The Fascination with Convection

Heat transference is defined as the method in which heat is travels from one object to another. Heat always moves from hot to cold. During class, we concurred that energy can never be created or destroyed, but only transferred. Though we have been studying this subject for many weeks, practical uses are still something that we do not grasp completely. A very ubiquitous form of heat transference is convection. Convection is heat transfer resulted by the up and down movement of gases and liquids. Convection occurs in the presence of heat, because hot air expands and becomes less dense, thus making it rise. Though this sounds like a simple process, convection is essential for humans and the rest of the planet.

As humans learned more about convection, it helped clarify many mysteries. Convection causes convection currents, because as hot air rises, the cold air descends. This can also happen in water. A convection current in a liquid is called circulation. If water is heated above a flame, the hot water would expand and float to the top, while the cooler and dense water from the surface descends to the bottom. Understanding this enabled humans to understand different things in the environment such as marine animal migration. Some ocean-based animals change their location based on the ocean currents, which is largely affected by the heat from the sun that causes the ocean create many currents through convection.

Also, convection is thought to play an important role in the transfer of energy between the center and surface of the sun. It also is the reason for the movement of magma beneath the surface of the earth. Some other examples of convection are: wind currents, hot air balloons, and the difference of temperature through a multi-storied building. While convection is a simple process, it affects the environment in countless ways. Infatuation

Bibliography:

"Heat Transfer." ChEE & Cooking. Web. 06 Nov. 2011. .

"Heat Transfer." Web. 06 Nov. 2011. .

"Heat Transfer: Conduction, Convection, Radiation." Welcome to Wisc-Online.com. Web. 06 Nov. 2011. .

Bryan, Julia, and Joshua. "How Do Ocean Currents Affect Migration Patterns of Sea Animals? Have Currents Been Changing in Ways That Are Bad for the Animals?"Oswalt Academy. Web. 06 Nov. 2011. .

Scholorly Sources:

"Handbook of Heat Transfer Applications (2nd Edition)." SAO/NASA ADS: ADS Home Page. Web. 06 Nov. 2011. .

De Vahl Davis, G. "Natural Convection of Air in a Square Cavity: A Bench Mark Numerical Solution - De Vahl Davis - 2005 - International Journal for Numerical Methods in Fluids." Wiley Online Library. Web. 06 Nov. 2011. .

Bioluminescence is Buggin'

When one thinks about cold heat, bioluminescence is probably one of the first things that come to their mind. Bioluminescence is defined as the production and emission of light by a living organism as the result of a chemical reaction during which chemical energy is converted to light energy. It is created by a reaction between luciferin and luciferase, which are a protein and an enzyme, and oxygen. Bioluminescence is a form of cold heat because it is almost 100% efficient: converting nearly all of the energy created from the reaction into light instead of heat or sound.

This insect is bioluminescent, because it produces and emits a light for the purpose of mating. If this insect is producing enough heat to nearly burn a human, it can be assumed that it had some type of problem: inefficiency of cells. If the chemical reaction is inefficient, it means that it would not convert as much energy into light and instead release an unusual amount of heat energy. Since it is hot enough to almost burn the skin of a human, it outlines an exothermic reaction, which is also a combusting reaction in this situation. Combustion is a chemical change accompanied by the production of heat and light. In this situation, the insect is not hot enough to fully combust, but if it emitted enough heat, it would.

Bibliography:

"Bioluminescence." Science Daily: News & Articles in Science, Health, Environment & Technology. Web. 30 Oct. 2011..

"Cold Fire in the Sea - Bioluminescence." ReefQuest Centre for Shark Research Home. Web. 30 Oct. 2011. .

"Conversion Efficiency of a PV Cell." Inventors. Web. 31 Oct. 2011. .

"What Is Combustion?" Physics Help and Math Help - Physics Forums. Web. 02 Nov. 2011. .

Sunlight

Heat transfer is a principal of thermal engineering (the heating or cooling of a process) that is specialized in the exchange of thermal energy (heat energy) from one physical system to another. There are many instances where we can see heat transfer. Some of these mechanisms includes heat conduction, convection, thermal radiation, and phase change transfer. In all these cases, energy in the form of heat is being transferred from a warmer object to one that is cooler. Since this energy transfer follows the law of conservation of momentum which says that energy cannot be created nor destroyed, we know that if one object is gaining heat energy, the other object is losing it.

The specific instance I’m using is thermal radiation. As we know from earlier classes and other research we have done, thermal radiation is heat generated by matter because of the charged particles in that matter, object with fast moving particles have more heat. Sunlight is an example of when heat transfer occurs. The electromagnetic waves (energy traveling through space) also known as radiation encounter an object. The waves will then transfer the heat to that object. A specific example of this is when sunlight comes in contact with a house. When the electromagnetic waves come in contact with the house the temperature inside that house goes up. The energy coming from the heat waves is converted in to kinetic energy (the energy something has because of its motion) in the particles of the object it is heating. This is why when you leave something out in the sun for too long, its internal temperature will go up. One way that the heat energy from the sun affects our ecological economy is that plants need heat energy to grow and survive. Though they do not need as much heat energy as light energy, the heat energy is still important to make the enzymes work.

Scholarly articles

Mark Bishop (Lead Author);Tom Lawrence (Topic Editor) "Heat transfer". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth June 24, 2008; Last revised Date June 24, 2008; Retrieved November 6, 2011 <http://www.eoearth.org/article/Heat_transfer>

Luebbers, Ralph H. "Heat Transfer." Encyclopedia of Earth. ©McGraw-Hill Companies, 2008. Web. 06 Nov. 2011. .

Heat Transfer

Heat transference is the exchange of thermal energy, or heat, between two substances. Anytime an object is heated, it is because of heat transfer since, due to the laws of conservation of energy, energy can neither be created nor destroyed; high concentrations of heat want to move to low concentrations of heat and visa-versa. Therefore, heat transference is what causes everything to heat up or cool down. On a chemical scale, quickly moving and hot molecules interact with slower moving and cooler molecules and transfer some of their energy (which in this case is in the form of heat) to them until the two substances reach equilibrium.

A good every-day example of heat transfer is when a person makes a snowball with bare hands. The person transfers energy to the snow in an effort to achieve equilibrium. The person’s hands will get colder as energy in the form of heat is transferred to the snowball. In contrast, the snowball will begin to melt as it absorbs some of the energy from the person’s hands. This is an excellent example of heat transfer because it occurs very often and is a simple representation of heat transfer.

Scholarly articles:

“The physiological equivalent temperature – a universal index for the biometeorological assessment of the thermal environment” by P. Höppe. International Journal of Biometeorology. May 26, 1999. http://www.springerlink.com/content/pu50qardua56k6em/

“Journal of Fluid Mechanics” by PR Owen and WR Thomson. Journal of Fluid Mechanics. March 28, 2006. http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=369150

Thermal Radiation as Heat Transference

Heat transference is the process by which heat moves between one substance and another. As we know from our study of the property of ‘q,’ energy is never created nor destroyed; rather it is just transferred through the release or gaining of heat between reactions between substances. radiation is one of the most common forms of heat transference that we encounter in our everyday lives. It is the process by which electromagnetic waves travel through space and when those waves come in contact with an object they emit heat. There are many different kinds of radiation and each has varying levels of harmfulness. Gamma rays for example, can be extremely detrimental to our health if one is overexposed to them, while microwaves have a much lower frequency, and therefore are much less harmful to us.

There are an infinite number of benefits to humans having harnessed the power of thermal radiation. All matter with a temperature greater than zero emits thermal radiation. Without it we wouldn’t be able to create hearths for our homes, have hot water, have light bulbs, use microwaves, having thriving nature, or cook over a stove.  Sunlight is a form of thermal radiation emitted from the sun, obviously. Sunlight is an essential agent in the process of photosynthesis which allows plants to grow and create fruits and vegetation from which we eat. Besides its domestic uses, sunlight also contributes to the sustaining of natural habitats which are essential to our ecosystem for numerous reason among which include contributing to photosynthesis to allow plants to thrive meaning with plants we can receive more oxygen and create habitats for creatures living there. Trees can also be cut down to sustain parts of our economy, to build homes, etc.

But for every benefit that heat transference brings to the environment, there is an equal and opposite negative toll it takes.  One of the most harmful effects of thermal radiation is the fact that by nature, thermal radiation has the capability to ignite matter. And while yes, this can often be a benefit to our environment, in many cases this can create grave danger; for example in dry areas like around Californian forests, these trees are susceptible to their ecological infrastructure igniting and having a forest fire occur. Additionally, heat transference is a contributing factor to Global Warming. Although the atmosphere is for the most part opaque and thermal radiation from Earth's surface is absorbed by the atmosphere, radiation still escapes into space. It is then subsequently absorbed and emitted back by atmosphere gases. This is what evidently contributes to Global Warming.

Bibliography:

1.       Huebsch, Russell. "Thermal Radiation Effects | EHow.com." EHow. Web. 02 Nov. 2011. <http://www.ehow.com/about_5544786_thermal-radiation-effects.html>.

2.       "Solar Radiation and the Earth's Energy Balance." Columbia University | Earth and Environmental Sciences. Web. 02 Nov. 2011. <http://eesc.columbia.edu/courses/ees/climate/lectures/radiation/>.

Scholarly articles:

1.      Höppe, P. "The Physiological Equivalent Temperature – a Universal Index for the Biometeorological Assessment of the Thermal Environment." Springer. International Journal of Biometeorology. Web. 2 Nov. 2011. <http://www.springerlink.com/content/pu50qardua56k6em/>.

2.      Howell, John R., and Robert Siegel. "Thermal Radiation Heat Transfer, Vol. 1." Taylor & Francis Publishing. Web. 02 Nov. 2011. <http://books.google.com/books?hl=en>.

3.      Wong, Nyuk Hien. "Investigation of Thermal Benefits of Rooftop Garden in the Tropical Environment." Science Direct. Elsevier Science Ltd. Web. 02 Nov. 2011. http://www.sciencedirect.com/science/article/pii/S0360132302000665.

Bioluminescence

Bioluminescence is the production and emission of light by a living organism (such as fireflies!) The animals that have bioluminescence contain two chemicals called luciferin, which is a pigment, and luciferase which is an enzyme. When luciferin reacts with oxygen it creates light, and the luciferase acts as a catalyst to speed up the reaction. The chemical reaction within the bug causes the heat that we fill when touching an animal with bioluminescence. For something to combust it must reach a temperature of 175 degrees Celsius. In this case, animals/insects with bioluminescence only reach around 100 degrees Celsius, which will certainly burn skins when contact is made, but will not cause the animal or insect to burst into flame and die. The reason why it does not reach temperatures as high as 175 degrees Celsius is because in order for combustion to occur, oxygen, a fuel, and energy. Within a bug or animal that has bioluminescence, there is not enough oxygen for the species to combust, but enough to produce heat.

Bugs makin' art

Biolumiescence is the emission of energy that is caused by living, ecological things. The most common living creature that is able to emit energy is insects and they do this in the form of light. Insects such as fireflies emit light in the form of bioluminescence. Bioluminescence is the reaction that occurs when the pigment luciferin, oxygen, and the enzyme luciferase come together. Usually the reaction occurs once the luciferin and the oxygen react with each other to produce light either inside of the cell or outside of the cell of the insect. The enzyme, luciferase, like most enzymes, is helpful in speeding up the chemical reaction that occurs between the pigment and the oxygen. This is why the pigment and the oxygen are necessary for insects to glow, without each of these the insect would not have any glowing capability.

Bioluminescent Insects Glowing in the Darkness, Karl Fabricius

Bioluminescence and Combustion

Bioluminescence is a natural Chemiluminescence that some animals are able to produce. Bioluminescence is the reaction between the pigment luciferin, the enzyme luciferase, and oxygen. The luciferin reacts with the oxygen to create light, and the luciferase speeds up the reaction (it is a catalyst). This reaction can occur either inside or outside the cell. It is a “cold light” because it doesn’t release a large amount of heat (only around twenty percent) in the chemical reaction that causes it.

Because the insect is using bioluminescence to produce light on its body there should be no way it can combust. Because such a small amount of kinetic energy is supposed to be released in bioluminescence it is strange that the bug is hot to the touch. It is not releasing the correct amount of heat and is wasting its energy on it. However, even though it is releasing too much kinetic energy it is still not hot enough to combust. When something undergoes combustion it reaches a high enough temperature that it is burned. Because bioluminescence releases such a small amount of kinetic energy the insect won’t reach a high enough temperature to actually start burning. In order for something to burn it also needs a significant amount of oxygen to fuel it. Our atmosphere only has twenty one percent oxygen so it is not enough to react and fuel the reaction that is needed for combustion.

"Bioluminescence." Wikipedia, the Free Encyclopedia. Web. 31 Oct. 2011. .

"Combustion." Wikipedia, the Free Encyclopedia. Web. 31 Oct. 2011. .

"HowStuffWorks "How Bioluminescence Works"" HowStuffWorks "Science" Web. 31 Oct. 2011. .

Bioluminescence in Bugs

Bioluminescence is the production and emission of light by a living organism as a result of a chemical reaction in which chemical energy is converted into light energy. Bioluminescence is a form of cold light emission, and less than 20% of the light is generated by thermal radiation. As the bug is emitting cold light, it is focusing a great deal of energy into not only producing light, but emitting warmth. As so much energy is going into emitting light, it would be impossible for the beetle to produce enough energy to create enough heat to reach a temperature in which combustion is possible. Combustion is an exothermic chemical reaction, in which heat is released and something is burned in the process. The temperature the bug would need to reach in order to combust is much too high for it to reach by merely emitting bioluminescence, which is not only cold light, but is focused on producing both light and warmth, and has no energy or heat left over in order for it to reach the temperature necessary for combustion.

"Chemistry - Bioluminescence." Chemistry Daily - Articles on Every Chemistry Topic. Web. 31 Oct. 2011.

BioLuminescence

Bioluminescence is light that is created by living creatures such as bugs, fish, bacteria, etc... Bioluminescence is known as cold light because it does not require or generate any energy as result. A pigment known as luciferin will react with oxygen to produce light inside or outside a cell with the enzyme luciferase speeding up these reactions. Luciferin and luciferase are just the type of enzyme and pigments used in animals which use bioluminescence. This pigment and enzyme are needed in order for the reaction to occur for light to be produced that is why not all animals and organisms cannot produce light. Bioluminescence is used for camouflage, attraction, and communication. If there was a bug which emmited light and heat as a result of its bioluminescence, it would mean that the bug is not an efficient bug. With Bioluminescence there is little heat produced, which is what makes it so efficient as opposed to incandescent lights. If a bug was producing enough heat to burn skin (<140 degrees) means that the bug is producing more heat than light making it an ineffective form of bioluninecence. Combustion though is a series of exothermic reactions with the production of heat and if the bug continued to produce more heat than the bug is able to handle it will combust. Given that skin burns at around 140 degrees Fahrenheit and at most 20 % of the energy is produced as a heat byproduct. If the bug was producing that much heat it would not combust unless the temperature was above boiling point. Water has a boiling point of 212 degrees farenheit and given that bugs are made of molecules other than water the boiling point would be actually more than 212 and so the bug would not combust until the amount of heat released would be more than the boiling point and much higher then it would be able to reach.

Bioluminescence

Bioluminescence is release of and discharge of light by a living organism. Bioluminescence is also a kind of Chemiluminescence. The most common example of bioluminescence in our everyday lives are when fireflies use it to light up at night. The most prevalent type of organisms to use bioluminescence are marine animals. Almost all marine animals utilize bioluminescence in their lifetime. The light through bioluminescence is released through a chemical pigment known as luciferin. They also produce something known as luciferase which is an enzyme. The emission of light in the organism is produced through a chemical reaction where luciferin is exposed to oxygen and luciferase is the key catalyst in the chemical reaction. Another chemical that is in involved in the reaction is something known as ATP which transports the chemical energy to different cells. The ATP brings the energy to the chemical reaction so it has the energy to make the reaction happen. Since this is a chemiluminescent reaction, the reaction is not powered through heat energy. Since the bug is hot to the touch it shows that it is emitting a lot of heat and not very efficient at this chemical reaction. The process of bioluminescence can happen outside of the cell or inside of the cell.

Combustion is a string of exothermic reaction between oxygen and a substance that is fueling. Even though this bug feels hot when a person touches it, combustion is still highly unlikely. This is because bioluminescence can cause a bug to reach temperatures close to 100 C. Combustion though, requires a temperature between 175 C - 475 C. The probability that combustion is occurring is highly improbable and it is most likely that the bug just got a bit hot from bioluminescence.

Bibliography:

http://science.howstuffworks.com/environmental/life/zoology/all-about-animals/bioluminescence.htm

http://www.eoearth.org/article/Combustion

Biouminescence

Bioluminescence is the emission of light by living creatures. This occurs when there is a chemical reaction inside of the bug and the energy is released as light. The type of light that occurs In Bioluminescence is a special type of light called cold light in which less than 20% of the light actually generates heat. This is the opposite of tipical light bulbs which use incandescent light which is a process where the bulb gets very hot and then emits light. The best pay off of luminescence is that it does not generate a lot fo heat nor does it require heat thus the name cold light. The bug does retain the 20% of heat that is created which is why the bug may seem hot but it would be improable that a bug every create enough energy to combust through cold light.

http://en.wikipedia.org/wiki/Bioluminescence

http://science.howstuffworks.com/environmental/life/zoology/all-about-animals/bioluminescence2.htm

http://en.wikipedia.org/wiki/Luminescence

Bioluminescent Bugs

Glowing insects and other organisms use luminescence to produce light. The glow is created from chemical compounds that neither require nor generate a large amount of heat. This is why the light that is produced is often referred to as, cold light. Bioluminescence itself it a form of cold light emission, meaning that less that 20% of the light, created by the bug, produces thermal radiation. It is for this reason that bugs do not combust. In order for a bug to combust it would have to reach an incredibly high temperature which is very unlikely because at the same time it is heating up, the bug is expending a large amount of energy to produce cold light. This effectively keeps the bug from reaching temperatures anywhere near combustion. The fact that this particular bug is hot enough to possibly burn skin, gives the indication that it is a pretty inefficient bug. Even though it is inefficient and reaches higher temperatures than most though, the bug would still be unlikely to reach a hot enough temperature to combust because it is constantly producing cold light to balance itself out to a certain extent.

"How Bioluminescence Work" How Stuff Works. Web. 30 Oct. 2011
http://science.howstuffworks.com/environmental/life/zoology/all-about-animals/bioluminescence.htm

"Bioluminescence" Wikipedia.org. Web. 30 Oct. 2011
en.wikipedia.org/wiki/Bioluminescence

This Bug!

Bioluminescence is defined as the production of light form a living thing, the energy that they produce is turned in to light. It is a form of Chemiluminescence which is where energy is released by a chemical reaction in the form of light. Bioluminescence usually applies to marine vertebrates and invertebrates. When these creatures produce the light, even though in this case it is to attract or scare away a mate, they also do it for protection and caution from their surroundings, like a defense mechanism. In this case, because we are looking at insects, it’s an invertebrate. Bioluminescence is also known as the cold light, usually not producing much heat but only light. Some insects will produce Luciferin( which reacts with oxygen to create light) as well as luciferase( which is an enzyme that speeds up the light producing reaction), but neither of these help to produce heat. In general bioluminescence produces less than 20% of light that gives off thermal radiation (heat). There are many lights such as incandescent light and infrared light that produce heat but as we can see Bioluminescence is not one of them. This does not apply to this case making this bug a different case. Combustion is the chemical reaction of fuel and an oxidant such as iron oxide. Oxidants are substances that remove electrons from another substance. This reaction is an exothermic one, which means that it is releasing energy in the form of heat and light. Usually when there is a combustion the result ranges from a glow to a flame. Even though this bug is giving off heat, and enough of it to burn our skin when we touch it, it is not giving off enough heat to make the bug burst in to flames. The amount of heat that would approximately be needed for a bug to burst in to flames is approximately between 150 - 215 degrees Celsius. That is a very high temperature and for the bug to be alive, it is not possible that it has reached this temperature or its species would have gone extinct. It is also not possible for the bug to have reached that temperature because bioluminescent usually does not produce heat (cold light) so even though the temperature is higher than usual, it is not high enough for it to combust. I believe that in this case the heat is another part of the bug’s defense mechanism. The bug uses the heat to scare off its predators and keep itself safe. The bug is probably a smaller insect and that’s why it needs the amount of protection that it does.

The picture of the bug above looks a bit like the bug described in the question because of the red glowing stripes on either of its sides. This bug is also bio luminescent but in this picture I think the prominent glow is coming from the tail area. The bug in this picture is a firefly.