Theory of relativity The theory of relativity, or simply relativity in physics, usually encompasses two theories by Albert Einstein: special relativity and general relativity.[1] Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space contracts and time dilates.Spacetime: space and time should be considered together and in relation to each other.The speed of light is nonetheless invariant, the same for all observers. The term "theory of relativity" was based on the expression "relative theory" (German: Relativtheorie) used in 1906 by Max Planck, who emphasized how the theory uses the principle of relativity. Scope[edit] The theory of relativity transformed theoretical physics and astronomy during the 20th century. In the field of physics, relativity improved the science of elementary particles and their fundamental interactions, along with ushering in the nuclear age. Two-theory view[edit] History[edit]
Tesla Turbine: Engine of the 21st Century? The Tesla Turbine could far surpass the efficiency of the internal combustion engine. Recuperative hydraulics can be used for low-speed, high-torque needs. by Sterling D. AllanPure Energy Systems NewsCopyright © 2007 MUNISING, MICHIGAN, USA -- Nikola Tesla created an engine design nearly 100 years ago that is as much as three or four times more efficient than the combustion engine design that has dominated for reasons other than science. At the time of his invention around 1909, Tesla was able to demonstrate a fuel efficiency of 60% with his bladeless turbine design. The politics of his day impeded Tesla's design from being implemented. Enter Environmental Scientist, Ken Reili , CEO of Phoenix Navigation & Guidance, Inc. Rieli and his associates in the popular Phoenix Turbine Builders Club that he founded, have resurrected and improved Tesla's Turbine design. In addition to transportation, potential applications range from home generators to public utilities to locomotive power. Modern Data
Thermodynamics Annotated color version of the original 1824 Carnot heat engine showing the hot body (boiler), working body (system, steam), and cold body (water), the letters labeled according to the stopping points in Carnot cycle Thermodynamics applies to a wide variety of topics in science and engineering. Historically, thermodynamics developed out of a desire to increase the efficiency and power output of early steam engines, particularly through the work of French physicist Nicolas Léonard Sadi Carnot (1824) who believed that the efficiency of heat engines was the key that could help France win the Napoleonic Wars.[1] Irish-born British physicist Lord Kelvin was the first to formulate a concise definition of thermodynamics in 1854:[2] "Thermo-dynamics is the subject of the relation of heat to forces acting between contiguous parts of bodies, and the relation of heat to electrical agency." Introduction[edit] A thermodynamic system can be defined in terms of its states. History[edit] Etymology[edit]
BirdCam, Round Two In the October 2013 issue, I described the hardware and software I used to create my "BirdTopia Monitoring Station", more commonly called BirdCam. If you've been visiting BirdCam recently, which a surprising number of folks have been doing, you'll notice quite a few changes (Figure 1). In this article, I describe the upgrades, the changes and some of the challenges along the way. If you like fun projects like these involving Linux, please read on and join in my birdy obsession! Figure 1. BirdCam has changed a lot. Slicing and Dicing One of the first changes I wanted to make to BirdCam was to zoom in a bit on the feeders. convert /dev/shm/original.jpg -crop 640x360+1800+1425 \ /dev/shm/birdbath.jpg convert /dev/shm/original.jpg -crop 1920x1080+220+130 \ /dev/shm/birdbath.jpg -gravity southeast -composite \ /dev/shm/final.jpg Figure 2. In the code snippet above, I crop out the small birdbath photo from the original camera photo and save it as birdbath.jpg. Time and Temp The WindowCam
Statistical mechanics Statistical mechanics is a branch of mathematical physics that studies, using probability theory, the average behaviour of a mechanical system where the state of the system is uncertain.[1][2][3][note 1] The present understanding of the universe indicates that its fundamental laws are mechanical in nature, and that all physical systems are therefore governed by mechanical laws at a microscopic level. These laws are precise equations of motion that map any given initial state to a corresponding future state at a later time. A common use of statistical mechanics is in explaining the thermodynamic behaviour of large systems. Statistical mechanics also finds use outside equilibrium. Principles: mechanics and ensembles[edit] In physics there are two types of mechanics usually examined: classical mechanics and quantum mechanics. Using these two ingredients, the state at any other time, past or future, can in principle be calculated. Statistical thermodynamics[edit] Fundamental postulate[edit]
SciPY for Scientists In my last article, I looked at NumPY and some of its uses in numerical simulations. Although NumPY does provide some really robust building blocks, it is a bit lacking in more sophisticated tools. SciPY is one of the many Python modules that build on NumPY's. To start, you need to import the main scipy module. import scipy This imports the common set of functions and objects used in SciPY. from scipy import signal The simplest package in SciPY probably is the constants sub-package. Linear algebra is one of the heavy uses of computational code. from scipy import linalg linalg.solve(A,b) In many physics and engineering problems, you need to find eigenvalues and eigenvectors. Most people default to using R to do statistics, but you don't have to. stats.ttest_1samp(x, m) where x is your data and m is your model. A topic near and dear to my heart is solving differential equations. Last, but not least, let's look at the weave sub-package.
Quantum mechanics Description of physical properties at the atomic and subatomic scale Quantum mechanics is a fundamental theory in physics that describes the behavior of nature at and below the scale of atoms.[2]: 1.1 It is the foundation of all quantum physics including quantum chemistry, quantum field theory, quantum technology, and quantum information science. Classical physics, the collection of theories that existed before the advent of quantum mechanics, describes many aspects of nature at an ordinary (macroscopic) scale, but is not sufficient for describing them at small (atomic and subatomic) scales. Most theories in classical physics can be derived from quantum mechanics as an approximation valid at large (macroscopic) scale.[3] Overview and fundamental concepts Quantum mechanics allows the calculation of properties and behaviour of physical systems. A fundamental feature of the theory is that it usually cannot predict with certainty what will happen, but only give probabilities. . and , where Here
Hack and / - Wiimote Control If you think about it, there are almost as many ways to interface with your computer as there are Debian-based distributions—and that's a lot. Besides the trusty keyboard and optical mouse, there are trackpoint mice, touchpads, touchscreens, twiddlers, joysticks, presentation remotes and even devices that measure your brain waves. Although I mostly stick with my tried-and-true keyboard and trackpoint mouse (fingers on home row, thank you), when I started hearing about all the interesting things people were doing with the Wiimote (the main controller from the Nintendo Wii), I knew I had to give it a try. Now traditionally, connecting a brand-new device to a Linux machine was an investment in Internet research, kernel module hacking, prayer and obscure programming skills I haven't used since college. First, your kernel needs the uinput module available and loaded. KERNEL=="uinput", GROUP="plugdev" Then, I made sure my user was a member of the plugdev group. Use the Wiimote as a Mouse
Fun with E-Ink, X and Gumstix I'm excited by E-paper and the promise it holds. You've probably already heard about E-Ink's E-Paper Display (EPD) and seen it in recent E-book reader products. The E-Ink display media needs no power to hold an image, and it reflects light just like real paper. I've even seen recent products that make use of the physical flexibility of the E-Ink film in order to create “rollable” displays. E-paper devices have been on the market since around 2006 or so. The AM200 kit serves to provide proof of concept for E-Ink. First, let's do a quick review of the hardware infrastructure we're using to better understand the software we need to add. Now, let's dig in to the software side of things. When your Gumstix board arrives, it could have one of two possible firmware configurations. The new software building block that we'll add to this system is something called deferred IO. Okay, now we can do some real work. Connected. The user name is root, and the password is gumstix. . Success!