Science & Nature
1413 sites
Subcategories:
- Astronomy & Space (390)
- Chemistry (7)
- Earth Sciences (24)
- Biology (76)
- Physics (29)
- Mathematics (51)
- Weather & Climate (100)
- Amateur Radio (681)
- Electronics (45)
https://handprint.com/ASTRO/bortle.html
A detailed reference page explaining the Bortle Dark Sky Scale, which measures night sky light pollution across nine categories from inner-city skies to pristine darkness. The site includes an adapted table of Bortle's indicators with color codes used in light pollution maps, plus five star charts covering key sky areas visible from the continental United States.
http://k3pgp.org/
K3PGP's Experimenter's Corner is a wide-ranging amateur radio and electronics hobbyist site covering everything from VLF to light, including moonbounce (EME), lasers, antenna construction, and weak signal work. Run by the operator K3PGP, the site spans decades of experimentation and also touches on astronomy, bicycle construction, and software.
http://science-workshop.com/
Science Workshop appears to be a science-oriented site, though its content is extremely minimal with only a single image visible at crawl time. The domain name suggests a focus on science education or hands-on scientific topics, but without further content the site's exact subject remains uncertain.
http://nags.net/
NAGS (Norske Amatørgeologers Sammenslutning) is the Norwegian association for amateur geologists, offering a comprehensive lexicon of Norwegian minerals, an index of articles from their geology magazine STEIN dating back to 1973, and listings of geology clubs across Norway. Visitors interested in rocks and minerals as a hobby will find this a rich hub for Norwegian earth science resources and community.
https://w9dup.org/
The official site of W9DUP, the DuPage Amateur Radio Club (DARC) based in Illinois, covering club news, membership, Field Day results, hamfests, ARES emergency preparedness, and local amateur radio events. Visitors can find an active club calendar, EchoLink and IRLP info, licensing education resources, and a showcase of the club's 7th-place national Field Day finish.
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.
https://lwca.net/
The Longwave Club of America (LWCA) is a dedicated organization serving enthusiasts of radio frequencies below 500 kilohertz, covering LF, VLF, MedFER, HiFER, and Part 15 experimental beacons. Members receive 'The Lowdown,' a bimonthly publication dating back to 1974, featuring DX loggings, homebrew antenna projects, natural radio phenomena, and news from operators around the world.
https://pgadey.ca/
Parker Adey is a math lecturer at the University of Toronto Scarborough who shares formal notes, informal blog posts, reading recommendations, and teaching materials spanning topology, linear algebra, and beyond. The site doubles as an academic hub with a CV, publications list, office webcam, and a decade of evolution captured in the Wayback Machine.
http://trx-manager.com/
TRX-Manager, created by Laurent F6DEX, is a CAT control, DXing, and logging software package supporting nearly 150 transceivers including models from Yaesu, Kenwood, Icom, and Elecraft. Though distribution has been discontinued, the site still provides updates for registered users and bilingual support in both English and French.
http://uksmg.org/content/deadband.htm
Written by Palle Preben-Hansen (OZ1RH), this technical article explains how radio amateurs can make long-distance contacts on the 50MHz (Six Meter) band by exploiting meteor scatter propagation even when the band appears dead. It covers meteor trail geometry, shower timing, diurnal and seasonal meteor rate variations, and practical operating techniques, with supporting figures and links to software and IARU procedures.