Contacts are basically very small eyeglasses made from a plastic material as oppose to glass. Contacts change the direction of rays of light to focus that light properly onto your retina and the nerves within it. There are contacts that correct both nearsightedness and farsightedness. If a person is nearsighted, the focus point of light rays is in front of your retina. If you are nearsighted, the light rays are not able to form a focus point before reaching the retina. Contacts fix both of these issues. Contact lens powers are calculated and expressed in diopters. Nearsighted lenses begin with a negative sign while farsighted lenses begin with a positive sign. The reason that contacts are so much thinner than eyeglasses is that they are a different distance from your eye. Contact lenses rest directly on our cornea so we can see everything without the feeling of looking into a lens. Eyeglasses are a bit further away from your eye and therefore need to be thicker to have a larger optic zone; you can only see through those lenses, most people with glasses have poor peripheral vision. You can think of this concept as if you were in your house loping out a window. If you are very close to the window you have a larger range of what you can see. If you were on the other side of the room you would only be able to see a much smaller percentage of what is outside. Eyeglasses are also thicker so that they do not break upon impact. Contacts don’t really fall off like glasses may. People should use contacts because they seem to be more convenient than glasses. Glasses can break pretty easily and also change a person’s appearance quite dramatically. I would recommend to anybody who needs to where glasses that they should at least try to wear contacts.
Most people only think of drugs as something a person can eat, smoke, or place into their blood stream. Thats the way I think of drugs as well. They make you feel better when you don’t feel good and can change your mood from angry or sad to happy in a matter of seconds. The only problem with drugs is that they are not good for your body and can be insanely addictive. Now think about music. Everybody listens to music, but why? Listening to your favorite song, makes you happy. This is because of a chemical called Dopamine. Dopamine is commonly released in the brain and makes you feel good so that you will do that thing again. It is released during times when you are doing things that feel good like eating your favorite food or having sexual intercourse. Listening to a certain genre of music can make you feel entirely different than another genre may have you feeling. It can bring on very intense feelings as well. Songs can bring back memories of good or bad times that a person never forgets. From my personal experience, when I’m down or tired, my favorite songs make me feel like I’m in heaven or utopia. I also know of a few songs that will put me in a horrible mood because they remind me of difficult times, or better times that I no longer have. Music can bring us into what feels like a different place, far away from the problems going on in our lives. Although it can’t make us hallucinate, music brings on a lot of the same feelings that we experience when we are high on drugs like marijuana, various prescription pills, or ecstasy. Dopamine is a very interesting chemical; it is basically what keeps us happy.
Styrofoam is made by a combination of air and polystyrene. The two are molded into cells and pressed together. The main component of styrofoam is the chemical styrene. Polystyrene itself is non-toxic to our bodies; but it can cause an inflammatory response when enclosed within us. Depolymerization can occur at higher temperatures; when this happens chain scission may occur and monomers can be released. Polymers, at low temperatures are highly preferred in most cases, but at higher temperatures you may approach the ceiling temperature.
The ceiling temperature is where polymerization and depolymerization are at equilibrium with each other. Styrofoam is not FDA-approved inherently but can be manufactured in such a way so that it is. Styrofoam with a high ceiling temperature is better used and much less dangerous. The average microwave cannot reach a temperature high enough to hit the ceiling temperature. The ceiling temperature of polystyrene is three hundred ninety-five degrees celsius. The polymer would already have began charring at this temperature; in other words, you would need to make the polystyrene very very hot in order to release such monomers.
Short term exposure to the chemical styrene can cause stomachaches or irritation/inflammation of your eyes and nose. If you are exposed to this chemical at high temperatures for a longer period of time you may experience headaches, fatigue, depression, hearing loss, nervous system disfunction, or other symptoms. The temperature at which styrofoam is dangerous to be around is much higher than the maximum temperature that a microwave can reach. Certain forms of polystyrene will react differently at different temperatures but I would say do not place styrofoam in a microwave just to be safe. Unless it is written that the styrofoam has been tested and is microwave safe, just use a different material to heat up your food.
A mirror starts out as clear glass; just a large panel. It is then cleaned with water and cerium oxide. Cerium oxide is a powder derived from a type of earth. Rotating brushes will scrub the glass and polish it on both the top and bottom sides. This is done to remove the many oils and other contaminants already on the glass surface. This does not take long; the machines used are in factories that have perfected the process. Next the glass is sprayed by very hot demineralized water; the minerals in everyday tap water would damage the metals used in the next step. The first metal used on the back side of the mirror is liquified tin; this is used to adhere the next metal applied, which is silver. Silver will otherwise not stick to glass and it is also in liquid form. When the silver is sprayed onto the tin it begins to harden, and you can start to see a slight reflection. The silver backing is what turns clear glass into a mirror. Next, sprayers rinse off the excess silver and it is recycled to be used for other mirrors.
Atop the silver, two layers of paint are sprayed onto the back to protect it, but that isn’t quite enough. A layer of copper is sprayed on and then sprayers take off the excess. It is then put through a dryer at the temperature of seventy-one degrees celsius. The moisture is evaporated in about seventy-five seconds and the panel is flipped with the copper side up. It passes through the curtain coater; which drops a continuous curtain of paint across the conveyor belt. With this fresh coat of paint, the mirror is put into an oven set at ninety-nine degrees celsius. When cured, it is put through the machine again for another coat and is cured at one hundred and eighteen degrees celsius. An acid wash removes any remaining residues and the mirror is then inspected. It’s pretty cool how mirrors are made, and it surprised me that it is all done on the back of the original glass panel as oppose to the front.
A human eye works a lot like a camera. There is a lens in the front of our eyes that bring images to focus on the back of our eyes. The retina, which this area has come to be called, is covered with special nerve cells that react to light. Within this nerve, there are rods and cones which contain pigments that react when struck by light. Pigments within cones react differently to different wavelengths within the light. The rods all react the same way to any wavelength; they don’t help with color vision but allow us to see at night because they are so sensitive to light. When all of the rods and cones in our nerves are working correctly, we can see any possible colors and should have somewhat perfect vision.
When the pigments in the cones are not working properly, this is when we see color deficiency, or color blindness. If any pigments are missing, even one, it can make it troublesome for your eyes to see certain colors. The most common form of color blindness is red-green color blindness; this is where green and red will basically appear to be the same color. The second most common is blue-yellow color blindness. Having these deficiencies can be really hard for some people and can actually affect what a person can or cannot do. Think about how essential our sight is; seeing colors differently from the rest of the world can make certain things in life very difficult. Achromatopsia is a case where there are no pigments present in the cones and one cannot see any color at all. Color blindness is a genetic condition that affects one out of every ten men to some degree; although it only occurs rarely in women. Color-blindness does not lead to any other health defects; though the lack of pigments may also affect how sharply your eyes can focus on an image.
Different solids react to fire in several different ways. Metals and Wood do not burn the same way. When wood burns, it loses mass. This is how ashes are created. Wood contains carbon and hydrogen and when they combine with the oxygen at high temperatures they create carbon dioxide and water vapor. When this mixture leaves the wood as smoke, ashes are what we have left over. The light mass is fragile and black and can be easily disintegrated into nothing. You can see this reaction when people smoke cigars or paper products. The paper is lit on fire which, in turn, burns the tobacco and paper into ash. Other examples of this are campfires and forest fires. When people light a fire in the woods or in their backyard the wood burns and eventually turns to ash. Sometimes, the campfires can cause forest fires which wipe out entire communities. Miles and miles of land can be turned to ash in a matter of hours and there is no way to stop it.
When everyday metals burn, they has a reciprocated reaction in relation to the wood. Metals such as aluminum, copper, and steel combine with oxygen at high temperatures to form oxides that actually stick to the metal. Because of this we can see an increase in mass when burning these metals. Metals do not form ash, they gain mass when burned. This process is similar to the rusting of iron; the metal is bonding with the oxygen, increasing it’s mass. When iron is heated, it causes a incandescent reaction. Iron glows red and orange when initially heated; as the temperature increases it gives off a white light. This is how heat energy is converted to light energy. We see light energy in the light bulbs that people use in their everyday lives.
When analyzing how paper is made it important to look at the source and understand trees. The bark protects the inner wood from dangers such as whether and insects. The next layer is the cambium, whose cells become both bark and the inner wood. Then there is sapwood which carries the nutrients throughout the tree. Finally, heartwood is the most inner layer of trunk which provides the tree with strength and structure. All of these durable cells that comprise the tree trunk form together to make fibers. These fibers are small cellulose strands which are stuck together with a natural adhesive called lignin. The separation and reorganization of these fibers makes paper. There are two categories of forester trees that are used for making paper: hardwood and softwood species. Hardwood trees such as oaks and maples have very short fibers and therefore yields weak but smooth paper. Hardwood trees are ideal for making printer paper, or loose lead paper to write on. Softwood trees have very long fibers and these fibers can be organized to make products like shipping containers that require strength. The finish of softwood paper is much more rough and doesn’t make ideal paper to write on. In order to get paper from trees workers must harvest these trees. Logs are transported to the paper company where they soak in soap water to rinse away impurities. Then these logs are put through a wood chipper and then the chips are pulped. In the pulping process the individual wood fibers are separated from one another, the finished product looks like a mushy, watery solution. The solution is spread out on a long screen so that the water an be drained. Then the fibers are squeezed together between rollers. The paper is now steamed and dried into long sheets. A calendar rolls over the sheet to make sure that the paper is consistently thick or thin. Once these sheets are formed the paper is cut, packaged and distributed.
Precipitation is formed and changes between a solid, liquid and gas because of three factors: temperature, pressure and humidity. Humidity is an important effect on the formation of snow because humidity is the measure of the amount of water air can hold. The amount of water the air can hold is dependent on the temperature. The higher the temperature, the move water the air molecules can bond with. When the humidity is high then there is enough water in the air to make precipitation. When the humidity is high there is a large amount of water in the air, if the temperature drops then the pressure also decreases. A drop in temperature squeezes the air molecules close together and squeezes out the water which makes rain or snow. Humanity affects snow in an interesting way because according to the temperature and pressure different snow shapes are formed. At low temperatures dendrites and sector plates are formed and at higher temperatures hollow columns, needles and thin plates are formed. Humidity not only affects snow formation but it also affects how and when snow melts. When the air is humid it is easier to transfer heat to ice from the air. Since the pressure is constant when snow is on the ground, the temperature of melting ice is at a fixed level according to Gibbs phase rule. If the air is more humid then more heat is being transferred to ice from the air and the snow melts. Humidity is affected by temperature and pressure and according to these three factors precipitation can be altered into different phases. In relation to snow, when the humidity is high pressure is high and temperature is low snow is formed. When the humidity is high, pressure is constant and temperature is high the snow melts.
Cement is used, most commonly, to permanently shut off water penetration to a given area. The first step in cementation is preparing the cement. It is crucial to know how much cement you will need for the job. It is also important to identify the proper set cement according to how dense you need the cement and the viscosity of the cement required. There are special mixers such as, hydraulic jet mixers, re-circulating mixers or batch mixers – these are all used to combine dry cement with water and create wet cement, otherwise known as slurry. Accelerators or retardants can be added to the cement to either decrease or increase the time it takes to set the cement. Cementation is possible according to a chemical reaction that ultimately yields the dry cement. First calcium oxide is produced by lime calcination which is possible at temperatures above 825 degrees Celsius at atmospheric pressure for ten hours. Then the calcium oxide is then mixed with water to make slaked lime. Slaked lime is an inorganic compound and appears as a colorless crystal or white powder. The excess water in the slaked lime is evaporated and the setting process takes place. There are forms of cement that harden underwater when constantly exposed to wet weather and this tends to be the hardest forms of cement. However when cement is placed above water the cement must set. The entire setting process is the chemical reaction that produces the cement, this reaction takes a significant amount of time due to the partial pressure of carbon dioxide. Typically the setting process requires a minimum time of 24 hours to complete. Once this is exposed long enough in the air the substance then becomes extremely hard and dense. Cementation is a chemical reaction that is used widely throughout the world for a variety of construction purposes because cement is a durable substance.
The change of season is always very obvious because of the changes to the trees. According to each season leaves vary in different colors the reason behind this change of color is due to the chemical imbalances in the leaves. Leaves receive their nutrients through the process of photosynthesis, which involves using sunlight to convert water and carbon dioxide into sugar. Leafs are a certain color because of the leaves pigmentation. In leaves there are three pigments; chlorophyll produces a green hue, carotenoid creates the yellow, orange and browns, and anthocyanin creates a red color. In autumn there is less hours of sunlight and the temperature slowly drops. Trees respond to the changing conditions are start to produce less and less chlorophyll, and at one point the tree stops producing chlorophyll. At this point the carotenoid which is already present in the leaves, becomes visible and the leaves will start to turn an orange and yellow color. Anthocyanins are very receptive to temperature and cloud cover conditions, when there are a number of sunny autumn days with warmer nights the leaves will be more red that season. The cool nights of autumn being to deprive trees of their nutrients because sugar sap can’t flow through the leaf veins and down into the branches and trunk. Anthocyanin is a protein that is releases as a form of protection so that the plant can recover some nutrients in the leaves before the fall off. The Anthocyanin buys the tree time to drain the leaves of all the glucose before the separation layer is formed. The veins in the leaves being to constrict and a separation layer is formed at the base of the leaf stem. When the layer is complete the leave is separated form the tissue that connects it to the branch and it falls off.
Basketball is a very scientific sport because this sport utilizes both psychics and biology. When a basketball player is engaged in the sport the are stimulating action potentials in their muscles, increasing stimulation of the cardiovascular system, and utilizing hand eye coordination. Then they are manipulating principles of physics to play the sport appropriately such a s trajectory, gravity, air pressure, force, and energy. An important aspect of basketball is dribbling. Dribbling, in basketball, is continuously bouncing the ball with one hand while walking or running down the court. Dribbling is possible because of momentum and energy. As the ball bounces multiple times it losses some energy because this energy is transferred. A basketball player must replace the lost energy by exerting a force on the ball over and over again so that the ball can continue to bounce. Another key component of the game is free throws. Free throws involve shooting the ball from a certain location. Professional Basketball players have mastered the science behind free throws because they practice them so often that their throws become an automated subconscious process and the brain takes over. Learning to throw a free throw involves the manipulation of the cerebral cortex however if they want this information to be stored they use rehearsal to memorize this action and it is then stored in the cerebellum. The cerebellum is not consciously accessible though, and this is why professional players can just naturally throw the ball without thinking too much about it. players take too much time and self monitor that their biology interfere with making the shot. A basketball player must practice free throws and utilize physics such as angles and momentum to arch the ball at an angle that will shoot the ball into the basket. Basketball is a complex sport that is extremely scientific because it requires a balance of biological factors coupled with forces and principles of physics.
When analyzing aerodynamics of flight the first essential reason that flight is possible is because of fluid dynamics. This essentially means that our atmosphere is a massive fluid layer and with physics it is possible to traverse through this layer. There are four basic aerodynamic forces that make flight possible, lift, weight, thrust and drag. Thrust and drag work as opposing aerodynamic forces, and so do weight and lift. Thrust pushes and pulls the airplane forward through space, and drag is the friction of the object moving through the fluid layer. Weight is the force of the gravitational pull on the airplane according to its mass. Lift works using the wings of a plane; the wings split the airflow in two different directions. The faster-moving air flows over the wing and exerts less pressure on it than the slower air moving underneath the wing, and the result is an upward push which is known as Bernoulli’s principle. When airplanes are about to take off an important element that pilots must consider is the angle of attack. This is the angle that a wing hits the oncoming air. the greater the angle of attack, the greater the lift. It is easier for a plane to increase altitude than it is to travel at a fixed level, because at an angle it is better for oncoming air to hit the wing and cause a lift. Flight is also possible because of flaps and slats which are operated in takeoff and landing to change the pressure of the oncoming air. During takeoff and landing, the flaps are extended downward which diverts more air and thus creates more lift. Flight is only possible because of a variety of aerodynamic forces and manipulation of these forces controlled by the pilot.
In a basic sense, nightmares are just bad dreams. They can make you feel scared and extremely on edge but they are not real so there really is nothing to get so worked up over. They have the power to wake you up from your slumber because they are characterized by vivid imagery and intense feelings of guilt, sadness, anxiety, or fear. Young children experience scary or bad dreams substantially more often than adults do. This is because between the ages of three and eight is when you can see a lot of separation anxiety. Nightmares at this young age express the usual struggle to cope with issues and fears. They tend to involve a child being chased by wild animals. This stage of development is quite normal for young children and should be viewed as such. Your kid does not need to go to the doctor or a therapist because he/she is having nightmares.
Around fifty percent of adults have reported having the occasional nightmare and they tend to occur more often in women than in men. Because adults do not have the same type of separation anxiety as young children, there are other causes to these bad dreams. Certain illnesses, especially with a fever, and medications could be a cause of nightmares. The main reason for adult nightmares is the stress and anxiety in most of their lives. Big changes in your life or stressful events can easily lead to scary dreams. Dreams where you are being chased are the most common form of a nightmare. Drowning dreams, natural and man made disasters, and falling can also be the theme of a frightening dream. While kids are usually chased by wild animals, adults are more likely to be chased by a shadowy figure during a nightmare. Nightmares can cause for a very scary or exciting night of sleep, but usually if you can find the source of the dreams, you will stop having them.
Global warming is the gradual heating of the earth and it’s atmosphere. Since the ice age, the planet’s temperature has been increasing; however, the numbers really started to explode after the industrial revolution. At this point in time, a ton of toxins were set free into the atmosphere from factories and power plants. These chemicals being burned caused CO2 and other greenhouse gases to begin destroying our ozone layer. The answer to global warming would be to somehow reverse the industrial revolution, or at least use more renewable sources of energy rather than coal, steam, and nuclear energy.
Some people believe that there is no way global warming can affect us in this lifetime. Religious folks may argue that God created this planet and all of the planets for a reason and he has them under control. Others think that the earth’s temperature can change drastically over periods of time; hence, the ice age. They believe man made inventions and greenhouse gases couldn’t possibly be depleting our ozone layer because global warming doesn’t exist. It has also been discussed that correlation does not equal causation. This means that an increase in temperature and an increase in CO2 levels don’t exactly mean that one causes the other. It can just be coincidental.
I’m quite sure that global warming does exist. You can see the air pollution that come out of cars and factories. It makes the air harder to breathe and you can see the chemicals going into our atmosphere. It’s no surprise to me that global warming is taking place. If we don’t change the way we live soon, polar bears won’t be the only mammals going extinct. Humans could become extinct as well. If the sun depletes our atmosphere enough, we will not be able to survive in such high temperatures.
A scientific theory is a concept that has been tested and experimented with and has been accepted as an explanation of something in our natural world. Evolution is a scientific theory that is also a very interesting topic of controversy. It is a unifying force in biology today. It stresses the idea that we have developed from animals over millions of years and therefore are connected to them in some way. Scientists have found transitional fossils and ring species backing up this theory. Fish fossils from different periods in the past show changes in their body structure to help them survive. Evolution is a solid theory with evidence to support it.
Creationism is the idea that the world as we know it was a divine creation. There is no scientific evidence to support this theory but it is still accepted by a large amount of people. It is a concept based on religion and the existence of God. Creationists may also be called anti-evolutionists. They believe that we were put on this Earth by God and have been reproducing ourselves since then without any evolution involved. Seeing that evidence has been found that living things adapt over time in order to survive, it is hard to believe such a religious theory.
I like to take the side of a theistic evolutionist. A person who believes in this theory understands and accepts both concepts on evolution and creationism. A theistic evolutionist would say that we are beings who were divinely created but we have developed through natural processes over time. This theory is also called evolutionary creationism. Why should we have to choose sides? Honestly, both of these theories discussing our origin don’t make complete sense on their own. Together they form a scientific and religious theory that makes sense and can be backed up by evidence.
It has been argued that the light bulb was the greatest invention of all time. The light bulb was invented by Thomas Edison in 1879. It is constructed of a wire filament surrounded by a glass bulb. The wire is heated to a high temperature by an electric wave passing through it. This creates a bright light which is contained by the glass bulb around it. The light bulb has changed the way the world works as a whole. Everybody uses light bulbs, but we don’t really appreciate them as much as we should. Imagine walking down the street at night with no lights anywhere. There are hundreds of situations where we need lights; without them we cannot live life as we know it.
Some people say that it is ridiculous to think that the light bulb was the greatest invention of all time. Can’t we use candles? Penicillin, indoor plumbing, and the telephone are often heard as well. Penicillin has saved millions of lives; indoor plumbing revolutionized the way we defecate; and the telephone has allowed us to talk to people hundreds of miles away, as if they were right next to us. Some also believe that writing was the greatest invention of all time. Before writing, we could not record any of our knowledge. This means that when people died, any stories or important information that they didn’t pass by word of mouth was gone forever.
I do not believe that the light bulb was the greatest invention of all time. The personal computer including the world wide web, in my opinion, was the most important invention of all time. It allowed us access to an amazing wealth of information and is a key player in the technological revolution. The internet has changed the way humans learn and communicate for the better and it is a major part of the world we live in today.
Many people think that testing our products, chemicals, or medicines on animals is cruel and needs to be stopped. They believe that if humans have the right to not be tested on, so do animals. Our classifications are different but the biological processes, feeling of pain, breathing, and emotions are quite common. The worst part of the whole concept is that animals do not get a say in the matter; they are forcibly experimented with and cannot do anything about it. The best argument in my opinion is the one surrounding the idea that they have feelings too. How would you like to have toxic chemicals poured into your eyes just to see what happens?
On the other side of things, animal testing is a very helpful process when it comes to the safety of the products that we purchase on a daily basis. Everything from the medicine we take in the morning to the shampoo we use in the shower is tested, usually on animals. Animal testing has lead to several medical breakthroughs such as the drug Herceptin. Herceptin was discovered by experimenting on mice in a laboratory. It has increased the survival rate for breast cancer. Mice are good animals to experiment on because of their short life expectancy and similar DNA to humans.
In my opinion, animal testing should only take place in a situation where you cannot test a product on anything else, or with any type of chemicals. Animals have feelings just like we do, the difference is when an animal dies that you aren’t close with it doesn’t impact you as it would if it were your own pet. Animal testing is done with random animals and so scientists believe that they are doing a justice by testing important theories on animals that nobody really cares about. Animal testing is a seemingly important process used by scientists, but it can be quite cruel depending on severity of the test.
Hey my name’s Max Cohen and I am going to be majoring in Business while at Penn State. I am taking this course because I have heard it contains interesting subject matter that I will enjoy learning about. Also my advisor explained that it would be a great way to fulfill my General Education requirements for science. It is not my intention to be a science major because although I did enjoy some of my high school science classes, I look forward to entering the Business world. Although there will not be a science major in my future, I do look forward to the wealth of information this course has to offer.