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/by2hit
The official web presence of the BY2HIT Amateur Radio Club at Harbin Institute of Technology in Harbin, China, reachable via the QSL.net callsign network. The site provides QSL card mailing information and serves as a landing page for this university-based ham radio club.
http://bcfmca.bc.ca/
The British Columbia Frequency Modulation Communications Association (BCFMCA) is a registered Canadian amateur radio charity operating VHF, UHF, and microwave repeaters across British Columbia, including FM, DMR, IRLP, and D-STAR modes. Visitors can check live system status, explore the repeater directory, browse coverage maps, and find membership and donation information for this active ham radio club.
https://cadxa.org/
The Central Arizona DX Association (CADXA) is a ham radio club founded in 1974 and based in Arizona, boasting over 100 members many of whom hold ARRL DXCC Honor Roll status. The site offers resources for DXers including QSL card checking, a DX calendar, contest calendars, club rosters, and information on joining one of the largest amateur radio DX clubs in the state.
http://twisterdata.com/
TwisterData.com is a meteorological data tool built in 2008 by storm chasers David Demko and Donald Giuliano, offering RAP, NAM, and GFS weather model forecasts with detailed atmospheric parameters like CAPE, hodographs, helicity, and sounding data. Designed with a clean, data-first philosophy, it pulls from NOAA datasets and is especially valuable for storm chasers, meteorologists, and serious weather enthusiasts who need raw model output without distractions.
https://w5yi.org/
W5YI Licensing Services Inc. is a nationwide Volunteer Examiner Coordinator (VEC) offering full-service amateur radio licensing support, including exam sessions, vanity call sign applications, license renewals, and club station licenses. The site also features a youth licensing program that covers FCC fees for applicants aged 25 and under, making it a practical hub for anyone pursuing or maintaining a ham radio license.
https://n9drb.com/
The personal ham radio page of Devin Berg (N9DRB), featuring his call sign details, QSO log, notes, and links to HamQTH, QRZ, and eQSL. Located in WW Locator EN44av, the site also participates in the Fediverse.Radio web ring, connecting it to a broader community of radio enthusiasts online.
https://www2.mmm.ucar.edu/projects/ncar_ensemble/legacy
Hosted by NCAR's Mesoscale and Microscale Meteorology Laboratory, this site provides real-time ensemble weather forecast products including surface conditions, precipitation probabilities, upper-air fields, and severe weather outlooks across multiple domains. Researchers and forecasters will find a rich array of ensemble visualization tools including postage stamp maps, plumes, soundings, reflectivity paintballs, and neighborhood probability products.
https://www.qsl.net/w4frc
The Ft. McCoy Amateur Radio Club (W4FRC) is a friendly ham radio club based in the Ocala National Forest area of Marion County, Florida, founded in October 1997. The site shares club meeting info, VE testing schedules, member photos, and an open invitation for newcomers to discover the hobby of amateur radio.
https://pk3.org/Astro/index.htm?k3ccdtools.htm=
Peter Katreniak's astronomy page covers CCD imaging and observations of planets, the Moon, the Sun, eclipses, and deep-sky objects. A hobbyist astronomer's showcase featuring telescope photography and tools like K3CCDTools, making it a great find for amateur astrophotographers.
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.