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://azastronomy.com/
Richard D. Jacobs, M.D. shares his CCD astrophotography captured from his backyard in Chandler, Arizona, showcasing diffuse nebulae, galaxies, star clusters, planetary nebulae, and solar system objects despite significant light pollution. The site also covers the technical side of amateur CCD imaging including astrometry, spectroscopy, and photometry, making it a useful resource for urban amateur astronomers.
https://users.usinternet.com/n0flq
Collin Witwer (N0FLQ) is a ham radio operator from Minneapolis, Minnesota who built this sprawling personal homepage packed with categorized links covering everything from ham radio and shortwave to space, electronics, weather, and beyond. The site serves as both a personal hub and a massive curated web directory, with a QSL card, live webcam, and links to local Minnesota resources making it a genuine snapshot of late-1990s hobbyist internet culture.
https://rammb-data.cira.colostate.edu/tc_realtime
Run by NOAA's Regional and Mesoscale Meteorology Branch at Colorado State University, this site tracks currently active tropical cyclones worldwide in real time using satellite imagery and meteorological data. Researchers and weather enthusiasts can browse live storm data, archived seasons going back to 2006, and products developed by NESDIS/STAR/RAMMB scientists.
https://ik3qar.it/rtty/1
IK3QAR's technical page covers RTTY digital radio operation, focusing on FSK and AFSK interface circuits with detailed wiring diagrams for connecting a PC soundcard to a transceiver. The site addresses practical problems like ground loop interference and signal reentry, offering schematics and tips for rigs including the Kenwood TS940.
https://www.qsl.net/k9jx
The Jacksonville Amateur Radio Society (JARS) of Jacksonville, Illinois maintains this club homepage featuring repeater frequencies, officer listings, and an extensive archive of their bi-monthly newsletter 'The Bandspread' dating back to 1995. A not-for-profit FCC-regulated organization, JARS hosts monthly meetings, operates two repeaters, and provides emergency communications support for the local community.
https://realhamradio.com/
K8CU's amateur radio station site features well-documented technical construction projects including high-power GS35B RF amplifiers, HF log periodic antennas, GPS frequency standards, and Six meter equipment. Vintage receiver restoration, mobile RFI solutions, and detailed technical articles make this a rich resource for serious radio amateurs worldwide.
https://gars.org.gg/
The Guernsey Amateur Radio Society (GARS) is a ham radio club based in the Channel Islands, meeting Friday evenings in a genuine World War II bunker at Beau Sejour Leisure Centre. The site offers a GU callbook, repeater information, QSL card bureau details, and membership resources for both local hams and visiting operators.
https://dictionary.obspm.fr/
Created by M. Heydari-Malayeri at the Paris Observatory, this trilingual etymological dictionary covers thousands of astronomy and astrophysics concepts in English, French, and Persian, tracing the roots and definitions of terms from the oldest to the newest. It stands out as a freely accessible, interdisciplinary reference that fills a gap left by conventional astronomical glossaries, with entries organized alphabetically and supplemented by historical and linguistic context.
http://damtp.cam.ac.uk/user/tong/teaching.html
David Tong, a professor at Cambridge University, offers a comprehensive collection of free lecture notes covering nearly every area of theoretical physics, from classical mechanics and electromagnetism to quantum field theory and string theory. The notes are aimed at undergraduates and graduate students and represent a genuinely deep academic resource, with dozens of individual courses each spanning multiple topics.
https://dxing.com/
DXing.com is a comprehensive reference site sponsored by Universal Radio Research, covering shortwave listening, scanner monitoring, ham radio, pirate radio, numbers stations, and more. Originally created by noted author Harry Helms, it features receiver surveys, frequency guides, QSL reporting tips, and columns from well-known radio writers like Glenn Hauser and Don Schimmel.