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://academics.cehd.umn.edu/hatch/default.htm
Produced by the staff of the James Ford Bell Museum of Natural History at the University of Minnesota, this reference site covers the distribution and ecology of native and introduced fish species found in Minnesota. Curated by Andrew M. Simons and Jay T. Hatch, it serves as both a scientific resource and a public education tool tied to the museum's fish collection.
http://w9az.com/
The Kankakee Area Radio Society (KARS) is an Illinois-based amateur radio club dedicated to promoting and advancing ham radio in the Kankakee region. The site features member resources including meeting schedules, repeater information, fox hunt events, archived newsletters, and a membership application.
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.
https://starinabox.net/
Star in a Box is an interactive educational tool from Las Cumbres Observatory that lets you animate and explore the full lifecycle of stars across a range of solar masses using the famous Hertzsprung-Russell diagram. Visitors can watch how a star's brightness, size, surface temperature, and mass evolve over billions of years, with downloadable data tables for independent investigation.
http://johncath.force9.co.uk/radio%20projects.htm
John Cath's radio project pages feature detailed amateur radio construction projects including a 17-page guide to building a 600W 50MHz solid state amplifier and a power splitter for 70cm. The site reproduces designs from RadCom magazine and the Radio Society of Great Britain, making it a useful reference for ham radio builders and experimenters.
http://srim.org/
James Ziegler's authoritative site hosts SRIM and TRIM, widely used scientific software packages that calculate the stopping and range of ions in matter for research and engineering applications. The site includes downloadable software, textbooks, tutorials, a historical review spanning 100 years of ion stopping research, and resources covering topics from cosmic ray soft errors to neutron damage.
http://cactus-intertie.org/
The Cactus Intertie System is a private UHF amateur radio network established in 1971, spanning large portions of the American Southwest and beyond through a web of remotely controlled base stations linked by full duplex RF. Run by Cactus Intertie, Inc., a 501(c)(3) nonprofit, the site covers membership, affiliate clubs, technical support, educational materials, and the network's extensive history across multiple states.
https://1x1callsigns.org/
A dedicated resource for amateur radio operators looking to reserve FCC-authorized one-by-one (1x1) special event call signs for conventions, festivals, and other community celebrations. The site includes an FCC regulations guide, a searchable 1x1 callsign database, coordinator listings, and a reservation request system for temporary station operation.
https://complex-analysis.com/
Created by Juan Carlos Ponce Campuzano, this interactive online textbook introduces complex analysis through visual applets built with GeoGebra, p5.js, and other JavaScript tools, making abstract mathematical concepts tangible and explorable. Covering topics from the Cauchy-Goursat Theorem to conformal mappings, it serves engineering and mathematics students with a beautifully designed, continually updated resource that includes Spanish and Italian translations.
https://marc-hq.org/
The Motorcycling Amateur Radio Club (MARC) is a community group that combines motorcycle riding with ham radio operation to support charity fundraising events like Bike MS rides in Southern California. The site includes a tech center, photo gallery, newsletters, event calendar, and membership information for riders and operators who want to combine their passions while giving back.