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://wiki.solarsails.info/index.php/Main_Page
SolarSailWiki is a community-edited wiki dedicated entirely to solar sail spacecraft, covering the science of light pressure, mission histories, technologies, and future applications for propellantless space travel. With sections on design, real-world missions like the Planetary Society's LightSail, books, papers, and conferences, it serves as a comprehensive reference for anyone fascinated by this elegant form of space propulsion.
http://rcra.wagnera.com/
The Red Cedar Repeater Association (RCRA) is a Wisconsin-based amateur radio club established in 1974, serving as trustee for the K9KGB repeater system covering West Central Wisconsin along the I-94 corridor. The site provides technical details on their 2-meter repeater frequencies, PL tones, and remote links, along with embedded National Weather Service radar tools useful for local operators.
http://stellar-database.com/scale.html
A concise educational page from stellar-database.com that walks readers through the mind-bending scale of the universe, from the Earth's diameter out to the edge of the known cosmos. It explains astronomical units, light-years, and parsecs with precise conversion figures, making vast cosmic distances tangible and comparable.
https://rrra.org/
Red River Radio Amateurs (RRRA) is the official website for an amateur radio club serving the Red River region, featuring club news, event calendars, repeater information, and resources for aspiring ham radio operators. The site covers POTA activations, net schedules, license testing, ARES meetings, and an active blog with technical posts from club members.
https://khleedril.org/blog
Dale Mellor is a scientific computer programmer, mathematician, and physicist who writes accessible math explainers like his 'Baby Steps for Adults' series alongside posts about science fiction, Star Trek, fine art, and daily life. The blog covers a genuinely eclectic range of intellectual interests, with mathematics and computing forming the clear backbone of the content.
http://icstars.com/HTML/SolarSection/HAlpha/OBSERVINGTHESUNHAlpha1.html
David Knisely's comprehensive H-Alpha handbook covers solar observation in remarkable technical depth, with dedicated sections on prominences, sunspot group classification, solar flares, and a full glossary of H-Alpha terminology. Part of the larger ICSTARS Astronomy site, this resource is a serious reference for amateur astronomers interested in observing the sun through hydrogen-alpha solar filters.
https://msuarc.egr.msu.edu/
The MSU Amateur Radio Club (W8SH) has been connecting students to ham radio at Michigan State University since 1919, with roots tracing back to the founding of what would become WKAR public radio. The site offers club membership info, repeater details, and original tools like POTAVis and FoxHuntr built by club members to help hams visualize POTA activations and practice radio direction finding.
https://ourcolorfulcosmos.com/
Steve Mazlin, MD shares his stunning astrophotography collection at Our Colorful Cosmos, featuring images organized into sections covering nebulae, galaxies, star clusters, and the solar system. The image-heavy site showcases deep-sky photography from a dedicated personal observatory, with a companion YouTube channel under the handle 'mazlinithegreat' for additional content.
http://sm0vpo.altervista.org/
Harry Lythall (SM0VPO/G4VVJ) shares an extensive collection of homebrew amateur radio construction projects, covering everything from QRP transmitters and receivers to circuit boards, oscillators, and RF amplifiers. The site is a treasure trove for hands-on ham radio enthusiasts, packed with schematics, datasheets, calculators, and practical guides for building your own radio equipment.
http://kcaprs.org./
The Kansas City APRS Organization is a regional group dedicated to Automatic Packet Reporting System (APRS) activity in the Kansas City area. This site serves as the hub for local amateur radio operators interested in real-time digital position tracking and packet radio communications.