In this path of loving, how can it possibly be That we see the world through You, and yet we don’t see You?
Rumi

What is the universe? The search for the answer to this fundamental question has been the starting point of philosophy and science. However, believers, mostly turn to religion for an ultimate answer. Most Muslim thinkers have considered the Divine Names as the primary things to be comprehended through which we can gain knowledge of the cosmos. And growing numbers of people have suggested that the universe is a hologram which makes us images of a higher reality. The first question that comes to mind is this: Can God’s manifestation, as explained in Sufi texts, promote to a holographic universe? The article, however, does not aim to answer this question, but rather to show that holographic model of the universe can feed our imaginations to perceive self-disclosure (tajalli) of God in everything. For this purpose, we will first concentrate on the main characteristics of a hologram, explore what is meant by a holographic universe, and then use these as metaphors to understand the cosmos in terms of God’s names.

What is a Hologram?

Holography is an imaging technique much like photography. However, in the case of holography, the image of the object is three-dimensional. The main instrument behind this dimensionality is the laser light. Let’s see how we can obtain a hologram, for example, of a flower. To achieve this, a beam of laser light is separated into two by a beam-splitter. One beam falls directly onto light-sensitive film. The other beam is reflected from the flower and then shines onto the same film. When these two beams overlap, they form an interference pattern on the film which is called a “hologram.” The pattern, which looks like the ripples formed by rain drops on a pond, can be seen once the film is developed. A three-dimensional image of the flower is produced as soon as the hologram is illuminated by another laser light. That is because the whole message of all the visual aspects of the flower is enfolded on the two-dimensional surface of the film. Actually, what happens is the revelation of the flower information, as recorded in the interference pattern. The startling feature is that if we cut the hologram in half and then illuminate one piece by a laser, we will still be able to produce the entire image. Even, if we keep cutting the film into smaller and smaller pieces, every single piece will still possess the whole information of the flower. Furthermore, we can see the different sides of the flower when we look at its image from different angles, giving us a convincing illusion of seeing a three-dimensional object.

The Holographic Universe

The idea that universe can be a hologram is brought forward by the fact that not only light waves, but also matter waves, can display the behavior of interference. A deeper level of interpretation for a holographic universe arose through the theoretical models that try to explain the coordinated action of the four fundamental forces in nature. These theories suggest 11 dimensions of space-time which actually appear four-dimensional on a human scale. This would, in a way, imply that the information of reality in eleven dimensions is projected onto the four-dimensional space-time substrate that we live in. However, it is with Gerard’t Hooft’s “Holographic Principle” that the holographic nature of all physical systems became apparent, for it explains how a three-dimensional physical system can be described by a theory based on a system’s two-dimensional surface area. Thus, the idea of a “holographic universe” was on stage once this principle had been applied to universe, the biggest physical system we know of. With the holographic model of universe comes the realization that each point in the universe contains the whole universe in itself: every grain of sand is connected to every planet in the cosmos, just as every subatomic particle comprises a web of interconnections by which it becomes intertwined with the human cell. David Bohm is one of the 20th century scientists known for recognizing this wholeness in nature. Bohm’s interpretation of the universe as a hologram came as an explanation to a 1982 experiment, performed by Alain Aspect and his team, which revealed how fast sub-atomic particles communicate with each other. Actually, the communication is found to be so fast, even faster than speed of light, as if particles “knew each others’ fates.” Bohm suggested that particles do not need any signal to communicate with each other simply because the separation between them is an illusion. The explicit separateness is a projection from a higher level of reality, that he calls Implicate Order, where everything is connected. The particle acts as if it knows the other particle’s fate because it has the other particle’s information within itself. Another scientist who saw the holography in action is neurophysiologist Karl Pribram. He was trying to find which specific locations in the brain are assigned to store our memories. His experiments revealed there is no such localization. Pribram claims that the pattern formed by the interference of electrical signals from each nerve cell in the brain is where, in fact, the memories are “stored.”

God’s Manifestation

Many Muslim thinkers, from Ghazzali to Ibn al Arabi, have presented God as Light, and all entities in the cosmos as the dim reflections of that Light. The Qur’an affirms this approach with its many verses, one of the best known being that “God is the light (nur) of the heavens and the earth” (24:35). However, since God has neither resemblance nor similarity to any of His creatures, this kind of description should not be considered as a likeness to the light we know of, but as a metaphor. The symbolism of light is used mainly to explain the relationship between God and creation. But first, one should know about Divine Names to understand this relationship.

In point of fact, in the Qur’an, the verses generally end with a mention of some of the Divine Names-The Life Giver, The Slayer, The Forgiver, The All-Provider, The All-Knowing, The Creator, etc. Actually, we name Him “Creator” after witnessing the effect of this name on creation. For example, we witness mercy on creation and so we call Him “The Merciful.” Everything from physical beings to the sciences manifests God’s names in some mode or another. All types of hearing originate from Him being “The All-Hearing.” “The All-Just” shines in the way the planets are placed in their orbits, while “The All-Provider” can be seen in how each and every animal is taken care of. Medicine reflects “The All-Healing,” while geometry reflects “The All-Shaping.” To explain God’s manifestation (zohur), Said Nursi once gave the example of the sun and its light in his Sixteenth Word: We can think the light from the sun as God’s light and its attributes as God’s attributes. For example, the heat of the white light can be thought as God’s Power, and brightness as God’s Knowledge. The moment the sun reflects, let’s say on a mirror, its heat and brightness are also there in addition to its image. In a similar manner, God manifests Himself in all beings with all His attributes. However there is ranking in this manifestation which depends upon the being’s abilities and quality. We can use the analogy of light to see how different qualities give rise to different manifestations. A flat mirror has the ability to produce the image of the object with its original size and shape, while mirrors in fun houses can cause distortions depending on the curvature. Actually, in Sufism, the fact that the Names are various and are being manifested to varying degrees is given as the reason for variety in the universe as well as in human beings. And thus, human beings, created with the most complex abilities, have the highest place in the ranking, while the heart, the subtlest faculty of a man is considered as the center of manifestation.

Taking the analogy of light further, and using the allegory of a hologram, we can better visualize the relationship between the creation and God and the idea of ranking in His manifestation. In our analogy, laser light represents God’s attributes, the hologram (film) represents four-dimensional space-time, and the interference pattern corresponds to interfering with God’s names. Therefore, everything in the cosmos can be viewed as a pattern of Divine Names enfolded throughout space and time. As a result, one can conclude that the

Divine Names are not so much ontological entities but simply the effect of such interference, like two lights overlapping. God’s attributes give birth to all existent things just as laser light interference gives birth to a hologram. This analogy is consistent with the Sufi texts that draw the distinction between God’s Names (asma) and Attributes (sifat). Imam Rabbani, a well known Islamic scholar, emphasizes this distinction in his Letters. Divine attributes (such as Existence, Having No Beginning, Eternal Permanence, Being Unlike the Created, Self-Subsistence, Life, Knowledge, Power, Speech, Will, Hearing, Seeing, and Creating) are the features that cannot be separated from God Himself (Dhat). But once God discloses Himself, the effects of the Attributes are manifested and we call these effects Divine Names. In a nutshell, this means, the Attributes are the sources of Names, just as the light is the source of interference.

Furthermore, with the analogy of space-time as a hologram, if we cut the space-time into an infinite number of pieces, the whole universe is present at every location. Mahmud Shabstari expresses perfectly such an interconnection and unity in all creation in his Gulshan-i Raz (The Mystic Rose Garden):

Know the world is a mirror from head to foot,

In every atom a hundred blazing suns.

If you cleave the heart of one drop of water,

A hundred pure oceans emerge from it.

If you examine closely each grain of sand,

A thousand Adams may be seen in it.

In its members a gnat is like an elephant;

In its qualities a drop of rain is like the Nile.

The heart of a barley-corn equals a hundred harvests,

A world dwells in the heart of a millet seed.

In the wing of a gnat is the ocean of the life,

In the pupil of the eye a heaven;

What though the grain of the heart be small,

It is a station for the Lord of both worlds to dwell therein. (Translated by E. H. Whinfield)

This way of looking at everything may lead a believer to embrace the doctrine of wahdat-al wujud, the interpretation of oneness of existence. This results in the denial of the existence of the universe and because of the belief that the only thing that exists is God. One remark necessary at this point is that this might sound a lot like pantheism. However, a critical distinction is that in pantheism, what is denied is God, not the universe. Actually, many people, in trying to integrate the perspective of holographic universe with Sufism, adopt the Sufi belief “hama ost,” meaning “All is He,” another name for wahdat-al wujud. But the holographic metaphor, as presented above, may better serve in our attempt to understand God’s Unity (tawhid) without denying the universe. Thinking all beings as an interference of God’s names is consistent with the faith that every entity is a Divine location. However, note that we drew the distinction between Divine Names and Divine Attributes. Every being is kept in existence through God’s names. Things exist not because God abides in them with his infinite Being. In other words, and most importantly, it is not that God Himself is everywhere in the cosmos, but rather that His Names are present at every point. He does not dwell in cosmos, but is, instead, the source of cosmos. He is eternal-while cosmos ceases to exist once its connection to Him is cut. This standpoint is referred in Sufism as “hama az ost,” meaning “All is from Him.” In this view, the existence of universe is not denied but its level of existence can be questioned. If the true existence is defined as God’s Absolute existence, the universe does not have a true existence but is still in a mode of existence which is temporal and contingent. This existential challenge is explained by Islamic thinkers through the example of a shadow. The relationship of creation to the Creator is like that between a shadow and the actual shape. Thus, the likeness witnessed in a shadow and a hologram is such that we can conceptualize God’s manifestation-but He is not limited by these dimensions.

In fact, the similitude of hologram can also help us to conceive the spiritual unveiling. Interference patterns originating from different objects can be recorded on the same film by projecting the laser beams at different and varying angles. In such a case, depending on the direction and frequency of the beam that you send through the film, a different three-dimensional image will appear. Two points to emphasize are that the use of laser light is necessary to see the higher dimensionality, and that one can see different realities. In a similar fashion, in a spiritual journey, a traveler needs to have radiance from God’s light to be able to witness further dimensions. With the light of God, spiritual unveiling occurs and a Sufi may see different instances of a reality depending upon His station, which Divine name He is reflecting on or reciting, etc. Thus, the complex information that every element in the universe can reveal about every other entity depends on the fact that God’s names denote each other. We can further use the notion of interference to delineate the concept of ranking in God’s manifestation. In an interference pattern, not all points have the same brightness. The degree of brightness depends on the location and the way the two lights overlap. There are even points where no light can be observed. This, however, does not mean there is no light there; it simply cannot be seen due to destructive interference. Extrapolating this into God’s manifestation, every entity is a Divine location, even if it cannot manifest Him.

To end this train of thought, we should find an answer to a mysterious question. If everything in four-dimensional space-time comes into existence once a higher reality is projected on the void of darkness by God’s Light, what, then, is that higher multidimensional reality? It is a reality which can only be witnessed by those who see behind the appearance of things-by those who free themselves from the material world and carnal desires. It is, perhaps, the Preserved Tablet (Lawh al-Mahfuz) mentioned in chapter, The Constellations (Buruj). Ultimately, this is a question that can only be answered by those who have purified their hearts and can see beyond.

Defining the target

Gravitational waves are generated only by the equivalent of a rotating or oscillating system — that is, two or more masses accelerating toward or away from each other and exhibiting a quadrupole moment of inertia.

Only such quadrupole and higher multipole sources can generate gravitational waves because, whereas there are negative electric charges, there are no negative masses. A negative electric charge oscillating back and forth is the equivalent of a positive charge moving in the opposite direction, and this equivalence enhances the generation of electromagnetic waves. Since there is just one gravitational polarity, however, a mass can oscillate only with respect to a counterweight. This counterweight reacts to the oscillation and generates a gravitational disturbance that almost, but not quite, cancels the disturbance of the body.

As explained by physicist Paul Davies of Australia’s University of Adelaide, the gravitational disturbances would completely cancel out but for the time required for them to travel between the masses. It is this out-of-phase imbalance in the disturbance’s cancellation that propagates a gravitational wave. For this reason, such waves are not generated by quiescent stars, those rotating on their axis symmetrically or even exploding symmetrically, because there is no quadrupole moment. However, that situation changes if they explode asymmetrically or change their shape.

On the other hand, a typical binary star system has a quadrupole moment and should produce a slow periodic gravitational wave. A near-enough binary star system would cause a measurable distortion a little in excess of one part in 1021 on Earth.

For the wave to lie in the gravitational-wave detector’s frequency range (typically 1000 +/-1 Hz.), though, the two stars of the binary must be in the final stage of coalescing, a rare situation. For comparison, a supernova is expected to produce damped exponential impulse waveforms, each of which lasts for 1 millisecond. A collision or collapse of a binary system between two neutron stars, or between a neutron star and a black hole, would produce gravitational waves with a sliding frequency in the 1 to 1000 Hz range, as one star spirals in on its partner.

Why are we searching?

A long time ago, in the Large Magellanic Cloud-one of our Milky Way’s two companion galaxies, a star exploded. In 1987, 160,000 years later, radiation from that event finally reached Earth. The first to see the brightening star were astronomers in the southern hemisphere.

Scarcely 24 hours earlier, in other parts of the world, other types of detectors had “seen” something. At the University of Rome (Italy) and the University of Maryland at College Park (the U.S.), gravitational-wave detectors registered 12 fairly large and about 100 small pulses over a period of 2 hours. Around the same time, the Mont Blanc Neutrino Observatory (France) registered five pulses of neutrinos over a 7-second interval. Similar recordings were made by neutrino detectors in Kamioka, Japan, and Frejus, France.

Astrophysicists are still debating the significance of those observations recorded on Feb. 23 and 24. But others claim the pulses registered in Rome and Maryland may have been due to actual gravitational radiation from an identifiable source — the supernova of 1987.

Physicists find this ambiguity unsatisfactory. They want to detect the gravitational waves themselves, directly and unequivocally. Indeed, the detection of waves has been called “the most important of all tests” of Einstein’s general theory of relativity by theoretician Kip S. Thorne of the California Institute of Technology (CalTech) in Pasadena. The sensing or reception of gravitational waves also may deepen astronomers’ understanding of the dynamics of such violent events as supernovas, exploding black holes, and the interactions between black holes and neutron stars. As a bonus, whatever is learned about detecting ultra-weak signals might help engineers measuring extraordinarily small displacements or strains.

The understanding, according to Einstein’s general theory of relativity, is that all objects exist in four-dimensional space-time (that is, in a continuum having three dimensions of space and one of time). The mass of every object curves space-time, a curvature that manifests itself as the gravitational field of the mass. The greater the mass, the greater the curvature of space-time, and the greater the gravitational field.

According to the same theory, massive objects that rotate or explode asymmetrically, or oscillate, give off gravitational waves or ripples that propagate through space-time, like ripples or waves on the surface of the ocean.

Gravitational waves conform to an inverse square law relationship, just like electromagnetic waves. The force of both types of energy declines in proportion to the square of their distance from their source. But gravitational waves are so much weaker than the Coulomb electric force, which renders the detection of such weak waves a monumental challenge to instrumentation.

The evidence that gravitational waves exist is compelling, albeit indirect. The firmest evidence relies on observations made over 7 years by astronomers Joseph Taylor, of Princeton University in New Jersey, and Russell Hulse, then at the University of Massachusetts at Amherst but now also at Princeton. Their measurements of radio waves from a binary pulsar designated PSR1913+16 show that the pulsar’s 8-hour orbit around the neutron star is gradually contracting; the faster the pulsar revolves around the neutron star, the smaller its orbit gets. As the rate of decrease agrees to within 0.5 percent with predictions derived from the general theory of relativity, the finding is excellent circumstantial evidence for orbital decay being a result of energy lost by gravitational radiation. Even though the gravitational radiation itself was not detected, Taylor and Hulse shared the 1993 Nobel Prize in Physics for this work.

But what would it take to observe the weak gravitational radiation directly? Gravitational waves are generally believed to travel at the speed of light and to deform or distort an object geometrically as they pass through it. For plane-polarized gravitational waves, the two directions are at 45 degrees to each other, not perpendicular as they are for light. In other words, a passing gravitational wave distorts an object first in one direction, then (in the next half-cycle) in another, rotated at a 45-degree angle to the initial direction. It takes another half gravitational wave cycle for the wave to distort at the 90-degree angle characteristic of electro-magnetic waves in the first half-cycle.

Resonant bar detector

In principle, it should be possible to sense this distortion and its after-effects with the aid of strain detectors attached to a suitable “antenna” — a space-time seismometer, if you will. But such an antenna resembles nothing familiar to electrical engineers. In its simplest manifestation, the antenna is a large solid cylindrical bar.

The pioneering resonant-bar detector was designed in the late 1950s and built in the early 1960s by Joseph Weber, professor of physics at the University of Maryland. Weber’s design called for a mechanically isolated cylinder of solid aluminum weighing several metric tons. Piezoelectric strain transducers attached at intervals around its circumference converted the vibrations induced by any passing gravitational wave into an electric signal. Weber’s bar resonated mechanically around 1 kHz, so that it would “ring” after being distorted by an incoming damped-exponential wave, the shape expected of a gravitational wave from a supernova. Subsequently, other bar detectors were built at many institutions around the world.

The main problem with resonant-bar antennas is their insensitivity. Even the latest of them yield dimensionless strain sensitivities of about one part in 1018 (that is, only 10-18 meter distortion per meter of length), too little to detect gravitational waves from any but the nearest and most violent events.

The laser alternative

The laser interferometer owes its sensitivity in detecting gravitational waves to an arrangement of mirrors suspended on vibration-isolated pendulums. Two pairs of mirrors create two light paths perpendicular to one another. A laser beam is split and the halves sent down each path, rebounding back and forth along the leg between the mirrors hundreds of times before being recombined. The multiple passes create the very long light path required to amplify the gravitational-wave input to detectable amplitude.

In brief, if a gravitational wave passes by, the pendulums holding the mirrors are expected to move a little apart in one leg and a little together in the other leg, in each case by the same tiny fraction of the laser light wavelength. Their movement would shift the relative phase of the two halves of the laser beam, momentarily upsetting the interference patterns that would otherwise be cancelled out. At that instant, the interference pattern would brighten by an amount proportional to the strength of the gravitational wave. The job of monitoring the interference pattern for brightening is handled by electro-optic detectors, which indicate when a passing gravitational wave is detected and which recover its variation over time.

Not only are laser-interferometer detectors potentially more sensitive than resonant-bar antennas, they are also better at detecting a variety of sources because they are inherently broadband. They respond to gravitational waves having a frequency from 10 Hz to 10 kHz, versus the resonant-bar antennas’ 1-Hz bandwidth at 1 kHz.

Input from space

A third and truly exotic method of detecting gravitational waves has been proposed: monitoring the Doppler shift of the carrier frequency (or rather, the retransmission of the tracking station’s frequency) from two or more interplanetary spacecraft simultaneously. This project is known as LISA (The Laser Interferometry Space Antenna).

The technique is analogous to laser interferometry. The idea is to detect the Doppler shift in a spacecraft’s microwave frequency as the craft is jostled by a passing gravitational wave — that is, as space-time is warped in its vicinity.

Inevitably, there are obstacles to overcome. Since the effects of a passing gravitational wave are so small, the reference oscillator must be extremely stable to detect any Doppler shift. Observers must also consider variations in the pressure of the solar wind (which differs from time to time and with the changing distance of the spacecraft from Earth), in forces from the attitude control thrusters (used to occasionally correct the space-craft’s orientation), and in the refraction of Earth’s atmosphere (through which the signal must travel). Subtracting all of these variations, the interplanetary detector is expected to have a theoretical sensitivity of about one part in 1016 — corresponding to a displacement of about 0.065 mm over the shortest distance from Earth to Jupiter, and one-eighth of that over the shortest distance from Earth to Mars.

The noise problem

Noise degrades the sensitivity of any gravitational-wave receiver. The interference is mostly due to seismic activity in the earth, acoustic interference (also known as microphonics) from inhabited surroundings, and heat (thermal noise). Especially troublesome are the non-Gaussian tails of noise distribution, which produce a significant number of false detections.

When a gravitational wave passes through the cylinder and distorts its shape, the moving input coil produces minute changes in the magnetic flux. That magnetic flux change then creates a relatively large variation in the voltage across the SQUID** junctions. In turn, these variations are passed along as voltage signals to succeeding stages of amplification — generally room-temperature FET amplifiers with optimal filtering for the anticipated signals. If tuned mechanical transformers or resonators are installed between the antenna and the transducer, transfer of the gravitational wave’s pulse is maximized and amplifier noise coupling is minimized.

Conclusion

Much is being done to achieve a breakthrough in the detection of gravitational waves. A recent High Frequency Gravitational Wave conference held at MITRE Corporation featured proposals and experiment descriptions that could lead to an apparatus that uses gravitational waves for communications. Several large laser interferometer gravitational wave observatories are online and taking data while making sensitivity improvements. The reader is urged to delve further (see references below) to see why there is so much excitement about this new window on the universe.

References

– Gibbs, W. W. “Ripples in Spacetime.” Scientific American, April 2002.

– Lewis, M. “Gravitational Waves versus Electromagnetic Wave Antennas.” IEEE Antennas and Propagation Magazine 37, no. 3, June 1995. Also see http://solo3.abac.com/gwinstitute/.

– Blair, D. The Detection of Gravitational Waves. Cambridge Univ.: 1991.

– Boughn, Stephen. “Detecting Gravitational Waves,” American Scientist, no. 68. March-April 1980, 174-83. (An overview of the early work in the search for gravitational waves.)

– Will, Clifford M. Was Einstein Right? New York: Basic Books, 1986. (A readable account of the binary pulsar PSR1913+16 and its role in providing evidence for gravitational waves.)

– Blair, David G., ed. The Detection of Gravitational Radiation. England and New York: Cambridge Univ. Press, 1991. (Sums up the state of the art in gravitational-wave receivers.)

– Misner, Charles, Kip S. Thorne, and John Wheeler. Gravitation. W. H. Freeman: 1973. (Still the most used book by students and practitioners in gravitational-wave research.)

– Thorne, Kip S. Black Holes and Time Warps: Einstein’s Outrageous Legacy. New York: W. W. Norton, 1994. See chapter 10: “The Ripples of Curvature,” which summarizes plans for the Laser Interferometry Gravitational-Wave Observatory (LIGO).

– E. Amaldi et al. “Coincidences among the Maryland and Rome Gravitational Wave Detector Data and the Mont Blanc and Kamioka Neutrino Detector in the Period of SN1987A.” Annals of the New York Academy of Sciences, vol. 571, 1990, 561-76. (Proceedings of the l4th Texas Symposium of Relativistic Astrophysics). (Discusses whether or not gravitational waves were detected along with the first sightings of the 1987 supernova).

– Grishchuk, Leonid. “Update on Gravitational Wave Research. Online at Los Alamos’ website on preprints gr-qc/0305051, 13 May 2003. (Provides a more technical treatment.)

** A superconducting quantum interference device (SQUID) is a mechanism used to measure extremely weak signals, such as subtle changes in the human body’s electromagnetic energy field.