The sun radiates an enormous amount of energy-at a rate of 3.9×1026 Joule per second. This is roughly equivalent to the energy of a 10 billion megaton TNT bomb every second. This huge amount of energy has been maintained for several billion years and will continue for several more. The fusion reaction of the Sun is a process in which hydrogen burns, transforming into helium, which is then followed by thermonuclear explosions. Isotopes of hydrogen, such as deuterium and tritium, are fused to form heavier helium. During this process the released energy can be as high as 17.6 MeV. The energy released from a 17 lbs deuterium fusion is equal to 1,000 kilotons of TNT. Every second the Sun fuses 675,000,000 tons of hydrogen into 653,000,000 tons of helium.

Scientists have attempted to make fusion work on the earth to make larger amounts of energy, thus solving our energy problems for the future. The first nuclear fusion trials were carried out for nuclear weapons. The released energy from the fusion trials was 500 times higher than that from the fission reactions of nuclear weapons¹. The energy released was equal to that of approximately 12 million tons of TNT. The civilian applications for energy production began in the early 1950s, and we are still trying to solve how to control this amount of energy in reactors.

In nuclear fusion, the negative and positive ions of hydrogen, called plasma, reach temperatures of 100 million degrees. To achieve the plasma parameters of the Sun, for example, the same temperature and density, the plasma must be heated to 100 million degrees Celsius and be kept dense and confined for at least 1 second.

Plasmas are mostly heated by Ohmic (resistive) heating, beam injection, or radio frequency heating. Ohmic heating is the result of an induced current being passed through the plasmas. This mechanism is also used to make electric bulbs and heaters work. Ohmic heating cannot attain plasma temperatures; such heating does not rise above 20-30 million degrees Celsius. When the temperature increases, the resistivity of the plasma decreases. Natural beam injection is one of the mechanisms used to obtain higher energy temperatures. Injecting a high-energy beam of neutral atoms into the plasma causes more collisions and increases the plasma temperature by transferring the atoms’ energy to the plasma. Radio frequency heating is another collision mechanism that increases the plasma temperature. Radio waves generated by oscillators transfer their energy at appropriate frequencies to ions or electrons, thus increasing the plasma temperature. Scientists have managed to get to high enough temperatures; however, these plasmas cannot be contained by the reactor walls easily and the reactions cannot be sustained. To prevent a loss of reaction control and to make the plasmas denser, magnetic confinement mechanisms have been developed such as TOKAMAK, Z-PINCH and ICF.

The TOKAMAK (Toroidal Chamber) device was invented in the late 1950s by the Russian physicists Igor Tam and Andrei Sakharov. In this system, mixtures of deuterium and tritium plasmas, confined by doughnut-shaped magnetic fields, are produced by the toroidal coils, which are then heated to very high temperatures. The temperature achieved by the Princeton Labs is 510 million degrees-almost 30 times greater than the temperature of the Sun. One of the major problems in TOKAMAK is that superconducting magnetic coils are needed for the electricity demand, but the superconducting magnets only operate at cold temperatures. So, a space between the plasma and coils must be maintained to avoid the plasma reaching the coils and damaging them. This mechanism is still assumed to be the best for the confinement of plasmas².

Another confinement system is the Z-pinch (Zeta-Pinch) pulse power device. The current flow of experimental devices is in the Z-axis, so the device was called the Z-pinch by the British scientists in the late 1950s. In this mechanism, very tiny wires, thinner than a human hair, are positioned in different configurations, such as cylindrical or nested geometries, and are then placed in an anode cathode gap.

Applying high voltage on the system causes the energetic plasmas to compress and heat the deuterium or tritium fuel in small pellets. The current flows through these wires axially, generating magnetic fields that confine the plasma. The temperature achieved is about 1.6 billion degrees; this result, reported by the Sandia National Labs, is almost 250 times higher than the interior of the Sun. Z-pinches produce the most powerful plasmas, but the generated plasmas are very unstable³.

Lasers were invented in 1962, and have been applied in many areas. Lasers were used in infusion research to confine the plasma in the late 1960s by scientists at Lawrence Livermore. This laser-based process is called ICF (Inertial Confinement Fusion). In this mechanism, laser light is used to compress and heat the pellet. The temperature achieved is about 100 million degrees Celsius and the plasma is compressed almost 1,000 times its liquid density. However, this confinement occurs in less than in a microsecond, which is not enough time to allow the ions to build on the energy of their own inertia.

Today, many countries have invested millions of dollars in confinement and ignition systems to create fusion power. ITER is an International TOKAMAK fusion project that will be built in France (for more information: http://www.iter.org/). Its participants have agreed to provide funding of $13.1 billion. When it is completed, the ITER will be one of the most expensive scientific projects in the world. However, despite the high cost, there are good reasons why scientists insist on the use of fusion. One of these is that no CO2 is produced during the process. Everyone is aware that CO2 has negative effects; for example, it leads to increased pollution and global warming. Another reason is the abundance of hydrogen available for fusion in seawater and on the earth’s crust. Another important reason is that fusion is safer than fission or other energy sources: There are no nuclear accidents, and in case of malfunction, the plasma is absorbed and cooled by the reactor walls. Also, the generated amount of radioactive particles is fewer than those generated by fission.

If everything goes well, scientists expect that fusion will be used as a source of energy in a couple of decades. If fusion is successful, it can provide clean, safe, reliable, sustainable, and widely applicable energy.

M. Fatih Yilmaz is a graduate researcher at Physics Department, University of Nevada.

Notes

1. Frisch O. R.: “The Discovery of Fission – How It All Began.” Physics Today 20 (1967), 11, pp. 43-48; http://en.wikipedia.org/wiki/Nuclear_fission.

2. http://en.wikipedia.org/wiki/Tokamak; http://www.ppdl.gov.

3. James Glanz, Science 18 July 1997:Vol. 277. no. 5324, p. 306 DOI: 10.1126/science.277.5324.306.

More than 99% of the matter in the universe is in a state of plasma. The energy that the Sun distributes comes from the core, which is like a blast furnace; here matter is pure energy or is converted to energy. In the core hydrogen atoms are combined and helium is created through nuclear fusion, which occurs at very high temperatures. During nuclear fusion, enormous amounts of energy are emitted. The total capacity of the Sun’s outer layer that emits energy is around 3.86 x 1,026 watts. However, only 1,368 watt per m² comes into the orbit of the Earth. This energy results in the light that we see when we look at the Sun. The core of the Sun is 160 times denser than water on Earth. The temperature in the core is about 15 million °C. If the Sun had not been created at this density and high temperature, such a great amount of energy could not be produced. The energy produced in the core is conveyed to the radiation zone, so called as energy here is conveyed by radiation. The energy produced in the core heats everything while moving to upwards and when it comes close to the outer layer, it loses heat and energy. For instance, there is 1-2 million °C of heat that is dissipated before the end of the radiation zone. At the point where the radiation zone ends, the density of the matter is equal to the density of water on Earth. The energy is conveyed by radiation in the interior part of the Sun, while being conveyed by convection in the outer layer. The source of energy that maintains the light and heat of the Sun is the furnaces at the core. The heat decreases in proportion to the distance from the core. Curiously enough, when moving away from the photosphere (radiation zone) towards the corona, one might think that the temperature in the solar atmosphere should decrease, but in fact it increases. The interior of the corona is almost as hot as the core of the Sun, but the temperature decreases in the outer part of the corona. The cooling process that begins when moving away from the core stops at the corona and the temperature rises from 100,000 °C to 1-5 million °C. Scientists have not yet resolved why the corona has this very high temperature.

The outer layer of the Sun is very stormy. We can compare the events in the outer layer to water boiling in a kettle. This layer is known as the convection zone, which is kept in place by the magnetic field in the corona. The gas pressure in this zone is relatively higher than the magnetic field pressure. Therefore the magnetic field retreats inward and is twisted as a result of the turbulent movements of gas. These movements fulfill the role of enlarging the magnetic field lines of the corona. In the corona, the magnetic field pressure is higher than the gas pressure. It is possible that the extra energy conveyed to the magnetic field is transferred to the plasma in the corona. The energy, in the state of hydromagnetic waves, is squeezed and converted into energy. But we do not know exactly how the energy in the magnetic field is converted to heat in the corona.

The most interesting research topics at the moment are the transfer of energy to the corona and the storage mechanisms for this energy. Matter is heated in the convection zone and expands and rises to the surface. It cools as it rises to the outer layer, becoming denser and then, in a plasma state, sinks down again. This cyclic movement, consisting of a rise and fall, is what is meant by the term “convection.” This movement is conducive to the conveyance of energy from the base of the convection zone to the top. The matter approaching the top cools down and becomes denser here, distributing its energy to the environment. The rising and falling movements of matter in this convection zone are similar to the circular movement observed in water boiling in a kettle. These movements cause the formation of strong magnetic fields in the outer layer of the Sun.
The extremely hot gas in the corona moves away from the Sun. When this hot gas mass heads to the planets it is known as “solar wind.” Solar winds are the officers in charge of changes in the climates of planets. This activity in the solar atmosphere causes atmospheric air currents that bring about snow and rain. There are relatively few magnetic fields in the outer layer of the Sun, while there are a number of magnetic fields in the solar atmosphere. The interplanetary magnetic field is formed as a result of the Sun’s magnetic field. Coronal mass ejections expand away from the Sun at speeds that measure as much as 1,250 miles per second. These blasts carry up to ten billion tons of plasma away from the Sun. It may take a few days for the matter, which covers distance at a speed of 60-600 miles per second, to reach the Earth. Solar flares move at the speed of light and can reach the Earth in eight minutes. If coronal mass ejections reach the atmosphere of the Earth, they can create geomagnetic storms. Auroras (radiation that can be observed in Polar zones) are the atmospheric events related to the coronal mass ejections. Large geomagnetic storms can cause electrical power outages and damage communication satellites.

Astronomers record the xrays that emanate from the Sun in the same way that a doctor records the occurrences of pain in patients. It has been discovered that there is a strong correlation between the density of solar flares and the pains of those who suffer migraines. Even if this correlation is statistically meaningful, more controlled research needs to be carried out to understand if there is any biological significance. The storage of magnetic energy in the solar atmosphere and the ejection of the same, like a sudden explosion, cause solar flares. A solar flare occurs when magnetic energy that has built up in the solar atmosphere is suddenly released. During such an explosion, radiation is emitted across virtually the entire electromagnetic spectrum. The amount of energy released is the equivalent of millions of 100-megaton hydrogen bombs exploding at the same time. Considering how just one hydrogen bomb is enough to destroy the entire world, we must thank the All-Powerful God Who placed the Sun at an ideal distance, protecting us both from freezing and burning. The energy released during a flare is typically to the order of 1027 ergs per second. This energy is ten million times greater than the energy released by a volcanic explosion.

The system in which magnetic fields are produced in the Sun can be the cause of some changes on Earth. For example, between the years of 1600 and 1850s solar activities decreased and low temperatures (a minor ice age) were recorded on Earth, especially in much of Europe and North America. Therefore, solar activity carries out its duty on the order of God and works for the adjustment of climates on Earth. It was determined that the temperature differences measured at 6 miles above the North Pole (in the boundary of troposphere/stratosphere) were related to a eleven-year cycle of sunspot explosions. The stratosphere heat over the Polar zones is relatively less cold when the Sun is active, depending on the stratospheric winds. However, the physical mechanisms have not yet been determined.

How do the planets stay in orbit around the Sun?

There are two hypotheses on this matter: one of them says that the revolving of the planets around the Sun while they are in their or bit is dependent on the movement around the common mass instead of on the force of gravity. The other theory is that the magnetic field forces, which are created as cycles in the core of the Sun, play an important role in interplanetary gravity. The difference between the hypotheses stems from the structure of the orbits in terms of causes. Circular orbit is formed by the force of gravity, while elliptic orbits are the result of common mass movement. Therefore, it would be more sensible to say that while explaining the phenomenon of planets staying in their orbit around the Sun that a role is played by both common mass movement and matter cycles in the core, reminiscent of the oscillations in the core of the Sun, and the magnetic field that is produced. There are a number of verses in the Qur’an about the Sun and the sky. One of these is: “And the Sun runs the course appointed for it for a term to its resting-place for the stability of it(s system)” (Yasin 36:38). Bediüzzaman Said Nursi says, The Sun is a light-diffusing tree, and the planets are its moving fruits. But unlike trees, the Sun is shaken so that the fruits do not fall. If it were not shaken, they would fall and be scattered.¹

The period of the actual rotation of the Sun is approximately 27 days. The active zones of the sunspots can be observed on the side of the Sun that faces the Earth. The Sun’s movement forms an interesting orbit. Although it is not solid (being in a gas and plasma state), the outer layer of the Sun has different speeds of rotation at different latitudes. Scientists have lately started to use acoustic detectors to receive the signals that emanate from the Sun. The acoustic detectors are used to understand the rising and falling wave movements that this noise causes on the surface of the Sun. Scientists are trying to understand how the sound waves behave in an environment made up of other material, such as oil and vinegar, which form a layer in the water, and they then try to decipher the inner structure of the Sun by making analogies with the events that occur within the Sun. The sound waves that are related to events that occur at the center of the Sun vibrate like a spring. Measurements are made by special acoustic detectors and these reflect the cycles within the Sun. The sound that emanates from the interior parts of the Sun is converted into magnetic waves. These magnetic waves always move, in the form of oscillations that first rise above (to the solar atmosphere) then fall down (to the core of the Sun). The movements within the center of the Sun display rhythmic motions, like water in a pool that has been disturbed. Measuring the smallest sound waves that come from the very core of the Sun, Steven Tomczyk (1994) found that the core of the Sun rotates in a way that is similar to the rotation of the Earth. To put it another way, he found out that the rotation at the core of the Sun occurred independently of latitude and depth, unlike movement in the outer layer of the Sun. While explaining the meaning of the word “li mustaqar” (resting-place) in the Qur’an, Nursi refers to this rotation as follows:

Since the All-Wise Maker operates behind the veil of apparent causality, He has tied the planets to the Sun by His law of gravity and causes them to revolve with distinct but regular motions according to His universal wisdom. To produce gravity, He has made the Sun’s movement on its axis an apparent cause. Thus a resting place means that “the Sun moves in the place determined for it for the order and stability of its own (solar) system.” Like the Divine law, that motion produces heat, heat produces force, and force produces gravity.²

Some astronomers compare the Sun to a bell that is periodically struck. They also state that the cycles that occur within the Sun and at the outer layer of the Sun play a role in the formation of magnetic fields, gravity forces, and the common mass center of the Sun. As a result of the interconnectivity of all these factors, how the planets revolve around the Sun while staying firmly in their orbits (without being scattered in terms of causes) can be explained. The existence of this huge star and its continuity in a controlled way is a serious matter, which, even though we often take this miracle for granted, must be contemplated. The fact that the Sun is so vital for us, yet that we have no control over it shows us that this fire ball is in the service of humanity thanks to the order of the Divine Will.

References

• http://hesperia.gsfc.nasa.gov/sftheory/cme.htm
• http://www.ucar.edu/publications/lasers/sun/what-sun.html
• http://athena.wednet.edu/curric/space/sun/sunanat.html

Notes

1. Nursi, The Words, The Light, Inc., NJ: 2005, p. 413. 2. Ibid.