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gdaunton

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Blog Entries posted by gdaunton

  1. gdaunton
    Not much is known about Dark Matter and Dark Energy, however one explanation of these objects could be that our current understanding of gravity is horribly wrong.

    These objects were first discovered by the Hubble Space Telescope in 1998. Before this time it was widely thought that the rate a which the universe was expanding was slowly decreasing from the rate at which it first started. However, as the Hubble Telescope observed supernova, it determined that the most distant had occurred 7.7 billion years prior. Using some complex math scientists determined that because this nova existed 7.7 billion years ago, the rate of expansion of the universe had to actually be accelerating. This puzzled scientists because there was no other force that could cause this that had been observed. So in order to explain this phenomenon they created Dark Matter and Dark Energy.

    Dark Energy was what scientists used to explain the energy which was casing the universe to expand faster. Little is known about what causes this force, but there are some prevailing theories. One theory attributes Dark Energy as a property of space its self, which plays nice with Einstein's earlier gravity theories. However other theory's see Dark Energy as proof that our current understanding of gravity is completely wrong.

    Dark Matter seems to be the more understood of the two mystery things. Dark Matter is mostly agreed to be the stuff that makes up the space in between real matter like stars, nebula, gas, and stuff like that. Although dark matter has just recently been discovered, scientists are confident in their understanding. This is because although dark matter is not directly visible, it can easily be found by the measurement of the way it bends and distorts light from distant galaxy's.


    Its odd how much is unknown about dark matter and energy. Seeing that normal matter takes up only 4.6% of the universe you would think that more would be know about the more abundant dark matter (23.3%) and dark energy (72.1%). As more is discovered about these objects, the way we see our universe could dramatically change.
  2. gdaunton
    If your like me, you love to play the video games, more recent games include Grand Thief Auto V. However, in most of these games guns and ammo are plentiful. Need a silenced pistol, machine gun, rocket launcher, most likely you have one on hand. But in all seriousness, how accurate is the arsenal that you carry on your back in most of these games?

    Well first lets look at GTA V. In GTA a character brings an average of 4-5 guns to a heist plus ammo. If these guns include a pistol, shotgun, machine gun, assault rifle, grenade launcher and rifle the weight adds up... if each gun has say 50 rounds the total weight is around 110 lbs and that doesn't include the weight of the grenades and sticky bombs. Not to mention that with only 50 rounds each you would run out of ammo very fast.



    Other games are worse, possibly the most weight intensive game is DOOM. The average weight is about 150 pounds, this includes a pistol, shotgun, chain gun, rocket launcher, plasma gun, chain saw, and, of course, the BFG.



    Carrying this much seriously inhibits mobility and endurance (I don't care how fit you are), just try to escape the cops with 110 pounds on your back. I'd also like to see you find a way to carry 110 pounds solely with your back without breaking it.

    Next time you decide to rob a bank, don't be fooled by these heavy inventory systems. Conserve ammo and guns, you can only carry so much. But remember kids, stay in school, robbing banks doesn't pay like it does in the games, especially if you don't take physics.
    (I do not condone robbing banks, if you wish to replicate the experience, play payday 2)
  3. gdaunton

    Plasma Globes

    By gdaunton,

    Plasma balls are awesome, they look really cool, and make for some mild entertainment, but how do they create that effect we all know and love?

    This globe of electricity was first discovered by Nikolai Tesla after his experimentation with high frequency currents in a sealed glass tube. He named his creation the "Inert Gas Discharge Tube." This lamp used the high voltage discharge from a Tesla coil to excite an inert gas that resided in the tube which created a streak of light.

    A usual globe today is made up of a electrode that is suspended in the middle of a glass globe, which is then filled with an inert gas and sealed at an intermediate pressure. Most of today's globes are filled with xenon gas, but other globes can be filled with neon, argon, krypton or even a mixture of gasses.
    An argon and a krypton globe.
    A neon and a krypton-xenon globe.

    So how does the electrode create the plasma inside the globe? Well first we need to apply a voltage to the electrode to create a stable electric field between it and the glass globe which allows the electrons move freely through the gas. Then at the same time we apply a second oscillating voltage on the electrode, the alternating electromagnetic field that this creates is what keeps the electrons moving in the gas. As the electrons gain more and more energy as they move around the globe they iodize the gas which creates the streaks of plasma light. Because of the pressure of the gas in the globe, the collisions between particles become more frequent. As the collisions become more numerous, the ions start to recombine with free electrons and turn the gas back to its unexcited state. This concentrates the electrical discharges into narrow tendrils which creates the light show everyone is familiar with.

    So what happens when you pump a whole lot more voltage than your supposed to through one. Well it gets very interesting of course, Give it a watch.


    Pictures from www.teslaboys.com
  4. gdaunton

    Kerbal Space Program

    By gdaunton,

    Recently I've been playing Kerbal Space Program. If you haven't heard about it yet it's this game where you build rocket ships and send them off into the great unknown. The thing that in unique about this game is that it has one of the most complicated physics engines I've seen in a game.

    This game is very realistic, and because of this is also very complicated. In order to get in orbit of the earth is a challenge all it's self. In order for your ship to be able to escape the atmosphere it needs stages. The trick is to design a ship that has a good balance between power and weight, so you need engines in each stage that can handle the load of all the other stages fuel. This is where the game gets tough, in order to go to other planets, you need to find a way to get loads of fuel into space, but can't escape the atmosphere with all the fuel on one rocket.

    At this point you set up space stations that hold fuel that can be docked to. These fuel check points aren't the only way to achieve interplanetary travel. You can also assemble your ship in-orbit by sending up separate parts and then attaching them together.

    All in all it is a fun game that implements very realistic physics and is loads of fun. Give it a play if you can, you wont regret it.


  5. gdaunton

    The Physics of Sailing

    By gdaunton,

    Sailing is very very old. The first representation of a sailboat was in Kuwait dating between 5000 and 5500 BC. This technology is not only old but also has some cool physics behind it.

    The basic principle of sailing is as follows:


    -As a boat sails across the wind the sail redirects the wind, causing the wind below the sail to be slower than the wind above the sail. This causes a low pressure system under the sail which causes lift to push the boat sideways and forwards.

    -As a boat sails with the wind, the wind simply pushes on the sail causing the boat to accelerate.


    However, in this new age, boats are being made that go faster than the wind that pushes them. How is this possible?


    Well think about this: doesn't it seem that when you roll down the windows on the highway that the wind is a lot faster outside the car than when you are stopped?

    The same thing happens with these massive sailboats. As the boat moves faster the relative wind speed increases and the boat continues to accelerate. To find this relative wind speed we use the equation vr = vb + vw where vb = the boats velocity and vw = the winds velocity. According to this equation the boat can continue to accelerate until the drag from the water matches the force of the relative wind pushing the boat forward.



    But in the case of the AC72's racing in the Americas cup, in order to sail faster and faster, they needed to find a way to reduce the drag from the water. To do this the boats rise up on hydrofoils and literally fly on top of the water.

    These foils also use a very basic physics principle: Bernoulli's principle. As water moves over the top of the foil it slows down where as the water under the foil stays the same speed. This creates a low pressure zone above the foil which creates lift.



    Air planes use this same principle to create lift to stay in the air.

    All these principals come together to make a 72 foot boat go 50 mph in 24 mph winds




    My sources:
    http://www.phys.unsw.edu.au/~jw/sailing.html
    http://www.unc.edu/~thriveni/sailing/lift.html
  6. gdaunton

    Salutations!

    By gdaunton,

    Hello, it's nice to see you.

    Wow, did last year go fast. AP-B was quite a voyage for me, and I would like to thank Mr. Powlin for leading the way in the best way possible. I learned a lot in AP-B and decided that I would like to learn more, and now here I am in Physics C.

    Anyway I should probably tell you a bit about myself. I am an avid programmer, I mostly code in java and have most of my experience in the android platform. I actually programmed the revised aplusphysics app (which you can find here) for android. You should download it and let me know what you think. So, instead of programming, I also spend a lot of my time sailing. I sail J/24's and 420's through the Rochester Yacht Club during the summer as well as during the fall and spring season of high school.

    I look forward to learning about how we can derive the equations we used in AP-B so I can better understand the equations and how to apply them. I also look forward to applying the physics we learn to things that happen in the real world, cause' that's the coolest part of physics (at least in my opinion).

    Regardless of what we do in physics this year I'm sure I'll have fun.


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