# Redshift Academy   Search by keyword: Astronomy

Astronomical Distance Units
Celestial Coordinates
Location of North and South Celestial Poles Chemistry

Balancing Chemical Equations
Stochiometry
The Periodic Table Classical Mechanics Classical Physics

Archimedes Principle
Bernoulli Principle
Center of Mass Frame
Comparison Between Gravitation and Electrostatics
Compton Effect
Coriolis Effect
Cyclotron Resonance
Dispersion
Doppler Effect
Double Slit Experiment
Elastic and Inelastic Collisions
Electric Fields
Error Analysis
Fick's Law
Fluid Pressure
Gauss's Law of Universal Gravity
Gravity - Force and Acceleration
Hooke's law
Ideal and Non-Ideal Gas Laws (van der Waal)
Impulse Force
Inclined Plane
Inertia
Kepler's Laws
Kinematics
Kinetic Theory of Gases
Kirchoff's Laws
Maxwell's Equations
Moments and Torque
Nuclear Spin
One Dimensional Wave Equation
Pascal's Principle
Phase and Group Velocity
Poiseuille's Law
Refractive Index
Rotational Dynamics
Simple Harmonic Motion
Specific Heat, Latent Heat and Calorimetry
The Gas Laws
The Laws of Thermodynamics
The Zeeman Effect
Young's Modulus Climate Change

Keeling Curve Cosmology

Baryogenesis
Cosmic Background Radiation and Decoupling
CPT Symmetries
Dark Matter
Friedmann-Robertson-Walker Equations
Hubble's Law
Inflation Theory
Introduction to Black Holes
Planck Units
Stephen Hawking's Last Paper
Stephen Hawking's PhD Thesis
The Big Bang Model
Vacuum Energy Finance and Accounting

Amortization
Annuities
Brownian Model of Financial Markets
Capital Structure
Dividend Discount Formula
Lecture Notes on International Financial Management
NPV and IRR
Periodically and Continuously Compounded Interest
Repurchase versus Dividend Analysis Game Theory

The Truel General Relativity

Basis One-forms
Catalog of Spacetimes
Curvature and Parallel Transport
Einstein's Field Equations
Geodesics
Gravitational Waves
Hyperbolic Motion and Rindler Coordinates
Quantum Gravity
Ricci Decomposition
Ricci Flow
Stress-Energy-Momentum Tensor
Tensors
The Area Metric
The Dirac Equation in Curved Spacetime
The Equivalence Principal
The Essential Mathematics of General Relativity
The Induced Metric
The Light Cone
The Metric Tensor
The Principle of Least Action in Relativity
Vierbein (Frame) Fields Group Theory

Basic Group Theory
Basic Representation Theory
Building Groups From Other Groups
Sets, Groups, Modules, Rings and Vector Spaces
Symmetric Groups
The Integers Modulo n Under + and x Lagrangian and Hamiltonian Mechanics

Classical Field Theory
Euler-Lagrange Equation
Ex: Newtonian, Lagrangian and Hamiltonian Mechanics
Hamiltonian Formulation
Liouville's Theorem
Symmetry and Conservation Laws - Noether's Theorem Macroeconomics

Lecture Notes on International Economics
Lecture Notes on Macroeconomics
Macroeconomic Policy Mathematics

Amplitude, Period and Phase
Arithmetic and Geometric Sequences and Series
Asymptotes
Augmented Matrices and Cramer's Rule
Binomial Theorem (Pascal's Triangle)
Completing the Square
Complex Numbers
Composite Functions
Conformal Transformations
Conjugate Pair Theorem
Contravariant and Covariant Components of a Vector
Derivatives of Inverse Functions
Double Angle Formulas
Eigenvectors and Eigenvalues
Euler Formula for Polyhedrons
Factoring of a3 +/- b3
Fourier Series and Transforms
Fractals
Gauss's Divergence Theorem
Grassmann and Clifford Algebras
Heron's Formula
Index Notation (Tensors and Matrices)
Inequalities
Integration By Parts
Introduction to Conformal Field Theory
Inverse of a Function
Law of Sines and Cosines
Line Integrals, ∮
Logarithms and Logarithmic Equations
Matrices and Determinants
Matrix Exponential
Mean Value and Rolle's Theorem
Modulus Equations
Orthogonal Curvilinear Coordinates
Parabolas, Ellipses and Hyperbolas
Piecewise Functions
Polar Coordinates
Polynomial Division
Quaternions 1
Quaternions 2
Regular Polygons
Related Rates
Similar Matrices and Diagonalization
Spherical Trigonometry
Stirling's Approximation
Sum and Differences of Squares and Cubes
Symbolic Logic
Tangent and Normal Line
Taylor and Maclaurin Series
The Essential Mathematics of Lie Groups
The Limit Definition of the Exponential Function
Tic-Tac-Toe Factoring
Trapezoidal Rule
Unit Vectors
Volume Integrals Microeconomics

Marginal Revenue and Cost Nuclear Physics Particle Physics

Feynman Diagrams and Loops
Field Dimensions
Helicity, Chirality and Weyl Spinors
Klein-Gordon and Dirac Equations
Regularization and Renormalization
Scattering - Mandelstam Variables
Spin 1 Eigenvectors Probability and Statistics

Box and Whisker Plots
Buffon's Needle
Categorical Data - Crosstabs
Chebyshev's Theorem
Chi Squared Goodness of Fit
Conditional Probability
Confidence Intervals
Data Types
Expected Value
Factor Analysis
Hypothesis Testing
Linear Regression
Monte Carlo Methods
Non Parametric Tests
One-Way ANOVA
Pearson Correlation
Permutations and Combinations
Pooled Variance and Standard Error
Probability Distributions
Probability Rules
Sample Size Determination
Sampling Distributions
Set Theory - Venn Diagrams
Stacked and Unstacked Data
Stem Plots, Histograms and Ogives
Survey Data - Likert Item and Scale
Tukey's Test
Two-Way ANOVA Programming and Computer Science

Hashing
How this site works ...
More Programming Topics
MVC Architecture
Open Systems Interconnection (OSI) Standard - TCP/IP Protocol
Public Key Encryption Quantum Computing

Density Operators and Mixed States
Entangled States
The Qubit Quantum Field Theory

Creation and Annihilation Operators
Field Operators for Bosons and Fermions
Lagrangians in Quantum Field Theory
Path Integral Formulation
Relativistic Quantum Field Theory Quantum Mechanics

Bohr Atom
Clebsch-Gordan Coefficients
Commutators
Dyson Series
Electron Orbital Angular Momentum and Spin
Heisenberg Uncertainty Principle
Multi Electron Wavefunctions
Pauli Spin Matrices
Photoelectric Effect
Position and Momentum States
Probability Current
Schrodinger Equation for Hydrogen Atom
Schrodinger Wave Equation
Spin 1/2 Eigenvectors
The Differential Operator
The Essential Mathematics of Quantum Mechanics
The Quantum Harmonic Oscillator
The Schrodinger, Heisenberg and Dirac Pictures
The WKB Approximation
Time Dependent Perturbation Theory
Time Evolution and Symmetry Operations
Time Independent Perturbation Theory
Wavepackets Semiconductor Reliability

The Weibull Distribution Solid State Electronics

Band Theory of Solids
Fermi-Dirac Statistics
Intrinsic and Extrinsic Semiconductors
The MOSFET
The P-N Junction Special Relativity

4-vectors
Energy and Momentum in Special Relativity, E = mc2
Invariance of the Velocity of Light
Lorentz Invariance
Lorentz Transform
Lorentz Transformation of the EM Field
Newton versus Einstein
Spinors - Part 1
Spinors - Part 2
The Continuity Equation
The Lorentz Group Statistical Mechanics

Entropy and the Partition Function
The Harmonic Oscillator
The Ideal Gas String Theory

Bosonic Strings
Extra Dimensions
Introduction to String Theory
Kaluza-Klein Compactification of Closed Strings
Strings in Curved Spacetime
Toroidal Compactification Superconductivity

Bardeen–Cooper–Schrieffer Theory
BCS Theory
Cooper Pairs
Introduction to Superconductivity
Superconductivity (Lectures 1 - 10)
Superconductivity (Lectures 11 - 20) Supersymmetry (SUSY) and Grand Unified Theory (GUT)

Chiral Superfields
Generators of a Supergroup
Grassmann Numbers
Introduction to Supersymmetry
The Gauge Hierarchy Problem The Standard Model

Electroweak Unification (Glashow-Weinberg-Salam)
Gauge Theories (Yang-Mills)
Gravitational Force and the Planck Scale
Introduction to the Standard Model
Isospin, Hypercharge, Weak Isospin and Weak Hypercharge
Quantum Flavordynamics and Quantum Chromodynamics
Special Unitary Groups and the Standard Model - Part 1
Special Unitary Groups and the Standard Model - Part 2
Special Unitary Groups and the Standard Model - Part 3
Standard Model Lagrangian
The Higgs Mechanism
The Nature of the Weak Interaction Topology Units, Constants and Useful Formulas

Constants Open Systems Interconnection (OSI) Standard - TCP/IP Protocol
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Virtually all networks in use today are based in some fashion on OSI. The core of this standard is the OSI Reference Model, a set of seven layers that define the different stages that data must go through to travel from one device to another over a network.

Application Set

• Layer 7: Application - This is the layer that actually interacts with the operating system or application whenever the user chooses to transfer files, read messages or perform other network-related activities.
• Layer 6: Presentation - Layer 6 takes the data provided by the Application layer and converts it into a standard format that the other layers can understand.
• Layer 5: Session - Layer 5 establishes, maintains and ends communication with the receiving device.

Transport Set

• Layer 4: Transport - This layer maintains flow control of data and provides for error checking and recovery of data between the devices. Flow control means that the Transport layer looks to see if data is coming from more than one application and integrates each application's data into a single stream for the physical network.
• Layer 3: Network - The way that the data will be sent to the recipient device is determined in this layer. Logical protocols, routing and addressing are handled here.
• Layer 2: Data - In this layer, the appropriate physical protocol is assigned to the data. Also, the type of network and the packet sequencing is defined.
• Layer 1: Physical - This is the level of the actual hardware. It defines the physical characteristics of the network such as connections, voltage levels and timing.

The OSI Reference Model is really just a guideline. Actual protocol stacks often combine one or more of the OSI layers into a single layer. A protocol stack is a group of protocols that all work together to allow software or hardware to perform a function. The TCP/IP protocol stack is a good example. It uses four layers that map to the OSI model as follows:

• Layer 1: Network Interface - This layer combines the Physical and Data layers and routes the data between devices on the same network. It also manages the exchange of data between the network and other devices.
• Layer 2: Internet - This layer corresponds to the Network layer. The Internet Protocol (IP) uses the IP address, consisting of a Network Identifier and a Host Identifier, to determine the address of the device it is communicating with.
• Layer 3: Transport - Corresponding to the OSI Transport layer, this is the part of the protocol stack where the Transport Control Protocol (TCP) can be found. TCP manages the assembling of a message or files into smaller data packets that are transferred to the Network Interface for transmission over the Internet where they can be received by a TCP layer of another device that reassembles the data packets from the originating device.
• Layer 4: Application - Layer 4 combines the Session, Presentation and Application layers of the OSI model. Protocols for specific functions such as e-mail (Simple Mail Transfer Protocol, SMTP) and file transfer (File Transfer Protocol, FTP) reside at this level.

A TCP packet consist of: IP is an Internet protocol (layer 2) that handles the address part of each packet so that it gets to the right destination. Basically, IP is responsible for managing the sending and receiving of data packets over the Internet. An IP packet consists of: • Protocol (the protocol of the packed encapsulated within the packet (i.e. TCP, UDP, etc.)
• Trailer (not shown) - The trailer, sometimes called the footer, typically contains a couple of bits that tell the receiving device that it has reached the end of the packet.
• It may also have some type of error checking. The most common error checking used in packets is Cyclic Redundancy Check (CRC). CRC is pretty neat. Here is how it works in certain computer networks: It takes the sum of all the 1s in the payload and adds them together. The result is stored as a hexadecimal value in the trailer. The receiving device adds up the 1s in the payload and compares the result to the value stored in the trailer. If the values match, the packet is good. But if the values do not match, the receiving device sends a request to the originating device to resend the packet.

The whole process can be summarized as follows:

• The Application layer sends the data (to be transferred to remote destination) to the Transport layer.
• The transport layer puts its header in the beginning and sends this complete packet (TCP-header + app-data) to the Iinternet layer.
• Along the same lines, The Iinternet layer puts its header in front of the data received from Transport layer (Note that data received from TCP = TCP-header + app-data).
• So now the structure of IP datagram becomes IP-header + TCP-header + app-data.
• This IP datagram is passed to the Network Interface layer which adds its own header to the IP datagram and then the whole packet is transmitted over network. For an ethernet connection this looks like: IP Routers
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After the IP datagram has been assembled, the local machine ships it down the wire to a router that picks up the frame. Routers are very smart. They can look at the network type and, if necessary, reformat the Data layer information before passing the data onto the destination or another router. The router has a map of the local internet in its memory and each frame is sent off to its destination via the best available route. In the process the IP datagrams are just re-framed with different headers and frame source and frame destination addresses.

The router uses the technique of packet switching and all of the packets in the message may or may not take the same route. In this way the network can dynamically balance the load across various pieces of equipment. If there is a problem with one piece of equipment in the network while a message is being transferred, packets can be routed around the problem, ensuring the delivery of the entire message. The routers that make up the main part of the Internet can reconfigure the paths that packets take because they look at the information surrounding the data packet, and they tell each other about line conditions, such as delays in receiving and sending data and traffic on various pieces of the network. 