“Science alone of all the subjects contains within itself the lesson of the danger of belief in the infallibility of the greatest teachers in the preceding generation. Learn from science that you must doubt the experts. As a matter of fact, I can also define science another way: Science is the belief in the ignorance of experts.” — Richard Feynman

One of the brighter ones among those who came after Einstein cautioned us to guard against our blind faith in the infallibility of old masters. Taking my cue from that insight, I, for one, think that Einstein’s century is behind us now. I know, coming from a non-practicing physicist, who sold his soul to the finance industry, this declaration sounds crazy. Delusional even. But I do have my reasons to see Einstein’s ideas go.

Let’s start with this picture of a dot flying along a straight line (on the ceiling, so to speak). You are standing at the centre of the line in the bottom (on the floor, that is). If the dot was moving faster than light, how would you see it? Well, you wouldn’t see anything at all until the first ray of light from the dot reaches you. As the animation shows, the first ray will reach you when the dot is somewhere almost directly above you. The next rays you would see actually come from two different points in the line of flight of the dot — one before the first point, and one after. Thus, the way you would see it is, incredible as it may seem to you at first, as one dot appearing out of nowhere and then splitting and moving rather symmetrically away from that point. (It is just that the dot is flying so fast that by the time you get to see it, it is already gone past you, and the rays from both behind and ahead reach you at the same instant in time.Hope that statement makes it clearer, rather than more confusing.).

Why did I start with this animation of how the illusion of a symmetric object can happen? Well, we see a lot of active symmetric structures in the universe. For instance, look at this picture of Cygnus A. There is a “core” from which seem to emanate “features” that float away to the “lobes.” Doesn’t it look remarkably similar to what we would see based on the animation above? There are other examples in which some feature points or knots seem to move away from the core where they first appear at. We could come up with a clever model based on superluminality and how it would create illusionary symmetric objects in the heavens. We could, but nobody would believe us — because of Einstein. I know this — I tried to get my old physicist friends to consider this model. The response is always some variant of this, “Interesting, but it cannot work. It violates Lorentz invariance, doesn’t it?” LV being physics talk for Einstein’s insistence that nothing should go faster than light. Now that neutrinos can violate LV, why not me?

Of course, if it was only a qualitative agreement between symmetric shapes and superluminal celestial objects, my physics friends are right in ignoring me. There is much more. The lobes in Cygnus A, for instance, emit radiation in the radio frequency range. In fact, the sky as seen from a radio telescope looks materially different from what we see from an optical telescope. I could show that the spectral evolution of the radiation from this superluminal object fitted nicely with AGNs and another class of astrophysical phenomena, hitherto considered unrelated, called gamma ray bursts. In fact, I managed to publish this model a while ago under the title, “Are Radio Sources and Gamma Ray Bursts Luminal Booms?“.

You see, I need superluminality. Einstein being wrong is a pre-requisite of my being right. So it is the most respected scientist ever vs. yours faithfully, a blogger of the unreal kind. You do the math.

Such long odds, however, have never discouraged me, and I always rush in where the wiser angels fear to tread. So let me point out a couple of inconsistencies in SR. The derivation of the theory starts off by pointing out the effects of light travel time in time measurements. And later on in the theory, the distortions due to light travel time effects become part of the properties of space and time. (In fact, light travel time effects will make it impossible to have a superluminal dot on a ceiling, as in my animation above — not even a virtual one, where you take a laser pointer and turn it fast enough that the laser dot on the ceiling would move faster than light. It won’t.) But, as the theory is understood and practiced now, the light travel time effects are to be applied on top of the space and time distortions (which were due to the light travel time effects to begin with)! Physicists turn a blind eye to this glaring inconstancy because SR “works” — as I made very clear in my previous post in this series.

Another philosophical problem with the theory is that it is not testable. I know, I alluded to a large body of proof in its favor, but fundamentally, the special theory of relativity makes predictions about a uniformly moving frame of reference in the absence of gravity. There is no such thing. Even if there was, in order to verify the predictions (that a moving clock runs slower as in the twin paradox, for instance), you have to have acceleration somewhere in the verification process. Two clocks will have to come back to the same point to compare time. The moment you do that, at least one of the clocks has accelerated, and the proponents of the theory would say, “Ah, there is no problem here, the symmetry between the clocks is broken because of the acceleration.” People have argued back and forth about such thought experiments for an entire century, so I don’t want to get into it. I just want to point out that theory by itself is untestable, which should also mean that it is unprovable. Now that there is direct experimental evidence against the theory, may be people will take a closer look at these inconsistencies and decide that it is time to say bye-bye to Einstein.

The special theory of relativity is an extremely well-tested theory. Despite my personal reservations about it, the body of proof for the validity of SR is really enormous and the theory has stood the test of time — at least so far. But it is the integration of SR into the rest of modern physics that makes it all but impossible to write it off as a failed theory. In experimental high energy physics, for instance, we compute the rest mass of a particle as its identifying statistical signature. The way it works is this: in order to discover a heavy particle, you first detect its daughter particles (decay products, that is), measure their energies and momenta, add them up (as “4-vectors”), and compute the invariant mass of the system as the modulus of the aggregate energy-momentum vector. In accordance with SR, the invariant mass is the rest mass of the parent particle. You do this for many thousands of times and make a distribution (a “histogram”) and detect any statistically significant excess at any mass. Such an excess is the signature of the parent particle at that mass.

Almost every one of the particles in the particle data book that we know and love is detected using some variant of this method. So the whole Standard Model of particle physics is built on SR. In fact, almost all of modern physics (physics of the 20th century) is built on it. On the theory side, in the thirties, Dirac derived a framework to describe electrons. It combined SR and quantum mechanics in an elegant framework and predicted the existence of positrons, which bore out later on. Although considered incomplete because of its lack of sound physical backdrop, this “second quantization” and its subsequent experimental verification can be rightly seen as evidence for the rightness of SR.

Feynman took it further and completed the quantum electrodynamics (QED), which has been the most rigorously tested theory ever. To digress a bit, Feynman was once being shown around at CERN, and the guide (probably a prominent physicist himself) was explaining the experiments, their objectives etc. Then the guide suddenly remembered who he was talking to; after all, most of the CERN experiments were based on Feynman’s QED. Embarrassed, he said, “Of course, Dr. Feynman, you know all this. These are all to verify your predictions.” Feynman quipped, “Why, you don’t trust me?!” To get back to my point and reiterate it, the whole edifice of the standard model of particle physics is built on top of SR. Its success alone is enough to make it impossible for modern physics to discard SR.

So, if you take away SR, you don’t have the Standard Model and QED, and you don’t know how accelerator experiments and nuclear bombs work. The fact that they do is proof enough for the validity of SR, because the alternative (that we managed to build all these things without really knowing how they work) is just too weird. It’s not just the exotic (nuclear weaponry and CERN experiments), but the mundane that should convince us. Fluorescent lighting, laser pointers, LED, computers, mobile phones, GPS navigators, iPads — in short, all of modern technology is, in some way, a confirmation of SR.

So the OPERA result on observed superluminalily has to be wrong. But I would like it to be right. And I will explain why in my next post. Why everything we accept as a verification of SR could be a case of mass delusion — almost literally. Stay tuned!

The constancy (and the resultant inviolability) of the speed of light, of course, comes from Einstein’s Special Theory of Relativity, or SR. This theory is an extension of a simple idea. In fact, Einstein’s genius is in his ability to carry a simple idea to its logically inevitable, albeit counter-intuitive (to the point of being illogical!) conclusion. In the case of SR, he picks an idea so obvious — that the laws of physics should be independent of the state of motion. If you are in a train going at a constant speed, for instance, you can’t tell whether you are moving or not (if you close the windows, that is). The statement “You can’t tell” can be recast in physics as, “There is no experiment you can device to detect your state of motion.” This should be obvious, right? After all, if the laws kept changing every time you moved about, it is as good as having no laws at all.

Then came Maxwell. He wrote down the equations of electricity and magnetism, thereby elegantly unifying them. The equations state, using fancy vector notations, that a changing magnetic field will create an electric field, and a changing electric field will create a magnetic field, which is roughly how a car alternator and an electric motor work. These elegant equations have a wave solution.

The existence of a wave solution is no surprise, since a changing electric field generates a magnetic field, which in turn generates an electric field, which generates a magnetic filed and so on ad infinitum. What is surprising is the fact that the speed of propagation of this wave predicted by Maxwell’s equations is c, the speed of light. So it was natural to suppose that light was a form of electromagnetic radiation, which means that if you take a magnet and jiggle it fast enough, you will get light moving away from you at c – if we accept that light is indeed EM wave.

What is infinitely more fundamental is the question whether Maxwell’s equations are actually laws of physics. It is hard to argue that they aren’t. Then the follow-up question is whether these equations should obey the axiom that all laws of physics are supposed to obey — namely they should be independent of the state of motion. Again, hard to see why not. Then how do we modify Maxwell’s equations such that they are independent of motion? This is the project Einstein took on under the fancy name, “Covariant formulation of Maxwell’s equations,” and published the most famous physics article ever with an even fancier title, “On the Electrodynamics of Moving Bodies.” We now call it the Special Theory of Relativity, or SR.

To get a bit technical, Maxwell’s equations have the space derivatives of electric and magnetic fields relating to the time derivatives of charges and currents. In other words, space and time are related through the equations. And the wave solution to these equations with the propagation speed of c becomes a constraint on the properties of space and time. This is a simple philosophical look on SR, more than a physics analysis.

Einstein’s approach was to employ a series of thought experiments to establish that you needed a light signal to sync clocks and hypothesize that the speed of light had to be constant in all moving frames of reference. In other words, the speed of light is independent of the state of motion, as it has to be if Maxwell’s equations are to be laws of physics.

This aspect of the theory is supremely counter-intuitive, which is physics lingo to say something is hard to believe. In the case of the speed of light, you take a ray of light, run along with it at a high speed, and measure its speed, you still get c. Run against it and measure it — still c. To achieve this constancy, Einstein rewrote the equations of velocity addition and subtraction. On consequence of these rewritten equations is that nothing can go faster than light.

This is my long-winded description of the context in which the speed violation measured at OPERA has to be seen. If the violation is confirmed, we have a few unpleasant choices to pick from:

1. Electrodynamics (Maxwell’s equations) is not invariant under motion.
2. Light is not really electromagnetic in nature.
3. SR is not the right covariant formulation of electrodynamics.

The first choice is patently unacceptable because it is tantamount to stating that electrodynamics is not physics. A moving motor (e.g., if you take your electric razor on a flight) would behave differently from a static one (you may not be able to shave). The second choice also is quite absurd. In addition to the numeric equality between the speed of the waves from Maxwell’s equations and the measured value of c, we do have other compelling reasons why we should believe that light is EM waves. Radio waves induce electric signals in an antenna, light knocks of electrons, microwaves can excite water molecules and cook food and so on.

The only real choice we are left with is the last one — which is to say SR is wrong. Why not discard SR? More reasons than a blog post can summarize, but I’ll try to summarize them any way in my next post.

Now, this effect raises an interesting question — what is the “real” thing that we see? If seeing is believing, the stuff that we see should be the real thing. Then again, we know of the light travel time effect. So we should correct what we see before believing it. What then does “seeing” mean? When we say we see something, what do we really mean?

Seeing involves light, obviously. It is the finite (albeit very high) speed of light influences and distorts the way we see things. This fact should hardly come as a surprise because we do know that there is a delay in seeing objects like stars. What is surprising (and seldom highlighted) is that when it comes to seeing moving objects, 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 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.

This disconnect between what we see and what is out there is not unknown to many philosophical schools of thought. Phenomenalism, for instance, holds the view that space and time are not objective realities. They are merely the medium of our perception. All the phenomena that happen in space and time are merely bundles of our perception. In other words, space and time are cognitive constructs arising from perception. Thus, all the physical properties that we ascribe to space and time can only apply to the phenomenal reality (the reality as we sense it). The noumenal reality (which holds the physical causes of our perception), by contrast, remains beyond our cognitive reach.

One, almost accidental, difficulty in redefining the effects of the finite speed of light as the properties of space and time is that any effect that we do understand gets instantly relegated to the realm of optical illusions. For instance, the eight-minute delay in seeing the sun, because we can readily understand it and disassociate it from our perception using simple arithmetic, is considered a mere optical illusion. However, the distortions in our perception of fast moving objects, although originating from the same source are considered a property of space and time because they are more complex. At some point, we have to come to terms with the fact that when it comes to seeing the universe, there is no such thing as an optical illusion, which is probably what Goethe pointed out when he said, “Optical illusion is optical truth.”

The distinction (or lack thereof) between optical illusion and truth is one of the oldest debates in philosophy. After all, it is about the distinction between knowledge and reality. Knowledge is considered our view about something that, in reality, is “actually the case.” In other words, knowledge is a reflection, or a mental image of something external. In this picture, the external reality goes through a process of becoming our knowledge, which includes perception, cognitive activities, and the exercise of pure reason. This is the picture that physics has come to accept. While acknowledging that our perception may be imperfect, physics assumes that we can get closer and closer to the external reality through increasingly finer experimentation, and, more importantly, through better theorization. The Special and General Theories of Relativity are examples of brilliant applications of this view of reality where simple physical principles are relentlessly pursued using the formidable machine of pure reason to their logically inevitable conclusions.

But there is another, competing view of knowledge and reality that has been around for a long time. This is the view that regards perceived reality as an internal cognitive representation of our sensory inputs. In this view, knowledge and perceived reality are both internal cognitive constructs, although we have come to think of them as separate. What is external is not the reality as we perceive it, but an unknowable entity giving rise to the physical causes behind sensory inputs. In this school of thought, we build our reality in two, often overlapping, steps. The first step consists of the process of sensing, and the second one is that of cognitive and logical reasoning. We can apply this view of reality and knowledge to science, but in order do so, we have to guess the nature of the absolute reality, unknowable as it is.

The ramifications of these two different philosophical stances described above are tremendous. Since modern physics has embraced a non-phenomenalistic view of space and time, it finds itself at odds with that branch of philosophy. This chasm between philosophy and physics has grown to such a degree that the Nobel prize winning physicist, Steven Weinberg, wondered (in his book “Dreams of a Final Theory”) why the contribution from philosophy to physics have been so surprisingly small. It also prompts philosophers to make statements like, “Whether ‘noumenal reality causes phenomenal reality’ or whether ‘noumenal reality is independent of our sensing it’ or whether ‘we sense noumenal reality,’ the problem remains that the concept of noumenal reality is a totally redundant concept for the analysis of science.”

From the perspective of cognitive neuroscience, everything we see, sense, feel and think is the result of the neuronal interconnections in our brain and the tiny electrical signals in them. This view must be right. What else is there? All our thoughts and worries, knowledge and beliefs, ego and reality, life and death — everything is merely neuronal firings in the one and half kilograms of gooey, grey material that we call our brain. There is nothing else. Nothing!

In fact, this view of reality in neuroscience is an exact echo of phenomenalism, which considers everything a bundle of perception or mental constructs. Space and time are also cognitive constructs in our brain, like everything else. They are mental pictures our brains concoct out of the sensory inputs that our senses receive. Generated from our sensory perception and fabricated by our cognitive process, the space-time continuum is the arena of physics. Of all our senses, sight is by far the dominant one. The sensory input to sight is light. In a space created by the brain out of the light falling on our retinas (or on the photo sensors of the Hubble telescope), is it a surprise that nothing can travel faster than light?

This philosophical stance is the basis of my book, The Unreal Universe, which explores the common threads binding physics and philosophy. Such philosophical musings usually get a bad rap from us physicists. To physicists, philosophy is an entirely different field, another silo of knowledge, which holds no relevance to their endeavors. We need to change this belief and appreciate the overlap among different knowledge silos. It is in this overlap that we can expect to find great breakthroughs in human thought.

The twist to this story of light and reality is that we seem to have known all this for a long time. Classical philosophical schools seem to have thought along lines very similar to Einstein’s reasonings. The role of light in creating our reality or universe is at the heart of Western religious thinking. A universe devoid of light is not simply a world where you have switched off the lights. It is indeed a universe devoid of itself, a universe that doesn’t exist. It is in this context that we have to understand the wisdom behind the statement that “the earth was without form, and void” until God caused light to be, by saying “Let there be light.”

The Quran also says, “Allah is the light of the heavens and the earth,” which is mirrored in one of the ancient Hindu writings: “Lead me from darkness to light, lead me from the unreal to the real.” The role of light in taking us from the unreal void (the nothingness) to a reality was indeed understood for a long, long time. Is it possible that the ancient saints and prophets knew things that we are only now beginning to uncover with all our supposed advances in knowledge?

I know I may be rushing in where angels fear to tread, for reinterpreting the scriptures is a dangerous game. Such alien interpretations are seldom welcome in the theological circles. But I seek refuge in the fact that I am looking for concurrence in the metaphysical views of spiritual philosophies, without diminishing their mystical and theological value.

The parallels between the noumenal-phenomenal distinction in phenomenalism and the Brahman-Maya distinction in Advaita are hard to ignore. This time-tested wisdom on the nature of reality from the repertoire of spirituality is now being reinvented in modern neuroscience, which treats reality as a cognitive representation created by the brain. The brain uses the sensory inputs, memory, consciousness, and even language as ingredients in concocting our sense of reality. This view of reality, however, is something physics is yet to come to terms with. But to the extent that its arena (space and time) is a part of reality, physics is not immune to philosophy.

As we push the boundaries of our knowledge further and further, we are beginning to discover hitherto unsuspected and often surprising interconnections between different branches of human efforts. In the final analysis, how can the diverse domains of our knowledge be independent of each other when all our knowledge resides in our brain? Knowledge is a cognitive representation of our experiences. But then, so is reality; it is a cognitive representation of our sensory inputs. It is a fallacy to think that knowledge is our internal representation of an external reality, and therefore distinct from it. Knowledge and reality are both internal cognitive constructs, although we have come to think of them as separate.

Recognizing and making use of the interconnections among the different domains of human endeavor may be the catalyst for the next breakthrough in our collective wisdom that we have been waiting for.

Logic in the form of Occam’s Razor should direct us to the latter possibility. But logic doesn’t apply to many or most of the fundamental hypotheses of life, which answer to a different set of rules. They answer to the mythos, the sum total of the intangible knowledge and wisdom passed down from the past, from the ancient, forgotten masters talking to us through our teachers and folklore, through the structure of our languages and the backdrop of our thoughts, and through the very foundation of our sense of being and consciousness. The mythos tell us that we do have free will, and the logic that came later is powerless to break this notion. So it may be that these words that flow out of my pen into this notepad and later to your computer screen were all predetermined and I had no choice but to write then down. But it certainly is not the way I feel. I do feel as though I can delete any word here. Heck, I can delete the whole post if I want to.

On the side of logic, I will describe an experiment that casts doubt on our notion of free will. From neuroscience, we know that there is a time lag of about half a second between the moment “we” take a decision and the moment we become aware of it. This time lag raises the question of who is taking the decision because, in the absence of our conscious awareness, it is not clear that the decision is really ours. In the experimental setup testing this phenomenon, the subject is hooked up to a computer that records his brain activities (EEG). The subject is then asked make a conscious decision to move either the right hand or the left hand at a time of his choosing. The choice of right or left is also up to the subject. The computer always detects which hand the subject is going to move about half a second before the subject is aware of his own intention. The computer can then order the subject to move that hand — an order that the subject will be unable to disobey. Does the subject have free will in this case?

In fact, I wrote about it in my book, and posted it here some time ago. In that post, I added that free will might be a fabrication of our brain after the real action. In other words, the real action takes place by instinct, and the sense of decision is introduced to our consciousness as an afterthought. Some of my readers pointed out that being unaware of a decision was not the same as having no free will over it. For instance, when you drive, you take a series of decisions without really being aware of them. It doesn’t mean that these decisions are not yours. Good point, but does it really make sense to call a decision yours when you don’t have any control over it, even if you would take the same decision if you did? If something flies into your eyes, you will flinch and close your eyes. Good survival instinct and reflex. But given that you cannot control it, is it a part of your free will?

A more elaborate example comes from hypnotic suggestion. I heard this story from one of the lectures by John Searle — a man was hypnotically instructed to respond to the word “Germany” by crawling on the floor. After the hypnosis session, when the man was lucid and presumably exercising his free will, the trigger word was used in a conversation. The man suddenly says something like, “I just remembered, I need to remodel my house, and these tiles look great. Mind if I take a closer look?” and crawls on the floor. Did he do it of his own volition? To him, yes, but to the rest, now.

So, how do we know for sure that our sense of free will is not an elaborate scam that our brain is perpetrating on “us” (whatever that means!)

Now I am actually pushing the argument a bit further. But think about it, how can the spaceless, massless, material-less entities that are our intentions make real changes in the physical world around us? In writing this post, how can I break the laws of physics in moving things around quite independent of their current state just because I want to?

Is free will an epiphenomenon — something that emerges after-the-fact? A good analogy is that of froth riding on the waves on a beach. The froth may be thinking, “Oh my god, what a tough life! I have to haul all these big waves back and forth. Every day of my life, no break, no vacation!” But that is not what is going on. The waves are just sloshing around, and the froth just happens to emerge. Are our lives just moving along on their own preordained paths, while we, like the epiphenomenal froth, think that we have control and free will?

Time, on the other hand, has no direct sensory backing. And for this reason, it becomes quite difficult to get a grip over it. What is time? We sense it indirectly through change and motion. But it would be silly to define time using the concepts of change and motion, because they already include the notion of time. The definition would be cyclic.

Assuming, for now, that no definition is necessary, let’s try another perhaps more tractable issue. Where does this strong sense of time come from? I once postulated that it comes from our knowledge of our demise — that questionable gift that we all possess. All the time durations that we are aware of are measured against the yardstick of our lifespan, perhaps not always consciously. I now wonder if this postulate is firm enough, and further ruminations on this issue have convinced me that I am quite ignorant of these things and need more knowledge. Ah.. only if I had more time.

In any case, even this more restricted question of the origin of time doesn’t seem to be that tractable, after all. Physics has another deep problem with time. It has to do with the directionality. It cannot easily explain why time has a direction — an arrow, as it were. This arrow does not present itself in the fundamental laws governing physical interactions. All the laws in physics are time reversible. The laws of gravity, electromagnetism or quantum mechanics are all invariant with respect to a time reversal. That is to say, they look the same with time going forward or backward. So they give no clue as to why we experience the arrow of time.

Yet, we know that time, as we experience it, is directional. We can remember the past, but not the future. What we do now can affect the future, but not the past. If we play a video tape backwards, the sequence of events (like broken pieces of glass coming together to for a vase) will look funny to us. However, if we taped the motion of the planets in a solar system, or the electron cloud in an atom, and played it backward to a physicist, he would not find anything funny in the sequences because the physical laws are reversible.

Physics considers the arrow of time an emergent property of statistical collections. To illustrate this thermodynamic explanation of time, let’s consider an empty container where we place some dry ice. After some time, we expect to see a uniform distribution of carbon dioxide gas in the container. Once spread out, we do not expect the gas in the container to coagulate into solid dry ice, no matter how long we wait. The video of CO2 spreading uniformly in the container is a natural one. Played backward, the sequence of the CO2 gas in the container congealing to solid dry ice in a corner would not look natural to us because it violates our sense of the arrow of time.

The apparent uniformity of CO2 in the container is due to the statistically significant quantity of dry ice we placed there. If we manage to put a small quantity, say five molecules of CO2, we can fully expect to see the congregation of the molecules in one location once in a while. Thus, the arrow of time manifests itself as a statistical or thermodynamic property. Although the directionality of time seems to emerge from reversible physical laws, its absence in the fundamental laws does look less than satisfactory philosophically.

You may consider the distinction between the two just another one of those philosophical hairsplittings, but it really is not. What space is, and even what kind of entity space is, has enormous implications in physics. For instance, if it is relational in nature, then in the absence of matter, there is no space. Much like in the absence of any family members, you have no family. On the other hand, if it is a container-like entity, the space exists even if you take away all matter, waiting for some matter to appear.

So what, you ask? Well, let’s take half a bucket of water and spin it around. Once the water within catches on, its surface will form a parabolic shape — you know, centrifugal force, gravity, surface tension and all that. Now, stop the bucket, and spin the whole universe around it instead. I know, it is more difficult. But imagine you are doing it. Will the water surface be parabolic? I think it will be, because there is not much difference between the bucket turning or the whole universe spinning around it.

Now, let’s imagine that we empty the universe. There is nothing but this half-full bucket. Now it spins around. What happens to the water surface? If space is relational, in the absence of the universe, there is no space outside the bucket and there is no way to know that it is spinning. Water surface should be flat. (In fact, it should be spherical, but ignore that for a second.) And if space is container-like, the spinning bucket should result in a parabolic surface.

Of course, we have no way of knowing which way it is going to be because we have no way of emptying the universe and spinning a bucket. But that doesn’t prevent us from guessing the nature of space and building theories based on it. Newton’s space is container-like, while at their heart, Einstein’s theories have a relational notion of space.

So, you see, philosophy does matter.

Stepping back a bit, rationality is quintessentially a worldview. By rational, we mean things that seem normal to our commonsense. So the notion of a nuclear bomb moving or obliterating a mountain is rational, although we have never seen it. You believe it because it is consistent with your worldview. I believe it too, trust me. I was a nuclear physicist not too long ago.

And a god (or faith) moving mountains is clearly ludicrous to our rationality. I’m not asking people to give equal rational weight to faith and bomb moving mountains. I’m merely encouraging them to examine why they believe in one and not the other. Calling one more rational is just another way of saying that you choose to believe one more than the other. Why?

Thinking along those lines, I come to the conclusion that it is only a question of worldviews or belief systems. I personally subscribe to your worldview based on rationality as well, which is why I consider myself also an atheist (although one of my readers thought I was merely confused )

A god as an old man hiding behind the clouds is not consistent with our worldview. But it may have been a metaphor for something else. Let me explain. We have these abstract concepts of happiness, perfection, grief etc. Are these things real? Should we believe they exist? Such questions don’t make too much sense because these concepts are all in our minds. But then, what isn’t?

Let’s take perfection, for instance. Let’s say we assign some human form to it, so that we could explain it to a child or something. We then call it, say, the goddess of perfection or whatever. Over generations, for whatever reason, the notion of perfection disappears from our awareness, but the metaphor of the goddess remains. Now, to somebody who believes in the reality perfection, and therefore the existence of the goddess, it is not a delusion. In that belief system, in that context and worldview, it makes perfect sense. But in the absence of the abstract concept of perfection, the goddess becomes a delusion.

I believe that a large part of our collective wisdom is handed down in the form of such metaphors. Instead of dismissing them as delusions because their context is gone, we should perhaps try harder to rediscover the lost concepts. I also believe such metaphors exist in other fields that seem to work well. Take, for instance, the Qi concept in traditional Chinese medicine, the five elements (or three body types) in Ayurveda and so on. To the extent that traditional Chinese medicine and Ayurveda work, there has to be some knowledge buried in those practices. If we write off their basis merely because their metaphors are not consistent with our rationality, we may be writing off some potential sources of new or forgotten knowledge.

In addition, I believe that some of our smarter geniuses indeed see delusional metaphors in what we take to be supremely real.

Blindness can be physiological, when the physical eye is not functioning properly. Or it can be neurological, when the eye is fne but the visual signal processing is impaired. For example, if our right visual cortex is damaged, we are blind on the left side. When examining a patient with such a neurological blindness on one side, Weiscrantz shined a little spot of light on the patient’s blind side. Weiscrantz then asked the patient to point to it. The patient protested that he could not see it and could not possibly point to it. Weiscrantz asked him to try anyway. The patient then proceeded to point accurately to the spot of light that he could not consciously perceive.

After hundreds of trials, it became obvious that the patient could point correctly in ninety-nine percent of trials, even though he claimed on each trial that he was only guessing. How did the patient determine the location of an invisible object and point to it accurately? The neurological reason is that we all have two visual pathways. The new visual pathway goes through the visual cortex. The old, backup pathway runs through our brain stem to the superior colliculus.

The cause of our patient’s blindness was that his visual cortex was damaged, and it did not get the signals from one eye and its optic nerves. But the signals took the parallel route to the superior colliculus, using the old pathway. This rerouting allowed him to locate the object in space and guide his hand accurately to point to the invisible object. What this syndrome of blind-sight shows us is that only the new visual pathway leads to a conscious experience. While the old pathway is perfectly usable (for survival, for instance), it does not lead to a conscious experience of vision.

An interesting neurological condition, no doubt. But blind-sight is more than that. It is a rather confounding philosophical conundrum. The spot of light that the patient could see — was it real? Sure, we know it was real. But what if all of us were blind-sighted? If some of us started developing a semblance of awareness as a result of our blind-sight, would we believe them, or call them delusional? If there are senses that we can be unaware of, how sure can we be of the “sensed”? Or of our “delusions”?

This post is an edited version of section in The Unreal Universe. The information comes from The Emerging Mind: Reith Lectures on Neuroscience (BBC Radio, 2003) given by V. S. Ramachandran, the director of the Center for Brain and Cognition, San Diego, CA, USA. My book refers to several examples of physiological brain anomalies and their perceptual manifestation from this lecture series.

Of all the sciences, physics seems to be the one most at odds with the God concept. Clearly, evolutionary biology is none too happy with it either, if Dawkins is anything to go by. But that analysis is for another post.

Let’s start by analyzing a physicist’s way of “proving” that there is no God. The argument usually goes something like this:

If there is a God who is capable of affecting me in any way, then there should be some force exerted by that God on me. There should be some interaction. Since the interaction is big enough to affect me, I should be able to use this particular interaction to “measure” the God-intensity. So far, I haven’t been able to measure any such God-related force. So either there is no God that affects me in any way, or there is a God that affects me through deviously disguised interactions so that whenever I try to measure the interaction, I’m always fooled. Now, you tell me what is more likely. By Occam’s Razor, the simplest explanation (that there is no God that can affect me) has the highest chance of being right.

While this is a good argument (and one I used to make), it is built on a couple of implicit assumptions that are rather tricky to spot. The first assumption is that we cannot be affected by an interaction that we cannot sense. This assumption is not necessarily true.

Modern cosmology needs at least one other kind of interaction to account for dark matter and dark energy. Let’s call this unknown interaction the dark interaction. Even though we cannot sense the dark interaction, we are subject to it exactly as all other (known) matter is. The existence of this interaction beyond our senses is sufficient to break the physicist’s proof. A plausible God can affect us, without our being able to sense it, through dark interactions.

But that is not the end of the story. The physicist can still argue, “Fine, if we cannot sense this God, how would we know he exists? And why do so many people claim they can feel him?” This argument is based on the assumptions on conscious experience and sensing. The hidden assumptions in the physicist’s questions (again, not necessarily true) are:

1. Sensing should lead to a conscious perception.
2. All humans should have the same sense modality.

An example of sensing that does not lead to conscious perception is the syndrome of blind sight. (I will post more on it later). A patient suffering from blind sight can point to the light spot he cannot consciously see. Thus, sensing without conscious perception is possible. The second assumption that all men are created equal (in terms of sensory modality) does not have any a priori reason to be true. It is possible that some people may be able to sense the dark interaction (or some other kind of interaction that God chooses) without being conscious of it.

So it is possible to argue that there is a God that affects us through a hitherto unknown interaction. And that some 95% of us can sense this interaction, and the others are atheists. What this argument illustrates is the plausibility of God. More precisely, it demonstrates the consistency of a concept of God with physics. It is not meant to be a proof of the existence of God. And that is why, despite the plausibility of God, I am still an atheist.

In retrospect, this argument did not have to be so complicated. It boils down to saying that there are limits on our knowledge, and to what is knowable. There is plenty of room for God outside these limits. It is also a classic argument by those who believe in God — you don’t know everything, so how do you know there isn’t a God?

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 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 you do, that is your 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 make sense of. 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 a far more plausible 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.

But, I am threading on real thin ice when I compare, however obliquely, senior executives to cabbies and slum dogs. They are (the executives, that is) clearly a lot more talented, which brings me to the famous talent argument for bonuses. What is this talent thing? Is it intelligence and articulation? I once met a taxi driver in Bangalore who was fluent in more than a dozen languages as disparate as English and Arabic. I discovered his hidden talent by accident when he cracked up at something my father said to me — a private joke in our vernacular, which I have seldom found a non-native speaker attempt. I couldn’t help thinking then — given another place and another time, this cabbie would have been a professor in linguistics or something. Talent may be a necessary condition for success (and bonus), but it certainly is not a sufficient one. Even among slum dogs, we might find ample talent, if the Oscar-winning movie is anything to go by. Although, the protagonist in the movie does make his million dollar bonus, but it was only fiction.

In real life, however, lucky accidents of circumstances play a more critical role than talent in putting us on the right side of the income divide. To me, it seems silly to claim a right to the rewards based on any perception of talent or intelligence. Heck, intelligence itself, however we define it, is nothing but a happy genetic accident.

Sections

• Bonus Plans of Mice and Men
• Hard Work
• Talent and Intelligence
• Talent Retention
• Profit Sharing
• Slippery Slopes

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.

In 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.

The topic of conversation on that day was a bit philosophical, and we were eagerly absorbing the words of wisdom emanating from Lee. He was describing to us how the Earth could be considered a living organism. Using insightful arguments and precisely modulated glib articulation (no doubt, forged by years of intellectual duels in world’s best universities), Lee made a compelling case that the Earth, in fact, satisfied all the conditions of being an organism.

Lee Smolin, by the way, lived up to our great expectations in later years, publishing highly acclaimed books and generally leaving a glorious imprint in the world of modern physics. He now talks to global audiences through prestigious programmes such as the BBC Hardtalk, much to our pride and joy.

The point in Lee’s view was not so much whether or the Earth was literally alive, but that thinking of it as an organism was a viable intellectual model to represent the Earth. Such intellectual acrobatics was not uncommon among us physics students.

In the last few years, Lee has actually taken this mode of thinking much farther in one of his books, picturing the universe in the light of evolution. Again, the argument is not to be taken literally, imagining a bunch of parallel universes vying for survival. The idea is to let the mode of thinking carry us forward and guide our thoughts, and see what conclusions we can draw from the thought exercise.

A similar mode of thinking was introduced in the movie Matrix. In fact, several profound models were introduced in that movie, which probably fuelled its wild box-office success. One misanthropic model that the computer agent Smith proposes is that human beings are a virus on our planet.

It is okay for the bad guy in a movie to suggest it, but an entirely different matter for newspaper columnist to do so. But bear with me as I combine Lee’s notion of the Earth being an organism and Agent Smith’s suggestion of us being a virus on it. Let’s see where it takes us.

The first thing a virus does when it invades an organism is to flourish using the genetic material of the host body. The virus does it with little regard for the well-being of the host. On our part, we humans plunder the raw material from our host planet with such abandon that the similarity is hard to miss.

But the similarity doesn’t end there. What are the typical symptoms of a viral infection on the host? One symptom is a bout of fever. Similarly, due to our activities on our host planet, we are going through a bout of global warming. Eerily similar, in my view.

The viral symptoms could extend to sores and blisters as well. Comparing the cities and other eye sores that we proudly create to pristine forests and natural landscapes, it is not hard to imagine that we are indeed inflicting fetid atrocities to our host Earth. Can’t we see the city sewers and the polluted air as the stinking, oozing ulcers on its body?

Going one step further, could we also imagine that natural calamities such as Katrina and the Asian tsunami are the planet’s natural immune systems kicking into high gear?

I know that it is supremely cynical to push this comparison to these extreme limits. Looking at the innocent faces of your loved ones, you may feel rightfully angry at this comparison. How dare I call them an evil virus? Then again, if a virus could think, would it think of its activities on a host body as evil?

If that doesn’t assuage your sense of indignation, remember that this virus analogy is a mode of thinking rather than a literal indictment. Such a mode of thinking is only useful if it can yield some conclusions. What are the conclusions from this human-viral comparison?

The end result of a viral infection is always gloomy. Either the host succumbs or the virus gets beaten by the host’s immune systems. If we are the virus, both these eventualities are unpalatable. We don’t want to kill the Earth. And we certainly don’t want to be exterminated by the Earth. But those are the only possible outcomes of our viral-like activity here. It is unlikely that we will get exterminated; we are far too sophisticated for that. In all likelihood, we will make our planet uninhabitable. We may, by then, have our technological means of migrating to other planetary systems. In other words, if we are lucky, we may be contagious! This is the inescapable conclusion of this intellectual exercise.

There is a less likely scenario — a symbiotic viral existence in a host body. It is the kind of benign life style that Al Gore and others recommend for us. But, taking stock of our activities on the planet, my doomsday view is that it is too late for a peaceful symbiosis. What do you think?

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.]

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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 is moving with respect to another system along the positive X axis of , then an object at rest in at a positive is receding while another object at a negative is approaching an observer at the origin of .

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 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.

Although it might seem like a hard core physics article, it is in fact an application of the philosophical insight permeating this blog and my book.

This blog version contains the abstract, introduction and conclusions. The full version of the article is available as a PDF file.

Journal Reference: IJMP-D Vol. 16, No. 6 (2007) pp. 983–1000.

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Abstract

The softening of the GRB afterglow bears remarkable similarities to the frequency evolution in a sonic boom. At the front end of the sonic boom cone, the frequency is infinite, much like a Gamma Ray Burst (GRB). Inside the cone, the frequency rapidly decreases to infrasonic ranges and the sound source appears at two places at the same time, mimicking the double-lobed radio sources. Although a “luminal” boom violates the Lorentz invariance and is therefore forbidden, it is tempting to work out the details and compare them with existing data. This temptation is further enhanced by the observed superluminality in the celestial objects associated with radio sources and some GRBs. In this article, we calculate the temporal and spatial variation of observed frequencies from a hypothetical luminal boom and show remarkable similarity between our calculations and current observations.

Introduction

A sonic boom is created when an object emitting sound passes through the medium faster than the speed of sound in that medium. As the object traverses the medium, the sound it emits creates a conical wavefront, as shown in Figure 1. The sound frequency at this wavefront is infinite because of the Doppler shift. The frequency behind the conical wavefront drops dramatically and soon reaches the infrasonic range. This frequency evolution is remarkably similar to afterglow evolution of a gamma ray burst (GRB).

Figure 1:. The frequency evolution of sound waves as a result of the Doppler effect in supersonic motion. The supersonic object S is moving along the arrow. The sound waves are “inverted” due to the motion, so that the waves emitted at two different points in the trajectory merge and reach the observer (at O) at the same time. When the wavefront hits the observer, the frequency is infinity. After that, the frequency rapidly decreases.

Gamma Ray Bursts are very brief, but intense flashes of rays in the sky, lasting from a few milliseconds to several minutes, and are currently believed to emanate from cataclysmic stellar collapses. The short flashes (the prompt emissions) are followed by an afterglow of progressively softer energies. Thus, the initial rays are promptly replaced by X-rays, light and even radio frequency waves. This softening of the spectrum has been known for quite some time, and was first described using a hypernova (fireball) model. In this model, a relativistically expanding fireball produces the emission, and the spectrum softens as the fireball cools down. The model calculates the energy released in the region as – ergs in a few seconds. This energy output is similar to about 1000 times the total energy released by the sun over its entire lifetime.

More recently, an inverse decay of the peak energy with varying time constant has been used to empirically fit the observed time evolution of the peak energy using a collapsar model. According to this model, GRBs are produced when the energy of highly relativistic flows in stellar collapses are dissipated, with the resulting radiation jets angled properly with respect to our line of sight. The collapsar model estimates a lower energy output because the energy release is not isotropic, but concentrated along the jets. However, the rate of the collapsar events has to be corrected for the fraction of the solid angle within which the radiation jets can appear as GRBs. GRBs are observed roughly at the rate of once a day. Thus, the expected rate of the cataclysmic events powering the GRBs is of the order of – per day. Because of this inverse relationship between the rate and the estimated energy output, the total energy released per observed GRB remains the same.

If we think of a GRB as an effect similar to the sonic boom in supersonic motion, the assumed cataclysmic energy requirement becomes superfluous. Another feature of our perception of supersonic object is that we hear the sound source at two different location as the same time, as illustrated in Figure 2. This curious effect takes place because the sound waves emitted at two different points in the trajectory of the supersonic object reach the observer at the same instant in time. The end result of this effect is the perception of a symmetrically receding pair of sound sources, which, in the luminal world, is a good description of symmetric radio sources (Double Radio source Associated with Galactic Nucleus or DRAGN).

Figure 2:. The object is flying from to through and at a constant supersonic speed. Imagine that the object emits sound during its travel. The sound emitted at the point (which is near the point of closest approach ) reaches the observer at before the sound emitted earlier at . The instant when the sound at an earlier point reaches the observer, the sound emitted at a much later point also reaches . So, the sound emitted at and reaches the observer at the same time, giving the impression that the object is at these two points at the same time. In other words, the observer hears two objects moving away from rather than one real object.

Radio Sources are typically symmetric and seem associated with galactic cores, currently considered manifestations of space-time singularities or neutron stars. Different classes of such objects associated with Active Galactic Nuclei (AGN) were found in the last fifty years. Figure 3 shows the radio galaxy Cygnus A, an example of such a radio source and one of the brightest radio objects. Many of its features are common to most extragalactic radio sources: the symmetric double lobes, an indication of a core, an appearance of jets feeding the lobes and the hotspots. Some researchers have reported more detailed kinematical features, such as the proper motion of the hotspots in the lobes.

Symmetric radio sources (galactic or extragalactic) and GRBs may appear to be completely distinct phenomena. However, their cores show a similar time evolution in the peak energy, but with vastly different time constants. The spectra of GRBs rapidly evolve from region to an optical or even RF afterglow, similar to the spectral evolution of the hotspots of a radio source as they move from the core to the lobes. Other similarities have begun to attract attention in the recent years.

This article explores the similarities between a hypothetical “luminal” boom and these two astrophysical phenomena, although such a luminal boom is forbidden by the Lorentz invariance. Treating GRB as a manifestation of a hypothetical luminal boom results in a model that unifies these two phenomena and makes detailed predictions of their kinematics.

Figure 3:.The radio jet and lobes in the hyperluminous radio galaxy Cygnus A. The hotspots in the two lobes, the core region and the jets are clearly visible. (Reproduced from an image courtesy of NRAO/AUI.)

Conclusions

In this article, we looked at the spatio-temporal evolution of a supersonic object (both in its position and the sound frequency we hear). We showed that it closely resembles GRBs and DRAGNs if we were to extend the calculations to light, although a luminal boom would necessitate superluminal motion and is therefore forbidden.

This difficulty notwithstanding, we presented a unified model for Gamma Ray Bursts and jet like radio sources based on bulk superluminal motion. We showed that a single superluminal object flying across our field of vision would appear to us as the symmetric separation of two objects from a fixed core. Using this fact as the model for symmetric jets and GRBs, we explained their kinematic features quantitatively. In particular, we showed that the angle of separation of the hotspots was parabolic in time, and the redshifts of the two hotspots were almost identical to each other. Even the fact that the spectra of the hotspots are in the radio frequency region is explained by assuming hyperluminal motion and the consequent redshift of the black body radiation of a typical star. The time evolution of the black body radiation of a superluminal object is completely consistent with the softening of the spectra observed in GRBs and radio sources. In addition, our model explains why there is significant blue shift at the core regions of radio sources, why radio sources seem to be associated with optical galaxies and why GRBs appear at random points with no advance indication of their impending appearance.

Although it does not address the energetics issues (the origin of superluminality), our model presents an intriguing option based on how we would perceive hypothetical superluminal motion. We presented a set of predictions and compared them to existing data from DRAGNs and GRBs. The features such as the blueness of the core, symmetry of the lobes, the transient and X-Ray bursts, the measured evolution of the spectra along the jet all find natural and simple explanations in this model as perceptual effects. Encouraged by this initial success, we may accept our model based on luminal boom as a working model for these astrophysical phenomena.

It has to be emphasized that perceptual effects can masquerade as apparent violations of traditional physics. An example of such an effect is the apparent superluminal motion, which was explained and anticipated within the context of the special theory of relativity even before it was actually observed. Although the observation of superluminal motion was the starting point behind the work presented in this article, it is by no means an indication of the validity of our model. The similarity between a sonic boom and a hypothetical luminal boom in spatio-temporal and spectral evolution is presented here as a curious, albeit probably unsound, foundation for our model.

One can, however, argue that the special theory of relativity (SR) does not deal with superluminality and, therefore, superluminal motion and luminal booms are not inconsistent with SR. As evidenced by the opening statements of Einstein’s original paper, the primary motivation for SR is a covariant formulation of Maxwell’s equations, which requires a coordinate transformation derived based partly on light travel time (LTT) effects, and partly on the assumption that light travels at the same speed with respect to all inertial frames. Despite this dependence on LTT, the LTT effects are currently assumed to apply on a space-time that obeys SR. SR is a redefinition of space and time (or, more generally, reality) in order to accommodate its two basic postulates. It may be that there is a deeper structure to space-time, of which SR is only our perception, filtered through the LTT effects. By treating them as an optical illusion to be applied on a space-time that obeys SR, we may be double counting them. We may avoid the double counting by disentangling the covariance of Maxwell’s equations from the coordinate transformations part of SR. Treating the LTT effects separately (without attributing their consequences to the basic nature of space and time), we can accommodate superluminality and obtain elegant explanations of the astrophysical phenomena described in this article. Our unified explanation for GRBs and symmetric radio sources, therefore, has implications as far reaching as our basic understanding of the nature of space and time.

The genetic explanation of good and evil above, though reasonable, may be a little too simplistic. Many morbid things are considered great or noble. Mindless brutality in wars, for instance, is thought of as a noble act of courage and sacrifice. Certain cruel social or cultural practices were once considered noble and are now considered abominable. Slavery, for instance, is one such custom that changed its moral color. The practice of slavery was condoned in some parts of the world while slave liberation was frowned upon, in an exact reversal of the current moral attitude.

Can we understand these apparent paradoxes in terms of our DNA replication algorithm? What exactly is the scope of the DNA replication algorithm? Obviously, it cannot be that a DNA wants (or is programmed) to replicate all DNAs. We would not be able to eat or survive in that case. Even the maxim “survival of the fittest” would not make any sense. Neither can it be that a DNA wants exact clones of itself. If that were true, it would not take a father and a mother to make a baby.

There is some behavioral evidence to suggest that DNA replication is optimized at sub-species or even intra-species level. A male lion, when he takes over a pride, kills or eats the cubs so that the lionesses of the pride have to mate with him. This behavior, however cruel and evil by our own genetic logic, makes sense to the male lion’s DNA replication program. His DNA is not interested in replicating the species DNA; it wants to replicate a DNA as close to itself as possible. Other examples of sub-species level optimization are easily found. Gorillas are fiercely territorial and protective of their groups. Their violent behavior in promoting their own specific DNA is in stark contrast to our perception of them as gentle giants.

Such blatant genetic motivations are mirrored in human beings as well; ethnic cleansing and racism are clear examples. We are also at least as territorial about our countries and homes as our gorilla cousins, as evidenced by the national boundaries and Immigration and Naturalization Services and so on. Even our more subtle socio-economic behavior can be traced back to a genetic sub-species level struggle for survival of our DNA.

This sub-species genetic division leads to the apparent paradox of the mixing of noble and the evil. Patriotism is noble; treason is evil. Spying for our country is bravery, while spying for some other country is clearly treason. Killing in a war is noble, but murdering a neighbor is clearly evil. A war for liberation is probably noble; a war for oil is not. Looking after our family is noble, but ignoring our own and looking after somebody else’s family is not that good.

Even though the actions and effects of each pair of these noble and evil deeds are roughly equivalent, their moral connotations are different. This paradoxical difference can be explained genetically by the notion that the DNA replication algorithm distinguishes between sub-species.

Ref: This post is an excerpt from my book, The Unreal Universe.

The genes in our body have only one motive–to get replicated. Our body is created in accordance with a blue print encoded in the genes to “run” this algorithm. How this algorithm gets mapped to our higher level goals and emotions is what life is all about to most people who are not physicists or biologists.

A simple mapping of this algorithm leads to the maxim in evolution “the survival of the fittest.” Any mutation that has the tiniest advantage in terms of survivability gets amplified over time. Similarly, all disadvantaged genes get wiped out.

But evolution in humans (and through our influence, the whole echo-system) has taken a new turn. Survival of the fittest used to mean the survival of the strongest or the smartest. For instance, if I had a genetic condition that made me prone to some life-threatening disease (in other words, if I was not very strong), my chances of passing on my genes would be a little smaller.

However, because of the advances in medicine, the survival chances for such disadvantaged genes are normalized to roughly the same level as those of the rest of the species. Then again, because of the dependence of the quality of health care on money, the survival chances get distorted in favor of the rich. So, is the mapping of the DNA algorithm now “the survival of the richest?”

Wealth is considered a product of intelligence. But intelligence (as defined by money-making ability) is not necessarily genetic. It may be, but we do not know that yet. So over several generations, it is not even the richest that survive, because time averages out the survival chances.

So what exactly is going to survive?

Ref: This post is an excerpt from my book, The Unreal Universe.

It is easiest to illustrate this inverted logic using examples. Suppose you are on a tropical island, enjoying the nice weather and the beautiful beach. You say to yourself, “This is perfect. This is paradise!” Of course, there is some specific gene containing the blue print of your brain process that leads you to feel this way. It stands to reason that there may have been genetic mutations at some point, which made some people hate this kind of paradise. They may have preferred Alaska in winter. Evidently, such genes had a slightly lower chance of survival because Alaskan winters are not as healthy as tropical paradises. Over millions of years, these genes got all but wiped out.

What this means is that the tropical paradise does not have an intrinsic beauty. It is not even that you happen to find it beautiful. Beauty does not necessarily lie in the eyes of the beholder. It is more like the eyes exist because we are the kind of people who would find such hospitable environments beautiful.

Another example of the inversion of logic in evolution is the reason we find cute babies cute. Our genes survived, and we are here because we are the kind of people who would find healthy babies cute. This reversal of causality has implications in every facet of our existence, all the way up to our notion of free will.

Ref: This post is an excerpt from my book, The Unreal Universe.