Milkyway's End

        Everything that has a start has an end too. The final state or the destiny or the future of a living organism, star, galaxy and the universe has, is to die as all involves life. The end in many cases can be predicted but its accuracy is proved only by time. With great efforts combined by the masters of Physics throughout the world, a picture of how our MILKYWAY galaxy, which is also known as AKASHGANGA will end in the time frame yielding a new galaxy.

        With the advancement in technology, we have figured out the answer to our galaxy's end. As per the experiments, physicists believe that our galaxy would die due to its collision with another galaxy heading towards it. The collision will not take place in a day or a year, rather it will be a process of many centuries. It is predicted that the galaxies would cross each other by side many times and will eventually form a new galaxy with a new black hole at its center. The velocity with which milkyway is heading is nearly 4,00,000 Km/hr yet its collision time is a lot ahead; somewhere around 5 to 6 billion years. Fortunately we will not see our galaxy dieing in front of our eyes and we being getting shrunk in the distance.

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.

Schrödinger's Cat

INTRODUCTION

Erwin Schrödinger

Schrödinger's Cat is a thought experiment which was devised by the Austrian physicist ERWIN SCHRÖDINGER in 1935. The thought experiment presents a cat that might be alive or dead, depending on an earlier random event.


PURPOSE
The above experiment illustrates the problem of the Copenhagen Interpretation of quantum mechanics when applied to everyday objects.


CONSTRUCTION
A cat along with a flask filled with a poison and a radioactive source is placed in a sealed box. A Geiger Counter is placed inside the box to detect radiation. The flask shatters when the radiation is detected. Due to the breaking of flask the poison is released in the box thereby killing the cat. Standing with Copenhagen Interpretation of the quantum mechanics implies that after a while, the cat is simultaneously alive & dead, contradicting the common experience.


EXPLANATION

Superposition of
two states

In common observation, a person defines or describes only one state of a system which is well-defined by a wave function associated with the system. As an example imagine a tree in a forest. Whether the tree in forest is standing or has fallen, either of two can be associated but not both. At particular instant of time, a system has only one state.


In Copenhagen Interpretation of quantum mechanics, a system stops being a superposition of two states and becomes either of two when an observation is made. This clearly shows that the wave function collapses to a single value whenever a conscious observation is made. Copenhagen Interpretation is an observer induced collapse.
When the cat is sealed inside the box, it is alive. Now after a while, there are two states that can be associated to the system(containing cat & flask)-"decayed nucleus/dead cat" or "undecayed nucleus/alive cat". The decay of the radioactive substance is small, may be one atom per hour. Now, when the box is opened, i.e. an observation is made, so the wave function of two states for a single system collapses into one state. If the atom has not decayed, then the cat is alive and if the atom has decayed, the cat is dead.

Collapse of the Wave Function

Another Video : http://www.youtube.com/watch?v=HCOE__N6v4o