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DanDuguay

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Everything posted by DanDuguay

  1. Holography is the art of 'lensless photography'. It is typically formed by reflected light captured on film. For example, a laser would hit an object. The object then reflects the light, and the reflection of the light is what is captured on the film. The images from a hologram contains more information than a traditionally photograph. The image is three dimensional and exhibits parallax. Holograms have cool properties that aren't displayed in photos. My personal favorite is that in a transmission hologram, the one previously explained, every piece of the film contains the whole image. So If you cut of a tiny corner of the film, you see the same image as the complete hologram. So you can cut the film up into a hundred different pieces and the image would be the same on all of them. Also, holographic images scale with wavelength. This is exciting because in theory, one could make a holographic image using x-rays, and view it using visible light. Although this has yet to be done, the potential is there and the benefits can be significant. Holograms are often thought as movie props, or just a smoke and mirror science, but holography is a very important part of the optics field. Holography has the potential to do many things. Holography is used in the laser lab in downtown Rochester. Holography can be used you decrease the size of lasers, which will help in power alternatives in the future. Holograms, while very fun, are also very useful.
  2. Soccer, the most popular game in the world, has a lot of physics under the surface. The first is Newtons first law. The law of inertia. The ball stays at rest until acted upon. usually by a players foot. Then it stops only by an outside force. This could be friction from the field, air resistance, or another player. You can also factor in Newton's other two laws as well as momentum and a variety of others. The best physics in my opinion however, is the bending of the ball on a shot, or the Magnus affect. The bend and dip on the ball is mostly because the player kicks the ball at a certain angle and velocity. The players put spin on the ball in order to neglect air resistance. On average, a shot is kicked at around 65 mph, after about 10 meters, the speed drops dramatically, and the drag on the ball will dramatically increase. As the velocity drops, the Magnus effect substantially increases and this is the major reason why the ball will dip and curve through the air.
  3. What is a laser you may be asking yourself No? Understandable, but I will tell you about them regardless Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. There are many variations of lasers but all have the same core parts. Those Parts are a medium, two mirrors, and an energy source. Energy from the power source excites the electrons in the medium. The excited electrons produce photons of light. There are two mirrors facing each other in a laser. One of the mirrors is completely reflective, the other is only partially reflective. The photons bounce back and forth twixt the mirrors. As a photon hits one of the mirror, it splits and also helps stimulate other electrons. This is called the gain. Naturally however, energy is lost and not all the photons make it to the other mirror. This is called the loss. As long as the gain outnumbers the loss, photons will continue to go through the partially reflective mirror, and those photons is what you see coming out of the lasers. There are many different kinds of mediums for lasers. There are dye lasers, gas lasers, crystal lasers and more. Also, you can have a lot of fun with laser pointers and diffraction gratings. If I figured out how to post videos on here, I would put a video, but alas, I cannot, so I implore you to explore the mystical youtube in pursuit of cool laser videos. They aren't hard to find.
  4. The selfie is something that has become hugely popular. People are constantly taking pictures with their phones and this has become a common part of our culture. With all these people taking pictures on their phones, the question arises, is it worth it to buy a camera or just use your phone? The major camera type is a DSLR ( digital single lens reflex). The DSLR I use for comparison is a Nikon D80 which is a pretty average DSLR so it will be a good representation of the average. There are many differences between the two. the first difference is in the lens structure. The iPhone has a five element fixed lens system. This means that there are a total of 5 lenses in the iPhone camera and they cannot move independently. This limits the phones ability to focus at different ranges. The average DSLR has a 16 element detachable lens system meaning that it has 16 lenses that can all move independently from each other. This allows for a much greater focus at every distance. The cameras also have different sensors in them. The iPhone has an 8 megapixel CMOS sensor. A CMOS sensor is cheap to produce and has a low power consumption, however, it isn't nearly as sensitive to lighting and contrasts in brightness and colors. The DSLR has a 10.2 megapixel CCD sensor. They are more expensive and less efficient but do better with contrast and are more sensitive. The difference is most notable in pictures with very dim lighting. This also has to do with a larger aperture on the DSLR too. The bigger the aperture, the more light that is able to come in. Lastly, there is a large discrepancy in pixel size. Contrary to popular belief, the amount of pixels doesn't really matter after you get above 8 megapixels because we cannot develop pictures and display pictures where anything past that would make a difference, unless you are printing a giant picture, which would be doubtful. Pixel size makes deeper colors and makes the camera able to display more contrast. The bigger the pixel size, the more photons the pixel is able to collect, ultimately leading to a better photo. One important note to add is that the processing on the iPhone has gotten very good. Many of the flaws in the camera can be fixed in the post processing. There are many apps and filters and such that can hide and fix any blemishes in photos. All in all, a DSLR is a better camera. It takes better pictures. However, for a phone, an iPhone camera isn't bad. So if you want to take serious pictures or are going on a trip and want clear vivid photos for your memories, a DSLR is the way to go, but for casual pictures, an iPhone will be more than suitable.
  5. The physics behind a hockey check is fairly simple. It is a basic collision. One force, the checker, is coming in with a mass and acceleration, onto and another player with a separate mass and acceleration. As Newton's law states, every action has an equal and opposite reaction. So the player with a bigger mass will be able to absorb more of the hit, and a smaller player, much less so. The Player who was hit will stay in motion unless acted upon by an outside force. A lot of times this is the boards. Many injuries occur by players going into the boards with a lot of force. The boards are unforgiving and do not have a lot of give meaning a short impact time witch means a lot more pain for the person being checked. However if a player is against the boards, he will be much safer when checked. The collision force would be transferred from the player to the boards back to the player and back to the original checker. For example, if a player gets hit by a 20N force, he will then transfer 20N to the boards but some of that force would come right back because of a recoil. This is why you often see the original checker fall down after making a check on someone who is along the boards. Lastly the players momentum is the ultimate determinate of the strength of the check. Momentum (p=mv) is constantly changing while on the ice. The players mass is a constant, so in order to increase their momentum, players will go faster. Higher velocity means more momentum, means bigger collision. Checking is an important part of the game and is all just applying forces to other players. So in conclusion, in order to deal the biggest hit, you want to maximize your mass and velocity, and when taking a hit, try to have the boards absorb the hit rather than just you.
  6. The Universe is a fascinating topic. How the universe was made can be traced back to many things, I don't wish to offend anyone, but I will not be talking about any divine powers, just some scientific theories. Most Theories start with a big bang of sorts. The big bang is really more of a cosmic stretch of the universe. Most people know about the big bang or at least the basics, so I will proceed to other theories about the origin of the universe. The first theory involves another dimension. The idea is that our universe is a 3-D ball bouncing around in a 4-D plane. We are not the only 3-D universe in this plane and these "balls" collide. This collision is a new 'big bang" and the cycle goes on. This would mean that the life of our universe expands and continues until it resets by colliding with another. There are flaws with this theory, like how can the balls be expanding because we know the universe is, what is the limit to the size? Also, it addresses nothing with the 4-D plane, we have no limits for that. Another theory is a similar one, dealing with the 4th dimension. This one says that the universe is constantly expanding and in doing so, thins out. The universe is created by the implosion of a 4-D star, and thins in 3-D until it creates the foundation of another universe. This theory explains the expansion and accelerating of the universe but again fails in any justification for it's 4-D claims. Lastly is the most abstract theory. This theory doesn't address the creation of the universe but addresses the idea of time itself. It is the idea that there is no past or future just a series of moments. Our perception of time is just the progression of these moments. By this theory, the origin of the universe is irrelevant because time itself doesn't exist, it's just a perceived illusion. I personally don't like this theory because it's impossible to prove, but it makes you think.
  7. So are you saying that in one of these dimensions you're actually good at super Mario??. Fascinating stuff Jake, and don't go putting your cats in radioactive boxes, alright big guy?
  8. I am a senior in high school. I enjoy physics. These are two facts about me. I have enjoyed math for quite some time now and the application of math is what really draws me to physics. I am taking AP Physics C because I enjoy a good challenge. I have a thirst for physics that cannot be quenched by any other class. This class offers a unique opportunity to expand my understanding and increase my skill in physics while at the same time makes me frequently consider my decision to take the class. From this class, I hope to gain a solid foundation in physics. Physics will be a major part of my future career and academic ventures, so I want to head in to the future with the tools that will allow me to not only survive, but flourish in my future environments. This year I am most excited about working with such an amazing teacher..... bonus points would be appreciated. But in all seriousness, I am excited to expand upon my knowledge of physics as well as learn more about the areas of physics that interest me. I also enjoy labs. Although theoretical physics is all fine and dandy, I really get my kicks from applying what we've learned in labs and experiments, as well as real world examples. I am most anxious about the difficulty and the workload. I have never dealt with a load this large and it is frightening to say the least. Not only is it a lot of work, but the work is challenging as well. This makes it rewarding but incredibly difficult as well. But as the ancient Chinese proverb says, "All things are difficult before they are easy".
  9. Jelliott, I can really relate to your analogies. I too wish to become a beautiful butterfly, to grow and grow until I burst with knowledge. although I find some of your post humorous as intended, I think you struck on very important ideas. I think hard problems can be torture but on the other hand, that makes them that much more rewarding when completed.

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