Tag Archives: Physics

Essays, Journal Articles, Discussion Forum Posts

Are Radio Sources and Gamma Ray Bursts Luminal Booms?

This article was published in the International Journal of Modern Physics D (IJMPD) in 2007. It soon became the Top Accessed Article of the journal by Jan 2008.

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 aluminalboom 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).

Sonic Boom
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 \gamma 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 \gamma 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 \gamma emission, and the spectrum softens as the fireball cools down. The model calculates the energy released in the \gamma region as 10^ {53}10^ {54} 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 10^410^6 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).

superluminality
Figure 2:. The object is flying from to A through and B 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 B) reaches the observer at O 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 A also reaches O. So, the sound emitted at A 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 \gamma 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 hypotheticalluminalboom 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.

CygA
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 \gamma 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.


Photo by NASA Goddard Photo and Video

The Big Bang Theory

I am a physicist, but I don’t quite understand the Big Bang theory. Let me tell you why.

The Big Bang theory says that the whole universe started from asingularity” — a single point. The first question then is, a single point where? It is not a single pointin spacebecause the whole space was a single point. The Discovery channel would put it fancifully thatthe whole universe could fit in the palm of your hand,” which of course it could not. Your palm would also be a little palm inside the little universe in that single point.

The second question is, if the whole universe was inside one point, what about all the points around it? Physicists would advise you not to ask such stupid questions. Don’t feel bad, they have asked me to shut up as well. Some of them may kindly explain that the other points may be parallel universes. Others may say that there are nootherpoints. They may point out (as Steven Weinberg does in The Dreams of a Final Theory) that there is nothing more to the north of the North Pole. I consider this analogy more of a semantic argument than a scientific one, but let’s buy this argument for now.

The next hurdle is that the singularity is in space-timenot merely in space. So before the Big Bang, there was no time. Sorry, there was nobefore!” This is a concept that my five year old son has problems with. Again, the Big Bang cosmologist will point out that things do not necessarily have to continue backwardsyou may think that whatever temperature something is at, you can always make it a little colder. But you cannot make it colder than absolute zero. True, true; but is temperature the same as time? Temperature is a measure of hotness, which is an aggregate of molecular speeds. And speed is distance traveled in unit time. Time again. Hmmm….

I am sure it is my lack of imagination or incompleteness of training that is preventing me from understanding and accepting this Big Bang concept. But even after buying the space-time singularity concept, other difficulties persist.

Firstly, if the whole universe is at one point at one time, one would naively expect it to make a super-massive black hole from which not even light can escape. Clearly then, the whole universe couldn’t have banged out of that point. But I’m sure there is a perfectly logical explanation why it can, just that I don’t know it yet. May be some of my readers will point it out to me?

Second, what’s with dark matter and dark energy? The Big Bang cosmology has to stretch itself a bit with the notion of dark energy to account for the large scale dynamics of the observed universe. Our universe is expanding (or so it appears) at an accelerating rate, which can only be accounted for by assuming that there is an invisible energy pushing the galaxies apart. Within the galaxies themselves, stars are moving around as though there is more mass than we can see. This is the so called dark matter. Althoughdarksignifies invisible, to me, it sounds as though we are in the dark about what these beasts are!

The third trouble I have is the fact that the Big Bang cosmology violates special relativity (SR). This little concern of mine has been answered in many different ways:

  • One answer is that general relativitytrumpsSRif there are conflicting predictions or directives from these two theories, I was advised to always trust GR.
  • Besides, SR applies only to local motion, like spaceships whizzing past each other. Non-local events do not have to obey SR. This makes me wonder how events know whether they are local or not. Well, that was bit tongue in cheek. I can kind of buy this argument (based on curvature of space-time perhaps becoming significant at large distances), although the non-scientific nature of local-ness makes me uneasy. (During the inflationary phase in the Big Bang theory, were things local or non-local?)
  • Third answer: In the case of the Big Bang, the space itself is expanding, hence no violation of SR. SR applies to motion through space. (Wonder if I could’ve used that line when I got pulled over on I-81. “Officer, I wasn’t speeding. Just that the space in between was expanding a little too fast!”)

Speaking of space expanding, it is supposed to be expanding only in between galaxies, not within them, apparently. I’m sure there is a perfectly logical explanation why, probably related to the proximity of masses or whatnot, but I’m not well-versed enough to understand it. In physics, disagreement and skepticism are always due to ignorance. But it is true that I have no idea what they mean when they say the space itself is expanding. If I stood in a region where the space was expanding, would I become bigger and would galaxies look smaller to me?

Note that it is necessary for space to expand only between galaxies. If it expanded everywhere, from subatomic to galactic scales, it would look as though nothing changed. Hardly satisfying because the distant galaxies do look as though they are flying off at great speeds.

I guess the real question is, what exactly is the difference between space expanding between two galaxies and the two galaxies merely moving away from each other?

One concept that I find bizarre is that singularity doesn’t necessarily mean single point in space. It was pointed out to me that the Big Bang could have been a spread out affairthinking otherwise was merely my misconception, because I got confused by the similarity between the wordssingularityand single.

People present the Big Bang theory in physics pretty much like Evolution in biology, implying the same level of infallibility. But I feel that it is disingenuous to do that. To me, it looks as though the theory is so full of patchwork, such a mathematical collage to cook up something that is consistent with GR that it is hard to imagine that it corresponds to anything real (ignoring, for the moment, my favorite questionwhat is real?) But popular writers have embraced it. For instance, Ray Kurzweil and Richard Dawkins put it as a matter of fact in their books, lending it a credence that it perhaps doesn’t merit.

End of Evolution

To a physicist, life is a neat example of electromagnetic interaction. To a biologist, however, life is a DNA replication algorithm. Let’s mull over the biology view for a few moments.

The genes in our body have only one motiveto get replicated. Our body is created in accordance with a blue print encoded in the genes torunthis 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 evolutionthe 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 nowthe 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.

The Unreal Universe — Seeing Light in Science and Spirituality

We know that our universe is a bit unreal. The stars we see in the night sky, for instance, are not really there. They may have moved or even died by the time we get to see them. This delay is due to the time it takes for light from the distant stars and galaxies to reach us. We know of this delay.

The same delay in seeing has a lesser known manifestation in the way we perceive moving objects. It distorts our perception such that something coming towards us would look as though it is coming in faster. Strange as it may sound, this effect has been observed in astrophysical studies. Some of the heavenly bodies do look as though they are moving several times the speed of light, while theirrealspeed is probably a lot lower.

Now, this effect raises an interesting questionwhat is therealspeed? If seeing is believing, the speed we see should be the real speed. Then again, we know of the light travel time effect. So we should correct the speed we see before believing it. What then doesseeingmean? When we say we see something, what do we really mean?

Light in Physics

Seeing involves light, obviously. The finite speed of light influences and distorts the way we see things. 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 is already eight minutes old by the time we see it. This delay is not a big deal; 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 tocorrectfor the distortions 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 isreallymoving 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 physicsspace and time. Another course of action is to accept the disconnection between our perception and the underlyingrealityand deal with it in some way.

Einstein chose the first route. In his groundbreaking paper over a hundred years ago, he introduced the special theory of relativity, in which he attributed the manifestations of the finite speed of light to the fundamental properties of space and time. One core idea in special relativity (SR) is that the notion of simultaneity needs to be redefined because it takes some time for light from an event at a distant place to reach us, and we become aware of the event. The concept ofNowdoesn’t make much sense, as we saw, when we speak of an event happening in the sun, for instance. Simultaneity is relative.

Einstein defined simultaneity using the instants in time we detect the event. Detection, as he defined it, involves a round-trip travel of light similar to Radar detection. We send out light, and look at the reflection. If the reflected light from two events reaches us at the same instant, they are simultaneous.
Another way of defining simultaneity is using sensingwe can call two events simultaneous if the light from them reaches us at the same instant. In other words, we can use the light generated by the objects under observation rather than sending light to them and looking at the reflection.

This difference may sound like a hair-splitting technicality, but it does make an enormous difference in the predictions we can make. Einstein’s choice results in a mathematical picture that has many desirable properties, thereby making further development elegant.

The other possibility has an advantage when it comes to describing objects in motion because it corresponds better with how we measure them. We don’t use Radar to see the stars in motion; we merely sense the light (or other radiation) coming from them. But this choice of using a sensory paradigm, rather than Radar-like detection, to describe the universe results in a slightly uglier mathematical picture.

The mathematical difference spawns different philosophical stances, which in turn percolate to the understanding of our physical picture of reality. As an illustration, let us look at an example from astrophysics. Suppose we observe (through a radio telescope, for instance) two objects in the sky, roughly of the same shape and properties. The only thing we know for sure is that the radio waves from two different points in the sky reach the radio telescope at the same instant in time. We can guess that the waves started their journey quite a while ago.

For symmetric objects, if we assume (as we routinely do) that the waves started the journey roughly at the same instant in time, we end up with a picture of tworealsymmetric lobes more or less the way see them.

But there is different possibility that the waves originated from the same object (which is in motion) at two different instants in time, reaching the telescope at the same instant. This possibility explains some spectral and temporal properties of such symmetric radio sources, which is what I mathematically described in a recent physics article. Now, which of these two pictures should we take as real? Two symmetric objects as we see them or one object moving in such a way as to give us that impression? Does it really matter which one isreal”? Doesrealmean anything in this context?

The philosophical stance in implied in special relativity answers this question unequivocally. There is an unambiguous physical reality from which we get the two symmetric radio sources, although it takes a bit of mathematical work to get to it. The mathematics rules out the possibility of a single object moving in such a fashion as to mimic two objects. Essentially, what we see is what is out there.

On the other hand, if we define simultaneity using concurrent arrival of light, we will be forced to admit the exact opposite. What we see is pretty far from what is out there. We will confess that we cannot unambiguously decouple the distortions due to the constraints in perception (the finite speed of light being the constraint of interest here) from what we see. There are multiple physical realities that can result in the same perceptual picture. The only philosophical stance that makes sense is the one that disconnects the sensed reality and the causes behind what is being sensed.

This disconnect is not uncommon in 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.

The ramifications of the two different philosophical stances described above are tremendous. Since modern physics seems to embrace 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 bookDreams 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 realityor whether ‘noumenal reality is independent of our sensing itor whether ‘we sense noumenal reality,’ the problem remains that the concept of noumenal reality is a totally redundant concept for the analysis of science.

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 readily understand it and disassociate 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.

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, isactually the case.In other words, knowledge is a reflection, or a mental image of something external, as shown in the figure below.
Commonsense view of reality
In this picture, the black arrow represents the process of creating knowledge, which includes perception, cognitive activities, and the exercise of pure reason. This is the picture that physics has come to accept.
Alternate view of reality
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 formidable machine of pure reason to their logically inevitable conclusions.

But there is another, alternative 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, as illustrated below.

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 the illustration, the first arrow represents the process of sensing, and the second arrow represents the cognitive and logical reasoning steps. In order to apply this view of reality and knowledge, we have to guess the nature of the absolute reality, unknowable as it is. One possible candidate for the absolute reality is Newtonian mechanics, which gives a reasonable prediction for our perceived reality.

To summarize, when we try to handle the distortions due to perception, we have two options, or two possible philosophical stances. One is to accept the distortions as part of our space and time, as SR does. The other option is to assume that there is ahigherreality distinct from our sensed reality, whose properties we can only conjecture. In other words, one option is to live with the distortion, while the other is to propose educated guesses for the higher reality. Neither of these options is particularly attractive. But the guessing path is similar to the view accepted in phenomenalism. It also leads naturally to how reality is viewed in cognitive neuroscience, which studies the biological mechanisms behind cognition.

In my view, the two options are not inherently distinct. The philosophical stance of SR can be thought of as coming from a deep understanding that space is merely a phenomenal construct. If the sense modality introduces distortions in the phenomenal picture, we may argue that one sensible way of handling it is to redefine the properties of the phenomenal reality.

Role of Light in Our Reality

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 deatheverything 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. 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 breakthroughs in human thought.

This philosophical grand-standing may sound presumptuous and the veiled self-admonition of physicists understandably unwelcome; but I am holding a trump card. Based on this philosophical stance, I have come up with a radically new model for two astrophysical phenomena, and published it in an article titled, “Are Radio Sources and Gamma Ray Bursts Luminal Booms?” in the well-known International Journal of Modern Physics D in June 2007. This article, which soon became one of the top accessed articles of the journal by Jan 2008, is a direct application of the view that the finite speed of light distorts the way we perceive motion. Because of these distortions, the way we see things is a far cry from the way they are.

We may be tempted to think that we can escape such perceptual constraints by using technological extensions to our senses such as radio telescopes, electron microscopes or spectroscopic speed measurements. After all, these instruments do not haveperceptionper se and should be immune to the human weaknesses we suffer from. But these soulless instruments also measure our universe using information carriers limited to the speed of light. We, therefore, cannot escape the basic constraints of our perception even when we use modern instruments. In other words, 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 reality, whether technologically enhanced or built upon direct sensory inputs, is the end result of our perceptual process. To the extent that our long range perception is based on light (and is therefore limited to its speed), we get only a distorted picture of the universe.

Light in Philosophy and Spirituality

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 thought experiment.

Once we appreciate the special place accorded to light in modern science, we have to ask ourselves how different our universe would have been in the absence of light. Of course, light is only a label we attach to a sensory experience. Therefore, to be more accurate, we have to ask a different question: if we did not have any senses that responded to what we call light, would that affect the form of the universe?

The immediate answer from any normal (that is, non-philosophical) person is that it is obvious. If everybody is blind, everybody is blind. But the existence of the universe is independent of whether we can see it or not. Is it though? What does it mean to say the universe exists if we cannot sense it? Ahthe age-old conundrum of the falling tree in a deserted forest. Remember, the universe is a cognitive construct or a mental representation of the light input to our eyes. It is notout there,” but in the neurons of our brain, as everything else is. In the absence of light in our eyes, there is no input to be represented, ergo no universe.

If we had sensed the universe using modalities that operated at other speeds (echolocation, for instance), it is those speeds that would have figured in the fundamental properties of space and time. This is the inescapable conclusion from phenomenalism.

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 thatthe earth was without form, and voiduntil God caused light to be, by sayingLet 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 foreign 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 or 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 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 endeavour may be the catalyst for the next breakthrough in our collective wisdom that we have been waiting for.

Uncertainly Principle

The uncertainty principle is the second thing in physics that has captured the public imagination. (The first one is E=mc^2.) It says something seemingly straightforwardyou can measure two complimentary properties of a system only to a certain precision. For instance, if you try to figure out where an electron is (measure its position, that is) more and more precisely, its speed becomes progressively more uncertain (or, the momentum measurement becomes imprecise).

Where does this principle come from? Before we can ask that question, we have to examine what the principle really says. Here are a few possible interpretations:

  1. Position and momentum of a particle are intrinsically interconnected. As we measure the momentum more accurately, the particle kind ofspreads out,” as George Gamow’s character, Mr. Tompkins, puts it. In other words, it is just one of those things; the way the world works.
  2. When we measure the position, we disturb the momentum. Our measurement probes aretoo fat,” as it were. As we increase the position accuracy (by shining light of shorter wavelengths, for instance), we disturb the momentum more and more (because shorter wavelength light has higher energy/momentum).
  3. Closely related to this interpretation is a view that the uncertainty principle is a perceptual limit.
  4. We can also think of the uncertainly principle as a cognitive limit if we consider that a future theory might surpass such limits.

All right, the last two interpretations are my own, so we won’t discuss them in detail here.

The first view is currently popular and is related to the so-called Copenhagen interpretation of quantum mechanics. It is kind of like the closed statements of Hinduism — “Such is the nature of the Absolute,” for instance. Accurate, may be. But of little practical use. Let’s ignore it for it is not too open to discussions.

The second interpretation is generally understood as an experimental difficulty. But if the notion of the experimental setup is expanded to include the inevitable human observer, we arrive at the third view of perceptual limitation. In this view, it is actually possible toderivethe uncertainty principle.

Let’s assume that we are using a beam of light of wavelength \lambda to observe the particle. The precision in the position we can hope to achieve is of the order of \lambda. In other words, \Delta x \approx \lambda. In quantum mechanics, the momentum of each photon in the light beam is inversely proportional to the wavelength. At least one photon is reflected by the particle so that we can see it. So, by the classical conservation law, the momentum of the particle has to change by at least \Delta p \approx constant\lambda from what it was before the measurement. Thus, through perceptual arguments, we get something similar to the Heisenberg uncertainty principle \Delta x \Delta p = constant.

We can make this argument more rigorous, and get an estimate of the value of the constant. The resolution of a microscope is given by the empirical formula 0.61\lambda/NA, where NA is the numerical aperture, which has a maximum value of one. Thus, the best spatial resolution is 0.61\lambda. Each photon in the light beam has a momentum 2\pi\hbar/\lambda, which is the uncertainty in the particle momentum. So we get \Delta x \Delta p = (0.61\lambda)(2\pi\hbar) \approx 4\hbar, approximately an order of magnitude bigger than the quantum mechanical limit. Through more rigorous statistical arguments, related to the spatial resolution and the expected momentum transferred, it may possible to derive the Heisenberg uncertainty principle through this line of reasoning.

If we consider the philosophical view that our reality is a cognitive model of our perceptual stimuli (which is the only view that makes sense to me), my fourth interpretation of the uncertainty principle being a cognitive limitation also holds a bit of water.

Reference

The latter part of this post is an excerpt from my book, The Unreal Universe.

Sex and PhysicsAccording to Feynman

Physics goes through an age of complacency once in a while. Complacency originates from a sense of completeness, a feeling that we have discovered everything there is to know, the path is clear and the methods well-understood.

Historically, these bouts of complacency are followed by rapid developments that revolutionize the way physics is done, showing us how wrong we have been. This humbling lesson of history is probably what prompted Feynman to say:

Such an age of complacency existed at the turn of the 19th century. Famous personas like Kelvin remarked that all that was left to do was to make more precise measurements. Michelson, who played a crucial role in the revolution to follow, was advised not to enter adeadfield like physics.

Who would have thought that in less than a decade into the 20th century, we would complete change the way we think of space and time? Who in their right mind would say now that we will again change our notions of space and time? I do. Then again, nobody has ever accused me of a right mind!

Another revolution took place during the course of the last centuryQuantum Mechanics, which did away with our notion of determinism and dealt a serious blow to the system-observer paradigm of physics. Similar revolutions will happen again. Let’s not hold on to our concepts as immutable; they are not. Let’s not think of our old masters as infallible, for they are not. As Feynman himself would point out, physics alone holds more examples of the fallibility of its old masters. And I feel that a complete revolution in thought is overdue now.

You might be wondering what all this has to do with sex. Well, I just thought sex would sell better. I was right, wasn’t I? I mean, you are still here!

Feynman also said,

Photo by “Caveman Chuck” Coker cc

The Philosophy of Special RelativityA Comparison between Indian and Western Interpretations

Abstract: The Western philosophical phenomenalism could be treated as a kind of philosophical basis of the special theory of relativity. The perceptual limitations of our senses hold the key to the understanding of relativistic postulates. The specialness of the speed of light in our phenomenal space and time is more a matter of our perceptual apparatus, than an input postulate to the special theory of relativity. The author believes that the parallels among the phenomenological, Western spiritual and the Eastern Advaita interpretations of special relativity point to an exciting possibility of unifying the Eastern and Western schools of thought to some extent.

Editor

Key Words: Relativity, Speed of Light, Phenomenalism, Advaita.

Introduction

The philosophical basis of the special theory of relativity can be interpreted in terms of Western phenomenalism, which views space and time are considered perceptual and cognitive constructs created out our sensory inputs. From this perspective, the special status of light and its speed can be understood through a phenomenological study of our senses and the perceptual limitations to our phenomenal notions of space and time. A similar view is echoed in the BrahmanMaya distinction in Advaita. If we think of space and time as part of Maya, we can partly understand the importance that the speed of light in our reality, as enshrined in special relativity. The central role of light in our reality is highlighted in the Bible as well. These remarkable parallels among the phenomenological, Western spiritual and the Advaita interpretations of special relativity point to an exciting possibility of unifying the Eastern and Western schools of thought to a certain degree.

Special Relativity

Einstein unveiled his special theory of relativity2 a little over a century ago. In his theory, he showed that space and time were not absolute entities. They are entities relative to an observer. An observer’s space and time are related to those of another through the speed of light. For instance, nothing can travel faster than the speed of light. In a moving system, time flows slower and space contracts in accordance with equations involving the speed of light. Light, therefore, enjoys a special status in our space and time. This specialness of light in our reality is indelibly enshrined in the special theory of relativity.

Where does this specialness come from? What is so special about light that its speed should figure in the basic structure of space and time and our reality? This question has remained unanswered for over 100 years. It also brings in the metaphysical aspects of space and time, which form the basis of what we perceive as reality.

Noumenal-Phenomenal and BrahmanMaya Distinctions

In the Advaita3 view of reality, what we perceive is merely an illusion-Maya. Advaita explicitly renounces the notion that the perceived reality is external or indeed real. It teaches us that the phenomenal universe, our conscious awareness of it, and our bodily being are all an illusion or Maya. They are not the true, absolute reality. The absolute reality existing in itself, independent of us and our experiences, is Brahman.

A similar view of reality is echoed in phenomenalism,4 which holds that space and time are not objective realities. They are merely the medium of our perception. In this view, all the phenomena that happen in space and time are merely bundles of our perception. Space and time are also cognitive constructs arising from perception. Thus, the reasons behind all the physical properties that we ascribe to space and time have to be sought in the sensory processes that create our perception, whether we approach the issue from the Advaita or phenomenalism perspective.

This analysis of the importance of light in our reality naturally brings in the metaphysical aspects of space and time. In Kant’s view,5 space and time are pure forms of intuition. They do not arise from our experience because our experiences presuppose the existence of space and time. Thus, we can represent space and time in the absence of objects, but we cannot represent objects in the absence of space and time.

Kant’s middle-ground has the advantage of reconciling the views of Newton and Leibniz. It can agree with Newton’s view6 that space is absolute and real for phenomenal objects open to scientific investigation. It can also sit well with Leibniz’s view7 that space is not absolute and has an existence only in relation to objects, by highlighting their relational nature, not among objects in themselves (noumenal objects), but between observers and objects.

We can roughly equate the noumenal objects to forms in Brahman and our perception of them to Maya. In this article, we will use the termsnoumenal reality,” “absolute reality,” orphysical realityinterchangeably to describe the collection of noumenal objects, their properties and interactions, which are thought to be the underlying causes of our perception. Similarly, we willphenomenal reality,” “perceived or sensed reality,” andperceptual realityto signify our reality as we perceive it.

As with Brahman causing Maya, we assume that the phenomenal notions of space and time arise from noumenal causes8 through our sensory and cognitive processes. Note that this causality assumption is ad-hoc; there is no a priori reason for phenomenal reality to have a cause, nor is causation a necessary feature of the noumenal reality. Despite this difficulty, we proceed from a naive model for the noumenal reality and show that, through the process of perception, we canderivea phenomenal reality that obeys the special theory of relativity.

This attempt to go from the phenomena (space and time) to the essence of what we experience (a model for noumenal reality) is roughly in line with Husserl’s transcendental phenomenology.9 The deviation is that we are more interested in the manifestations of the model in the phenomenal reality itself rather than the validity of the model for the essence. Through this study, we show that the specialness of the speed of light in our phenomenal space and time is a consequence of our perceptual apparatus. It doesn’t have to be an input postulate to the special theory of relativity.

Perception and Phenomenal Reality

The properties we ascribe to space and time (such as the specialness of the speed of light) can only be a part of our perceived reality or Maya, in Advaita, not of the underlying absolute reality, Brahman. If we think of space and time as aspects of our perceived reality arising from an unknowable Brahman through our sensory and cognitive processes, we can find an explanation for the special distinction of the speed of light in the process and mechanism of our sensing. Our thesis is that the reason for the specialness of light in our phenomenal notions of space and time is hidden in the process of our perception.

We, therefore, study how the noumenal objects around us generate our sensory signals, and how we construct our phenomenal reality out of these signals in our brains. The first part is already troublesome because noumenal objects, by definition, have no properties or interactions that we can study or understand.

These features of the noumenal reality are identical to the notion of Brahman in Advaita, which highlights that the ultimate truth is Brahman, the one beyond time, space and causation. Brahman is the material cause of the universe, but it transcends the cosmos. It transcends time; it exists in the past, present and future. It transcends space; it has no beginning, middle and end. It even transcends causality. For that reason, Brahman is incomprehensible to the human mind. The way it manifests to us is through our sensory and cognitive processes. This manifestation is Maya, the illusion, which, in the phenomenalistic parlance, corresponds to the phenomenal reality.

For our purpose in this article, we describe our sensory and cognitive process and the creation of the phenomenal reality or Maya10 as follows. It starts with the noumenal objects (or forms in Brahman), which generate the inputs to our senses. Our senses then process the signals and relay the processed electric data corresponding to them to our brain. The brain creates a cognitive model, a representation of the sensory inputs, and presents it to our conscious awareness as reality, which is our phenomenal world or Maya.

This description of how the phenomenal reality created ushers in a tricky philosophical question. Who or what creates the phenomenal reality and where? It is not created by our senses, brain and mind because these are all objects or forms in the phenomenal reality. The phenomenal reality cannot create itself. It cannot be that the noumenal reality creates the phenomenal reality because, in that case, it would be inaccurate to assert the cognitive inaccessibility to the noumenal world.

This philosophical trouble is identical in Advaita as well. Our senses, brain and mind cannot create Maya, because they are all part of Maya. If Brahman created Maya, it would have to be just as real. This philosophical quandary can be circumvented in the following way. We assume that all events and objects in Maya have a cause or form in Brahman or in the noumenal world. Thus, we postulate that our senses, mind and body all have some (unknown) forms in Brahman (or in the noumenal world), and these forms create Maya in our conscious awareness, ignoring the fact that our consciousness itself is an illusory manifestation in the phenomenal world. This inconsistency is not material to our exploration into the nature of space and time because we are seeking the reason for the specialness of light in the sensory process rather than at the level of consciousness.

Space and time together form what physics considers the basis of reality. Space makes up our visual reality precisely as sounds make up our auditory world. Just as sounds are a perceptual experience rather than a fundamental property of physical reality, space also is an experience, or a cognitive representation of the visual inputs, not a fundamental aspect of Brahman or the noumenal reality. The phenomenal reality thus created is Maya. The Maya events are an imperfect or distorted representation of the corresponding Brahman events. Since Brahman is a superset of Maya (or, equivalently, our senses are potentially incapable of sensing all aspects of the noumenal reality), not all objects and events in Brahman create a projection in Maya. Our perception (or Maya) is thus limited because of the sense modality and its speed, which form the focus of our investigation in this article.

In summary, it can be argued that the noumenal-phenomenal distinction in phenomenalism is an exact parallel to the BrahmanMaya distinction in Advaita if we think of our perceived reality (or Maya) as arising from sensory and cognitive processes.

Sensing Space and Time, and the Role of Light

The phenomenal notions of space and time together form what physics considers the basis of reality. Since we take the position that space and time are the end results of our sensory perception, we can understand some of the limitations in our Maya 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.11

The exclusivity of EM interaction is not limited to our long-range sense of sight; all the short-range senses (touch, taste, smell and hearing) are also EM in nature. In physics, the fundamental interactions are modeled as fields with gauge bosons.12 In quantum electrodynamics13 (the quantum field theory of EM interactions), photon (or light) is the gauge boson mediating EM interactions. Electromagnetic interactions are responsible for all our sensory inputs. 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, red shift 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 phenomenal reality, whether built upon direct sensory inputs or technologically enhanced, is made up of a subset of EM particles and interactions only. What we perceive as reality is a subset of forms and events in the noumenal world corresponding to EM interactions, filtered through our sensory and cognitive processes. In the Advaita parlance, Maya can be thought of as a projection of Brahman through EM interactions into our sensory and cognitive space, quite probably an imperfect projection.

The exclusivity of EM interactions in our perceived reality is not always appreciated, mainly because of a misconception that we can sense gravity directly. This confusion arises because our bodies are subject to gravity. There is a fine distinction betweenbeing subject toandbeing able to sensegravitational force. The gravity sensing in our ears 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.

This assertion that there is no sensing in the absence of EM interactions brings us to the next philosophical hurdle. One can always argue that, in the absence of EM interaction, there is no matter to sense. This argument is tantamount to insisting that the noumenal world consists of only those forms and events that give rise to EM interaction in our phenomenal perception. In other words, it is the same as insisting that Brahman is made up of only EM interactions. What is lacking in the absence of EM interaction is only our phenomenal reality. In the Advaita notion, in the absence of sensing, Maya does not exist. The absolute reality or Brahman, however, is independent of our sensing it. Again, we see that the Eastern and Western views on reality we explored in this article are remarkably similar.

The Speed of Light

Knowing that our space-time is a representation of the light waves our eyes receive, we can immediately see that light is indeed special in our reality. In our view, sensory perception leads to our brain’s representation that we call reality, or Maya. Any limitation in this chain of sensing leads to a corresponding limitation in our phenomenal reality.

One limitation in the chain from senses to perception 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 importance of the speed of light, however, is respected only in our phenomenal Maya. Other modes of perception have other speeds the figure as the fundamental constant in their space-like perception. The reality sensed through echolocation, for instance, has the speed of sound as a fundamental property. In fact, it is fairly simple to establish14 that echolocation results in a perception of motion that obeys something very similar to special relativity with the speed of light replaced with that of sound.

Theories beyond Sensory Limits

The basis of physics is the world view called scientific realism, which is not only at the core of sciences but is our natural way of looking at the world as well. Scientific realism, and hence physics, assume an independently existing external world, whose structures are knowable through scientific investigations. To the extent observations are based on perception, the philosophical stance of scientific realism, as it is practiced today, can be thought of as a trust in our perceived reality, and as an assumption that it is this reality that needs to be explored in science.

Physics extends its reach beyond perception or Maya through the rational element of pure theory. Most of physics works in thisextendedintellectual reality, with concepts such as fields, forces, light rays, atoms, particles, etc., the existence of which is insisted upon through the metaphysical commitment implied in scientific realism. However, it does not claim that the rational extensions are the noumenal causes or Brahman giving raise to our phenomenal perception.

Scientific realism has helped physics tremendously, with all its classical theories. However, scientific realism and the trust in our perception of reality should apply only within the useful ranges of our senses. Within the ranges of our sensory perceptions, we have fairly intuitive physics. An example of an intuitive picture is Newtonian mechanics that describenormalobjects moving around atnormalspeeds.

When we get closer to the edges of our sensory modalities, we have to modify our sciences to describe the reality as we sense it. These modifications lead to different, and possibly incompatible, theories. When we ascribe the natural limitations of our senses and the consequent limitations of our perception (and therefore observations) to the fundamental nature of reality itself, we end up introducing complications in our physical laws. Depending on which limitations we are incorporating into the theory (e.g., small size, large speeds etc.), we may end up with theories that are incompatible with each other.

Our argument is that some of these complications (and, hopefully, incompatibilities) can be avoided if we address the sensory limitations directly. For instance, we can study the consequence of the fact that our senses operate at the speed of light as follows. We can model Brahman (the noumenal reality) as obeying classical mechanics, and work out what kind of Maya (phenomenal reality) we will experience through the chain of sensing.

The modeling of the noumenal world (as obeying classical mechanics), of course, has shaky philosophical foundations. But the phenomenal reality predicted from this model is remarkably close to the reality we do perceive. Starting from this simple model, it can be easily shown our perception of motion at high speeds obeys special relativity.

The effects due to the finite speed of light are well known in physics. We know, for instance, that what we see happening in distant stars and galaxies now actually took place quite awhile ago. A moreadvancedeffect due to the light travel time15 is the way we perceive motion at high speeds, which is the basis of special relativity. In fact, many astrophysical phenomena can be understood16 in terms of light travel time effects. Because our sense modality is based on light, our sensed picture of motion has the speed of light appearing naturally in the equations describing it. So the importance of the speed of light in our space-time (as described in special relativity) is due to the fact that our reality is Maya created based on light inputs.

Conclusion

Almost all branches of philosophy grapple with this distinction between the phenomenal and the absolute realities to some extent. Advaita Vedanta holds the unrealness of the phenomenal reality as the basis of their world view. In this article, we showed that the views in phenomenalism can be thought of as a restatement of the Advaita postulates.

When such a spiritual or philosophical insight makes its way into science, great advances in our understanding can be expected. This convergence of philosophy (or even spirituality) and science is beginning to take place, most notably in neuroscience, which views reality as a creation of our brain, echoing the notion of Maya.

Science gives a false impression that we can get arbitrarily close to the underlying physical causes through the process of scientific investigation and rational theorization. An example of such theorization can be found in our sensation of hearing. The experience or the sensation of sound is an incredibly distant representation of the physical causenamely air pressure waves. We are aware of the physical cause because we have a more powerful sight sense. So it would seem that we can indeed go from Maya (sound) to the underlying causes (air pressure waves).

However, it is a fallacy to assume that the physical cause (the air pressure waves) is Brahman. Air pressure waves are still a part of our perception; they are part of the intellectual picture we have come to accept. This intellectual picture is an extension of our visual reality, based on our trust in the visual reality. It is still a part of Maya.

The new extension of reality proposed in this article, again an intellectual extension, is an educated guess. We guess a model for the absolute reality, or Brahman, and predict what the consequent perceived reality should be, working forward through the chain of sensing and creating Maya. If the predicted perception is a good match with the Maya we do experience, then the guesswork for Brahman is taken to be a fairly accurate working model. The consistency between the predicted perception and what we do perceive is the only validation of the model for the nature of the absolute reality. Furthermore, the guess is only one plausible model for the absolute reality; there may be different suchsolutionsto the absolute reality all of which end up giving us our perceived reality.

It is a mistake to think of the qualities of our subjective experience of sound as the properties of the underlying physical process. In an exact parallel, it is a fallacy to assume that the subjective experience of space and time is the fundamental property of the world we live in. The space-time continuum, as we see it or feel it, is only a partial and incomplete representation of the unknowable Brahman. If we are willing to model the unknowable Brahman as obeying classical mechanics, we can indeed derive the properties of our perceived reality (such as time dilation, length contraction, light speed ceiling and so on in special relativity). By proposing this model for the noumenal world, we are not suggesting that all the effects of special relativity are mere perceptual artifacts. We are merely reiterating a known fact that space and time themselves cannot be anything but perceptual constructs. Thus their properties are manifestations of the process of perception.

When we consider processes close to or beyond our sensor limits, the manifestations of our perceptual and cognitive constraints become significant. Therefore, when it comes to the physics that describes such processes, we really have to take into account the role that our perception and cognition play in sensing them. The universe as we see it is only a cognitive model created out of the photons falling on our retina or on the photosensors of the Hubble telescope. Because of the finite speed of the information carrier (namely light), 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 only a part of our perception of an unknowable realitya perception limited by the speed of light.

The central role of light in creating our reality or universe is at the heart of western spiritual philosophy as well. 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 notion thatthe earth was without form, and void'until God caused light to be, by sayingLet there be light.Quran also says, “Allah is the light of the heavens.The role of light in taking us from the void (the nothingness) to a reality was 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 advances in knowledge? Whether we use old Eastern Advaita views or their Western counterparts, we can interpret the philosophical stance behind special relativity as hidden in the distinction between our phenomenal reality and its unknowable physical causes.

References

  1. Dr. Manoj Thulasidas graduated from the Indian Institute of Technology (IIT), Madras, in 1987. He studied fundamental particles and interactions at the CLEO collaboration at Cornell University during 1990-1992. After receiving his PhD in 1993, he moved to Marseilles, France and continued his research with the ALEPH collaboration at CERN, Geneva. During his ten-year career as a research scientist in the field of High energy physics, he co-authored over 200 publications.
  2. Einstein, A. (1905). Zur Elektrodynamik bewegter Körper. (On The Electrodynamics Of Moving Bodies). Annalen der Physik, 17, 891-921.
  3. Radhakrishnan, S. & Moore, C. A. (1957). Source Book in Indian Philosophy. Princeton University Press, Princeton, NY.
  4. Chisolm, R. (1948). The Problem of Empiricism. The Journal of Philosophy, 45, 512-517.
  5. Allison, H. (2004). Kant’s Transcendental Idealism. Yale University Press.
  6. Rynasiewicz, R. (1995). By Their Properties, Causes and Effects: Newton’s Scholium on Time, Space, Place and Motion. Studies in History and Philosophy of Science, 26, 133-153, 295-321.
  7. Calkins, M. W. (1897). Kant’s Conception of the Leibniz Space and Time Doctrine. The Philosophical Review, 6 (4), 356-369.
  8. Janaway, C., ed. (1999). The Cambridge Companion to Schopenhauer. Cambridge University Press.
  9. Schmitt, R. (1959). Husserl’s Transcendental-Phenomenological Reduction. Philosophy and Phenomenological Research, 20 (2), 238-245.
  10. Thulasidas, M. (2007). The Unreal Universe. Asian Books, Singapore.
  11. Electromagnetic (EM) interaction is one of the four kinds of interactions in the Standard Model (Griffths, 1987) of particle physics. It is the interaction between charged bodies. Despite the EM repulsion between them, however, the protons stay confined within the nucleus because of the strong interaction, whose magnitude is much bigger than that of EM interactions. The other two interactions are termed the weak interaction and the gravitational interaction.
  12. In quantum field theory, every fundamental interaction consists of emitting a particle and absorbing it in an instant. These so-called virtual particles emitted and absorbed are known as the gauge bosons that mediate the interactions.
  13. Feynman, R. (1985). Quantum Electrodynamics. Addison Wesley.
  14. Thulasidas, M. (2007). The Unreal Universe. Asian Books, Singapore.
  15. Rees, M. (1966). Appearance of Relativistically Expanding Radio Sources. Nature, 211, 468-470.
  16. Thulasidas, M. (2007a). Are Radio Sources and Gamma Ray Bursts Luminal Booms? International Journal of Modern Physics D, 16 (6), 983-1000.

Perception, Physics and the Role of Light in Philosophy

Reality, as we sense it, is not quite real. The stars we see in the night sky, for instance, are not really there. They may have moved or even died by the time we get to see them. This unreality is due to the time it takes for light from the distant stars and galaxies to reach us. We know of this delay.

Even the sun that we know so well is already eight minutes old by the time we see it. This fact does not seem to present particularly grave epistemological problemsif we want to know what is going on at the sun now, all we have to do is to wait for eight minutes. We only have to ‘correctfor the distortions in our perception due to the finite speed of light before we can trust what we see. The same phenomenon in seeing has a lesser-known manifestation in the way we perceive moving objects. Some heavenly bodies appear as though they are moving several times the speed of light, whereas their ‘realspeed must be a lot less than that.

What is surprising (and seldom highlighted) is that when it comes to sensing motion, we cannot back-calculate in the same kind of way as we can to correct for the delay in observation of the sun. If we see a celestial body moving at an improbably high speed, we cannot calculate how fast or even in what direction it is ‘reallymoving without first having to make certain further assumptions.

Einstein chose to resolve the problem by treating perception as distorted and inventing new fundamental properties in the arena of physicsin the description of space and time. One core idea of the Special Theory of Relativity is that the human notion of an orderly sequence of events in time needs to be abandoned. In fact, since it takes time for light from an event at a distant place to reach us, and for us to become aware of it, the concept of ‘nowno longer makes any sense, for example, when we speak of a sunspot appearing on the surface of the sun just at the moment that the astronomer was trying to photograph it. Simultaneity is relative.

Einstein instead redefined simultaneity by using the instants in time we detect the event. Detection, as he defined it, involves a round-trip travel of light similar to radar detection. We send out a signal travelling at the speed of light, and wait for the reflection. If the reflected pulse from two events reaches us at the same instant, then they are simultaneous. But another way of looking at it is simply to call two events ‘simultaneousif the light from them reaches us at the same instant. In other words, we can use the light generated by the objects under observation rather than sending signals to them and looking at the reflection.

This difference may sound like a hair-splitting technicality, but it does make an enormous difference to the predictions we can make. Einstein’s choice results in a mathematical picture that has many desirable properties, including that of making further theoretical development more elegant. But then, Einstein believed, as a matter of faith it would seem, that the rules governing the universe must be ‘elegant.However, the other approach has an advantage when it comes to describing objects in motion. Because, of course, we don’t use radar to see the stars in motion; we merely sense the light (or other radiation) coming from them. Yet using this kind of sensory paradigm, rather than ‘radar-like detection,’ to describe the universe results in an uglier mathematical picture. Einstein would not approve!

The mathematical difference spawns different philosophical stances, which in turn percolate to the understanding of our physical picture of reality. As an illustration, suppose we observe, through a radio telescope, two objects in the sky, with roughly the same shape, size and properties. The only thing we know for sure is that the radio waves from these two different points in the sky reach us at the same instant in time. We can only guess when the waves started their journeys.

If we assume (as we routinely do) that the waves started the journey roughly at the same instant in time, we end up with a picture of two ‘realsymmetric lobes more or less the way see them. But there is another, different possibility and that is that the waves originated from the same object (which is in motion) at two different instants in time, reaching the telescope at the same instant. This possibility would additionally explain some spectral and temporal properties of such symmetric radio sources. So which of these two pictures should we take as real? Two symmetric objects as we see them or one object moving in such a way as to give us that impression? Does it really matter which one is ‘real’? Does ‘realmean anything in this context?

Special Relativity gives an unambiguous answer to this question. The mathematics rules out the possibility of a single object moving in such a fashion as to mimic two objects. Essentially, what we see is what is out there. Yet, if we define events by what we perceive, the only philosophical stance that makes sense is the one that disconnects the sensed reality from the causes lying behind what is being sensed.

This disconnect is not uncommon in 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 of ‘things-in-the-worldas we sense it. The underlying reality (which holds the physical causes of our perception), by contrast, remains beyond our cognitive reach.

Yet there is a chasm between the views of philosophy and modern physics. Not for nothing did the Nobel Prize winning physicist, Steven Weinberg, wonder, in his book Dreams of a Final Theory, why the contribution from philosophy to physics had been so surprisingly small. Perhaps it is because physics has yet to come to terms with the fact that when it comes to seeing the universe, there is no such thing as an optical illusionwhich is probably what Goethe meant 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, as shown in the figure below.

ExternalToBrain

In this picture, the black arrow represents the process of creating 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 formidable machine of pure reason to their logically inevitable conclusions.

But there is another, alternative 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, as illustrated below.

AbsolutelToBrain

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 the illustration, the first arrow represents the process of sensing, and the second arrow represents the cognitive and logical reasoning steps. In order to apply this view of reality and knowledge, we have to guess the nature of the absolute reality, unknowable as it is. One possible candidate for the absolute reality is Newtonian mechanics, which gives a reasonable prediction for our perceived reality.

To summarize, when we try to handle the distortions due to perception, we have two options, or two possible philosophical stances. One is to accept the distortions as part of our space and time, as Special Relativity does. The other option is to assume that there is a ‘higherreality distinct from our sensed reality, whose properties we can only conjecture. In other words, one option is to live with the distortion, while the other is to propose educated guesses for the higher reality. Neither of these choices is particularly attractive. But the guessing path is similar to the view accepted in phenomenalism. It also leads naturally to how reality is viewed in cognitive neuroscience, which studies the biological mechanisms behind cognition.

The twist to this story of light and reality is that we seem to have known all this for a long time. 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 voiduntil God caused light to be, by saying ‘Let there be light.

The Koran 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?

There are parallels between the noumenal-phenomenal distinction of Kant and the phenomenalists later, and the Brahman-Maya distinction in Advaita. Wisdom on the nature of reality from the repertoire of spirituality is 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 still unable 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.

In fact, as we push the boundaries of our knowledge further and further, we are discovering hitherto unsuspected and often surprising interconnections between different branches of human efforts. Yet, how can the diverse domains of our knowledge be independent of each other if all knowledge is subjective? If knowledge is merely the cognitive representation of our experiences? But then, it is the modern fallacy to think that knowledge is our internal representation of an external reality, and therefore distinct from it. Instead, recognising and making use of the interconnections among the different domains of human endeavour may be the essential prerequisite for the next stage in developing our collective wisdom.

Box: Einstein’s TrainOne of Einstein’s famous thought experiments illustrates the need to rethink what we mean by simultaneous events. It describes a high-speed train rushing along a straight track past a small station as a man stands on the station platform watching it speed by. To his amazement, as the train passes him, two lightening bolts strike the track next to either end of the train! (Conveniently, for later investigators, they leave burn marks both on the train and on the ground.)

To the man, it seems that the two lightening bolts strike at exactly the same moment. Later, the marks on the ground by the train track reveal that the spots where the lightening struck were exactly equidistant from him. Since then the lightening bolts travelled the same distance towards him, and since they appeared to the man to happen at exactly the same moment, he has no reason not to conclude that the lightening bolts struck at exactly the same moment. They were simultaneous.

However, suppose a little later, the man meets a lady passenger who happened to be sitting in the buffet car, exactly at the centre of the train, and looking out of the window at the time the lightening bolts struck. This passenger tells him that she saw the first lightening bolt hit the ground near the engine at the front of the train slightly ahead of when the second one hit the ground next to the luggage car at the rear of the train.

The effect has nothing to do with the distance the light had to travel, as both the woman and the man were equidistant between the two points that the lightening hit. Yet they observed the sequence of events quite differently.

This disagreement of the timing of the events is inevitable, Einstein says, as the woman is in effect moving towards the point where the flash of lightening hit near the engine -and away from the point where the flash of lightening hit next to the luggage car. In the tiny amount of time it takes for the light rays to reach the lady, because the train moves, the distance the first flash must travel to her shrinks, and the distance the second flash must travel grows.

This fact may not be noticed in the case of trains and aeroplanes, but when it comes to cosmological distances, simultaneity really doesn’t make any sense. For instance, the explosion of two distant supernovae, seen as simultaneous from our vantage point on the earth, will appear to occur in different time combinations from other perspectives.

In Relativity: The Special and General Theory (1920), Einstein put it this way:

‘Every reference-body (co-ordinate system) has its own particular time; unless we are told the reference-body to which the statement of time refers, there is no meaning in a statement of the time of an event.

The Story So Far …

In the early sixties, Santa Kumari Amma decided to move to the High Ranges. She had recently started working with KSEB which was building a hydro-electric project there.The place was generically called the High Ranges, even though the ranges weren’t all that high. People told her that the rough and tough High Ranges were no place for a country girl like her, but she wanted to go anyways, prompted mainly by the fact that there was some project allowance involved and she could use any little bit that came her way. Her family was quite poor. She came from a small village called Murani (near a larger village called Mallappalli.)

Around the same time B. Thulasidas (better known as Appu) also came to the High Ranges. His familty wasn’t all that poor and he didn’t really need the extra money. But he thought, hey rowdy place anyway, what the heck? Well, to make a long story short, they fell in love and decided to get married. This was some time in September 1962. A year later Sandya was born in Nov 63. And a little over another year and I came to be! (This whole stroy, by the way, is taking place in the state of Kerala in India. Well, that sentence was added just to put the links there, just in case you are interested.) There is a gorgeous hill resort called Munnar (meaning three rivers) where my parents were employed at that time and that’s where I was born.

 [casual picture] Just before 1970, they (and me, which makes it we I guess) moved to Trivandrum, the capital city of Kerala. I lived in Trivandrum till I was 17. Lots of things happened in those years, but since this post is still (and always will be) work in progress, I can’t tell you all about it now.

In 1983, I moved to Madras, to do my BTech in Electronics and Communication at IIT, Madras. (They call the IITs the MIT of India, only much harder to get in. In my batch, there were about 75,000 students competing for about 2000 places. I was ranked 63 among them. I’m quite smart academically, you see.) And as you can imagine, lots of things happened in those four years as well. But despite all that, I graduated in August 1987 and got my BTech degree.

In 1987, after finishing my BTech, I did what most IITians are supposed to do. I moved to the states. Upstate New York was my destination. I joined the Physics Department of Syracuse University to do my PhD in High Energy Physics. And boy, did a lot of things happen during those 6 years! Half of those 6 years were spent at Cornell University in Ithaca.

That was in Aug. 1987. Then in 1993 Sept, the prestigious French national research organization ( CNRS – “Centre national de la recherche scientifique”) hired me. I moved to France to continue my research work at ALEPH, CERN. My destination in France was the provencal city of Marseilles. My home institute was “Centre de Physique des Particules de Marseille” or CPPM. Of course, I didn’t speak a word of French, but that didn’t bother me much. (Before going to the US in 1987, I didn’t speak much English/Americanese either.)

End of 1995, on the 29th of Dec, I got married to Kavita. In early 1996, Kavita also moved to France. Kavita wasn’t too happy in France because she felt she could do much more in Singapore. She was right. Kavita is now an accomplished entrepreneur with two boutiques in Singapore and more business ideas than is good for her. She has won many awards and is a minor celebrity with the Singapore media. [Wedding picture]

In 1998, I got a good offer from what is now the Institute for Infocomm Research and we decided to move to Singapore. Among the various personal reasons for the move, I should mention that the smell of racisim in the Marseilles air was one. Although every individual I personally met in France was great, I always had a nagging feeling that every one I did not meet wanted me out of there. This feeling was further confirmed by the immigration clerks at the Marignane airport constantly asking me to “Mettez-vous a cote, monsieur” and occassionally murmuring “les francais d’abord.”  [Anita Smiles]

A week after I moved to Singapore, on the 24rth of July 1998, Anita was born. Incredibly cute and happy, Anita rearranged our priorities and put things in perspective. Five years later, on the 2nd of May 2003, Neil was born. He proved to be even more full of smiles.  [Neil Smiles more!]

In Singapore, I worked on a lot of various body-based measurements generating several patents and papers. Towards the end of my career with A-Star, I worked on brain signals, worrying about how to make sense of them and make them talk directly to a computer. This research direction influenced my thinking tremendously, though not in a way my employer would’ve liked. I started thinking about the role of perception in our world view and, consequently, in the theories of physics. I also realized how these ideas were not isolated musings, but were atriculated in various schools of philosophy. This line of thinking eventually ended up in my book, The Unreal Universe.

Towards the second half of 2005, I decided to chuck research and get into quantitative finance, which is an ideal domain for a cash-strapped physicist. It turned out that I had some skills and aptitudes that were mutually lucrative to my employers and myself. My first job was as the head of the quantitative analyst team at OCBC, a regional bank in Singapore. This middle office job, involving risk management and curtailing ebullient traders, gave me a thorough overview of pricing models and, perhaps more importantly, perfect understanding of the conflict-driven implementation of the risk appetite of the bank.

 [Dad] Later on, in 2007, I moved to Standard Chartered Bank, as a senior quantitative professional taking care of their in-house trading platform, which further enhanced my "big picture" outlook and inspired me to write Principles of Quantitative Development. I am rather well recognized in my field, and as a regular columnist for the Wilmott Magazine, I have published several articles on a variety of topics related to quants and quantitative finance, which is probably why John Wiley & Sons Ltd. asked me to write this book.

Despite these professional successes, on the personal front, 2008 has been a year of sadness. I lost my father on the 22nd of October. The death of a parent is a rude wake-up call. It brings about feelings of loss and pain that are hard to understand, and impossible to communicate. And for those of us with little gift of easy self-expression, they linger for longer than they perhaps should.

Unreal Time

Farsight wrote:Time is a velocity-dependent subjective measure of event succession rather than something fundamental – the events mark the time, the time doesn’t mark the events. This means the stuff out there is space rather than space-time, and is an “aether” veiled by subjective time.

I like your definition of time. It is close to my own view that time is “unreal.” It is possible to treat space as real and space-time as something different, as you do. This calls for some careful thought. I will outline my thinking in this post and illustrate it with an example, if my friends don’t pull me out for lunch before I can finish. :)

The first question we need to ask ourselves is why space and time seem coupled? The answer is actually too simple to spot, and it is in your definition of time. Space and time mix through our concept of velocity and our brain’s ability to sense motion. There is an even deeper connection, which is that space is a cognitive representation of the photons inputs to our eyes, but we will get to it later.

Let’s assume for a second that we had a sixth sense that operated at an infinite speed. That is, if star explodes at a million light years from us, we can sense it immediately. We will see it only after a million years, but we sense it instantly. I know, it is a violation of SR, cannot happen and all that, but stay with me for a second. Now, a little bit of thinking will convince you that the space that we sense using this hypothetical sixth sense is Newtonian. Here, space and time can be completely decoupled, absolute time can be defined etc. Starting from this space, we can actually work out how we will see it using light and our eyes, knowing that the speed of light is what it is. It will turn out, clearly, that we seen events with a delay. That is a first order (or static) effect. The second order effect is the way we perceive objects in motion. It turns out that we will see a time dilation and a length contraction (for objects receding from us.)

Let me illustrate it a little further using echolocation. Assume that you are a blind bat. You sense your space using sonar pings. Can you sense a supersonic object? If it is coming towards you, by the time the reflected ping reaches you, it has gone past you. If it is going away from you, your pings can never catch up. In other words, faster than sound travel is “forbidden.” If you make one more assumption – the speed of the pings is the same for all bats regardless of their state of motion – you derive a special relativity for bats where the speed of sound is the fundamental property of space and time!

We have to dig a little deeper and appreciate that space is no more real than time. Space is a cognitive construct created out of our sensory inputs. If the sense modality (light for us, sound for bats) has a finite speed, that speed will become a fundamental property of the resultant space. And space and time will be coupled through the speed of the sense modality.

This, of course, is only my own humble interpretation of SR. I wanted to post this on a new thread, but I get the feeling that people are a little too attached to their own views in this forum to be able to listen.

Leo wrote:Minkowski spacetime is one interpretation of the Lorentz transforms, but other interpretations, the original Lorentz-Poincaré Relativity or modernized versions of it with a wave model of matter (LaFreniere or Close or many others), work in a perfectly euclidean 3D space.

So we end up with process slowdown and matter contraction, but NO time dilation or space contraction. The transforms are the same though. So why does one interpretation lead to tensor metric while the others don’t? Or do they all? I lack the theoretical background to answer the question.

Hi Leo,

If you define LT as a velocity dependent deformation of an object in motion, then you can make the transformation a function of time. There won’t be any warping and complications of metric tensors and stuff. Actually what I did in my book is something along those lines (though not quite), as you know.

The trouble arises when the transformation matrix is a function of the vector is transforming. So, if you define LT as a matrix operation in a 4-D space-time, you can no longer make it a function of time through acceleration any more than you can make it a function of position (as in a velocity field, for instance.) The space-time warping is a mathematical necessity. Because of it, you lose coordinates, and the tools that we learn in our undergraduate years are no longer powerful enough to handle the problem.