Category Archives: Philosophy

Philosophy is never too far from physics. It is in their overlap that I expect breakthroughs.

Books, Creative, Philosophy, Science

The God Delusion

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I am an atheist. So I agree completely with all the arguments of The God Delusion. As a review of the book, that statement should be the end of it. But somehow the book gave me a strange feeling of dissatisfaction. You see, you may believe in God. Or you may not. Or you may actively believe that there is no God. I fall in this the last category. But I still know that it is only my belief, and that thought fills me with a humility that I feel Dawkins lacks.

Now, it is one thing to say that the concept of God is inconsistent with the worldview you have developed, perhaps with the help of science. The concept is indeed very inconsistent with my own personal worldview, which is why I am an atheist. But it is quite a different matter to discount the concept as a delusion. I believe that our knowledge is incomplete. And that there is plenty of room for a possible God to hide beyond the realms of our current knowledge. Does it mean that we should call our ignorance God and kneel before it? I don’t think so, but if somebody does, that is their prerogative.

You see, it is all a question of what your worldview is. And how much rigor and consistency you demand of it. So, what is a worldview? In my opinion, a worldview is the extension of your knowledge. We all have a certain amount of knowledge. We also have a lot of sensory data that comes in every moment that we have to process. We do most of this processing automatically, without conscious effort. But some of the higher level data and information that we encounter merit a closer analysis. How do we do it, given that we may not know much about it? We use our commonsense, our pre-conceived notions, the value systems our parents and teachers left in us and so on. One of these things that we use, or perhaps the totality of these things, is our worldview.

Let’s take an example. Douglas Adams tells us that dolphins are actually smarter than us and have regular inter-galactic communication. Well, we have no way of refuting this claim (which, of course, is only a joke). But our worldview tells us that it is unlikely to be true. And we don’t believe it — as though we know it is not true.

Another example, one that Bertram Russell once cited. Scripture tells us that faith can move mountains. Some people believe it. Science tells us that a nuclear blast can, well, move mountains. Some people believe that too. Note that most people haven’t directly witnessed either. But even for those who believe in the faith-mountain connection, nuclear energy moving mountains is far more plausible a belief. It is just a lot more consistent with our current worldview.

Now, just because God is a delusion according to Dawkins’s worldview (or mine, for that matter), should you buy it? Not unless it is inconsistent with yours as well. Worldviews are hard to change. So are our stances vis-a-vis God and science, when seen as belief-systems — as the movie Contact vividly illustrates. If you missed it, you should watch it. Repeatedly, if needed. It is a good movie anyway.

It is true what they say about a scientific worldview being inconsistent with any sensible notion of a god. But worldviews are a funny thing. Nothing prevents you from tolerating inconsistencies in your worldview. Although Dawkins goes to some length to absolve Einstein of this lack of consistency, the conventional wisdom is that he did believe in God. The truth of the matter is that our collective knowledge (even after adding Einstein’s massive contribution) is limited. There really is plenty of room beyond its limits for God (or eight million gods, if I were to believe my parents), as I will try to show in my next post.

That, however, is only the tip of the iceberg. Once we admit that there are limits to our knowledge, and to what is knowable, we will soon find ourselves staring at other delusions. What is the point it discounting a God delusion, while embracing a space-delusion? In a universe that is unreal, everything is a delusion, not just God. I know, you think it is just my sanity that is unreal, but I may convince you otherwise. In another post.

Books, Philosophy

Helen Keller

The story of Helen Keller is the story of the dark reality that traps you in the absence of your senses. It is also an illustration of the role of language in breaking out of that darkness. Born a healthy child on June 27, 1880 in Alabama, Helen Keller was a perfectly happy baby — until the tender age of 19 months, when she was stricken with a strange illness that “they called acute congestion of the stomach and brain.” The terrible illness left her blind and deaf — “closed my eyes and ears and plunged me into the unconsciousness of a new-born baby,” as she would later write in her autobiography.

Disconnected from the physical world, Helen was trapped in her dark, silent reality (or the lack thereof). She did not even have thoughts or words in her mind, because the tragedy happened before she started talking. She could not learn from her parents like normal children, because she was blind and deaf. There were no special schools at that time for disadvantaged children like her. When she was seven, Helen’s parents contacted Alexander Graham Bell, the inventor of the telephone, who was also an educator of the deaf. Through his help, they found Anne Sullivan to tutor Helen. Anne Sullivan had special methods of making hand signs to spell out objects. Sadly, none of these tricks worked with Helen for a few frustrating months. She could not make the connection between the hand movements and the objects. It looked as though Helen would be doomed to her dark reality for ever. Here is how she made the connection and broke free from darkness. (This block quote is from Helen Keller’s autobiography “The Story of my Life,” which was ffirst published in 1903 and is in the public domain according to the US copyright laws.)

One day, while I was playing with my new doll, Miss Sullivan put my big rag doll into my lap also, spelled “d-o-l-l” and tried to make me understand that “d-o-l-l” applied to both. Earlier in the day we had had a tussle over the words “m-u-g” and “w-a-t-e-r.” Miss Sullivan had tried to impress it upon me that “m-u-g” is mug and that “w-a-t-e-r” is water, but I persisted in confounding the two. In despair she had dropped the subject for the time, only to renew it at the first opportunity. I became impatient at her repeated attempts and, seizing the new doll, I dashed it upon the floor. I was keenly delighted when I felt the fragments of the broken doll at my feet. Neither sorrow nor regret followed my passionate outburst. I had not loved the doll. In the still, dark world in which I lived there was no strong sentiment or tenderness. I felt my teacher sweep the fragments to one side of the hearth, and I had a sense of satisfaction that the cause of my discomfort was removed. She brought me my hat, and I knew I was going out into the warm sunshine. This thought, if a wordless sensation may be called a thought, made me hop and skip with pleasure.

We walked down the path to the well-house, attracted by the fragrance of the honeysuckle with which it was covered. Some one was drawing water and my teacher placed my hand under the spout. As the cool stream gushed over one hand she spelled into the other the word water, first slowly, then rapidly. I stood still, my whole attention fixed upon the motions of her fingers. Suddenly I felt a misty consciousness as of something forgotten — a thrill of returning thought; and somehow the mystery of language was revealed to me. I knew then that “w-a-t-e-r” meant the wonderful cool something that was flowing over my hand. That living word awakened my soul, gave it light, hope, joy, set it free! There were barriers still, it is true, but barriers that could in time be swept away.

The mystery of language is at the genesis of reality; it is what sweeps away the dark barriers standing between us and our conscious awareness of reality. It took Helen Keller out of nothingness into a world of reality, and if it is not the Word in “The Word was God,” I will never know what is.

Photo by The Library of Congress

Philosophy

What is the Word?

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I know very little about religion. Although my smart-ass comments may appear, once in a while, as profound, I’m really ignorant in matters of theology and religion. After all, I have no formal background in these fields that scholars spend their whole life exploring. So, forgive me if this post comes across as pontificating on something I’d better leave to the scholars; but I cannot help wondering what the Word is. I mean, when they say, “In the beginning, there was the Word,” what exactly is the word?

The verse, John 1:1 “In the beginning was the Word, and the Word was with God, and the Word was God”, is again something people have spent much time researching and pondering over. My cursory search unearthed a couple of lines of thought. These lines were mostly concerned with the accuracy of the translation of the verse from Greek, which was complicated by the lack of “the” or “a” articles in the original language. So the verse could be translated as, for instance, “The Word was the God,” consistent with the monotheist notion of Christianity. Or it could be “The Word was a god,” giving quite a different, perhaps pagan, coloration to the issue.

For obvious (atheistic) reasons, I am not interested in this aspect of the verse, nor in these lines of thought. I found another translation, allegedly more literal, that went like, “When the beginning began, the Word was already there.” This suited my purpose better. Still, what exactly was this Word?

My understanding of this statement is as follows. In the philosophy of language, it can be argued that life, universe and everything exists in language, in thoughts, in your brain. The term “language” as defined here doesn’t just mean the communication tool, it also encompasses your thoughts and ideas. It is the vehicle of your thought process. In the absence of language, you have no thoughts, only animal instincts. You have no conscious awareness, only unthinking reactions to your surroundings. You don’t know that you exist, you don’t know that the world exists. The nothingness that engulfs you in the absence of a language is most poignantly depicted in the inspiring story of Helen Keller, coming up in a few days.

In my view, the “Word” that was there in the beginning is language, the ensemble of your thoughts and ideas, and the thought-processing mechanism. It creates our reality. Before we had language, we had no reality; we had nothing. And John 1:1 is a statement of intention to attribute this world of reality, or the opposite of nothingness, created by language to God. And, to me, this statement is the clearest proof that the saint knew how god was born. Obviously, I am rushing in where angels fear to tread. This view of mine will not be embraced (or even tolerated) by anybody who believes in the theological meaning attached to this text of scripture. And to them, I humbly point out that it is just a view, a mere mortal’s view at that! It probably only goes to show that “The devil can cite Scripture for his purpose!”

Creative, Philosophy, Physics, Quotes, Science

Change the Facts

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There is beauty in truth, and truth in beauty. Where does this link between truth and beauty come from? Of course, beauty is subjective, and truth is objective — or so we are told. It may be that we have evolved in accordance with the beautiful Darwinian principles to see perfection in absolute truth.

The beauty and perfection I’m thinking about are of a different kind — those of ideas and concepts. At times, you may get an idea so perfect and beautiful that you know it has to be true. This conviction of truth arising from beauty may be what made Einstein declare:

But this conviction about the veracity of a theory based on its perfection is hardly enough. Einstein’s genius really is in his philosophical tenacity, his willingness to push the idea beyond what is considered logical.

Let’s take an example. Let’s say you are in a cruising airplane. If you close the windows and somehow block out the engine noise, it will be impossible for you to tell whether you are moving or not. This inability, when translated to physics jargon, becomes a principle stating, “Physical laws are independent of the state of motion of the experimental system.”

The physical laws Einstein chose to look at were Maxwell’s equations of electromagnetism, which had the speed of light appearing in them. For them to be independent of (or covariant with, to be more precise) motion, Einstein postulated that the speed of light had to be a constant regardless of whether you were going toward it or away from it.

Now, I don’t know if you find that postulate particularly beautiful. But Einstein did, and decided to push it through all its illogical consequences. For it to be true, space has to contract and time had to dilate, and nothing could go faster than light. Einstein said, well, so be it. That is the philosophical conviction and tenacity that I wanted to talk about — the kind that gave us Special Relativity about a one hundred years ago.

Want to get to General Relativity from here? Simple, just find another beautiful truth. Here is one… If you have gone to Magic Mountain, you would know that you are weightless during a free fall (best tried on an empty stomach). Free fall is acceleration at 9.8 m/s/s (or 32 ft/s/s), and it nullifies gravity. So gravity is the same as acceleration — voila, another beautiful principle.

World line of airplanesIn order to make use of this principle, Einstein perhaps thought of it in pictures. What does acceleration mean? It is how fast the speed of something is changing. And what is speed? Think of something moving in a straight line — our cruising airplane, for instance, and call the line of flight the X-axis. We can visualize its speed by thinking of a time T-axis at right angles with the X-axis so that at time = 0, the airplane is at x = 0. At time t, it is at a point x = v.t, if it is moving with a speed v. So a line in the X-T plane (called the world line) represents the motion of the airplane. A faster airplane would have a shallower world line. An accelerating airplane, therefore, will have a curved world line, running from the slow world line to the fast one.

So acceleration is curvature in space-time. And so is gravity, being nothing but acceleration. (I can see my physicist friends cringe a bit, but it is essentially true — just that you straighten the world-line calling it a geodesic and attribute the curvature to space-time instead.)

The exact nature of the curvature and how to compute it, though beautiful in their own right, are mere details, as Einstein himself would have put it. After all, he wanted to know God’s thoughts, not the details.

Life and Death, Philosophy, Topical, Work and Life

Of Dreams and Memories

I recently watched The Diving Bell and the Butterfly (Le scaphandre et le papillon), which describes the tragic plight of the French journalist Jean-Dominique Bauby, who suffered a severe stroke and became “locked-in.” During my research days, I had worked a bit on rehabilitation systems for such locked-in patients, who have normal or near-normal cognitive activities but no motor control. In other words, their fully functional minds are locked in a useless body that affords them no means of communication with the external world. It is the solitary confinement of the highest order.

Locked-in condition is one of my secret fears; not so much for myself, but that someone close to me might have to go through it. My father suffered a stroke and was comatose for a month before he passed away, and I will always wonder whether he was locked-in. Did he feel pain and fear? So I Googled a bit to find out if stroke patients were conscious inside. I couldn’t find anything definitive. Then it occurred to me that perhaps these stroke patients were conscious, but didn’t remember it later on.

That thought brought me to one of my philosophical musings. What does it mean to say that something happened if you cannot remember it? Let’s say you had to go through a lot of pain for whatever reason. But you don’t remember it later. Did you really suffer? It is like a dream that you cannot remember. Did you really dream it?

Memory is an essential ingredient of reality, and of existence — which is probably why they can sell so many digital cameras and camcorders. When memories of good times fade in our busy minds, perhaps we feel bits of our existence melting away. So we take thousands of pictures and videos that we are too busy to look at later on.

But I wonder. When I die, my memories will die with me. Sure, those who are close to me will remember me for a while, but the memories that I hold on to right now, the things I have seen and experienced, will all disappear — like an uncertain dream that someone (perhaps a butterfly) dreamt and forgot. So what does it mean to say that I exist? Isn’t it all a dream?

Books, Creative, Life and Death, Philosophy

The Razor’s Edge by W Somerset Maugham

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May be it is only my tendency to see philosophy everywhere, but I honestly believe Maugham’s works are the classics they are because of their deep philosophical underpinnings. Their strong plots and Maugham’s masterful storytelling help, but what makes them timeless is the fact that Maugham gives voice to the restlessness of our hearts, and puts in words the stirring uncertainties of our souls. Our questions have always been the same. Where do we come from? What are we doing here? And where are we headed? Quo vadis?

Of all the books of this kind that I have read, and I have read many, The Razor’s Edge takes on the last question most directly. When Larry says, out of the blue, “The dead look so awfully dead.” we get an idea of what his quest, and indeed the inquiry of the book, is going to be.

Larry Darrell is as close to human flawlessness as Maugham ever gets. His cynical disposition always produced vivid characters that were flawed human beings. We are used to snobbishness in Elliott Templeton, fear and hypocrisy in the vicar of Blackstable, self-loathing even in the self-image of Philip Carey, frivolity in Kitty Garstin, undue sternness in Walter Fane, the ludicrous buffoonery of Dirk Stroeve, abysmal cruelty in Charles Strickland, ultimate betrayal in Blanche Stroeve, fatal alcoholism in Sophie, incurable promiscuity in Mildred — an endless parade of gripping characters, everyone of them as far from human perfection as you and me.

But human perfection is what is sought and found in Larry Darrell. He is gentle, compassionate, single-mindedly hardworking, spiritually enlightened, simple and true, and even handsome (although Maugham couldn’t help but bring in some reservations about it). In one word, perfect. So it is only with an infinite amount of vanity that anybody can identify himself with Larry (as I secretly do). And it is a testament to Maugham’s mastery and skill that he could still make such an idealistic character human enough for some people to see themselves in him.

As I plod on with these review posts, I’m beginning to find them a bit useless. I feel that whatever needed to be said was already well said in the books to begin with. And, the books being classics, others have also said much about them. So why bother?

Let me wind up this post, and possibly this review series, with a couple of personal observations. I found it gratifying that Larry finally found enlightenment in my native land of Kerala. Written decades before the hippie exodus for spiritual fulfillment in India, this book is remarkably prescient. And, as a book on what life is all about, and how to live it to its spiritual fullness in our hectic age, The Razor’s Edge is a must read for everybody.

Debates, Philosophy, Physics, SFN - Science Forums

The Big Bang Theory – Part II

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After reading a paper by Ashtekar on quantum gravity and thinking about it, I realized what my trouble with the Big Bang theory was. It is more on the fundamental assumptions than the details. I thought I would summarize my thoughts here, more for my own benefit than anybody else’s.

Classical theories (including SR and QM) treat space as continuous nothingness; hence the term space-time continuum. In this view, objects exist in continuous space and interact with each other in continuous time.

Although this notion of space time continuum is intuitively appealing, it is, at best, incomplete. Consider, for instance, a spinning body in empty space. It is expected to experience centrifugal force. Now imagine that the body is stationary and the whole space is rotating around it. Will it experience any centrifugal force?

It is hard to see why there would be any centrifugal force if space is empty nothingness.

GR introduced a paradigm shift by encoding gravity into space-time thereby making it dynamic in nature, rather than empty nothingness. Thus, mass gets enmeshed in space (and time), space becomes synonymous with the universe, and the spinning body question becomes easy to answer. Yes, it will experience centrifugal force if it is the universe that is rotating around it because it is equivalent to the body spinning. And, no, it won’t, if it is in just empty space. But “empty space” doesn’t exist. In the absence of mass, there is no space-time geometry.

So, naturally, before the Big Bang (if there was one), there couldn’t be any space, nor indeed could there be any “before.” Note, however, that the Ashtekar paper doesn’t clearly state why there had to be a big bang. The closest it gets is that the necessity of BB arises from the encoding of gravity in space-time in GR. Despite this encoding of gravity and thereby rendering space-time dynamic, GR still treats space-time as a smooth continuum — a flaw, according to Ashtekar, that QG will rectify.

Now, if we accept that the universe started out with a big bang (and from a small region), we have to account for quantum effects. Space-time has to be quantized and the only right way to do it would be through quantum gravity. Through QG, we expect to avoid the Big Bang singularity of GR, the same way QM solved the unbounded ground state energy problem in the hydrogen atom.

What I described above is what I understand to be the physical arguments behind modern cosmology. The rest is a mathematical edifice built on top of this physical (or indeed philosophical) foundation. If you have no strong views on the philosophical foundation (or if your views are consistent with it), you can accept BB with no difficulty. Unfortunately, I do have differing views.

My views revolve around the following questions.

These posts may sound like useless philosophical musings, but I do have some concrete (and in my opinion, important) results, listed below.

There is much more work to be done on this front. But for the next couple of years, with my new book contract and pressures from my quant career, I will not have enough time to study GR and cosmology with the seriousness they deserve. I hope to get back to them once the current phase of spreading myself too thin passes.

Philosophy, Physics, Science

Why the Speed of Light?

What is so special about light that its speed should figure in the basic structure of space and time and our reality? This is the question that has nagged many scientists ever since Albert Einstein published On the Electrodynamics of Moving Bodies about 100 years ago.

In order to understand the specialness of light in our space and time, we need to study how we perceive the world around us and how reality is created in our brains. We perceive our world using our senses. The sensory signals that our senses collect are then relayed to our brains. The brain creates a cognitive model, a representation of the sensory inputs, and presents it to our conscious awareness as reality. Our visual reality consists of space much like our auditory world is made up of sounds.

Just as sounds are a perceptual experience rather than a fundamental property of the physical reality, space also is an experience, or a cognitive representation of the visual inputs, not a fundamental aspect of “the world” our senses are trying to sense.

Space and time together form what physics considers the basis of reality. The only way we can understand the limitations in our reality is by studying the limitations in our senses themselves.

At a fundamental level, how do our senses work? Our sense of sight operates using light, and the fundamental interaction involved in sight falls in the electromagnetic (EM) category because light (or photon) is the intermediary of EM interactions. The exclusivity of EM interaction is not limited to our the long range sense of sight; all the short range senses (touch, taste, smell and hearing) are also EM in nature. To understand the limitations of our perception of space, we need not highlight the EM nature of all our senses. Space is, by and large, the result of our sight sense. But it is worthwhile to keep in mind that we would have no sensing, and indeed no reality, in the absence of EM interactions.

Like our senses, all our technological extensions to our senses (such as radio telescopes, electron microscopes, redshift measurements and even gravitational lensing) use EM interactions exclusively to measure our universe. Thus, we cannot escape the basic constraints of our perception even when we use modern instruments. The Hubble telescope may see a billion light years farther than our naked eyes, but what it sees is still a billion years older than what our eyes see. Our perceived reality, whether built upon direct sensory inputs or technologically enhanced, is a subset of electromagnetic particles and interactions only. It is a projection of EM particles and interactions into our sensory and cognitive space, a possibly imperfect projection.

This statement about the exclusivity of EM interactions in our perceived reality is often met with a bit of skepticism, mainly due to a misconception that we can sense gravity directly. This confusion arises because our bodies are subject to gravity. There is a fine distinction between “being subject to” and “being able to sense” gravitational force.

This difference is illustrated by a simple thought experiment: Imagine a human subject placed in front of an object made entirely of cosmological dark matter. There is no other visible matter anywhere the subject can see it. Given that the dark matter exerts gravitational force on the subject, will he be able to sense its presence? He will be pulled toward it, but how will he know that he is being pulled or that he is moving? He can possibly design some mechanical contraption to detect the gravity of the dark matter object. But then he will be sensing the effect of gravity on some matter using EM interactions. For instance, he may be able to see his unexplained acceleration (effect of gravity on his body, which is EM matter) with respect to reference objects such as stars. But the sensing part here (seeing the stars) involves EM interactions.

It is impossible to design any mechanical contraption to detect gravity that is devoid of EM matter. The gravity sensing in our ears again measures the effect of gravity on EM matter. In the absence of EM interaction, it is impossible to sense gravity, or anything else for that matter.

Electromagnetic interactions are responsible for our sensory inputs. Sensory perception leads to our brain’s representation that we call reality. Any limitation in this chain leads to a corresponding limitation in our sense of reality. One limitation in the chain from senses to reality is the finite speed of photon, which is the gauge boson of our senses. The finite speed of the sense modality influences and distorts our perception of motion, space and time. Because these distortions are perceived as a part of our reality itself, the root cause of the distortion becomes a fundamental property of our reality. This is how the speed of light becomes such an important constant in our space time. The sanctity of light is respected only in our perceived reality.

If we trust the imperfect perception and try to describe what we sense at cosmological scales, we end up with views of the world such as the big bang theory in modern cosmology and the general and special theories of relativity. These theories are not wrong, and the purpose of this book is not to prove them wrong, just to point out that they are descriptions of a perceived reality. They do not describe the physical causes behind the sensory inputs. The physical causes belong to an absolute reality beyond our senses.

The distinction between the absolute reality and our perception of it can be further developed and applied to certain specific astrophysical and cosmological phenomena. When it comes to the physics that happens well beyond our sensory ranges, we really have to take into account the role that our perception and cognition play in seeing them. The universe as we see it is only a cognitive model created out of the photons falling on our retina or on the photo sensors of the Hubble telescope. Because of the finite speed of the information carrier (namely photons), our perception is distorted in such a way as to give us the impression that space and time obey special relativity. They do, but space and time are not the absolute reality. They are only a part of the unreal universe that is our perception of an unknowable reality.

[This again is an edited excerpt from my book, The Unreal Universe.]

Debates, Philosophy, Physics

What is Space?

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This sounds like a strange question. We all know what space is, it is all around us. When we open our eyes, we see it. If seeing is believing, then the question “What is space?” indeed is a strange one.

To be fair, we don’t actually see space. We see only objects which we assume are in space. Rather, we define space as whatever it is that holds or contains the objects. It is the arena where objects do their thing, the backdrop of our experience. In other words, experience presupposes space and time, and provides the basis for the worldview behind the currently popular interpretations of scientific theories.

Although not obvious, this definition (or assumption or understanding) of space comes with a philosophical baggage — that of realism. The realist’s view is predominant in the current understanding of Einstien’s theories as well. But Einstein himself may not have embraced realism blindly. Why else would he say:

In order to break away from the grip of realism, we have to approach the question tangentially. One way to do it is by studying the neuroscience and cognitive basis of sight, which after all provides the strongest evidence to the realness of space. Space, by and large, is the experience associated with sight. Another way is to examine experiential correlates of other senses: What is sound?

When we hear something, what we hear is, naturally, sound. We experience a tone, an intensity and a time variation that tell us a lot about who is talking, what is breaking and so on. But even after stripping off all the extra richness added to the experience by our brain, the most basic experience is still a “sound.” We all know what it is, but we cannot explain it in terms more basic than that.

Now let’s look at the sensory signal responsible for hearing. As we know, these are pressure waves in the air that are created by a vibrating body making compressions and depressions in the air around it. Much like the ripples in a pond, these pressure waves propagate in almost all directions. They are picked up by our ears. By a clever mechanism, the ears perform a spectral analysis and send electric signals, which roughly correspond to the frequency spectrum of the waves, to our brain. Note that, so far, we have a vibrating body, bunching and spreading of air molecules, and an electric signal that contains information about the pattern of the air molecules. We do not have sound yet.

The experience of sound is the magic our brain performs. It translates the electrical signal encoding the air pressure wave patterns to a representation of tonality and richness of sound. Sound is not the intrinsic property of a vibrating body or a falling tree, it is the way our brain chooses to represent the vibrations or, more precisely, the electrical signal encoding the spectrum of the pressure waves.

Doesn’t it make sense to call sound an internal cognitive representation of our auditory sensory inputs? If you agree, then reality itself is our internal representation of our sensory inputs. This notion is actually much more profound that it first appears. If sound is representation, so is smell. So is space.

Figure
Figure: Illustration of the process of brain’s representation of sensory inputs. Odors are a representation of the chemical compositions and concentration levels our nose senses. Sounds are a mapping of the air pressure waves produced by a vibrating object. In sight, our representation is space, and possibly time. However, we do not know what it is the representation of.

We can examine it and fully understand sound because of one remarkable fact — we have a more powerful sense, namely our sight. Sight enables us to understand the sensory signals of hearing and compare them to our sensory experience. In effect, sight enables us to make a model describing what sound is.

Why is it that we do not know the physical cause behind space? After all, we know of the causes behind the experiences of smell, sound, etc. The reason for our inability to see beyond the visual reality is in the hierarchy of senses, best illustrated using an example. Let’s consider a small explosion, like a firecracker going off. When we experience this explosion, we will see the flash, hear the report, smell the burning chemicals and feel the heat, if we are close enough.

The qualia of these experiences are attributed to the same physical event — the explosion, the physics of which is well understood. Now, let’s see if we can fool the senses into having the same experiences, in the absence of a real explosion. The heat and the smell are fairly easy to reproduce. The experience of the sound can also be created using, for instance, a high-end home theater system. How do we recreate the experience of the sight of the explosion? A home theater experience is a poor reproduction of the real thing.

In principle at least, we can think of futuristic scenarios such as the holideck in Star Trek, where the experience of the sight can be recreated. But at the point where sight is also recreated, is there a difference between the real experience of the explosion and the holideck simulation? The blurring of the sense of reality when the sight experience is simulated indicates that sight is our most powerful sense, and we have no access to causes beyond our visual reality.

Visual perception is the basis of our sense of reality. All other senses provide corroborating or complementing perceptions to the visual reality.

[This post has borrowed quite a bit from my book.]

Articles and Essays, Philosophy, Physics, Science, Unpublished

Light Travel Time Effects and Cosmological Features

This unpublished article is a sequel to my earlier paper (also posted here as “Are Radio Sources and Gamma Ray Bursts Luminal Booms?“). This blog version contains the abstract, introduction and conclusions. The full version of the article is available as a PDF file.

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Abstract

Light travel time effects (LTT) are an optical manifestation of the finite speed of light. They can also be considered perceptual constraints to the cognitive picture of space and time. Based on this interpretation of LTT effects, we recently presented a new hypothetical model for the temporal and spatial variation of the spectrum of Gamma Ray Bursts (GRB) and radio sources. In this article, we take the analysis further and show that LTT effects can provide a good framework to describe such cosmological features as the redshift observation of an expanding universe, and the cosmic microwave background radiation. The unification of these seemingly distinct phenomena at vastly different length and time scales, along with its conceptual simplicity, can be regarded as indicators of the curious usefulness of this framework, if not its validity.

Introduction

The finite speed of light plays an important part in how we perceive distance and speed. This fact should hardly come as a surprise because we do know that things are not as we see them. The sun that we see, for instance, is already eight minutes old by the time we see it. This delay is trivial; if we want to know what is going on at the sun now, all we have to do is to wait for eight minutes. We, nonetheless, have to “correct” for this distortion in our perception due to the finite speed of light before we can trust what we see.

What is surprising (and seldom highlighted) is that when it comes to sensing motion, we cannot back-calculate the same way we take out the delay in seeing the sun. If we see a celestial body moving at an improbably high speed, we cannot figure out how fast and in what direction it is “really” moving without making further assumptions. One way of handling this difficulty is to ascribe the distortions in our perception of motion to the fundamental properties of the arena of physics — space and time. Another course of action is to accept the disconnection between our perception and the underlying “reality” and deal with it in some way.

Exploring the second option, we assume an underlying reality that gives rise to our perceived picture. We further model this underlying reality as obeying classical mechanics, and work out our perceived picture through the apparatus of perception. In other words, we do not attribute the manifestations of the finite speed of light to the properties of the underlying reality. Instead, we work out our perceived picture that this model predicts and verify whether the properties we do observe can originate from this perceptual constraint.

Space, the objects in it, and their motion are, by and large, the product of optical perception. One tends to take it for granted that perception arises from reality as one perceives it. In this article, we take the position that what we perceive is an incomplete or distorted picture of an underlying reality. Further, we are trying out classical mechanics for the the underlying reality (for which we use terms like absolute, noumenal or physical reality) that does cause our perception to see if it fits with our perceived picture (which we may refer to as sensed or phenomenal reality).

Note that we are not implying that the manifestations of perception are mere delusions. They are not; they are indeed part of our sensed reality because reality is an end result of perception. This insight may be behind Goethe’s famous statement, “Optical illusion is optical truth.”

We applied this line of thinking to a physics problem recently. We looked at the spectral evolution of a GRB and found it to be remarkably similar to that in a sonic boom. Using this fact, we presented a model for GRB as our perception of a “luminal” boom, with the understanding that it is our perceived picture of reality that obeys Lorentz invariance and our model for the underlying reality (causing the perceived picture) may violate relativistic physics. The striking agreement between the model and the observed features, however, extended beyond GRBs to symmetric radio sources, which can also be regarded as perceptual effects of hypothetical luminal booms.

In this article, we look at other implications of the model. We start with the similarities between the light travel time (LTT) effects and the coordinate transformation in Special Relativity (SR). These similarities are hardly surprising because SR is derived partly based on LTT effects. We then propose an interpretation of SR as a formalization of LTT effects and study a few observed cosmological phenomena in the light of this interpretation.

Similarities between Light Travel Time Effects and SR

Special relativity seeks a linear coordinate transformation between coordinate systems in motion with respect to each other. We can trace the origin of linearity to a hidden assumption on the nature of space and time built into SR, as stated by Einstein: “In the first place it is clear that the equations must be linear on account of the properties of homogeneity which we attribute to space and time.” Because of this assumption of linearity, the original derivation of the transformation equations ignores the asymmetry between approaching and receding objects. Both approaching and receding objects can be described by two coordinate systems that are always receding from each other. For instance, if a system K is moving with respect to another system k along the positive X axis of k, then an object at rest in K at a positive x is receding while another object at a negative x is approaching an observer at the origin of k.

The coordinate transformation in Einstein’s original paper is derived, in part, a manifestation of the light travel time (LTT) effects and the consequence of imposing the constancy of light speed in all inertial frames. This is most obvious in the first thought experiment, where observers moving with a rod find their clocks not synchronized due to the difference in light travel times along the length of the rod. However, in the current interpretation of SR, the coordinate transformation is considered a basic property of space and time.

One difficulty that arises from this interpretation of SR is that the definition of the relative velocity between the two inertial frames becomes ambiguous. If it is the velocity of the moving frame as measured by the observer, then the observed superluminal motion in radio jets starting from the core region becomes a violation of SR. If it is a velocity that we have to deduce by considering LT effects, then we have to employ the extra ad-hoc assumption that superluminality is forbidden. These difficulties suggest that it may be better to disentangle the light travel time effects from the rest of SR.

In this section, we will consider space and time as a part of the cognitive model created by the brain, and argue that special relativity applies to the cognitive model. The absolute reality (of which the SR-like space-time is our perception) does not have to obey the restrictions of SR. In particular, objects are not restricted to subluminal speeds, but they may appear to us as though they are restricted to subluminal speeds in our perception of space and time. If we disentangle LTT effects from the rest of SR, we can understand a wide array of phenomena, as we shall see in this article.

Unlike SR, considerations based on LTT effects result in intrinsically different set of transformation laws for objects approaching an observer and those receding from him. More generally, the transformation depends on the angle between the velocity of the object and the observer’s line of sight. Since the transformation equations based on LTT effects treat approaching and receding objects asymmetrically, they provide a natural solution to the twin paradox, for instance.

Conclusions

Because space and time are a part of a reality created out of light inputs to our eyes, some of their properties are manifestations of LTT effects, especially on our perception of motion. The absolute, physical reality presumably generating the light inputs does not have to obey the properties we ascribe to our perceived space and time.

We showed that LTT effects are qualitatively identical to those of SR, noting that SR only considers frames of reference receding from each other. This similarity is not surprising because the coordinate transformation in SR is derived based partly on LTT effects, and partly on the assumption that light travels at the same speed with respect to all inertial frames. In treating it as a manifestation of LTT, we did not address the primary motivation of SR, which is a covariant formulation of Maxwell’s equations. It may be possible to disentangle the covariance of electrodynamics from the coordinate transformation, although it is not attempted in this article.

Unlike SR, LTT effects are asymmetric. This asymmetry provides a resolution to the twin paradox and an interpretation of the assumed causality violations associated with superluminality. Furthermore, the perception of superluminality is modulated by LTT effects, and explains gamma ray bursts and symmetric jets. As we showed in the article, perception of superluminal motion also holds an explanation for cosmological phenomena like the expansion of the universe and cosmic microwave background radiation. LTT effects should be considered as a fundamental constraint in our perception, and consequently in physics, rather than as a convenient explanation for isolated phenomena.

Given that our perception is filtered through LTT effects, we have to deconvolute them from our perceived reality in order to understand the nature of the absolute, physical reality. This deconvolution, however, results in multiple solutions. Thus, the absolute, physical reality is beyond our grasp, and any assumed properties of the absolute reality can only be validated through how well the resultant perceived reality agrees with our observations. In this article, we assumed that the underlying reality obeys our intuitively obvious classical mechanics and asked the question how such a reality would be perceived when filtered through light travel time effects. We demonstrated that this particular treatment could explain certain astrophysical and cosmological phenomena that we observe.

The coordinate transformation in SR can be viewed as a redefinition of space and time (or, more generally, reality) in order to accommodate the distortions in our perception of motion due to light travel time effects. One may be tempted to argue that SR applies to the “real” space and time, not our perception. This line of argument begs the question, what is real? Reality is only a cognitive model created in our brain starting from our sensory inputs, visual inputs being the most significant. Space itself is a part of this cognitive model. The properties of space are a mapping of the constraints of our perception.

The choice of accepting our perception as a true image of reality and redefining space and time as described in special relativity indeed amounts to a philosophical choice. The alternative presented in the article is inspired by the view in modern neuroscience that reality is a cognitive model in the brain based on our sensory inputs. Adopting this alternative reduces us to guessing the nature of the absolute reality and comparing its predicted projection to our real perception. It may simplify and elucidate some theories in physics and explain some puzzling phenomena in our universe. However, this option is yet another philosophical stance against the unknowable absolute reality.