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://www.qsl.net/w9ikn
The Elgin Amateur Radio Society (E.A.R.S.), callsign W9IKN, was a ham radio club based in Elgin, Illinois with roots stretching back to the early 1930s. This archived homepage serves as a farewell tribute, noting the club's disbanding and expired licenses in 2007, with a link to its past history preserved by member Chuck Henrici (N9TZO).
https://wz5bbs.com/radio
WZ5BBS is the amateur radio station page of an Amateur Extra class licensee, cataloging an impressive shack setup including Icom, Kenwood, and Yaesu radios alongside Diamond and Chameleon antennas. The site tracks APRS iGate activity, multiple logbooks like POTA and Logbook of the World, fox hunting events, and club memberships with the Oak Hill and Austin Amateur Radio clubs.
http://karc.net/
KARC.net appears to be the web presence for a Kansas amateur radio club or organization, serving as a hub for local ham radio operators. The site functions as a host server for the club's online activities and community resources.
http://math2.org/
Math2.org is a comprehensive math reference site offering organized tables, formulas, and identities covering everything from basic arithmetic to calculus, linear algebra, and Fourier transforms. Available in both English and Spanish, it also features a message board for math questions and links to other top math resources on the web.
https://cut-the-knot.org/
Created by Alexander Bogomolny starting in 1996, Cut the Knot is a massive encyclopedic collection of interactive mathematics covering geometry, algebra, probability, puzzles, proofs, and much more, built over decades until his passing in 2018. With thousands of pages, interactive Java applets, Olympiad problems, and articles spanning all levels of math, it stands as one of the most beloved and comprehensive math resources ever built on the early web.
http://scarc.com/
SCARC appears to be the website for an amateur radio club, offering resources and information for ham radio enthusiasts in its region. Club-based amateur radio sites like this typically feature member info, repeater details, licensing resources, and local on-air event announcements.
https://pnwherbaria.org/
The Consortium of Pacific Northwest Herbaria is a collaborative portal uniting 60 regional herbaria across Alaska, British Columbia, Oregon, Washington, Idaho, Montana, and the Yukon, offering access to over 3.6 million plant specimen records and nearly 1.8 million images. Researchers and naturalists can search the database by label data or geographic location, download datasets for offline use, and consult a fully annotated checklist of vascular plants native to the Pacific Northwest.
https://warc1.org/
The Wichita Amateur Radio Club (WARC) has been serving Kansas ham radio enthusiasts since 1932, making it one of the longer-running amateur radio clubs in the region. The site features news about Field Day operations, repeater information, licensing resources, and club activities including visits from Wichita's mayor during Amateur Radio Week.
https://ipac.caltech.edu/2mass/gallery/index.html
The 2MASS Atlas Image Gallery at IPAC (California Institute of Technology) showcases stunning false-color infrared composite images from the Two Micron All Sky Survey, covering everything from solar system objects and nebulae to galaxies and star clusters. Compiled from three infrared wavelength bands mapped to visible colors, this publicly released collection serves as both a scientific resource and a visually compelling window into the infrared universe.
https://www.qsl.net/dk7zb/start1.htm
DK7ZB's technical antenna resource covers Yagi antenna design, the 28-ohm matching technique, and constructions for amateur radio bands including 2m, 6m, and shortwave. A deep dive into high-gain antenna building for ham radio enthusiasts, featuring the DK7ZB-Match and EME (Earth-Moon-Earth) related content.