| Cite_Wise Manufacturers of Endnote, a tool for bibliographic and scientific reference organization and citation. |
| Clemex_Technologies_Inc_ Provides digital imaging solutions for the acquisition, archiving, and analysis of images used in quality control and research laboratories. |
| CoHort_Software CoHort Software creates graphics and statistics software for scientists and engineers. CoPlot is an extremely versatile program for creating publication-quality scientific graphs, maps, and technical |
| Energy_Science_and_Technology_Software_Center The ESTSC is the U.S. Department of Energy's central repository and distribution point for Federally funded software dealing with all forms of energy, energy conservation, waste management, mathematic |
| eXY,_Data_Analysis_and_XY_Plot_Package Shareware Windows application. Capabilities include Least-squares, Akima and Cubic spline interpolation. Creative freedom with page layouts allows shared/multiple plot axis, dimensioning and inclusion |
| Field_Precision Finite-element software for electromagnetics, bioengineering, and shock hydrodynamics |
| Genamics_SoftwareSeek A fully searchable database of more than 1200 free and commercial software packages for science. |
| GNU_Scientific_Library The GNU Scientific Library (GSL) is a numerical library for C and C++ programmers. It is free software under the GNU General Public License. |
| Henry_Thorson_Consulting Customized scientific computer applications on Unix and Windows platforms and distributed systems. Bothell, Washington, USA |
| Hoare_Research_Software_Ltd_ We are New Zealand's supplier for the world's best technical business, statistics, mathematics, engineering and scientific software for your needs: including MATLAB, SPSS, Mathematica, Mathcad, and Si |
| HVLCOM_Software Free Software WinRoot, Nonlinear System Equation Roots Solver, Serial Terminal for buffalo, a FREE 68HC11 Simulator. |
| Inspiration_Software_-_Strategic_Transitions_Inc_ Inspiration Software- a graphic organizer ideal for both education and business diagramming , concept mapping and process mapping. |
| Linux_Software_Encyclopedia Scientific and other software for Linux. |
| Matrox_Imaging__Scientific_and_Industrial_Imaging Designer and manufacturer of PC-based hardware and software for machine vision, image analysis, medical imaging and video surveillance. |
| Media_Cybernetics_Image_Analysis_Software Makers of industry standard Windows and Mac image analysis software including Image-Pro Plus and Gel-Pro Analyzer. |
| Multidisciplinary_Software_Systems_Research_Corporation Custom science, engineering, and mathematical software for business, academia, research, and government. |
| Neyer_Software Sensitivity test and analysis software for Windows platforms. Also includes descriptions of the algorithms used and a glossary. |
| Noesys General purpose software for visualizing a variety of scientific data as surfaces. [Win9x/NT, Power Mac] |
| Northern_Lights_Software_Associates Nova for Windows tracks an unlimited number of satellites in real time. |
| Perfectly_Scientific,_Inc_ the scientific algorithm company. Experts in compression, wavelets, FFT, general transforms, color graphics, Monte Carlo, fractals, convolution,signal processing, matrix algebra, genetic algorithms, |
| PhotoModeler_-_photogrammetric_software PhotoModeler Pro is a Windows program that extract measurements and 3D models from photographs |
| Purebits_Homepage_-_Professional_Audio_Software Home of Sample Champion, a real-time software tool designed for high precision acoustic measurements. |
| ScanIt ScanIt is a utility for obtaining numerical data from a scanned or bitmapped graph. Features: an intuitive interface for defining axes, a snap function, automated tracing curves and symbols. Program d |
| Scientific_Computing The use of modern computer science techniques is rapidly becoming an accepted and invaluable component of nearly all facets of basic and applied research. This forum will address many of the exciting |
| Scientific_Image_Processing Pixlock develops and distributes 'Exbem', a software for scientific image processing and analysis, for Apple Macintosh. |
| Scientific_Imaging_Software,_Systems_and_Solutions Noesis offers a family of 2D and 3D imaging software and systems to extract quantitative information from a wide range of scientific images. Windows 95, NT 4.0, 2000. |
| Scientific_Software Choose from thousands of scientific, academic and laboratory software programs. |
| Scientific_Volume_Imaging Deconvolution and visualization software for microscopy, available on Windows, Mac, Irix and Linux. |
| SciMetrics Provides the SciFit program for scientific data analysis, as well as consulting services. |
| Sciproof Software for the preparation and editing of scientific manuscripts. |
| SigmaPlot Graphing software for scientists. Product details, demonstration for download, and online purchasing. |
| Soft_Analytics_Home_Page Low-cost simulation software for engineering and science. Analysis and design consulting for communication systems. |
| Software_for_Science_Initiative Information, links and interactive on-line processing services for scientists, developers and users of scientific (particularly, imaging) software. |
| Startek_Technology Custom software solutions for mechanical, electrical and chemical engineering applications, including instrument interface and communications. Boronia, Victoria, Australia. |
| Summit_Research_Services Pharmacokinetics and metabolism software and services for research and education. |
| SYTEK_Canada SYTEK Canada specialises in developing custom scientific applications. |
| United_Devices,_Inc_ Headquartered in Austin, Texas, is a technology company that develops the infrastructure required to aggregate unused computing resources on the Internet. |
| Absolute_Astronomy Facts and statistical information about planets, moons, constellations, stars, galaxies, and Messier objects. |
| Astronomical_Applications_Department,_U_S__Naval_Observatory Computes the position, brightness, and other observable characteristics of celestial bodies, as well as the circumstances of astronomical phenomena. Includes information on calendars and related topi |
| Astronomical_Optical_Interferometry The use of multiple telescopes to produce high resolution images - commonly used at most modern observatories. A literature review article. |
This is the web version of the Usenet Physics FAQ (Frequently Asked Questions). Its purpose is to provide good answers to questions that have been discussed often insci.physics and related usenet newsgroups. The articles in this FAQ are based onthose discussions and on information from good reference sources. That does not meanthat they are always perfect and complete. If you have corrections, updates oradditional points to make please send an email to the editor, document.write(donsAdrs()) (his cv is here). If you want to write up an article following anews group discussion about a subject not yet covered here then feel free to send it tothe editor, but please do not use this address to ask new questions. Ask them in theappropriate newsgroup instead.If you are new to the Physics newsgroups, welcome! Please read thearticle An Introduction to the PhysicsNewsgroups. It will help you find the right newsgroup for your questions andwill give you other crucial advice about appropriate netiquette for these groups. Above all you should check carefully to see if your questions are answered in this FAQbefore posting.This FAQ was created by Scott Chase in 1992. The web version was created,maintained and enlarged by Michael Weiss and Philip Gibbs. Others who have writtenfor the FAQ are credited at the top of the items they submitted while many more who havemade smaller contributions have been thanked privately.The FAQ is not available in text-only form and is no longer posted to the usenetgroups. This is because it is too big and some articles use images and equationswhich cannot be transformed into text.This document is copyright. Please read the copyright notice for copyright details andarchival information. 
How do you add velocities in special relativity? Can special relativity handle acceleration? Does a clock's acceleration affect its timing rate? What are the equations for a relativistic rocket? The barn and the pole The rigid rotating disk in relativity The Twin Paradox Bell's Spaceship Paradox The superluminal scissors Can you see the Lorentz-Fitzgerald Contraction? Relativity in chemistry: the color of gold What is relativistic mass? 
What would a relativisticinterstellar traveller see?General Relativity and Cosmology What causes gravity? Is pi constant in relativity? What is gravitational radiation? Does gravity travel at the speed of light? Is energy conserved in General Relativity? Olbers' Paradox What is dark matter? Do atoms get bigger as the universeexpands? What causes the Hubble redshift? Where is the centre of the universe? Mercury's orbital precession Time travel - fact or fiction? Is the cosmological constant nonzero?Black Holes What is a black hole, really? How does the gravity get out ofthe black hole? What happens to you if you fall into ablack hole? If you go too fast, do you become ablack hole? What is Hawking Radiation? The black hole information loss problem Is the Big Bang a black hole?