| Vacuum_Technology_and_Vacuum_Coating_Forum Discuss subjects about vacuum physics, vacuum and coating systems, evaporation coating and sputtering technology. |
| Vacuum_Technology_Guide Links to buyers guides, organizations, research, eZines and journals world-wide. |
| Vacuum_Technology_Lessons Lessons and practical exercises on Vacuum Technology. |
| Vacuüm_Specials,_The_Netherlands Specialised in the implementation, construction, manufacturing of components and subsystems and the realisation of complex projects on a turnkey basis regarding vacuum technology and cryogenic applica |
| What_is_vacuum? Nice web-site for beginners who want to know "what vacuum is"... |
| Foreign_Policy_In_Focus__Environment Issue papers on environmental matters that relate to U.S. foreign policy. |
| Greenleaf_Publishing Specialist publisher in the business and environment sector, including the journals Greener Management International and The Journal of Corporate Citizenship. Online book catalog, journal tables of co |
| League_of_Women_Voters__Materials_on_Natural_Resources_Protection Available brochures and publications on several environmental topics. |
| Okno_Group Publishes books and periodical series on environmental and health care topics in eastern Europe, Russia and Central Asia. Includes Environment & Health Online. |
| Science_and_the_Environment_Bulletin Bi-monthly online publication from Environment Canada, featuring news and information on leading-edge environmental science and technology. |
| United_Nations_Environment_Programme_Book_Shop Distribution point for UNEP publications. Most reports and magazines are only available for purchase, but are few items can be read online. |
| Water_Resources_Publications,_LLC Publisher's online catalog, including descriptions of available books, CDs, and other publications in the area of water resources sciences. |
| Are_There_Pictorial_Examples_of_Covariant_and_Contravariant_Vectors We present pictorial means of distinguishing contravariant vectors (or simply vectors) from covariant vectors (or linear forms). |
| The_Cosmological_Constant An overview of why Einstein added an extra term in general relativity, and why it is still examined. |
| The_5D_Spacetime_Consortium We are a group of physicists and astronomers working on a 5-dimensional version of general relativity. |
| Derivation_of_gravitational_waves_in_Einstein,_Brans-Dicke_and_Rosen_theories_of_gravity_ Mathematical derivation of gravitational waves to quadrupole order in the Brans-Dicke scalar-tensor and Rosen bi-metric theories of gravity. |
| Dulkyn__Scientific_Center_for_Gravitational-Wave_Research Research includes detection of periodic gravitational radiation from relativistic astrophysical objects, investigation of infra-low-frequency variations of Terrestrial gravity field in the role of cry |
| An_Essay_on_General_Relativity This site contains a comprehensive introduction to the basic ideas and tests of general relativity |
| Experimental_Gravitational_Physics_Using_Drag-Free_Satellites Covers current and past projects in experimental gravitational physics using Drag-Free Satellites including the Relativity Gyro, Equivalence Principle, and LISA. |
| General_Relativity_Simulation_Contest The purpose of this Contest is to prove General Relativity using a (simple) algorithm. |
| Gravitational_Lensing A popular site with interactive demonstrations of gravitational lensing. The background material is at a graduate level |
| Gravitational_Waves__An_Introduction This paper presents an elementary introduction to the theory of gravitational waves. This article is meant for students who have had an exposure to general relativity, but results from general r |
| Gravity_Probe_B Gravity Probe B is the relativity gyroscope experiment being developed by NASA and Stanford University to test two extraordinary, unverified predictions of Albert Einstein's general theory of relati |
| Handbook_of_Space_Astronomy_and_Astrophysics_-_Relativity A collection of equations important to both special relativity and general relativity. |
| Hyperspace_at_the_University_of_British_Columbia Includes links to online journals, news and preprint archives, as well as lists of faculty at this university. |
| Interactive_Experiments_in_Gravity Try an experiment that illustrates the gravitational attraction between two objects or use a Java applet to understand how orbits work in strongly curved space-time. |
| Lecture_Notes_on_General_Relativity Sean M. Carroll's lecture notes from a one-semester graduate-level course he taught at MIT in 1996. Notes are in postscript format. |
| NOVA_Online/Einstein_Revealed Profile of Albert Einstein, with additional teaching resources, Shockwave demonstrations, and animations of relativity concepts. |
| Physics_Bookshelf_-_Relativity A collection of articles about relativity |
| Publications_in_Physics_and_Mathematics_by_Walter_Pfeifer A textbook for relativistic quantum mechanics is presented. The Dirac equation is dealt with in detail. |
| QMW_Hyperspace A set of hypertext based services for general relativity research provided by the QMW Relativity group. |
| Relativity Provides information on the history, experiments and paradoxes of relativity. |
| Relativity_bookmarks Rob Salgado's bookmarks |
| Ricci A Mathematica package for doing tensor calculations in differential geometry and general relativity. |
| Shapiro_Radar_Bounce_Test A two part overview of the Shapiro radar bounce test of general relativity. (The two parts consist of a section for normal people, and one for nerds) |
| Solving_Einstein\'s_Equations_in_Three_Dimensions This is a Mathematica notebook showing how to plot light cones in two plus one spacetime dimensions with a point mass. |
| The_Special_Theory_of_Relativity Self-tutorial with short essays, questions and answers. |
| Why_Time_is_Absolute,_and_Relative,_But_Never_Universal An article by Vincent Sauvé elaborating upon a materialist view of the absolute and relative nature of time. |
| Wrong__Some_Scientifically_Inaccurate_Claims_Concerning_Cosmology_and_Relativity Easy to understand 'debunking' of some common misconceptions about cosmology and relativity and why they are wrong. |
| Gravity_of_Gravity An experiment at the University of Washington seeks to determine whether the gravitational binding energy of an object generates gravity of its own. (October 26, 1999) |
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Please copy/paste the following text to properly cite this HowStuffWorks article:Brain, Marshall. "How Thermoses (Vacuum Flasks) Work." 01 April 2000. HowStuffWorks.com. <http://home.howstuffworks.com/thermos.htm> 02 December 2008. Inside this Article Introduction to How Thermoses (Vacuum Flasks) Work Heat Transfer Inner Workings of a Thermos Experiments to Try The Biggest Thermos Lots More Information See more » See all Household Appliances articles Home & Garden Videos 
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Most people have or are familiar with the "Thermos" (also known as a vacuum flask or a dewar). I can remember as a kid having one that came with my lunch box. One day my mother might put grape juice in it and at lunch I would have nice, cold grape juice. The next day she would put hot soup in it and I would have hot soup for lunch. And I can remember asking, "How does it know whether to keep stuff hot or cold?" Where's the switch, in other words...
Or, similarly, "You heat things up in an oven and cool them down in a refrigerator -- how come this thing can do both?" In this edition of HowStuffWorks, we will learn how a Thermos "knows" what to do.
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