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)
https://chemguide.co.uk/index.html
Chemguide, created by Jim Clark, is a comprehensive chemistry reference site aimed at helping students aged 14 through A-level understand topics ranging from atomic structure and bonding to organic reaction mechanisms and physical chemistry. Covering major UK exam syllabuses including GCSE, CIE Cambridge International, and Edexcel, it serves as an authoritative free study aid with deep topic coverage across all major chemistry disciplines.
http://mndmr.net/
MNDMR.net is the home of Minnesota's first in-house DMR repeater CBRIDGE network, providing information about connected repeaters, talkgroups, and codeplugs for digital radio users in the region. The site serves the local amateur radio community with resources for the MNSTATE and MNTAC talkgroups on the Brandmeister network.
http://calendarzone.com/
The Calendar Zone, created by Janice McLean, is a comprehensive categorized directory of calendar-related links covering art, celestial, cultural, religious, historical, and reform topics. With over 7 million visitors since 1999, it serves as a one-stop hub for anyone curious about calendar systems, moon phases, lunar cycles, and the history of timekeeping across cultures.
http://muzique.com/
Jack Orman's AMZ is a deep well of DIY guitar effects pedal knowledge, offering free schematics, project guides, a lab notebook, and a blog covering circuits for fuzzboxes, boosters, overdrives, and more. With decades of content, PCB boards for sale, and downloadable ebooks, it stands as one of the most comprehensive stompbox electronics resources on the old web.
http://www.baltimoremd.com/qrpwebring
Created by Thom LaCosta (K3HRN), this is the hub page for the QRP Amateur Radio Web Ring, connecting low-power ham radio enthusiast sites across the web. Visitors can join the ring, edit their site entry, retrieve replacement HTML fragments, and browse the full ring layout.
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://www.qsl.net/w5www/ron.html
Ron (W5WWW) maintains this hub page collecting all the amateur radio webrings he belongs to, including the Radio Amateur Ring, Amateur Radio World Ring, HAMs on The Net, and Ham Radio Chat rings. A useful snapshot of how the early ham radio online community organized itself through interconnected webring networks.
http://lists.contesting.com/_3830
The 3830 mailing list archives preserve decades of amateur radio contesting discussion, spanning from 1996 through 2023. Operators and contesters can browse monthly threads or search the full archive to find score postings, contest strategies, and community conversation going back nearly 30 years.
https://eclipse.gsfc.nasa.gov/SEgoogle/SEgoogle2001/SE2017Aug21Tgoogle.html
Fred Espenak's NASA Eclipse Website hosts an interactive Google Maps tool showing the precise path of totality for the August 21, 2017 total solar eclipse, including central line, northern and southern limits, and 10-minute interval markers. Hosted by NASA's Goddard Space Flight Center, the page provides detailed data on greatest eclipse, greatest duration, lunar limb profiles, and eclipse weather resources.
http://sk3bg.se/contest
SM3CER Contest Service, run by Jan-Eric Rehn of Sweden, is a comprehensive hub for amateur radio contesters featuring a worldwide contest calendar, contest rules, results, and software links. Active since 1997, the site aggregates mailing lists, DX spotting tools, callsign lookups, and contest-related resources that make it an indispensable reference for serious ham radio operators.