth, tell his or her wristwatch that it's time to beam home for dinner on planet X below and sit down at the dinner table as soon as the words leave his mouth.


By: Ankit Jain

Time as Curled Dimension

        Today we understand that time is a necessary dimension in our universe to define the state of an object completely. Unlike the 3 other dimensions, time cannot be visualised as an axis.(Note: The graph we plot against time axis is only a form of representation to study variation of other quantities with time. Time is never an axis.) Then where is the time dimension? It might seem absurd if it is proposed that time is a dimension curled with other 3 dimensions, but it can be proved.


        Let us analyse this situation. Let there be a particle of mass 'm' (take any value for mass here, as it would not affect our analysis). Whenever we encounter an equation describing the motion of a particle, it is generally of the form s=ax+by+cz but not of the form s=ax+by+cz+dt (here dt is not a differential, d is a constant). Rather it is of the form s=axt+byt+czt+dzt. Suppose a particle moves in space such that its coordinates change from P(x1,y1,z1) at t1 time to Q(x2,y2,z2) at t2 time. If we do not associate time dimension with x,y and z then we would surely describe the equation to be s=ax+by+cz+dt1, but how do we visualise the fourth term? Moreover, we can see that the particle has moved in all dimensions. The movement of the particle in space is x,y,z but in space-time continuum it is xt,yt,zt. Lets say that at t1 the position of particle is s1=x+y+z+t1 and at t2 it is s2=x+y+z+t2 (Taking the constants a=b=c=d=1 for sake of simplicity). Analysing this we find that the positions are separated in time but not it space, implying that the position of the particle has not changed even though we have considered the particle to be motion. This is actually not possible. Since the particle has moved in space and in time with time being  a parameter to measure the position in every dimension it is concluded that the time is a curled dimension.

Space Time Continuum

A general misunderstanding of common people is that we live in a world that has significantly only three dimensions- length, breadth and height. For a longer time the physicists thought that the universe is in three dimension (3D). It was Einstein who proved that our universe has one more dimension- time. The fourth cannot be represented as an axis on a paper (for better understanding only, in many areas time is represented as an axis). He suggested that our universe is a space time continuum. The dimensions originated for the purpose of defining the state of an object at any instant of time completely.

To understand it in a better way, lets try out a simple exercise. Let us assume that time is not the fourth dimension. Now with three dimensions we will try to define the state of an object at a certain difference of time. Consider a person A who is at point P(x1,y1,z1) at a time say t1. Say at this instant your friend makes a phone call. Now the person moves from point P and reaches point Q(x2,y2,z2) at time say t2. Now if your friend asks you "Where is A ?", you answer him Point Q. Alternatively if he asks "Where was A when I made a phone call ?". The answer will be point P. This shows that if we do not use time as the fourth dimension, the sense of 'when' i.e. the time of occurrence is lost and we would be unable to define the state of an object completely.