General Reference

This collection of Mathematics-related resources is maintained by the Florida State University Department of Mathematics as a free service to the online community.

The Search Engine for Astronomy and Astrophysics covering over 100,000 pages.

The Sheffield Chemdex: the directory of chemistry on the WWW since 1993.

From its inception, the Stanford Encyclopedia of Philosophy (SEP) was designed so that each entry is maintained and kept up to date by an expert or group of experts in the field. All entries and substantive updates are refereed by the members of a distinguished Editorial Board before they are made public. Consequently, our dynamic reference work maintains academic standards while evolving and adapting in response to new research.

This is a dictionary of algorithms, algorithmic techniques, data structures, archetypical problems, and related definitions. Algorithms include common functions, such as Ackermann's function. Problems include traveling salesman and Byzantine generals. Some entries have links to implementations and more information. Index pages list entries by area and by type.

An interactive unit conversion calculator hosted by the National Oceanographic Data Center. Conver area, length, mass, pressure, speed, temperature, and volume units.

Online encyclopedia of western signs and ideograms. Symbols.com contains more than 1,600 articles about 2,500 Western signs, arranged into 54 groups according to their graphic characteristics.

The goal of this handbook is to help scientists and engineers incorporate statistical methods in their work as efficiently as possible. By NIST/SEMATECH.

The island of Hawai`i has one of the youngest and most diverse landscapes on Earth. Built by countless eruptions of lava and tephra and sculpted by faults, landslides, and water, the Big Island is a remarkable window into the early histories of the other, much older Hawaiian Islands. The images below illustrate the striking landscapes of Hawaiian volcanoes and the islands they've built in the past few million years. You'll also find images of recent eruptions and the work that we do to improve our understanding of volcanoes and issue timely warnings when hazardous activity threatens people and property. See description of images on this Web site.

The USGS photo glossary of volcano terms contains nearly 80 geologic terms for describing volcanic activity, volcanic rocks, and geologic structures and is liberally illustrated with photos for each term. The relationships between terms are explained and examples are provided from historical eruptions. The website is supported by the UGSG Earthquake Hazards Program.

Useful Information About the Earth. Metric system, conversion factors. Length. Volume. Mass and weight. Speed. Energy. Power. Pressure. Temperature. Scientific notation. Celsius or centigrade vs. fahrenheit. Earth. Oceans. Major types of oceanic phytoplankton. Classification of marine organisms. Geologic time scale.

A simple, easy to use website with various tools for finding time and date information, including a world clock with the time in various locations and time zones around the world, a time zone converter, personal world clock, countdown to the new year, monthly calendar, and more.

A clickable world atlas. Includes continent and world region maps, and ocean floor maps.

You've seen other atlases. They're typically big books of paper maps. The pages in this atlas are here on the Internet whenever you need them. This is a new portrayal of America in maps. We use new technologies, but we honor traditions of accuracy, reliability, and innovation. You've found the single best Federal source for national maps and geographic information on the Web. The people and places of the United States are here. Topics include agriculture, biology, boundaries, climate, environment, geology, government, history, mapping, people, transportation, and water.

Science.gov is a gateway to authoritative selected science information provided by U.S. Government agencies, including research and development results.

Online conversions between different metrics of length, weight, temperature, pressure, energy, frequency, power, and more.

megaConverter.com is an ever-growing set of weights, measures and units conversion/calculation modules. megaConverters allow users to discover things like how many seconds old they are, the difference between a gallon in the USA and a gallon in the UK, how many nanometers in an inch, how many quarts in a chaldron, and what the heck a nebuchadnezzar is. Every module has its own on-line info system built in. You don't have to count on your fingers here! For just about anything you can think of, megaConverter can show you its equivalent. They're convenient, educational and fun. megaConverter will become an indispensable source for conversions as well as interesting information (and hundreds of jokes) on the megaResource pages. Be careful, you're bound to learn something. There are a ton (that's 4,540,000 carats) of modules available now and many more coming.

This dictionary includes: all the units of the International System of Units (SI); many other units of the metric system used in everyday life or in science, either currently or recently; various non-metric scientific units such as the astronomical unit, the electronvolt, and the parsec; all the units of the English traditional systems I've encountered that can be defined with reasonable precision; selected traditional units from cultures other than English; and certain measurement terms and notations which are not "units of measurement" in a strict sense, but which are used much as if they were.

The Current Index to Statistics is a bibliographic index to publications in statistics and related fields. References are drawn from 162 core journals (as of 2003) that are fully indexed, non-core journals from which articles are selected that have statistical content, proceedings and edited books, and other sources. The Current Index to Statistics is a joint venture of the American Statistical Association and the Institute of Mathematical Statistics.

Math, physics, computing, chemistry, units, calculations, noise & vibration, famous scientists and engineers, timeline of historical events.