How The Sun Produces Heat And Light Energy Essays Examples

The sun is known as the greatest provider of energy to earth. The main two main forms of energy produced by the sun are heat and light energy. For many years, scientists were puzzled by the working mechanism of the sun. Questions were asked regarding how the sun produces the vast amount of heat and light energy that supports and indeed sustains the life on earth. Scientists and experts in various fields of study provided different theories about the production of heat and energy by the sun and some even clashed with each other. For example, there were constant clashes between evolutionary biologists, geologists and theoretical physicists on how the sun works and how it produces energy (Bahcall, 2001). In recent, there has been more consensus on how the sun exactly produces heat and light energy. This has been facilitated by decades of intensive studies and theoretical derivations. This does not however mean that the current theoretical explanations about the production of heat and light by the sun are 100% accurate. There is still a lot of research going on and in future, fully conclusive theoretical explanations about the production of heat and energy by the sun are expected to be given.
First of all, scientists agree that the sun produces heat and light through nuclear reactions that take place in its core. The core is the most important component of the sun and nearly everything that the sun is able to do is facilitated by its core. Temperatures and pressures at the sun’s core are extremely high such that nuclear reactions are able to take place. The type of nuclear reactions that take place in the sun’s core are force fusion. This is whereby nuclei from different atoms merge to form new nuclei (The Life-Giving Sun, 2015). This type of reaction is also the one that is applied in hydrogen bombs and it is, therefore, no surprise that when these reactions occur in the sun’s core, the ultimate result is the production of vast amounts of energy (The Life-Giving Sun, 2015). However, there is one particular reaction that is considered to be the most important in the sun’s core. This reaction is usually referred to as the “proton-proton cycle” (The Life-Giving Sun, 2015).
In this reaction, nuclei from hydrogen atoms are converted into helium nuclei via a series of reactions. These reactions lead to the production of high-energy photons which are in scientific terms referred to as gamma rays.
These gamma rays move through the layer surrounding the sun’s core that is radioactive in nature. This layer is in fact quite dense as it takes up about three-fifths of the sun’s total radius (Coffey, 2010). This layer also comprises of hot thermal material. No thermal convection takes place in this layer and as the altitude rise, the materials becomes cooler (Coffey, 2010).
Another noteworthy characteristic of this region is that the adiabatic lapse rate is higher than the temperature gradient and consequently, the temperature gradient cannot facilitate convection. The heat is essentially transferred because helium and hydrogen ions emit photons which travel only a short distance before being reabsorbed (Coffey, 2010).
The proton-proton cycle chain takes place about 9.2 x 1037 times in every second (Coffey, 2010).
The fusion of the hydrogen nuclei into the helium nuclei actually releases about 0.7% of the fused mass in energy form. In simple mathematical terms, the sun dispenses energy at an enormous mass conversion rate of four million metric tonnes per second.
For energy to get through or get past this layer into the next layer that is known as the “convective layer”, it may take up to a million years. This is primarily because as it has been mentioned, the photons constantly get intercepted, absorbed and then re-emitted (The Life-Giving Sun, 2015).
The helium nuclei actually make up about 62% of the total mass while the remaining mass is made of hydrogen. One the other hand, hydrogen makes up the higher percentage of the convective and the radioactive layers (72%) while helium takes up about 26%.
Heavier elements then take up about 2% of the mass (The Life-Giving Sun, 2015). The fusion taking place in the sun’s core is usually transported to the solar surface where it is either emitted in form of light energy or is ejected as high energy particles (Estefani, 2013)
The convection is layer is characterized by a solar plasma that is not hot enough or dense enough to transfer heat from the interior part of the sun via radiation. In this layer, thermal convection takes place because of the presence of thermal columns that transmit hot material to the proceeding layer which is the photosphere (Coffey, 2010).
The material that goes to the photosphere later in cools off and sometimes, it can then fall back to the convectional zone base and actually receive greater heat from the radiative zone’s top part (Coffey, 2010).
The outermost part of the sun that is visible to earth is the photosphere. In this part, visible sunlight emerge can spread into space when where it also reaches Earth. Although the some of the sun’s UV rays are filtered by the atmosphere, some form of this energy still passes through and reaches the earth. This energy once reaching Earth reflects back into the atmosphere. It is from this reflected energy that the earth absorbs some and in the process becomes heated.
The sun also has another layer that is known as the ‘thermonuclear core”. This layer has a spherical shape because of gravity’s action constricting towards the center. This layer has a radius of about 170,000km. This makes about 10% of the total mass of the sun. The layer can also be found about 530,000 km into the surface of the sun.
The sun general has a density if about 150g/cm3. Its temperature in Kelvins is 13,600,000. The core is actually the only section of the sun that produces a significant amount of heat via fusion.
As it has been mentioned other sections of the sun are actually heated by heat energy transferred from the core and outwards to these outer layers. It has also been shown that this passage of heat is not an easy process as there are many layers between the sun’s core and the surface and when it finally manages to reach the surface it has the ability to escape as sunlight.
There is also another layer between the convection and the radiation zone. Although it does not receive a lot of attention from scholars, it is, however, critical in the production of both heat and light energy. This layer is known as ‘tacholin” (Estefani, 2013). This layer is about 150,000km deep and has a thickness of about 30,000km. The pressure and density levels are much lower here. In addition, masses in this layer behave like liquids or gases.
This layer also experiences heat convection which is propagated through chaotic movement. Here, particles vibrating more intensely rise to upper parts where they give out high energy photons and other particles to the surface. They lose energy and, therefore, the fall to the lower area where they are once again re-reenergized through electromagnetic radiation. This leads to the generation of stronger particles that vibrate to give off heat energy.
One thing that is extremely important to note is that proton-proton chain reaction described earlier is not very efficient (Johnson, 2015). In fact, there are several dimensions of the way this reaction can actually happen.
First of all, it is imperative that two protons be travelling at extremely high velocities towards one another. In addition, the two protons must be one flight path. This is so as to ensure that they do not miss or bounce off each other (Johnson, 2015).
There are also other conditions that must prevail once the two photons meet each other. Once the two fuse, the helium nucleus that results must undergo a decay process. Here, the one of the electrons is pulled towards the nucleus, and thus it become a Deuterium (Hydrogen-2) nucleus. This is one of Hydrogen’s isotopes. After this, this Deuterium nucleus has to collide with another proton and the result is usually a Helium-3 nucleus (Johnson, 2015). This then decays once again to form a nucleus of Hydrogen-3. It does not end there as this nucleus has to once again collide head on with another proton. This collision results in the formation of the Helium-4 nucleus which is actually the normal Helium (Johnson, 2015).
As observed, this process actually involves a total of three proton-proton collisions. This renders the process slow.
However, the fusion process does not have to occur always as described above. There is a different process that actually works more efficiently than the one described above. In this process, two protons juts like before have to fuse to form a Helium-2 nucleus (Johnson, 2015). This is followed by the decaying to form the deuterium nucleus which is a hydrogen isotope.
This deuterium nucleus then has to collide with another proton leading to the formation of a Helium-3 nucleus which then goes on to decay to form a Hydrogen-3 nucleus. It is from here that things then get different (Johnson, 2015). The Hydrogen-3 nucleus finds another nucleus of the same kind (that is another Hydrogen-3) nucleus where the two then go on to collide head on (Johnson, 2015). The result, in this case, is quite fascinating. Spattering occurs where two Hyrogen-1 nuclei and one Helium-4 nuclei are formed. These are basically normal Hydrogen and normal Helium. These have the ability to then fuse again.
As seen therefore, there are several variations to how the fusion takes place inside the sun's core therefore producing the vast amount of heat and light energy that then progressively travels through the sun’s layer to finally be emitted as heat or light.
The first variation as observed is quite slow as it involves three steps. The second variation also comprises of several steps but is not as slow as the first one. In addition, scientist are still trying to theorize other ways or other mechanisms through which fusion takes place in the sun’s core to produce energy.
The sun also contains some other elements that scientists also believe play a role in the production of heat and light energy. These elements include oxygen, nitrogen and carbon (Johnson, 2015). In fact, in recent days, scientist have proposed a new process taking place in the sun’s core and that includes these mentioned elements. This is known as a CNO cycle. The letters are abbreviations of the three elements (Johnson, 2015).
This process has however been just postulated but has not actually been proven. Scientists have not yet proven whether the two processes, that is the proton-proton cycle and the CNO cycle can occur concurrently or at the same time.
There are more studies being conducted on the same and in future, scientists aim to establish fully whether this process indeed occurs and whether it affects the proton-proton cycle.
As shown from the discussion above, the sun is the greatest provider of energy to earth. The two major forms of energy produced by the sun are heat and light energy, and these find great usage on earth. The process through which these forms of energy are produced have not been authenticated, but the majority of scientists believe that nuclear fusion inside the sun’s core is responsible for the production of the two forms of energy. In nuclear fusion, two hydrogen nuclei fuse to form a Helium nuclei. However, as shown in the above discussion, this fusion is not straight forward and involves several steps. The energy produced in the sun’s core has to pass through several layers of the sun before reaching the surface where it is then dissipated into space with some reaching the earth and being reflected into the atmosphere before finally being absorbed. Future studies on this subject will, however, shed more light on this issue and accurate information on how heat and light energy are produced by the sun will be established.

References

Bahcall, J. N. (2001). How the Sun shines. SLAC Beamline (CA, USA), 311(astro-ph/0009259), 2-12.
Coffey, J. (2010). How Does The Sun Produce Energy. Retrieved from http://www.universetoday.com/75803/how-does-the-sun-produce-energy/
Estefani, G. (2013). How does the Sun generate energy? Retrieved from http://www.artinaid.com/2013/04/how-does-the-sun-generate-energy/
Johnson, C. (2015). Sun and Stars - How the Sun Works - Nuclear Fusion: Creating Light and Heat. Retrieved from http://mb-soft.com/public2/sunworks.html
The Life-Giving Sun. (2015). Retrieved from http://earthguide.ucsd.edu/virtualmuseum/ita/07_2.shtml