Science & Nature
1439 sites
Subcategories:
- Astronomy & Space (396)
- Chemistry (8)
- Earth Sciences (26)
- Biology (79)
- Physics (30)
- Mathematics (59)
- Weather & Climate (104)
- Amateur Radio (682)
- Electronics (47)
http://choisser.com/packet
Larry Kenney (WB9LOZ) presents an 18-part introductory series on packet radio, originally written in 1988 for the San Francisco Amateur Radio Club newsletter and revised multiple times through the 1990s. The series covers everything from basic concepts and TNC commands to BBS usage, node networks, and the National Traffic System, making it a comprehensive self-study guide for amateur radio operators interested in packet operations.
https://ucolick.org/~sla/leapsecs/deltat.html
Steve Allen's detailed reference site on the history and technical implications of leap seconds, delta time, and precision time scales used in astronomy and timekeeping. It features plots, tables, historical data, and analysis of the ongoing ITU-R debate over whether to abandon leap seconds from UTC.
https://faraday.physics.utoronto.ca/GeneralInterest/Harrison/Flash
Created by a University of Toronto physicist, this collection features 99 Flash animations covering topics from Quantum Mechanics and Relativity to Chaos and Fluid Mechanics, making abstract physics concepts visually intuitive. A bonus tutorial teaches how to build your own physics animations in Flash, and the animations are available in multiple languages under a Creative Commons license.
https://www.andrews.edu/~burton/mathlinks/coolmathlinks.htm
A curated collection of mathematics education links compiled at Andrews University, organized into sections for teachers, parents, and students across K-12 grade levels. The directory covers lesson plans, interactive activities, problem-solving resources, and NCTM-aligned curriculum materials from across the early web.
https://meteor.geol.iastate.edu/~jdduda/chasing/chasing.html
Jeff Duda, a geology student turned meteorology researcher, chronicles a decade of storm chasing with detailed chase accounts, busts, and lifetime statistics including 71 tornadoes over 111 chases and 52,000+ miles. Each year from 2008 to 2017 has its own dedicated page, making this a substantial firsthand log of severe weather pursuit across the Great Plains and Midwest.
http://aberdeenastro.org.uk/
The Aberdeen Astronomical Society (AAS) is a Scottish astronomy club based in Aberdeenshire, hosting regular meetings, dark sky observing sessions, and public talks both in person and via Zoom. The site features aurora photography by members, an interactive star chart for Aberdeen, upcoming event listings, and a night sky section covering visible astronomical events from the local area.
https://hamradio.in/index.php
Hamradio.in is an Indian amateur radio community hub featuring technical projects, news, and event announcements for ham radio enthusiasts across India. Visitors can find hands-on build projects like DSB transceivers and DDS VFOs, coverage of events like Hamfest India and the Lamakaan Amateur Radio Convention, and discussions of digital modes like FT8.
https://chicagofmclub.org/
The Chicago FM Club (CFMC) is a Chicagoland amateur radio club established in 1965 with over 150 members, operating five repeaters and hosting nightly nets, monthly fox hunts, and the annual Radio Expo ham fest. The site covers club membership, FCC exam testing, public service events, and social gatherings for hams in the greater Chicago area.
https://winsystem.org/
The WIN System is a linked amateur radio repeater network based around the KA6WIN reflector, connecting operators across multiple nodes via IRLP and ALLStar technology. The site offers operating tips, member rosters, net schedules, FAQs on repeater use and antenna selection, and information on joining the network or becoming an affiliate.
https://frankdeboosere.be/klimaatukkel/klimaatjuni.php
Belgian meteorologist Frank Deboosere presents detailed interactive climate charts for Uccle, Belgium, tracking temperature, precipitation, and sunshine duration across decades. The graphs plot 30-year rolling averages against current normals, making long-term climate trends and changes visually accessible to anyone curious about local Belgian climate history.