“It’s my fault, all my fault; I should’ve tried harder,” he said. A quintessential characteristic of his – always pinning the blame on no one other than himself.

They were closing us down; there was no more hope.

He had returned hopeful after the bidding: his paperwork had been in order, and he’d been at it for weeks, day and night. In fact, he hadn’t slept much since the great wave had hit them on the 16th of July. I recall seeing his worried sleepless face on the morning of the 17^th; he hadn’t slept a wink. He’d been up all night making “namaz” (prayers) for his country. He’d been confused by the events. The slowly emerging, dizzying “facts” confounded him.

The wave had been the talk of the staffroom in the days to follow. Some said that their country had just been making good progress and now everything, who knows maybe 10 or 15 years of building, had been lost, all in a single night. Teachers, first by the hundreds and then by the thousands, had been sacked, and their licenses revoked. I was shown a picture of a teacher with an angelic appearance who had been put to death because he had allegedly been involved in terrorism. The morale dropped with each passing day and the friendly smiles and warm greetings turned into frowns and drooping shoulders. I woke up each morning with a sense of angst and prayed for peace, justice, and truth to prevail in my colleagues’ country. The realization started setting in that they wouldn’t be able to return home that year. Their children would not be able to see their grandparents the next holiday. And with the school being shut down, they had no idea where to go. They told me that it’s become too dangerous to contact their families; people are being detained by the thousands. Some told me that their parents believed the news and not their own accounts of what had happened; a certain blindness had descended upon their countryfolk.

My colleagues are deeply patriotic. There were Turkish flags and laminated Turkish words labeling things and framed pictures of the Hagia Sophia and Istanbul on the walls of the school.

Talk about the failed coup eventually ceased in the staffroom and my colleagues refused to be dispirited further by it. Weeks went by and everyone kicked into survival mode. CV’s were being updated, job applications were being sent out in a frenzy, reference letters were being written, and my friends had nowhere to go. They were stranded or worse, they’d become alleged “terrorists.” My friends: terrorists? Ludicrous!

I’ve known them for over five years and the only allegation I could make against them is that they work too hard! Most work seven days a week. Our staffroom was open 24 hours and I’d often see them working in there as late as 11 at night. They had once compelled me to redo a video promo I’d made about the school just to insert a clip of the Prime Minister at the time, Erdoğan, and his wife who had attended a Turkish Olympiad (Türkçe Olimpiyatları) where Ghanaians had performed a traditional Turkish dance. Both Erdoğan and his wife were deeply touched. I’m not sure if I had gotten my facts straight… so he, Erdoğan, was blaming my colleagues of plotting against him? The reasoning behind this had confounded myself and my colleagues alike.

They’ve travelled land and sea to make other nations pro-Turkish and pro-Turkey. Never had I picked up on an ounce of resentment against Turkey from my devoted colleagues.

And when my colleague had exerted his final efforts and realized that the fight to keep the school open had been lost, he sighed and said: “It’s my fault, all my fault; I should’ve tried harder.” My heart broke upon hearing these words uttered by a man who teaches his students on weekends and until eleven o’clock at night to help prepare them for their exam the next day. My heart was shattered when I heard those words from the man who had learned to push on with his teaching responsibilities despite an onslaught of dengue fever, his shirt completely soaked and his eyes deeply sunken.  “You should rest Abi,” I said to him. “I will rest in the hereafter,” he stoically replied.

My heart was crushed when he still blamed himself when powers beyond his control had worked against him, the man who had once removed the tie from his neck and wrapped it up neatly and made it a gift to me following my comment about its beauty. How can my heart go on if the man – who took me to his unfurnished house, save for a mattress on the floor, to give me his own mattress when mine was infested with bed bugs – is labelled a “terrorist”? Tell me, how should I respond? What should I do to convince people that none of this is his fault, that he’s a man of peace, a teacher by trade and nothing more, that he’s nothing less than a saint? Tell me, what should I do?

Gravitational waves can be defined as the vibration of space-time. Sky is an ocean in which the waves are stationary.

When you throw a rock into the water, when a taut rope is plucked, when a spring is compressed and then released, or when our larynx vibrates, what forms is a wave. In each case, the medium where the wave forms is different: water, air, etc. Interestingly, light waves do not need a medium to travel.  A common feature of all kinds of waves is that they have wavelengths, frequencies and amplitudes. Another important feature they have is that there needs to be a source that triggers the wave. A spring, for example, needs to be compressed to produce the wave.

Gravitational waves, on the other hand, can be defined as the vibration of space-time. These waves were predicted by Einstein in 1916 in relation to the general theory of relativity. Let us consider that all interstellar and intergalactic space is filled up with a substance similar to water. Then when, say, two black holes collide, space itself ripples like water. In fact, discussions have long continued over the existence of ether, a substance that forms the texture and essence of matter. If there are waves in space, then it is highly likely that there is ether that fills up space as well.

In a very interesting narration, the Prophet Muhammad, peace be upon him, is reported to have suggested that heavens are not a vacuum: “The sky is a wave held back” (Tirmidhi, Tafsir surah, 57/1). Bediuzzaman Said Nursi, in his interpretation of this hadith, says, “[Sky] is an ocean in which the waves are stationary” (The Gleams, Twelfth Gleam); in other words, heavens are a sea whose waves have settled, calmed and become still. The Qur’anic verse 36:40 reads “It is not for the sun to overtake the moon, nor does the night outstrip the day. All (the celestial bodies and systems) float (swim) in an orbit (determined for each).” We can infer from this verse that space is likened to a sea because floating or swimming can occur in a substance but not in a vacuum.

The discovery of gravitational waves

Gravitational waves were discovered by a team of experimental physicists on February 11, 2016, that is, exactly one hundred years after they were predicted by Einstein in 1916, and the discovery earned three physicists, Rainer Weiss, Barry C. Barish, Kip S. Thorne, the Nobel Prize in 2017. The LIGO observatory (www.ligo.caltech.edu/page/what-are-gw) used an extremely sensitive interferometer to detect the gravitational waves produced by the collision of two black holes, one having 29 times the mass of the sun and the other 36, 1.3 billion years ago. The researchers used such a precise mechanism that it (the interferometer) could measure the distance to the nearest star to an accuracy smaller than the width of a human hair.

The LIGO observatory used an extremely sensitive interferometer to detect the gravitational waves produced by the collision of two black holes, one having 29 times the mass of the sun and the other 36, 1.3 billion years ago.

The working principle of an interferometer is based on the idea of splitting a laser beam from a single source into two components and then recombining them. The split beams get to the target at the same time after diverging at a right angle and being reflected back from two mirrors. Scientifically speaking, there is not any phase difference between the two. However, if the beams are subject to an effect like gravitational waves, the waves cannot get to the target at the same time, or in scientific terms, an interference pattern is formed on the screen because of the phase difference. In the same way, the waves generated by the collision of two black holes had an impact on the movements of the perpendicular laser beams as they ran past the area that housed the interferometer built by the LIGO team and caused a time difference in their arrival at the detector. In this experiment, the effect of the gravitational waves was measured by directing laser lights through L-shaped vacuum tunnels four kilometers long. The length of the tunnels was so precisely adjusted as to measure a difference, if any, as small as a proton.

The reason why the laser interferometer was so finely tuned is that the waves generated by two colliding black holes are so infinitesimally weak that only such an experimental mechanism could capture them. In other words, the experiment had to be precise beyond the atomic scale because the gravitational waves that reached the solar system could change the distance between the sun and the earth by just the size of an atom. To reiterate, the mechanism was designed so precisely that it can detect differences between laser beams as short as ten-thousandths the size of a proton. It should be remembered that a proton is a very, very small particle in the nucleus of an atom with a diameter of 10^-15 (one-million millionth) of a millimeter.

Furthermore, the gravitational waves were discovered simultaneously by two separate interferometers, which were located at a distance of 3220 km from each other. The reason for the dual measurement tools was to ensure that the waves were indeed gravitational waves.

What has excited scientists most about the discovery of gravitational waves, besides their confirmation of Einstein’s theory, is the fact that we will be able to exploit gravitational waves in addition to light and radio waves in order to explore space. It can be foreseen that telescopes working with gravitational waves can be developed or advanced laser interferometers can be built in space and discover other gravitational waves.

Gravitational waves are generated in space all the time. Large-scale phenomena such as the collision of two black holes or the explosion of supernovae cause ripples in the sea of space. It is highly likely that systems that can detect these waves will provide us with new information about the fabric of space and thus lead to new discoveries.

The fact that gravitational waves were discovered using technological tools is an excellent example of how technology can nurture science. Moreover, this study proves that some discoveries can only be made by big teams like those in the CERN experiments.

It is postulated that the universe rippled violently during the first creation as a result of the tremendous expansion, the effects of which might still exist and should warrant new studies. It is only a matter of time that a super-sensitive mechanism could confirm the Big Bang theory. It is believed that the gravitational waves generated at the very beginning of this expansion are still present and experimental designs such as that in the LIGO are likely to discover them. The Qur’anic verse 51: 47 is considered to be referring to this expansion: “And the heaven, We have constructed it mightily; and it is surely We Who have vast power, and keep expanding it.”

It is almost certain that technological progress will lead to new discoveries that will provide us with deeper insights into the incredible composition of the universe. Bediuzzaman describes the universe as “a rosebud, wrapped in thousands a variety of veils of unity” (The Rays, Second Ray, Third Station). Every new discovery is going to show us the magnificent secrets of this rosebud.

In our times, the Big Bang Theory is generally accepted to be the starting point of the universe. When the Big Bang happened, the universe and light were simultaneously created. The universe came into being at elevated temperatures from a single particle.

For the events that happened after the Big Bang, the most recent and accepted theory is the Inflation Theory. According to this theory, right after the Big Bang, the universe started inflating at an incredible rate, quantum fluctuations were scattered throughout the universe, and a homogenous inflation happened which allowed galaxies to be formed. Light was created at this period for the very first time.

What is “light” and what is the wisdom behind it?

Ibn Sina was the first scientist stating is was possible to measure the speed of light. And Newton used the marble example to explain the phenomenon of light containing colors of different wavelengths. Modern theories state that light is composed of weightless and charge-less particles called photons. Light is now known to be electromagnetic waves that carry energy as well as having the characteristics of refraction and reflection. A major discovery occurred in 1975, when the Danish scientist Ole Romer was observing the satellites of Jupiter. During this study, he was able to prove that the particle model proved to be insufficient, as was seen from the diffraction of light (changing its direction after having passed a narrow slit)..

Although the wave model is more dominantly talked about in modern times, it is known that both models are true.

Femto photography

Various experiments have been done to understand the properties of light. One of these experiments was a photography technique applied by Dr. Edgerton, in 1964. In this photo, the image of the apple right after the bullet passed through it was captured. This famous photograph, which was captured in a millionth of a second, inspired Prof. Ramesh Raskar from MIT (USA) to take a photo of light in order to see it by naked eye. Raskar developed a camera that can take up to a trillion frames per second. This would make it possible to visualize the human body without using X-ray. The wave like property of light was studied by this new technology called Femto Photography.

Light is the fastest substance in the universe. As long as it does not change its environment, the movement of light is linear because of its electromagnetic wave properties. If it passes to a different but transparent environment, it continues its movement. If it passes to an environment where the refractive index is larger than its original environment, it comes closer to the line accepted to be vertical to the surface (normal) and vice versa.

The speed of light and all electromagnetic waves in an empty, airless environment is 299,792,458 m/s (300 thousands kilometers). With this incredible speed, the Earth could be toured 7 times a second. The letter c represents this speed in science, and it’s based on the Latin name for speed: celeritas. While passing through any object (air, water, glass etc.) the speed of light is smaller than c.

If a laser pointer is activated for a thousandth of a second (a couple of femto seconds), a photon cluster is formed which is approximately 1 mm in width. This cluster of photons has a speed millions of times greater than the bullet passing through the apple.

What if the femto photo of a cluster of photons that were sent from the bottom of a glass bottle full of water was taken? How would the light appear in slow motion? Although this short journey of light takes place in less than a nano-second, it is possible to capture how it moves in slow motion by reducing the speed ten billion times with the femto camera. With this femto camera, it is possible to measure the average speed of light in a tomato and gain knowledge about its interior texture and quality without touching it. When a bunch of photons are sent to the surface of a sample, a three dimensional picture of it can be constructed by the high resolution detection of the photons that are reflected at different times from the sample.

With the science of light, technology for transportation that does not require a driver can be developed, creatures can be saved from natural disasters by the reflection of light on windows, and many new age surgery technologies can be developed.

In order for the eye to see, light needs to exist. One of the latest and most astonishing pieces of research done about light is the femto photography technology. By this technology, it will be possible to visualize the human body without the use of X-ray. If there was a femto camera incorporated in our cell phones, we would be able to understand the quality of the tomatoes we were buying when we went to the grocery store without having to touch them. By harnessing the great gift of light, we can make the great gift of life even better.

South-east Asia was hit by such a giant wave just before the New Year. A calamity that was fatal; an earthquake followed by a tsunami that abated only after leaving behind a death toll of 300,000. Like all past calamities, this tsunami also brought to doubting minds suspicions that lead to a denial of the existence of All-Merciful God. “A Nursi Reader” provides insights for us on how to approach disasters and events that are apparently “evil,” basing the argument on a critical question: is the creation of evil evil?

Perhaps in a disaster in which people can do nothing but surrender to their imminent destiny; but at other troubled times there is only one bosom upon which we can rest our heads-that of our mother. A man came to Prophet Muhammad, peace and blessings be upon him, and said, “O the Messenger of God! Who is more entitled to be treated with the best companionship by me?” The Prophet said, “Your mother.” The man said. “Who is next?” The Prophet said, “Your mother.” The man further said, “Who is next?” The Prophet said, “Your mother.” The man asked for the fourth time, “Who is next?” The Prophet said, “Your father.”

In another tradition the Prophet is reported to have said, “God has forbidden you to be undutiful to your mothers, to withhold (what you should give) or demand (what you do not deserve), and to bury your daughters alive. And God has disliked that you talk too much about others, ask too many questions (in religion), or waste your property.” As clearly seen in the tradition the Prophet lists improper manners to our mothers along with such atrocities as “burying daughters alive.” The lead article in this issue is a reference for us to frequently turn to in order to appreciate and re-appreciate the value of our mothers.

Full of mysteries, joys, and sorrows, life for humanity starts in the wombs of our mothers (this alone should suffice for the lifetime of thanks that we need to offer to them). But when exactly does life start for a yet unborn baby? Olgun Hasgul presents a comprehensive embryological study, guided by Qur’anic teaching in “Ensoulment: When Does Human Life Begin?”

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.

In today’s cellular communication systems, cellular phones operate in several frequency bands. European systems use the Global System for Mobile Communications (GSM) at around 900 MHz and 1800 MHz; American systems use 850 MHz and 1900 MHz, frequencies that fall between the operating frequency ranges of televisions and microwaves. This frequency range is called non-ionizing, for the wave’s energy does not release electrons from atoms in living tissue. For instance, an X-ray is an ionizing wave that, to a degree, damages exposed biological material. Therefore, most concerns deal with RF energy’s heating effect rather than with ionization.

Technical Motivation

The electromagnetic spectrum extends from DC (direct current) to ionizing radiation. Scientists divide this spectrum into subregions. Cellular phones fall into the ultra-high frequency (UHF) regime, specifically from 300 MHz to 3000 MHz. By itself, a continuous UHF wave carries no information and does not enhance communication. It only becomes useful when modulation, defined as means carrying the information on a high frequency carrier, like UHF, is applied. The most common modulation techniques are amplitude modulation (AM) and frequency modulation (FM).

The capacity of the spectrum’s given section to carry information is limited by the Shannon Theorem. According to this theorem, channel capacity can be increased by increasing the system’s signal-to-noise ratio. In wired communications, channel capacity can be increased by adding more parallel optical fibers. Channel capacity in wireless communications can be increased by transmitting weak signals that attenuate rapidly near the transmitter and thus provide a given portion of the electromagnetic spectrum to be utilized many times. How a given spectrum is allocated among users affects the channel capacity. Therefore, there are several coding techniques, the most common of which are Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), and Code Division Multiple Access (CDMA).

Neglecting some small details, an electromagnetic (EM) wave’s energy is expressed in terms of power density (W/m2) across a surface. Power density measures an incident EM wave’s strength. Easily measured, it is a very preferable metric to UHF fields. For uncontrolled environments, the American National Standards Institute and the Institute of Electrical and Electronics Engineers (ANSI/IEEE C95.1) recommend a 2 to 20 W/m2 for an average external exposure to UHF. The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has similar power density recommendations for limiting the general public’s exposure to RF energy so that people will not be overheated by RF energy. As a comparison, for example, summer sunshine peaks around 1000 W/m2.

However, as power density is not a good indicator inside a living organism, scientists have defined a Specific Absorption Rate: SAR (in W/kg). For uncontrolled environments, ANSI/IEEE limits the spatial-average SAR to 0.08 W/kg whole body and to 1.6 W/kg averaged over any 1 gram of tissue. Also, 1998 ICNIRP restrictions are similar to ANSI/IEEE’s. The SAR can be estimated in three ways.

– Micro-antenna: Small antennas can determine a tissue’s electric field as well as its SAR. But it is difficult to place the antenna, and the tissue’s properties may not be known.

– Miniature thermal probes: Since RF energy heats the tissue, this technique detects the heat and the SAR in the neighborhood of the temperature cell, which then can be computed accordingly. However, this method also seems very difficult technologically.

– Numerical modeling: The numerical modeling of macroscopic bodies enables a numerical simulation, known as the Finite Difference Time Domain (FDTD), that can estimate the SAR. However, this process can be time-consuming and expensive.

Possible Health Issues

An EM wave can effect a biological change in living tissue in two ways: Depositing enough energy while passing through the biological material to alter some structures, or depositing packets of energy larger than the bond energy. Yet neither way seems to be possible, for the photon energy within the UHF zone is far less than the bond energy or the energy required to alter a living tissue’s structures. Therefore, many scientists now argue that UHF radiation at subthermal power levels can cause some biological damage.

Due to relatively low exposure levels, relatively small populations, and a lack of reliable dose estimates, proving or disproving the existence of RF exposure’s biological hazards remains an issue for epidemiology (e.g., statistical analysis of health records and animal studies).

Epidemiological Studies

Epidemiological studies were conducted among people who worked in a high frequency environment, such as radar stations. Search criteria were not limited to cellular and personnel communication system (PCS) frequencies. Due to the nature of radar and other military equipment, broader frequency ranges were covered. The epidemiology of cancer and RF radiation includes studies of cancer mortality rates among those exposed to RF energy.

Throughout these studies, people’s records were searched to determine if their cancer was due to RF exposure. These studies were made in various institutions, including the Radar Laboratory of the Massachusetts Institute of Technology, the U.S. Navy and Air Force, and the Polish military. There was no conclusive evidence that RF exposure increases the risk of cancer. Also, due to the lack of comparisons with total cancer, it was suggested that RF exposure does not have a strong effect on cancer.

Since brain cancer takes a long time to develop and epidemiological studies tell nothing about future risks, these studies have not proved or disproved that RF exposure increases the risk of cancer.

Animal Studies

Animals are the other source of information that potentially may answer people’s concerns. Experiments have studied rats exposed to certain power levels of RF energy. However, these studies found no link between cell phones and cancer.

In 1999, a Motorola-funded research program concluded that exposing rats to pulse-modulated 837 MHz RF energy, very close to that radiated by a digital cell phone, does not cause or develop brain cancer. A study in April 2000 reported that this conclusion is valid for continuous-wave RF (analog cell phones). But a 1995 study at the University of Washington (Seattle) reported that exposing rats to RF radiation at an average whole-body exposure of 1 W/kg of body weight caused breaks in their brain cells’ DNA, which is an indication of cancer. No other study has confirmed this finding.

Other studies have focused on different aspects of RF radiation rather than brain cancer. They searched animals for certain diseases and noticed an increase in disease rate. However, despite such research findings, animal studies seem to be far removed from human health.

Conclusion

Epidemiological findings and animal studies have neither proved nor disproved the health hazards of mobile phones. A February 2000 essay by the U.S. Food and Drug Administration (FDA) stated that: There is currently insufficient scientific basis for concluding either that wireless communication technologies are safe or that they pose a health risk to millions of users. Research activity continues. For example, France’s International Agency for Research on Cancer has received a research project of 8 million euros from the European Commission for a 3-year, wide epidemiological study. Also, the FDA and the Cellular Telephone Industry Association have undertaken a $1 million research project to clarify the health risks of mobile phones.

Meanwhile, some researchers are trying to find the head’s SAR by using electromagnetic simulations (FDTD). So far, they have discovered that it is strongly affected by the cell phone’s position as well as the head’s shape and properties. Therefore phone-makers are trying to design handset designs to reduce the SAR. However, it seems that the debate will remain until scientific proof is confirmed and made available.

• References
• http://www.fda.gov/cdrh/ocd/mobilphone.html.
• IEEE Spectrum. Are Mobile Phones Safe? (August 2000): 23-28.
• Moulder et. al. Cell Phones and Cancer: What is the Evidence for a Connection? Radiation Research Society, 151 (1999): 513-31.

These words attempt to pierce the veil of habit that develops in our minds from not looking into the reason for things. The perfection of the order operative in the universe is of such a degree that it prevents us from being aware of it. In the same way, we only become aware of the faultless operation of the watches we have worn on our wrists for years when they stop working.

In the world-view developed upon the foundation of Newton’s laws of motion, the universe was likened to a flawlessly operating watch. Events were tied to one another in a cause-effect relationship and our knowing the laws of this relationship allowed us to predict events with great accuracy. It was possible to determine with mathematical exactness a wide range of phenomena, from the times of eclipses of sun and moon to the amount of fuel and the speed needed to put an object into orbit around the earth. The success of these ‘natural laws’ led many people to believe that they completely expressed and ‘ruled’ the whole order of the universe.

Because God creates and sustains all things and events from behind the veil of universal general laws, because certain events (causes) are followed reliably by similar events (effects) each time they (the causes) occur, it begins to be supposed that the causes are responsible for or ‘create’ the effects. This is, of course, a gross error, as no number of causes suffices to create even a little effect; for every event even the tiniest, the whole universe must be presupposed first, including the laws operative within it. Moment by moment, all things and all events are created and sustained by God, Who wills from an infinite range of alternative possibilities a particular actuality.

The clockwork model of the universe derived from Newtonian or classical physics is not a complete account of the phenomena which we observe in the universe. Already in the late 19th century, scientists had been bewildered by the lines that turned up in the light spectra emitted by heated gases: the steady, stable clockwork model predicted did not happen. Also, there were problems explaining the behaviour of light: sometimes it made more sense as a beam of particles, sometimes as a wave.

Today our understanding of the universe is very far from the ‘clockwork’ model. The shift in understanding occurred in the first quarter of the 20th century, beginning in 1900 with the publication of Max Planck’s work on radiation. The problem Planck worked on for six years was that the actually measured radiation from hot bodies did not conform to the values predicted by the classical theory. He put forward the suggestion that bodies radiating energy did so, not evenly and continuously, but unevenly and discontinuously in tiny packets or ‘quanta’. So startling was this suggestion that, despite confirmation by experiment, Planck himself thought of his theory as solving the problem of radiation by a sort of trick.

But then, in 1905, Albert Einstein published an article using the notion of packets of energy of definite sizes to explain how electrons are ejected from metal when light (radiation) falls on it. Whereas classical theory had predicted that the voltage (measure of the energy of the electrons ejected) would be proportional to the intensity of the light (radiation), Einstein showed that it was proportional instead to the frequency of the radiation. The conformity of this explanation with experimentally observed results gained Einstein the Nobel Prize. (Einstein didn’t receive the prize for his famous theory of relativity.) The significance of these findings and theories was not fully appreciated at the time.

A few years later in 1910, Ernest Rutherford did a ground-breaking experiment. He bombarded a thin layer made up of gold atoms with high energy particles and showed that the atom contained an extremely small positively-charged nucleus with negatively-charged electrons moving around it. Following the classical physics model, these electrons should have been small particles orbiting the nucleus in the same way as the planets orbit the sun, steadily losing energy until they fell on to the nucleus-in other words, the atom should have been unstable. Again it was a rejection of the classical model, three years later, by Niels Bohr, that helped solve the problem. Bohr argued that the electrons must move in fixed orbits until deflected by the absorption or emission of a unit of energy.

Atoms emit radiation after various external signals and only at specific wave lengths. As Einstein said, every different color of light is composed of energy packets inversely proportional to its wave-length (frequency). Because the Planck constant (h) is very small, the energy of these packets is also very, very small. For example, a normal light bulb emits 1020 light packets (photons) a second. Each of these photons is created when an activated atom or molecule passes to its normal or ‘basic state.’ Thus light, which allows us to see and which is a basic building block of life, develops as a result of the motions (in wave form) of electrons. The concepts of classical physics could successfully explain many of the events of daily life, but it couldn’t explain events on the subatomic level.

During those years (1910-1925) physics fell into a state of

confusion because of the many measurements that conflicted with general theory and could not be explained by it. This situation was to lead W. Pauli (later to discover the principle fundamental to the understanding of the structure and characteristics of elements) to say he would rather have been a singer or gambler than a physicist. Actually in order to explain the observations being made, the whole way in which physical events had been understood required fundamental revision by wholly new methods. This was achieved by Werner Heisenberg, a 24 year-old physicist described by his teachers as a person who dealt with the essence of a subject rather than getting bogged down in detail, a person with powerful concentration and ambition. Perhaps the success of this young mind can be explained by the critical perspective he developed through reading the works of great men such as Kant and Plato, which was later supported with sound knowledge he got from great physicists. Heisenberg, who relaxed from work by climbing rocks and reading poetry, said: ‘It was around three in the morning when the calculations were completed and the solution to the problem appeared in front of me. First I experienced a great shock. I was so excited that I didn’t even think about sleeping. I left the house and, sitting on a rock, I waited for the sunrise.’

Like the other scientists who established quantum physics, Heisenberg was a philosopher-physicist. The philosophy he accepted and advocated that allowed him to interpret atomic events is as follows: ‘Even though it is successful with classical physics, the language we use to explain physical events in the atom or its surroundings is insufficient. For this reason, after making a specific measurement in a quantum system (for example, an atom), using that knowledge we can get a theory that will tell us what kind of results we can find in the next measurement. But it’s not possible to say anything about what takes place between the two measurements.’

What pushed Heisenberg to make such a statement was that the mathematical tools he used to develop a theory that could explain the observed discontinuity of energy in light and atoms were abstract concepts that had not been used before. In classical physics the numbers we know were used to give value to matter’s position, speed, size, etc. In Heisenberg’s quantum mechanics, these sizes were expressed with infinite dimensional n x n matrices which enabled physicists to calculate the properties attributed to electrons (energy, position, momentum, angular momentum) in an approximate way. Because these abstract mathematical expressions didn’t have an equivalent in everyday spoken language, it wasn’t possible to approach them with a classical understanding. It was observed that in order to measure the position of an electron, the experimenter necessarily altered its velocity. This problem was formally expressed in 1927 in Heisenberg’s famous Uncertainty Principle.

Independently of Heisenberg, Erwin Schrodinger made another significant breakthrough in mathematical description of electrons. Inspired by the hypothesis put forward two years earlier by De Broglie about the wave properties of matter particles, Schrodinger developed a ‘wave mechanics’ by which the movement of particles could be calculated. (figure: 1) But the fundamental question remained as to what these strange and original ‘waves of matter particles’ or ‘waves accompanying matter particles’ were.

The mathematical formulations devised by Heisenberg and Schrodinger are complementary in the sense that physicists use whichever best resolves the particular calculations they are trying to make. There is no formally distinct space between the scientists and the phenomena they are seeking to understand and manipulate: their means of observation and manipulation (the mathematics) in some sense ‘posit’, put in place, the very phenomena whose place (among other properties) they are trying to determine. Alongside the notion of an infinite array of rows and points, as invented by Heisenberg, to plot the position or motion of a sub-atomic particle, physicists and philosophers of physics have begun to speak of arrays of events or ‘stories’ to try to explain, in something resembling ordinary language, the ideas they are handling. This cannot be described as a world-view in the way that the Newtonian physics confirmed and sustained a world-view, but it is nevertheless a clear and distinct disposition which, instead of excluding God as the Force Who wound up the clockwork and then retired from His creation, admits the in-completeness and uncertainty of human knowledge as a structural element of reality-in other words, the uncertainty is not a function of our present ignorance (to be relieved by future knowledge), but an actual constituent of the way reality is.

Quantum physics, at least figuratively and metaphorically, has became a vehicle for the interpretation of such concepts as matter, beyond-matter, energy, existence and non-existence in a way nearer to Divine sources; and led to many physicists settling accounts with their conscience and turning towards God Who is understood to be simultaneously transcendent and immanent, there and here.