Binoculars & Telescopes

Calculate section lengths for a multiband linked dipole, standard dipole, or inverted-V antenna by frequency. Enter the HF bands or exact operating frequencies you want to use. The calculator returns the starting cut length for each dipole leg, individual linked sections, link positions, and the complete active antenna length for every band. Linked dipole geometry […]

Direct expert answer There is no fixed “20 km range” specification for binoculars: a binocular does not stop working at a particular distance. At roughly 12 miles, usable detail depends on magnification, optical resolution, atmospheric haze and heat shimmer, target contrast, and—critically—image stability. For serious long-distance terrestrial observation, 15×56 is the most balanced configuration in […]

← Part I: from the Tower of Babel to Tsiolkovsky’s dream Part II: how a Dream Became an Engineering Calculation ⟶ Chapter 13. The major engineering dead ends: why aren’t we in orbit yet? The turn of the millennium brought not just an understanding of the underlying physics, but also a harsh collision with the […]

← Part I: from the Tower of Babel to Tsiolkovsky’s dream Part III: The Space Elevator in the 21st Century ⟶ We’re continuing our investigation into the space elevator. Chapter 8. Down to Earth: Yuri Artsutanov’s revolutionary reversal The concept Konstantin Tsiolkovsky proposed in 1895 had one fundamental weakness: it assumed building the tower from […]

← Part II: how a Dream Became an Engineering Calculation Part III: The Space Elevator in the 21st Century ⟶ Dear readers! Today’s piece isn’t a typical article — it’s a full investigation. We’ve already crossed into the second quarter of the 21st century. Once-unimaginable technologies are within reach, and we’re preparing for a flight […]

On June 24, 2026, the mysterious shortwave radio station known as UVB-76 transmitted an unusually large number of encrypted voice messages, marking what monitoring communities describe as one of the most active days in its recent history. According to reports tracking the station’s activity via radio monitoring groups and dedicated Telegram channels, the station broadcast […]

Amateur Radio Direction Finding (ARDF) is a special competitive outlet for those who want to combine the physical challenge of outdoor navigation with the technical puzzle of radio science. ARDF is an international amateur radio sport, colloquially known in many parts of the world as “fox hunting” or “transmitter hunting” . Participants use specialized radio […]

The walkie-talkie is so simple that it is generally assumed to be private as well. But is it so? Does someone listen to your conversations? Can a walkie talkie be tracked and used to reveal your location? Most importantly.To answer these questions, it’s useful to understand how these devices work in the first place. How […]

As a sports enthusiast, I understand the thrill of live sporting events. Whether you’re in the nosebleeds of a stadium or cheering from the sidelines of a local game, a good pair of binoculars can transform your experience, bringing the action right to your eyes. But with countless options on the market, how do you […]

In the world of science, where the names of great men often overshadow the achievements of women, there are stories that deserve to be told with special passion and care. The story of Katharine Blodgett is one of them. Imagine Thomas Edison, whose inventions transformed everyday life—but now imagine a woman who, like him, revolutionized […]