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running_dry last won the day on March 24 2014

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  1. Launch Time: a few minutes Team Members Present: Olivia and Josh Play-by-Play: The solid boosters fire and the rocket lifts off, navigation aided by SAS. The boosters loose fuel around 10km and they are decoupled and the main engine fires. The rocket soars well past 50km and main engine runs out of fuel, third stage separates and radial engines fire while Josh attempts to burn sideways to achieve orbit but he waited too long to fly sideways and to boot runs out of fuel very fast. The team makes a split second decision to EVA Jebediah before the rocket lands back on Kerbal. after a brief EVE Jebediah returns to the cockpit and straps in for a rough landing. The capsule catches fire during reentry but does not burn up and the parachutes deploy successfully for a safe landing in the ocean. Photographs: see bottom Time-of-Flight: will edit later but not very long Summary: We did not meet to goal of manned orbit but we did do a successful EVA and a manned launch to at least 274km, well past 50km. If only one challenge is allowed to be met per post then we would like to claim the first documented EVA. Opportunities / Learnings: we need more fuel for the third stage "orbiter" capsule and must start angling the rochet much sooner. Also, use fuel or the main engine more slowly Strategies / Project Timeline: We will modify our craft to achieve and manned orbit or maybe an unmanned satellite, as well as research orbital mechanics in the game in order to achieve orbit more efficiently. Milestone Awards Presented: First EVA for $60000, third place manned launch to 50km (?) for $7500 Available Funds: we recovered the craft and received half the cost back, bringing the cost of the rocket to $17540.60 our balance to $68643.6. Assuming that we receive both awards we will have $136143.6
  2. Team Name: Dyrleo Enterprises Available Funds: $86,184.20 Vehicle Name: 50k take two Vehicle Parts List and Cost: TT18-A Launch Stability Enhancer (4x200), Rockomax Mainsail Liquid Engine (850), Rockomax X200-32 Fuel Tank (2x6600), Rockomax BACC Solid Fuel Booster (4x800), standard canard (4x500), aerodynamic nosecone (4x680), Rockomax adapter (50), struts (4x250), TR18-D stack separator (600), FL-T400 Fuel Tank (850), Rockomax Mark 55 Radial Mount Liquid Engine (4x850), TT-38K Radial Decoupler (4x600), command pod mk1 (600), parachute (422), radial parachute (2x700) +10% tax = $35081.20 Design Goals: Produce a stable manned orbit or Kerbin. Launch Goal: Learn through experience how to put a rocket in orbit about Kerbin Pilot Plan: The pilot will keep the rocket traveling straight up and then turn and burn sideways once a certain and unknown altitude is reached Illustrations:
  3. In December of 2013 physicists discovered a way to approximate the amplitude of scattering sub-atomic particles in a way that is much, much simpler than the old method. The idea is that given a set of parameters and whatnot, a geometric object, which is being called an amplituhedron, can be constructed such that it's volume equals the amplitude of a scattered particle from a quantum interaction. The old method involved using hundreds to millions of Feynman diagrams, which show possible ways the particle could scatter, and summing the probability of each situation occurring. Even a simple interaction had to be modeled by a formula several billion terms long but the amplituhedron process reduces that to just a few pages of work. For example, the diagram to the left represents an 8 gluon particle interaction. If the same calculation were to be done with the Feynman method it would involve around 500 pages of calculations. The implications of this are enormous, and this may be a big step in the direction of a functional unified field theory.
  4. I would like to take a step back from physics to propose another law on the effects of procrastination on the APlusPhysics blogs. I have already explored the relationships between amount of procrastination and both quality of blog posts and hours slept the night they are due. Every time I refresh the "dashboard" page five new posts pop up, and I have noticed that the same posts don't stay on the front page for very long. It would seem that we are all hurting ourselves in terms of views by all waiting until the last possible second to do these because in the time that it takes to write the next post, your last post has already disappeared, never to be seen again by anybody. On the other hand increased site traffic might expose your blog to more potential readers. All of this of course really only matters if you care about how many people read your posts (I do, just because I take the time to write them). I could also be mistaken about how the dashboard works....
  5. I just found a video of a man playing a Tesla coil as a musical instrument. With a guitar. Basically, the guitar still works the same way but rather than sending its MIDI signals (notes and such) to an amp, it is being sent to a Tesla coil. Tesla coils work by sending alternating current through a wires coiled into a torus (donut shape). The changing current charges a larger torus trough electromagnetic induction. The voltage induced in the second coil is much greater than the first which allows a capacitor to be charged to the extreme where it trows visible electricity to the nearest conductor. When the coil is turned on it makes a noise, so the trick to making music with a Tesla coil is to alternate current at a frequency at which our brain can interpret music (it turns out to me about 440 hertz). Notes can be created by modulating the amplitude of the current. In the case of the guitar, the players input on the strings is used to modulate the amplitude. Here's the video i was talking about: And then I found this and my mind was blown... METAL!!!
  6. Kickstarter is full of cool stuff but a project called Altergaze really caught my eye. What it is is a 3D printed platform with a set of up to 3 lenses inside and a holder for your smartphone. The lenses magnify the screen so that it takes up your entire field of view, allowing you to watch video and whatnot in giant, beautiful panoramic views. And the beauty of it is that since it it 3D printed, the firm starting it is making the templates open source and offering partnerships to just about anyone with a 3D printer. They supply the lenses but you get to choose colors and can modify the phone holder to accommodate any kind of phone you want. You can check out their kickstarter page here: https://www.kickstarter.com/projects/278203173/altergaze-mobile-virtual-reality-for-your-smartpho?ref=category The physics comes in with the lenses. The lenses magnify and bend your field of view by refracting light in such a way that makes your phone's screen everything you see.
  7. The second major type of telescope is the reflecting telescope. The reflecting telescope was invented by Newton and considered an improvement on Galileo's design. Most reflecting scopes still use Newton's design. Reflecting scopes use a wide concave mirror at the back of the tube to bring light to a focal point in front of the mirror which is then usually reflected sideways toward the eyepiece by a flat, angled mirror. There are also compound scopes that work like reflecting scopes but there is a hole in the center of the concave mirror and the mirror at the foal point reflects light back through the hole where it is magnified by an eyepiece at the end of the tube. Below are diagrams of both reflecting and compound telescopes. Now for some pros and cons. Refractor tubes are usually longer and skinnier, thus have smaller apertures (and cost more per unit of aperture length); while reflectors are wider and shorter with larger apertures (and less cost per unit of aperture length). Because of this, refractors are usually more expensive and better for observing close planets while reflectors are better for observing deep sky objects like galaxies and nebulae.
  8. Last night I happened to look up as I was walking inside at around 10 and noticed that I could see a lot of stars. Like a lot. I am quite a fan of stargazing but despite owning a telescope I have always done it with my naked eyes. But I was in the mood to see some planets in detail so I lugged down the old telescope from the attic and dusted her off only to make a distressing discovery- all the eyepieces were missing (you need those if you want to see anything). My dad and I scoured the dust and cobweb infested boxes in our attic for half an hour but came up empty handed, and I had to resign to reading a book. Now that you have gotten through my exceptionally boring story, I would like to tell you how telescopes work. The basic function of a telescope is to collect, focus and magnify the light emitted from celestial bodies (stars, planets, nebulae, galaxies, ect...). In many cases, it is actually more important to collect and filter light than it is to magnify it. The ability of a telescope to collect light is related to it's aperture- which is it's lens or mirror diameter- and it's ability to magnify depends on magnification. Aperture is usually harder to expand as it depends on the diameter of the telescope tube but magnification can be changed as easily as screwing in a new eyepiece. The first telescope created by Galileo was a refracting telescope. Contrary to popular belief, Galileo did not invent this technology but he was the first to apply it to the art of stargazing. Refracting scopes use a large objective lens at the front of the tube to collect and bring light into a focal point in the middle of the tube. From there it can be focused and magnified by the eyepiece. Below is a diagram of how light travels through refracting lenses. Check out my next post for reflecting telescopes and closing thoughts.
  9. In December of 2013 the European Space Agency launched Gaia, the most accurate telescope to ever be put into space. Its 1 gigapixel camera (that's 1 billion pixels or 1000 megapixels) is said to be able to measure a human thumbnail from the moon or detect the width a human hair from a distance of 1000 Km, which is some pretty incredible imaging science right there. Whats more, telescopes work better where its dark, so the ESA is putting it in orbit around the sun, around the L2 lagrange point which is out past the moon- which sounds funky but let me explain. L2 is 1500000 Km from the Earth in the direction away from the sun, and from there Gaia will orbit the sun with the same period as the Earth, but free of much of the Earth's light and gravity. Rather than staying still at the L2 point however, ESA is using advanced flight dynamics to put Gaia into a 3 dimensional pendulum-like orbit about L2. [below are visuals of the L2 lagrange point and Gaia's motion around it] The period of Gaia's motion around L2 is going to be about a year an a half. From its orbit around L2, Gaia will operate for at least 5 years creating a very accurate map of over a billion stars, a million quasars and search for exoplanets. The images produced by NASA's hubble telescope are stunning, but with much superior imaging technology and being a million kilometers farther from earth than the Hubble, I can't wait to see what Gaia sends back.
  10. I have been somewhat obsessed with space lately. I also recently learned that there are spacecraft outside of our solar system, which for some reason just seems really cool to me. In September of 2013 Voyager 1 officially left the heliosphere, which is the area in space dominated by solar winds and charged particles from the sun and extends about twice the distance from Pluto as Pluto is from the sun. The deep space probe Voyager 2 was launched on August 20th, 1977 and Voyager 1 was launched two weeks later on September 5th. Voyager 2 has yet to breach into interstellar space. Despite the fact that it was launched earlier, because it is traveling slower than Voyager 1 at some 15 Km/s relative to the sun compared to 1's 17 Km/s. The original purpose of the Voyager mission was to explore the outer planets of the solar system. After providing great data on Saturn, Neptune and Pluto in the 80's the mission was extended to gather data on interstellar space, space dominated by radiation from stars other than our sun. Both probes are still gathering and sending data back to the earth, which takes about 17 hours to travel from the probe's transmitter to NASA's Deep Space Network, a global array of giant radio communication dishes. The probes will be able to record and transmit data until 2025 when their nuclear batteries are expected to die and then they will sail though the cosmos for the rest of eternity, lonely travelers among unknown worlds.
  11. A few days ago scientists confirmed that there is liquid water on Enceladus one of Saturn's 53 or so moons. The surface of Enceladus is covered in a thick sheet of ice but NASA's Cassini spacecraft which has been orbiting Saturn since 2004 has sent back images of geysers of ice, water vapor and organic compounds shooting out from cracks in the ice at the south pole of Enceladus. This was the first sign that there may be liquid water below the ice. Also, NASA noticed slight changes in Cassini's trajectory and the wavelength of it's radio signals which suggested that Enceladus has a greater mass at the south pole. In addition, it has long been known that Enceladus is flatter at the south pole than anywhere else. The best explanation for both phenomena is that there exists a large body of liquid water, which is both denser and has less volume than ice, underneath the south pole. This subterranean ocean is estimated to be about the size of lake superior and is particularly exciting because it is thought to sit above a layer of rock that could provide chemical reactions which when coupled with the organic molecules in the geysers could possibly produce simple organisms. Unfortunately Cassini doesn't have the instruments needed to properly test the makeup of the molecules in the geysers and the ice above the lake on Enceladus is somewhere around 20 miles thick so a much more sophisticated robot would need to be sent in order to search for life. Below are a Cassini picture of the ice plumes at the south pole and a rendering of Enceladus's cross section.
  12. First of all I have to say that I'm surprised that nobody here has blogged about this yet. But in case you haven't heard yet, March 17th was a big day for science, and physics in particular. Researchers from Harvard University and the Smithsonian released evidence of distortion in the cosmic background radiation (shown to the right) caused by gravitational waves from when the universe went through inflation after the big bang. The idea is that in the 1x10-35th of a second after the big bang the universe expanded very rapidly at a speed much larger than the speed of light (and yes, that is possible since its the universe itself was moving). So what exactly does this mean? First of all, it is direct evidence that the big bang happened. There still may be a little uncertainty but the team that found this distortion has been looking at it for three years ruling out every other possibility so chances are it's exactly what they say it is. It also may have profound effects on our understanding of physics. Gravity waves were the last untested part of Einstein's theory of general relativity and with this evidence its now a complete theory. There is also a chance that it may lead to a unified theory of modern physics. As of now general relativity (the physics of very large things) and quantum mechanics (physics of very small things) don't work together but this discovery could help bridge the gap between the two. Also, most of the current theories of inflation include the existence of multiple universes and this evidence narrows down the theories a lot to the ones that include a multi-verse. The possibilities with this are endless because there is a chance that other universes will have laws of physics different than our own, which would be crazy but awesome to study. Scientific breakthroughs of this magnitude don't happen often but when they do they usually lead to a vastly improved understanding of the mechanisms of the universe.
  13. In the last few minutes I have noticed a lot of activity on the Aplusphysics blog, which is strange because it's almost midnight. Oh wait, blogs are due tomorrow? That explains something. Right now is the time when everyone cranks out those last couple posts that should have been done weeks ago, and I'm just as guilty as the rest of you. I want to be asleep right now more than anythi- hold it right there, if I'm writing this blog post I must want a good physics grade more than sleep. I also just discovered an interesting connection here. Amount of procrastination has an inverse relationship with hours of sleep the night before midterms start. I would also like to argue that the line illustrating this trend has a vertical asymptote at the y-axis because in theory if all of my work was done right now I could sleep for an infinite number of hours nevermind that was dumb- I won't live forever. I have created several graphs illustrating my point. I don't like them.
  14. So the other day I was skiing along on one of those straight, flat trails so I was naturally a little bit bored. So I decided to see how high I could jump. I pushed off the ground pretty hard and... got like 2 inches of air. I was pretty disappointed in myself so I tried again. This time a squatted down and pushed off the ground with as much force as my skinny legs could muster and... 2.5 inches. Whats wrong with me? So I stopped and tried to jump vertically while not moving and I got much higher (although it was still pretty embargoing). I stood there for a minute and tried to figure out what was going on. Why can I jump higher while standing still than while moving? Eventually I hypothesized that while standing still the vector of the downward force created to make the jump is directed normal to the ground, maximizing the reaction from the ground; however if you try to jump while sliding across the snow on your skis some of the force is applied parallel to the ground due to your forward motion, in effect creating the same magnitude of the resultant force vector but at an angle which trades some vertical height for horizontal distance. Or maybe I'm just really bad at jumping...
  15. Today was one of those days when all the roads were covered in snow, which is bad for driving and even worse for running. A few steps in that salty slush and you'll be slipping all over the place. What I've found is that snow sticks to the bottom of my shoes and stays there, so rather than my rubber soles trying to get traction with snow, there is just more snow trying to get traction with the snow. This drastically reduces the coefficient of static friction between my shoes and the road, causing my feet to slip every step which gets really annoying after about 20 feet. Also less frictional force means less effect from newton's third law and more energy wasted every step making running a tedious task at best.
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