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://rfcafe.com/
RF Cafe is a comprehensive resource for RF and electronics engineers, offering formulas, reference data, vintage magazine archives, software tools, forums, and a massive parts and services directory. Running since 1996, the site blends technical depth with nostalgia, featuring scanned articles from classic publications like QST, Popular Electronics, and Radio-Craft alongside modern engineering utilities.
https://winsystem.org/
The WIN System is a linked amateur radio repeater network based around the KA6WIN reflector, connecting operators across multiple nodes via IRLP and ALLStar technology. The site offers operating tips, member rosters, net schedules, FAQs on repeater use and antenna selection, and information on joining the network or becoming an affiliate.
https://pskreporter.info/pskmap.html
PSKReporter is a real-time propagation mapping tool that aggregates reception reports from amateur radio operators worldwide, showing who is hearing whom across bands and digital modes like FT8, JT65, and PSK31. Created by Philip Gladstone, the interactive map lets operators filter signals by callsign, country, grid square, mode, and time window, making it an invaluable tool for monitoring radio propagation conditions.
https://weathertogether.net/weather-links
WeatherTogether is a community weather resource offering an extensive curated directory of weather observation tools, model data, radar, satellite imagery, and oceanographic resources from major institutions like NOAA, NWS, and various universities. The sheer breadth of categorized links covering surface observations, upper air data, aviation weather, and ocean conditions makes it a valuable one-stop reference for weather enthusiasts and professionals alike.
https://theodoregray.com/PeriodicTable
Theodore Gray's landmark site documents his handcrafted wooden periodic table desk, which contains actual samples of all 118 chemical elements, with thousands of photos, rotatable 3D images, videos, and detailed information for each element. With over 2,379 samples, 471 minerals, and a wealth of interactive features including an element-spelling game and reaction balancing, this is one of the most thorough and visually stunning chemistry reference sites on the web.
http://scarcnj.org/
The Sussex County Amateur Radio Club (SCARC) is a New Jersey-based ham radio club operating under call sign W2LV, dedicated to education, public service, and advancing the amateur radio hobby. The site features meeting schedules, repeater listings, net information, contest announcements, and details about their annual Hamfest at the Sussex County Fairgrounds, which doubles as the 2025 ARRL Hudson Division Convention.
https://skyhound.com/sh/dso_guide.html
Skyhound's Guide to Deep Sky Objects is a comprehensive reference covering every major category of deep sky objects, from open star clusters and globular clusters to quasars and gravitational lenses. Each section explains what the objects are, how they appear through a telescope, and highlights notable examples like the Veil Nebula, Einstein's Cross, and the Pleiades.
https://tube.be/
A specialized reference guide cataloging the vacuum tube types used in shortwave radio broadcast transmitters, organized alphabetically and numerically for easy lookup. The site also lists manufacturers, rebuilders, and distributors worldwide, including companies like Thales, Eimac, Penta Laboratories, and Xuguang, making it a practical industry directory for broadcast engineers.
http://bas-astro.com/
BAS Astro appears to be an astronomy club or society website, with the domain name strongly suggesting a regional or local astronomical association. The site likely serves as a hub for amateur astronomers to share observations, events, and resources.
https://www.qsl.net/yo8ps/links.html
YO8PS is the ham radio site of Sorin Parlog, a Romanian amateur radio operator whose links page compiles an extensive curated collection of ham radio resources including dealers, manufacturers, clubs, antenna resources, contesting groups, and callsign servers. The sheer breadth of categorized links makes this a useful reference point for hams looking to find suppliers, organizations, and special interest groups across North America and beyond.