Friday, April 19, 2013

Evolution and God

          We've been through a lot of Physics lately, so I thought we might take a break and discuss some other things I came across..

                The scientific reason we're living right here at this moment is because of the earth's suitable specs, it is at a distance from the sun that allows it to retain water within it and neither freeze nor boil it. It's the reason we didn't end up a dry planet like those closer to the sun nor freezing gaseous like the ones farther.

        When scientists say that water gave life to everything, they literally mean the sentence. It is believed that all of the various lifeforms we see today, from tiny bacteria to gigantic blue whales, developed from one simple organism that formed from the ocean's simple molecules over three billion years ago. This organism -known as the common ancestor- multiplied, forming its species and over a long period of time (millions of years) developed to more sophisticated ones, each with specific traits suited to where they are and what they need to do in order to survive. This organism developed into another known as Cyanobacteria which was the first organism to be capable of photosynthesis. Sexual reproduction began around 1.2 billion years ago, and since then organisms started developing much faster. The bacteria soon evolved to become more sophisticated water plants, and some other bacteria developed into tiny fish. Some of the more developed fish developed into amphibians like reptiles who used their limbs to crawl the lands and eventually call it home, losing their water compatibility and developing more land-suitable traits. Some even got themselves a pair of wings and became the birds we know today!
             
            What I was just talking about is the process of Evolution, first brought up by the seemingly notorious Charles Darwin. He suggested that every species develops a certain trait or characteristic (either physical or mental) to meet the demands of survival. Giraffes have long necks to reach for food on trees, camels have an extra stomach to save water and food in desert terrain, fish have gills to perform respiration underwater, chameleons and tigers use their skin as camouflage, flowers have that sweet scent to attract insects which in turn help in pollination and reproduction of this flower's species. I could go on forever, but the idea is: Every characteristic of these organisms is there for a functional reason.

          Darwin's theory became the result of a huge debate when the theory spoke of the Human Species (Homo Sapiens) in his book "The Descent of Man". He suggested that we evolved from apes, specifically chimpanzees, and there everybody went to make jokes like "If... then I'm a monkey's uncle". Many despised his theory, mostly religious people, because supposedly God created us himself. We can never be descendants of some stupid chimpanzees because we are God's perfect creation they said. I think it was a matter of ego for those people rather than conviction. After all, nobody likes to be proven wrong.

          The opposite picture shows the embryos of a human (up) and a dog (down). Notice the similarities in the structures of both, the human even has a tail (labelled L)! Fortunately it grows to become a series of vertebrae in our backs, not protruding like in other mammals. This is because we dismissed the need for such a structure to provide balance for us. The human's head though seems to be bigger than the dog's, this is what is known as adaptation. We need bigger brains because we need to use it much more than the puppy!

           Let's go back about 3000 years ago. The ancient Egyptians apparently made up their own Gods and started worshiping them, about the same time the Greeks were hailing Zeus and begging Poseidon to stop the earthquakes. Why is it that these primitive civilizations were so concerned with supreme beings that they made up their own and worshiped them? Did they really believe their own lie? Did they feel secure when they convinced themselves that some omnipotent beings are watching over them? One thing is certain, the priests had to emphasize on the importance of pleasing the Gods to please themselves. They were among the wealthiest of people at the time. Even kings would pay them grandly for their blessings when going to war. It seemed like a good business for those people.

       However, I think the true reason behind Man's countless attempts to forge deities throughout the ages lies in their unanswered questions. Many of the universe's wonders remain undiscovered till this day in spite of all the technologies we have acquired. We automatically attribute that which we do not comprehend to the Gods.

          I conclude with the following opinion: Darwin's theory proved to be acceptable among the scientific community. It has provided predictions that met experimental success. There is no reason to deny it. However this does not mean we shall claim the nonexistence of a God. There is not much evidence that allows us to make such a claim yet.  We'll have to wait before building up any stable fact about the matter. Each expert in every field has a specific thinking pattern that grants them facility in dealing with problems within the field, and we can simulate them with a little knowledge and thoughtfulness.
         

Thursday, April 4, 2013

Introduction to Relativity

         Relativity was a major breakthrough in theoretical physics in the early 20th century. It can be applied on the simplest and most complex situations alike. A simple idea of how relativity works would be the following example: Imagine sitting with a pretty girl for one hour, you'll feel how fast time passed by at the end of the hour. Now imagine that you are studying a subject you do not like, you'll feel that 10 minutes of study seem like an hour, and that time is passing by slowly. Hence, depending on your situation, you will have a different 'sense' of time.

       The theory of relativity has more to do than with our sense, it was used to describe how gravity works, and the effects that Newton never came across. A very famous thought experiment is as follows: Imagine the sun suddenly disappeared into nowhere. What will happen to us (Earth)? According to Newton, gravity is an instantaneous force, hence the effect of the sun disappearing is that we will float out of orbit the second it vanishes, wandering in space with Earth's inertia in a straight line. That was what Newton assumed (sounds logical enough?).

        The genius of Einstein lies in his totally different perception of the universe, he viewed everything in his own imaginative way. His calculations had led him to a cosmic speed limit (speed of light in vacuum) which could never be exceeded. Like a car which has a maximum speed, the universe as well has speed limits! So how in the world could something like gravity have an instantaneous effect if light itself which is the fastest couldn't? Light takes about 8 minutes to reach us from the sun, so if you're looking at the sun right now you're actually seeing it 8 minutes ago in cosmic time. This enigma led him to the following conclusion.
         
          He imagined space and time to be linked together as one fabric of several dimensions (The three dimensions of space plus that of time which makes up four dimensions known as space-time). That 'fabric' is where all cosmic bodies float in. Imagine having an elastic surface on which you put a weight heavy enough to considerably bend that fabric downwards towards the shape of the body (in this case celestial bodies are round in shape so they will distort space-time in a roundly manner). The reason we are attracted to the sun is not because there's an invisible rope tying us with it, as Newton had imagined, but because we simply float into that distorted curvature -the distorted space-time- caused by the sun's shape. If you don't get it yet, try to imagine the effects of a whirlpool. That kind of explains the centripetal force along with gravity!

         So we now know that gravity works due to the distorted curvatures in space-time which we only logically follow. Back to the thought experiment, what will happen to the earth if the sun suddenly disappears? According to Einstein's view that we just discussed, the sudden disappearance will result in a space-time that's trying to get back to it's normal shape (flat), this will generate a wave that starts from the middle of the distorted area that will travel to compensate for the sudden up-bend of space-time. We will not be affected by the sun's disappearance until that wave reaches us. Einstein calculated the speed of that wave to be exactly the speed of light, thus we will float out of orbit the moment the last sun ray reaches us. Everything makes sense now! :)

         What you have just read about is only half of the theory of relativity, called the General Relativity, which basically describes the effects of gravitation as we have discussed. The other halve -Special Relativity- was brought up by the earlier Galileo Galilei in the 16th century when he suggested that all uniform motion is relative, meaning that observers at different points in the universe will not agree on the same calculations due to their different positions hence their measurements being only a relative matter according to each's inertial frame of reference. Einstein expanded on this idea thoroughly in his 1905 paper "On the Electrodynamics of Moving Bodies". The effects described by this theory include time dilation, length contraction and the relativity of simultaneity. We will be exploring these effects some other time.