Good Morning! A new day again! I got up by quarter to 6 AM and after some physical exercise I sat searching the net. Now, as it's obvious to get questions round your mind all the time; I hit upon the answer.com and soon I came across a plethora of unanswered question stuck across the page… I got interested with the nature of the questions so, I decided to look at the science questions and the first question peeking at me was "Where was science invented?" Now such questions are obviously good for your health for it lets you laugh at least 15 minutes and we everyone know the benefits of laughter…
But after humor, as it always happens, philosophy starts pouring in and I really wondered about the person asking that question… may be crazy… or he may be pretending to know the answer. We know that invention needs an inventor and the obvious question that follows is “was science invented” and who then is its inventor. The common folks would say its Archimedes or Galileo less informed ones may extol Einstein but question is did they invent science? Obviously not, inertia or gravity existed long before Galileo or Newton had discovered it. And if the fundamental constants of physics like Planck’s Constant, Velocity of Light, Charge of electron, etc, would vary even by one millionth of its present value universe as it is would not have been possible!… err…wiping out the possibility of me writing a blog in this mid noon as well. Nevertheless, things had worked out perfectly and the constants were affixed appropriate values or in technical words were “fine tuned” to keep us happy. Now physicists are on their usual rat race for churning out the answers out of some bizarre mathematics of what they call “string theories” (for your information this string has already died in the hands of a membrane). They have speculated that geometries of space may be the reason behind the constants and have consoled us telling that we live in one of the most probable universes; which has got no experimental backups! Well, it is said too much philosophies spoil the broth! But the question made me think…
The next candidate was enough challenging it came with a straight face “How did Edwin Hubble Change the World?” Now, interestingly the sun rises from the east before and after Hubble; positions of the galaxies and stars have not altered since then, neither had he turned the world into a sci-fi mumbo jumbo. Well, microscopically he had added a few more entropy like every living system does (in that respect he hasn’t changed the world more than a hippo or the bacteria) perhaps with a few more additions to the global population kitty. Yet he had changed the world and he changed it almost completely. He is credited with demonstrating the first flaw in Einstein’s General Relativity Field Equations which Einstein had himself admitted as the biggest blunder of his life.
Well, so what did Hubble actually do? To understand his discovery let us take the example of a whistling train (hey brat how whistling train jumps into our cosmological discussion…hold your breath soon you’ll get to know). Did you ever notice that a whistling train running towards you? You may have observed that its shrillness increases or if it recedes away its shrillness decreases. That is the frequency of the sound depends upon the relative velocity of the train and you (i.e. source and observer), it increases if the source moves towards the observer and decreases if it recedes away.
This is called Doppler Effect in sound. Similar effect is noticed in case of light waves too with a little modification, known as Doppler Effect in light. Now as shrillness is an effect of frequency in sound similarly color is the effect of frequency in light waves. So if a light source moves away from us we must observe decrease in frequency of the light.
This is the Electromagnetic Spectrum (it is the broader classification of waves that contains light waves.
And we can see that the red light has got the lowest frequency while the violet has got the highest frequency in the visible band of electromagnetic waves (light). So we expect the light from a heavenly body moving away from us would appear reddish. This is what Hubble had discovered in distant galaxies and stars by his long research and extremely precise observations of the cosmos; he found that the galaxies are receding away from us and he also found that further they are from the earth faster is their speed. He found an astonishing result that after certain distance known as the Hubble’s Radius, the speed of receding galaxies increases beyond the velocity of light and light or radiation beyond Hubble’s radius would never reach earth, no matter how long one waits because light would never get the time to reach earth. Thus, what happens beyond Hubble’s radius will be left unknown.
This was the tremendous achievement of Hubble he showed us “infinite and static universe” was actually finite and increasing. Did humans ever wonder or even speculate such result even philosophically? Well, there’s an oriental philosophy called Vedanta and one of its schools “The Qualified Vedanta” predicted not only expansion but also contraction of the physical universe about 2000 years ago!
Hubble’s demonstration has changed the whole of cosmology. It led to the correction of Einstein’s General Relativity Field Equations, cosmological models like Friedman Universe, Big Bang Theory, Steady State theory, etc, out of which Big Bang theory is the most promising candidate. Recently, it has been able to verify its prediction of Cosmological Microwave Background Radiation (CMBR) with the cosmological observations.
Well, my tea is ready, hot and fuming and cheers Mr. Hubble good work!
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