By the rate of Doppler change that the signals come back, we can actually gauge the speed of that aircraft.

One of the most fascinating aspects of radar technology is its ability to track aircraft all the way down to the ground, even at distances of around 100 miles. Given the calculation of Earth’s curvature, 100 miles should result in a drop of 6,666 feet. This seems impossible because radar operates at microwave frequencies (2 to 6 gigahertz or higher) and relies on line-of-sight. If you can’t see it, radar shouldn’t work.

However, we can track aircraft from their altitude all the way to the ground, 100 miles away, where the target should be over 6,000 feet below the curvature. This challenges the ball model of Earth. In air traffic control, there are two types of radar: short-range airport-based radar, which covers up to 60 miles, and en route radar for long flights and high altitudes, which can detect targets up to 200 miles away.

Radar must have a direct line to the airplane. During my 24 years in the field, I never questioned the shape of the Earth. It never occurred to me that a target might be too low to be seen at a certain distance.

In reality, knowing what we know about Earth’s curvature, any airplane below 26,000 feet at 180 miles should be invisible to radar if the Earth were a ball. Yet, this happens thousands of times a day. Aircraft, especially those that are not pressurized and can’t fly above 11,000 feet, operate at lower altitudes. These planes, often flying at 6,000 to 8,000 feet from places like Bermuda to Miami, prove the Earth is flat every time they are detected by radar.

This is undeniable proof. Even at 200 miles, radar can detect planes at altitudes that should be impossible if the Earth were a sphere. This phenomenon occurs repeatedly, challenging the conventional understanding of Earth’s shape.