How are Fighter Jets Invisible?
In the past two decades, the technology surrounding military aircraft has substantially advanced. The future of high-tech aircraft is uncertain, but one thing is for sure—jets are becoming stealthy. New innovations have allowed certain aircraft to become nearly invisible to almost all methods of detection. But how exactly can an object become invisible?
How do aircraft become detected?
In order to understand how these aircraft can go undetected, it is first necessary to understand how they can be detected. There are a few things that make an aircraft detectable: acoustics, thermal, radar, and sight. But once you see or hear a fighter jet, it is probably too late. So, it is important to detect aircraft from far away. Radar is most commonly used for long-distance detection. A radar antenna works by shooting photons outwards and waiting for them to bounce off the aircraft and return to the receiver, which determines the range, distance, and speed of the aircraft.
How can an aircraft work to not be detected by radar?
The simplest way to not be detected by radar is to simply become smaller or use oblique angles. If a radar wave hits an aircraft on a flat surface, the particles will bounce directly back to the receiver. However, if the particles hit an extremely curved or oblique angle, the particles will be directed away from the receiver. Instead of deflecting the radar particles, you can also absorb them. Specialized paints have been developed so that when radar particles hit them, they get absorbed and turn into heat. However, the nature of these paints is not known—much like the aircraft themselves, there is a high level of secrecy around their undetectable technology.
Fun fact: B-2 spirit bomber, the modern U.S. stealth bomber, reflects so much of the radar particles that when the particles return to the receiver if any, it shows up as a large bird. Keep in mind that the B-2 has a wingspan of 172ft!