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Refraction and the human eye
you probably always woundered how we could see out of our eyes. At least EYE always have..... of course there has to be some sort of physics to it right? well of course there is and refraction is there to prove it. Refraction is the phenomenon which makes image formation possible by the eye as well as by cameras and other systems of lenses. Most of that refraction in the eye takes place at the first surface, since the transition from the air into the cornea is the largest change in index of refraction which the light experiences. About 80% of the refraction occurs in the cornea and about 20% in the inner crystalline lens.
While the inner lens is the smaller portion of the refraction, it is the total source of the ability to accommodate the focus of the eye for the viewing of close objects. For the normal eye, the inner lens can change the total focal length of the eye by 7-8%. Common eye defects are often called refractive errors and they can usually be corrected by relatively simple compensating lenses.
Light that passes through the pupil opening, will enter the crystalline lens. The crystalline lens is made of layers of a fibrous material that has an index of refraction of roughly 1.40. Unlike the lens on a camera, the lens of the eye is able to change its shape and thus serves to fine-tune the vision process. The lens is attached to the ciliary muscles. These muscles relax and contract in order to change the shape of the lens. By carefully adjusting the lenses shape, the ciliary muscles assist the eye in the critical task of producing an image on the back of the eyeball.
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Ferro Fluid
This is an example of how magnets can be used for levitation, or hovering if you will. All this is, is simply the force of the magnet overcoming the force of gravity of the magnet and the liquid. In this way, a "hover board" would be nothing other than a force keeping something off the ground, which is just what a normal force is when you have an object sitting on the floor. However, using magnets for levitation is cool because you cannot see the force acting on the object, and the force can also be transferred through things, putting your hand between something being levitated by a magnet would not stop the magnetic repulsion, which is pretty cool to think about and even cooler to see.
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A Lunar Event you can't Miss!
The moon does some strange things if you haven't noticed! And something very strange is happening this Saturday, April 4th! A so called, "Blood Moon", is to occur that will be the shortest of the century, these are very rare occurrences that are very interesting to examine.
The blood moon occurs only when the sun, moon and earth are lined up perfectly with the earth in the middle. The earth as it lines up with the sun casts a large shadow which then envelopes the moon as it passes into the earths shadow. As it does this the moon becomes darker and eventually a reddish hue. The moon is turning red for a certain reason because the atmosphere of the earth filters out the blue light of the sun leaving only the red light to shine on the moon giving it it's signature red moon color.
This blood moon occurrence happens to be a special one though, that is because usually a blood moon occurs twice a year, but when it occurs four times, like it will this year, it is known as a tetrad.
So if a blood moon is when the moon is blood red, a blue moon is when the moon is blue right? Surprisingly no! A blue moon has nothing to do with the color of the moon unlike the blood moon. So what is a blue moon? Well it is a confusing tail.
Originally the idea was traced to the "Maine Farmers's Almanac", which stated a blue moon was the third full moon in a season that contains four full moons instead of three which is a rare occurrence. But the idea was misinterpreted by another author who stated a blue moon is the second full moon in a month with two full moons, this was published and adopted as common knowledge.
Now when you're friends start talking about the lunar cycles at the lunch table you can contribute useful information into the conversation. Enjoy your Saturday night which I'm sure you'll spend doing something other than watching the moon!
Blue moon information from space.com
Picture from toonpool.com
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Crossbows and stuff
Crossbows are a very a cool weapon. They use tension and potential energy to shoot arrows. You first pull the string back, which requires a large amount of force, lock it in place with the spring system and then pull the trigger which drops the lock and sends the string and arrow launching forward at a high velocity. When the string is pulled back and locked in place, potential energy is built up. The more potential energy that is built up, the faster and stronger the arrow will launch once the trigger is pulled. Crossbows are fairly simple, yet very deadly.
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Tokyo Drift
Drifting is when a driver oversteers,or the car exceeds its tire's limits of adhesion, to cause a loss of traction in the rear wheels, when the rear slip angle of a car is greater than the front slip angle. In doing so the front wheels point in the opposite direction of the turn, the car is going left but the wheels are pointed right. Every time we turn a vehicle we resist the change of direction due to Inertia. Simply put, inertia is the amount of resistance to a change in velocity or momentum. Newton's first law of motion connects to this because he said that an object at rest stays at rest or continue with constant velocity unless acted upon by an outside force. So an object will continue as it was unless some external force comes in and messes everything up. Inertia is most often masked by effects of friction and air resistance both decrease speed of moving objects and gravity.The friction between the tires and the road and allow the front wheels to break traction. Turning the steering wheel in the opposite direction, intertia of the car that is trying to slide in the opposite direction is added to the force applied by the engine and the friction of traction between the tires and the road. If the car is front-wheel drive, the rear tires weigh less so they break traction first which causes the rear to slide out. Lifting the throttle makes another weight transfer and enables the rear wheel to weigh even less. Such physics was applied in the movie Fast and Furious: Tokyo Drift. the main character had to master the physics of drifting to beat the antagonist. This called from some amazing racing/drifting scenes. Physics is everywhere whether we acknowledge it or not. But be careful when trying to drift - no saying that you should try, honestly I can't stop you- if the center of gravity is too high you will roll over instead of sliding.
Drifting scene from Fast and Furious: Tokyo Drift :
Learn to drift:
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Sitting on my couch and watching television
When I sit on my couch and watch television (Netflix), there is a lot of physics involved. For example, I do not do any work, because I stay in the same place for hours. Sometimes I get up to go to the kitchen for food, but then I go back to the couch, so my displacement is zero. Also, sound waves, which are mechanical and longitudinal, travel from the television to my ears, which are about ten feet away from each other.
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The physics behind welding
Welding, as most people know, is when you use a torch to melt a material to another material, as well as add some filler material for strength. However, there are a lot of different welds that can be made, and a lot of different ways you can make them. For example, some common types of energy sources for welding include a gas flame, lasers, electric arcs, electron beams, ultrasound, and friction. For the purpose of this post, I'll be talking about laser welding, since it is newer, and involves lasers which are just inherently cool. Welding using a laser beam consists of a concentrated laser beam, which provides a lot of energy making a weld fast, deep, and within a small area. Because of the extreme heat of the laser, however, some materials can be prone to cracking. It is also important to focus the laser properly, as the weld is the most effective when the focal point is just below the surface of the material being welded. Laser welding also has some advantages over electron beam welding, primarily that it can be done in air and is not required to be done in a vacuum, and does not produce x-rays. Welding is just one of those things you dont think about that much, and don't realize how important it is to so many every day things, and it is really cool that innovations are still being made in welding to adapt new technologies, such as lasers, into a hundred year old proscess.
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Quarter Review
At the end of last quarter, I wrote a blog post about how I needed to change a few things because of the disaster that had come about in all my classes but especially physics. I feel that over the course of the past 10 weeks, I have changed the way that I learn and study. I find that I am more focused to get things done and understand them in a timely manner. I use all of the time given to me efficiently as well. Before this quarter, I found myself wasting class time and not doing the work that I needed to do in order to understand the content.
Now that the learning is almost done for most classes and we move into the studying for exams during the last quarter, I need to remember the success that I have had during this quarter and continue it on. I know I can do it. We are now in the final stretch of high school and I am ready for it all.
Until next time,
RK
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Stage Curtains
If you have ever went to see a concert, play, musical or any other performance on a stage, it is very likely that there were curtains involved. Tonight, i was partly responsible for the curtains at the IHS Talent show. The contraption that allows the curtains to move across the stage is a simple pulley system using two pulleys and a rope in-between. When the rope is pulled in one direction, it creates a torque on the pulley and causes it to spin. This spinning either opens or closes the curtain (depending the direction pulled). This contraption is also very common with close-able curtains in your home. And this is a very simple example but i realized thats some of the most simple things help the most!
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The Big 3-0
I Googled "how much force is in a single keystroke" and I'm going to trust a source that says 12.9 N. This will help me in my overall (obviously hypothetical) analysis.
Since this is my final blog post of the year I wanted to sort of wrap it up as well as possible and somehow tie in all of my other blogs. Using an online "character counter", I found out that there are a combined 50,015 characters across my 29 other blog posts, which have an array of topics ranging from pole vaulting to doomsday to Monte Alban. Not accounting for any backspacing, 50,015 is an accurate count of all of the characters I've put into these blogs. Utilizing the accepted force of a keystroke as being 12.9 N, that means I applied an accumulative 645,193.5 N to my keyboard for the purpose of these blogs. That's over 145,000 lbs of force, which seems like far too high of a number but I'm going to accept it regardless for the purpose of making this more interesting. I now wonder what type of things I could accomplish utilizing this much force that does not involve analyzing the physics behind a bladeless fan or a Mexican resturaunt.
I could:
Break 230 backboards (see blog no. 29)
Throw a football very far
Probably jump pretty high
Write 28 blog posts and have enough left over force to perfectly emulate the biting force of an adult Great White Shark
Push the ground really hard and pretend that the dent was caused by 32 1/4 Ford Explorers being stacked on top of each other.
As you can see, if I could somehow have concentrated all of the force that I put into the creation of these blogs into a single motion, then I could have pulled off some of the most incredible feats in the history of mankind. But alas, the people are left with 30 thoughtful, well crafted and occasionally humorous blog posts that will some day be hanging in a digital art gallery. Oh what could have been...
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physics of silly games
A slinky is an extremely fun toy if you are 3 years old, or even 73 years old! The way it transfers energy back and forth throughout it is very similar to a wave. A wave can either be longitudinal or transverse, but in this case, a slinky is like a longitudinal wave. It bunches up at some points, but then expands out with different distances between each metal ring. Waves are found in every day life such as jump rope as well. As you spin the rope constantly around, it represents half of a wave. If you were to play the "Jumping over the rope game" as we used to call it in the olden days, waves are traveling through that rope even more. As you get a steady pace on the rope, more waves are in it. If we wanted to find the speed of the rope, you could use the equation v=fh( h=wave length). You would measure the rope and then calculate how long it is and how long it would take for the wave to hit the crest 10 times. This would give you the frequency and wave length of the wave. Waves are every where and can be tons of fun!
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Physics of Acoustics
Reflection is the change in direction of a wave front at an interface between two different mediums so that the wave front returns into the medium in which it originated. Common examples of this include the reflection of light, sound and water waves. In acoustics, reflection causes echoes. This is why when you go to a school concert, there are those white barriers behind the performers. They are there to reflect the sound from coming from the instruments to the crowd. Acoustics also play an important role in understanding how waves behave because the angle in which the waves hit the acoustics walls, the angle remains the same as it bounces off the acoustics barrier.
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Why Colliding Objects Make Sound
If a tree falls in the forest, and no one is around to hear it, does it make a sound?
When a ball hits the ground or an axe hits a tree, we can hear a noise signaling this collision. Obviously, sound waves are produced, but where exactly do they come from?
When two objects collide, one of two things can happen: an elastic or inelastic collision. In the case of elastic, no kinetic energy is lost. Inelastic, however, involves a loss of kinetic energy. Where does it go?
Part of it goes to heat, but another part of it causes the sound waves to be produced because they need energy. When two objects collide, the molecules of the object vibrate a little, which in turn vibrates the air molecules, creating a longitudinal wave.
So, if a tree falls, it does make a sound because the laws of physics don't stop just because there isn't a human to watch it.
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universal Gravitation
We all know that gravity is the reason for things falling but nobody really knows why. We do know how to find and calculate gravity which helps us understand it better. Newtons law of universal gravitation helps to understand a little more of how gravity works. It states that any two things with mass have a gravitational force between them. The more mass and the closer they are means the more gravity they have. So all of us are pulling on everything with mass all the time but our masses are so small compared to the mass of the earth that it does not have an effect. The Law of Universal Gravitation does not just apply to objects on earth but the entire universe thats why its called universal. Using this law we can discover the gravitational force on any planet that we know the mass of before we even go there.
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Symphony of Science: The Quantum World!
A video combining the amazing lectures, clips and television shows of some of the most famous celebrities and scientists on the planet. Combine it with music and you get the best thing ever.
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Physics of Playing Guitar
When one plays a guitar, it is so important to remember all the physics behind it. Waves have a lot to do with the sound we hear from them. For example, without a large amplitude, it would not be heard. And when one changes notes, it changes the frequency that is heard. Because the wave is longitudinal, it needs a medium to travel through which is why in a vacuum you would not be able to hear someome playing. The pulses vibrate parallel to the wave because in a longitudinal wave thats their path.
Also, playing the guitar has a lot to do with mechanical energy as one strums the strings. Without the physical motion of the player, there would be no sound. Overtones are a cool thing string instruments have that have a lot to di with waves, which is another physics point!
Next time one picks up a guitar remember all the physics behind it!!!
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physics of working out
Working out is the act of building mucsle and exercising your body. In preforming acts of runnig lifting or endurance, you engage in a variety of physics topics including friction, resistence, energy, forces and momentum.
For working out, the act of building mucsle demonstrates an example of resistance and or friction. When lifting heavy objects or moving in a forceful manor, it requires you to condemn in motion that essentialy tears the musles cause the force required is working out your mucsles and you gain strength when they grow back allowing you to deliver a greater force.
In terms of energy, chemical energy is converted, therefor conserved and then transfered to the body in a new form of mechanical energy which allows you to move things and or run and exercise to get in shape. Continueing to expell energy requires more energy to keep up your endurance and allowing maximum potential to work out. By having stored energy or potential enrgy, you have the ability to move and then its transfered to kinetic energy in your work out secssion.
In terms of momentum, bigger and more heavy objects when being lifted contribute a greater momentum against your body inhibiting a greater level or degree of diffuculty for bigger objects and will make more of an impact for you. Because of the more intensive strain it provides. Lesser momentum makes it easier to life and "no pain no gain" implies you will not see great results.
Working out is an action that delivers wide diverse physics topics which are good to understand so you know what is happennning to yourself durring work outs.
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physics in horns
the Doppler effect is when the frequency of a sound wave becomes higher the closer you get to it and then the pitch lowers as it passes you again. when an ambulance is speeding down the street with its sirens on the pitch of the siren changes as it passes you. when it is coming towards you its pitch and frequency start to increase and then reach a maximum as the ambulance is right next to you. then as it drives passed you again the pitch and frequency of the siren lowers the farther and farther away it gets from you. the Doppler effect is the difference in frequency and pitch the siren makes as it passes you.
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Physics of water skiing
Water skiing involves many different components of physics. The fundamentals of it are based mainly on angles and gravity. When you are trying to get up, you have to make sure you keep your ski at a certain angle so that the water pushes down on the ski, creating a downward force that enables you to stand up. Once the force of the water pushing up on the ski is equal to the force of gravity pulling down on the ski, you are able to stay on top of the water.
Tension is also involved in water skiing because the rope from the boat to your hand pulls tightly, creating tension. When the tension in the rope is constant, you will be traveling at the same speed as the boat pulling you. However, since the rope from the boat to the water skier keeps you moving in a circular path. Since you are moving in a circular path, there is also centripetal force. When the centripetal force is high, the water skier may be moving faster than the boat itself.
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Waves of a sporting event
During a sporting event, the players are the ones expected to perform physical activities. However, within the game and the stadium, there are many other types of physics. A few examples are waves. Waves range from the stadium fans, to the sounds of the players, to the light waves lighting up the stadium. One of the most common waves is performed by the fans, but must be done with a lot of concentration and coordination. A stadium wave has most, if not all of the crowd performing a transverse wave that usually has a very long period because of how long it takes to complete. A transverse wave is a type of wave where the direction of energy transfer is perpendicular to its oscillations. The sound waves created by the players and cheering fans are classified as mechanical and longitudinal waves. They are mechanical because they require a medium to travel through, and they are longitudinal because the air particles are caused to move back and forth. Finally, there are light waves which are classified as transverse and electromagnetic. They are electromagnetic because they do not need a medium to travel through , and are transverse due to the same reasoning as the stadium waves. There's a lot of physics within sports and the players, but the rest of the environment contributes to physics as well, as much, if not more than the actual players.
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Go Karting
When I was in Jacksonville I went to a go kart place called the Autobahn Indoor Speedway. These weren't your typical go karts however. At the Autobahn the cars reached speeds up to 50 mph! Drivers have to wear helmets for safety and the speed made for some pretty intense races. There was a lot of physics involved in driving the cars. One of the most important parts of learning how to be as fast as possible was getting used to knowing how much and when to brake around turns. Braking too much will slow you down and can cause wrecks, however not braking enough can cause you to slam your car into the wall, also slowing you down and putting you at risk of wrecks. The only way to do this was through friction. By stopping the rotation of the wheels the tires then grinded against the concrete ground creating friction which is what would slow down your car. Also many forces were exerted with the bumping of cars and from running into walls. If my car ever rammed into another, the force exerted from my car onto his was the same amount of force his exerted onto mine. A lot of centripetal acceleration also takes place at all 4 of my wheels. Even if my car is moving at a constant velocity, the wheels are constantly changing direction as they spin and therefore accelerating inward. Finally the force of gravity is always constant on me and my car. Gravity exerts a force of 9.81 m/s^2, which is what keeps me and my car from flying off of the track. The Autobahn Indoor Speedway was a pretty intense go karting place and I had a lot of fun racing!
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physics of football
Football seems pretty stupid to me. Athletes line up across from eachother, then run at eachother as fast as they can. However, football is my favorite sport to watch. There is alot of large forces coliding in football. Every colision can be related back to physics. The force of anything is determind by its mass and acceleration. The larger the mass of an athlete and the more acceleration an athelete has the larger the force the athlete can produce. NFL players can produce large forces on eachother. This leads to big hits and head injuries.
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The Flash
So, I was watching The Flash awhile ago and they were dealing with particle accelerators. As you know, Flash was created by a particle accelerator explosion that caused him to transform into a man with super speed. I know that doesn't actually but what is in a particle accelerator? What is a particle accelerator? A particle accelerator is a machine that uses electromagnetic fields to shoot charged particles to almost the speed of light, while containing them in beams. Particle accelerators have made big discovers, especially in medicine. They have been used for finding x-rays as well as the discover of a neutron. As of today, there are 10,000 scientists using particle accelerators for x-rays for research in physics, chemistry, biology, etc. Basically they are used for research purposes. That's all for now on particle accelerators. Tune in next time for more physics.
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Feynman
I was doing a little research this past weekend on Richard Feynman and came across a speech that he gave at a meeting of the American Physical Society in December of 1959. Of course, Feynman did many great things but I want to focus solely on this speech which basically foreshadows the amazing things that we would be able to do with nanotechnology. You can read a copy of the speech here, http://www.zyvex.com/nanotech/feynman.html , but I thought I would point points that were most memorable to me. Feynman discussed the concept of writing 24 volumes of the Encyclopedia of Brittanica on the head of the pin. He announced that it would be possible if it is demagnified by 25,000 times and each dot is readjusted by photoengraving. In order to read this small print, we would have to make a mold of the lettering and evaporate gold at an angle so that the little letters will appear clearly in a silica film under an electron microscope. If all 24 million books throughout the world were placed onto pinheads, they would use up the area of about a million pinheads. I thought it was very interesting that although we wouldnt be able to read off the head of a pin, we could send books with little effort to devastated countries and underdeveloped nations. It is incredible to think that over 50 years ago, someone thought of this and to compare this idea with the progresswe have made through the years in nanotechnology.
A very promising lead that emerged from Richard Feynman’s speech was the ability to write on a small- scale. In 1990, the image of atomic manipulation caused quite an uproar. In 1981, scientists developed the scanning tunnelingmicroscope to assist them in seeing single atoms clearly.(Keiper) The image, spelling out “IBM” in just 35 atoms, was created out of xenon atoms and was just the beginning of new advances. By picking up and placing atoms in a desired location, scientists broke through to another new level. Feynman’s speech predicted that this would be possible, as he couldn’t see why it wouldn’t work. Feynman was definitely before his time with many of the topics addressed in his speech but for this particular one, it may have been just what the world needed to get off on the right foot in research and development.
Sorry that's so long and boring; I found it interesting
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