The boundless set of concentric spheres

The boundless set of concentric spheres

The Big bang theory, as we know it, seems to work beautifully in explaining the present universe and the origin of the observable universe. We tend to use the word observable rather loosely but it does have a subtle importance to it because the universe is very different from the universe we observe, in my opinion. The big bang theory takes us back to the beginning of the observable universe and the age is estimated to be around 13.7 billion years. This estimation comes from the fact that the radiation emitted after the big bang has taken this long to cool to this present temperature that we see.

When we look deep into the sky and look at a star X which is Y light years (distance travelled by light in one year) away, we are looking at the star, Y years ago in the past. This star might not exist now for all we know. When we look at the sun we are looking at the light that was emitted 8 minutes ago. When I look at the screen in front of me, I am looking at it a billionth of a second in the past. Our senses are such that we need a medium to observe and that medium is light. The very innate property of light having a cosmic speed limit restricts us to view the universe only in one direction, the past.

Past, present and future might be coexisting in different frames of references. For instance, my past in space-time can be the future that is yet to be unraveled by an inhabitant in some other part of the universe and the future that we unravel as we travel through the passage of space-time might be overlapping with another inhabitants’ past.

From the scientific findings, we have come to a consensus that the big bang originated from some primeval particle that was extremely dense. This particle exploded giving rise to the universe that we have come to know of. However, it is not clear how this particle came into existence. Some of the greatest minds have suggested that it was due to random quantum fluctuations. If this were the case, taking into account the expansion of the universe, the model in my opinion should be a collection of concentric spheres with the origin as the primeval particle or the big bang. According to this model, the observers are on the surface of the sphere. The sphere that we exist in would be the sphere with a radius of 13.7 billion light years. It would be impossible for someone to travel from one point on one of the concentric spheres to a diametrically opposite point because by the time we get there the sphere would have increased in size.General relativity,however allows that trough wormholes. There also might be spheres that exist beyond the realms of the present sphere and it would also impossible to get to that sphere because we always look into the past as we look farther into the cosmos. Perhaps the sphere is some sort of a cosmic snow globe which allows /gives us the illusion of travelling far and yet never reaching the edge of the so called universe. However we can reach spheres that have smaller radii than ours but inhabitants on the smaller sphere may have no idea that we even exist since we would be beyond the realms of their observable universe. Similarly we might not know about any inhabitants that might exist beyond our sphere. This is why the term observable becomes so important. The universe that might exist beyond the observable universe can never be observed just like the concept of infinity.

Krish Ramkumar

Free Will

   Krish Ramkumar                                                            

                                                                Free Will

The ability of species to make choices based on consequences could be simply called as free will. Is this free will really a choice that we make or is it simply an illusion? There is no way to know. Free will to me seems like a deterministic approach to reality. But there are quantum uncertainties that are present at every nook and corner of the universe. We as humans, I think can be sure that the free will is simply a decision that originates in our brains. We also know that the brain consists of several neurons that are ultimately made of electrons. After all, every entity in the observable universe is made up of electrons or quarks to be more precise. Let us for now take electron as the elemental particle. From quantum mechanics, we deduce that these particles are highly uncertain and it is impossible to pinpoint their path. To put it simply they are random and unpredictable which makes them non-deterministic. When the most elemental process of making decisions is based on such uncertainty, why is it that we think free will as deterministic? This aspect of reality really confuses me because it seems like the very act of decision making is completely random. If this is the case, the universe by itself is completely random. 

Infinite or finite

Krish Ramkumar

2/18/13

Is the universe infinite or finite?

This question has been the age old conundrum in all of theoretical physics and philosophy. What was there before the big bang? Although string theorists have come up with a theory that explains the origin of the big bang, the question “what was there before that” remains unanswered. If the universe were in fact finite, mankind might be able to arrive at a universal theory that explains everything through science. But, What if the universe were infinite? The fact that the universe is never ending seems extremely dissatisfying and unconvincing to me.

On the contrary, mankind did not create the universe which implies that the universe need not function according to the laws of physics or under any other philosophical theory for that matter. We are insignificant subjects that are merely trying to; in a way decipher GOD’s own cosmic code. Whether this is really possible or not, I don’t have a clue. But from the aspect of theoretical physics, we certainly are getting closer to cracking “some” code.

For all we know, the universe might actually be infinite, albeit unconvincing. To get a feel for this idea, let us look at 2 points x and y separated by a “finite” distance. We all know from basic logic that there are infinite number of points between points x and y. The word finite loses its meaning when we talk about distance between two points. The entire number system by itself was created by mankind so that we didn’t have to deal with the concept of infinity. For instance take the famous Achilles and tortoise paradox. Achilles and tortoise agree to race with tortoise getting a 10 m head start. As the tortoise reaches the 10 m mark, Achilles also begins to run. Since Achilles is 10 times faster than the tortoise, by the time he reaches the 10 meter mark, the tortoise has travelled only 1 m ( tortoises’ speed is 1/10^th that of Achilles). When Achilles reaches the 11 m mark the tortoise also has travelled another one tenth of a meter (11.1m) and so on. As the infinite series continues, it is impossible for Achilles to catch up with the tortoise.

The most elemental quantity in the universe seems to be infinity. If there could be an infinite number of points between two arbitrary points x and y then why can’t the universe at large be infinite.

Achilles eventually winning the race makes this one of the most interesting paradoxes. Infinity as a concept could be the fundamental idea behind the universe.