Stealth technology is cool. It's what gave the US domination over the skies during the latter half of the Cold War, and the biggest component of the US's information dominance in both war and peace, at least prior to the rise of global internet connectivity and cybersecurity. Yet the core idea is almost embarrassingly simple.

So how does stealth work?

Photo by Steve Harvey on Unsplash

When we talk about stealth, we’re usually talking about evading radar. How does radar work?

Radar antennas emit radio waves in the sky. The waves bounce off objects like aircraft. When the echoes return to the antenna, the radar system can then identify the object's approximate speed, position, and size.

Picture courtesy of Katelynn Bennett over at bifocal bunny

So how would you evade radar? You can try to:

Blast a bunch of radio waves in all directions (“jamming”). This works if you’re close to the radar antenna, but kind of defeats the point of stealth.
Build your plane out of materials that are invisible to radio waves (like glass and some plastics) and just let the waves pass through. This is possible, but very difficult in practice. Besides, by the 1970s [...]

The original text contained 2 footnotes which were omitted from this narration.

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First published:
December 8th, 2025

Source:
https://www.lesswrong.com/posts/MxivaKjaAX9mkJzAK/how-stealth-works

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Narrated by TYPE III AUDIO.

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Images from the article:

Stealth bomber aircraft viewed from below against clear blue sky.

Illustration of satellite dish transmitting signals to airplane in flight.

Diagram showing Mr. Radar with satellite dish head facing mirror with distance arrow.

Diagram showing satellite dish person unable to detect signal path around obstacle.

Stealth fighter aircraft flying above desert terrain with open weapons bay.

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“How Stealth Works” by Linch

LessWrong (30+ Karma)