14 billion years ago, a stupendous event occurred- the Big Bang- which was the beginning of everything we know of. The irony is that it was neither big, as it started from the tiniest of the point, and neither was there a bang, since there was no one around to listen. Space and time also started at that point. Why did the Big Bang happen; and why did the universe evolve the way it is now, are questions to which the answer is, ‘We have no idea.’ This is the title of the wonderful book by Jorge Cham and Daniel Whiteson, where the mysteries of the universe come out bare like nowhere else for the layperson. The universe is a big place and it humbles human beings to the most sub-atomic level. Most of the universe has no explanation. This is perhaps the most charming and wittiest book in physics where complex concepts in physics get an explanation in the simplest manner. The layperson would be wonder-struck at the universe during the reading of the book. The reader might even be angry at the authors for ending the book so soon!
The universe has three components: matter as we know, dark matter, and dark energy. The latter two are complete mysteries to us. The matter as we know, as we have understood, after so much progress in science and technology, comprises a minuscule 5% of the entire universe. Dark matter is everywhere and constitutes 27%; and dark energy, a whopping 68%. We have no idea about the nature and purpose of these ‘dark’ forces. Unexplained gravitational effects around matter in the universe led to the discovery of ‘dark matter.’ Dark energy came to the table when scientists realised that universe is spreading outwards at accelerating speed. The accelerating power, which is anti-gravitational, is because of this dark energy. We are stuck at the pathetic minuscule improper understanding of the 5% constituting the ordinary matter and call ourselves kings. However, the scope for future learning is huge. Scientists will not be sitting at home doing nothing because of ‘complete knowledge of everything’ for some time.
The 5% which comprises of everything we know of, from planets to cakes, is also in the hazy area of knowledge. We barely know about the mysteries of matter. At huge distances and the speed of light, Einstein’s relativity works to explain. At the sub-atomic level, it is quantum theory. However, the biggest problem is that there is no reconciliation of the two grand-dads of physics. At instances like Big Bang or the center of Black Holes, places which require a quantum theory of gravity, infinities of a weird kind spit out making our smart physicists look not so smart. Technology wise, we have had some of the most brilliant achievements reaching out to the stars, but explanation of matter at the deepest level still has some deficiencies. Maybe, there is a deeper theory which explains the world.
String theory seems to be a candidate for a ToE or ‘Theory of Everything.’ The classical standard model with its basic particles and forces-four of them- explains nearly about everything except gravity. The beauty of string theory is that gravity comes out as a natural outcome of this theory. The ugly thing about string theory however is that it works in 10 or 26 dimensions! The uglier thing is that it is purely mathematical. The theories are not testable at all. The energy required to prove the string theory would require a particle smasher the size of our solar system. Clearly, not a very distinct possibility soon. Physics works by the principle of falsifiability. The problem with string theory is that it is not even falsifiable. Some physicists joke about string theory saying that it is a ‘Theory of Anything.’ It would be heartening for Indians to note that the most advanced mathematics used in string theory have some contributions from Srinivasa Ramanujan, the great mathematical genius.
Gravity, electromagnetic force, the strong force, and the weak force are the four fundamental forces involved in the matter we know of. Except gravity, the other three get unified into a single force. Gravity plays a big spoiler defying unification with other forces. Another mystery of gravity is that is an extremely weak force. Run a comb through the hair and put it near pieces of paper. Electromagnetic force created in the comb pull the paper pieces, going against the entire gravitational pull of the Earth! One of the explanations could be multiple dimensions where gravity is leaking. The reason that the other three are relatively strong is that they confine themselves to the three-dimensional world we know of. However, gravity might be cutting across the multiple dimensions and hence, its strength comes down in our world. Just a theory, just a theory.
Time is the most peculiar thing in physics, arguably of course. There are at least a thousand more candidates in physics in terms of peculiarity. The paradoxes arise from the limit imposed on the speed of light in vacuum, a maximum of 186,000 miles per second or 300,000 Kilometers per second. Einstein’s theory of relativity explained to a certain extent these ambiguities of time. Light moves at a fixed speed with respect to an object moving towards or against the source of light at any speed– a counter-intuitive idea. In the gross world, if we are travelling at a certain speed, the speed of an object coming towards us gets an addition to our speed. Similarly, a vehicle moving in the same direction as us would appear slower as its speed would subtract from ours. Nothing like this happens with light. Irrespective of the speed of the observer, light will move at the same speed. The outcome of this effect is that all events in time are with respect to the observer. Two events can occur at the same time, one after the other, or in a reverse sequence depending on the speed and direction of the observer with respect to the events! There is a huge paradox here, a big mystery.
Objects shrink in size, time flow decreases, mass increases, and ageing slows as speed increases. The last part is attractive, but one needs to travel at near light speeds. At such speeds, there would be few who could appreciate your agelessness. It is great to know that light itself never ages. The photons travelling from the edge of the observable universe from our perspective might have taken billions of years; but for light itself-it has been an instantaneous travel. Nothing bends the mind more than when thinking about time.
Space is equally peculiar as time. We tend to think of it as a passive arena where all the action takes place. Physics however shows that space is anything but that. It is an active element playing a very important role in the interactions of matter in the universe. It can bend, distorted by gravity; and the so called ‘vacuum’ of space be a source of limitless energy. The nature of space and time has mystified the best scientists and philosophers since time immemorial. Space started at the Big Bang moment and has been expanding ever since. There is a question like ‘What happened before the Big Bang and what was before the Bang?’ The answer is, ‘You cannot ask that question.’ Space and time did not exist prior to that event. Unless we invoke the hugely untestable theory of multiverses, where our universe is one of the infinite. Well, according to the mathematical string theory, there are 10 raised to the power of 500 of these universes.
After the origin of space and time, there was another equally stupendous event called ‘Inflation.’ According to this beautiful theory, a few milliseconds after the Big Bang, the universe expanded by an order of millions in the briefest of milliseconds. The orders of magnitude are like an atom blowing up to the size of the solar system in a billionth of a second! Of course, the next question of why this happened has a studied silence for an answer. The Big Bang along with inflation is the explanation of the entire universe we see around. Till the very beginning of the Big Bang to the present time, almost all the observable events in the universe have found a fit explanation by invoking these two theories. However, why they should have happened gets back to the title of the book.The universe is remarkably flat and uniform and the reason for this is ‘Inflation’, proposed first by Alan Guth, which occurred so early in the origin of the universe.
The universe is expanding at an accelerating rate thanks to the dark energy and a time will come when there are only free atoms going around in the cosmos. But before, a time will come when the light from the edges of the universe would never be able to travel to us as the universe would be expanding at a faster rate. This implies that there will be areas which will be permanently unobservable. In such a far-off time, maybe another universe would spring up from the vast emptiness of space. Or maybe, universes are coming into existence on a constant basis, each with its own set of laws and rules. Life may originate in some where the beings may wonder at the universe like us and in some, life as we know may never come about.
Why should the universe exist at all? This single question has stumped theologians, philosophers, scientists across time and place in a big way; however, the answer seems elusive. The only solution perhaps would come from Advaita which claims that the universe is a superimposition and it does not exist as such. It is a play of Consciousness only. At a very fundamental level, reality is fuzzy, both at the macro level of the cosmos and the mini-micro level of the sub-atomic world. However, humanity never loses its inquisitive nature and it will always takes leaps and jumps to discover the mysteries of the unknown world. It is part of the fun and the mind needs to do something to justify its existence too!
This book has great cartoons and they are an integral part of the book. The format is in large font which makes for some easy reading. A book I must recommend to every person who has looked at the stars and wondered at our place in the universe. There can never be any regrets on purchasing the book. How often do you get a witty, funny book on serious physics filled with cartoons?
RANDOM MUSINGS 