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://hamuniverse.com/antennas.html
Hamuniverse.com, run by N4UJW, is a comprehensive ham radio resource site with a dedicated Antenna Design Lab offering hundreds of antenna projects, designs, and build guides for amateur radio operators. Visitors can browse antenna types by band, explore digital modes, study for license exams, and tap into a wide range of technical articles covering everything from repeaters to emergency power.
https://mathcs.clarku.edu/%7Edjoyce/hilbert/toc.html
Created by David E. Joyce of Clark University, this site presents the full text of David Hilbert's famous 1900 lecture outlining 23 unsolved mathematical problems that shaped 20th-century mathematics. Each problem links to its own dedicated page with references to key solutions and related works, making it an invaluable reference for anyone studying the history and foundations of mathematics.
https://www.qsl.net/n1irz
Dave Finley (N1IRZ) shares his deep expertise in amateur radio through articles on Morse Code training, radio history, and radio astronomy, including information about his published book 'Morse Code: Breaking the Barrier.' The site covers an impressive range of topics from the Koch Method of CW training to QRP radio kits, six meters, and the history of ham radio in Socorro, New Mexico.
http://jouscout.com/astro/belmont/belmontd.htm
A detailed double star catalog organized by constellation, compiled by the Belmont Society, listing star pairs with their right ascension, declination, separation, and color descriptions. The catalog is notable for its emphasis on the visible colors of stars, with evocative notes on hues like yellow, blue, orange, and even elusive green, making it a useful observing reference for amateur astronomers.
https://solarham.com/
SolarHam is a comprehensive real-time space weather monitoring hub, tracking solar flux indices, sunspot regions, geomagnetic forecasts, CME activity, and X-ray data from sources like NOAA, SOHO, and STEREO. Packed with live imagery, solar wind feeds, and 3-day geomagnetic outlooks, it serves as an essential reference for amateur radio operators, aurora chasers, and space weather enthusiasts alike.
https://qsl.net/wa5mc
The Atchafalaya Amateur DX Association Inc. (AADXA) is a ham radio club based in Amelia, Louisiana, with a full organizational presence including officer listings, membership applications, meeting minutes, newsletters, and repeater information. Developed by Guy R. Morrison (WA5MC), the site also features field day photos, a guestbook, and club constitution documents, making it a solid hub for local amateur radio enthusiasts.
http://yarc.org/
The Yonkers Amateur Radio Club (W2YRC) is a New York-based ham radio club affiliated with the ARRL, featuring repeater frequencies, EchoLink and WiresX node info, and a full calendar of events including Field Day, fox hunts, and VE testing sessions. Members and visitors can find meeting schedules, study guides, software resources, a photo gallery, and membership renewal options all in one place.
https://valleystargazers.com/
The Shenandoah Valley Stargazers (SVS) is an amateur astronomy club based in the Staunton, Waynesboro, and Harrisonburg, Virginia area, offering observing events, astrophotography, education, and community outreach. The club operates its own observatory in Stokesville, VA and welcomes families, groups, and the public to explore the night sky together.
https://smas.us/
The Southern Maryland Astronomical Society (SMAS) is an amateur astronomy club that meets twice monthly at the Nanjemoy Creek Observatory in southern Maryland, home to a Celestron CGE 1400 Schmidt-Cassegrain 14-inch telescope. Members range from beginners to seasoned observers with decades of experience, and the club welcomes donations and new members to support its nonprofit mission.
http://xjubier.free.fr/en/site_pages/solar_eclipses/TSE_1973_GoogleMapFull.html
Xavier Jubier's interactive Google Map documents the path and details of the June 30, 1973 total solar eclipse over Mauritania, offering a precise geographic visualization of this historical celestial event. The map-based format makes it easy to explore the eclipse's path of totality across the region with geographic context.