Measurement can be direct, like measuring length directly with tape or a ruler. But it can also be indirect, like measuring distance by emitting a sound, listening for it, and measuring the delay the sound is received after being bounced back by an object.
Flat-Earthers like to discredit measurement results —like the distance to the Sun— by mentioning these are just results of calculation, not measured directly. In reality, many everyday instruments do measure indirectly. They measure a different value, then use calculations to get the desired calculation.
Continue reading “Direct and Indirect Measurements”
Marine radars can only detect objects above the horizon. The curvature of the Earth limits their detection range.
Some marine radars are marketed using their maximum ranges, which far exceed the typical over-the-horizon distances to another vessel. Flat-Earthers noticed the fact and used it as “evidence” against Earth’s curvature. In reality, the specified ranges are radar signal ranges. Earth’s curvature still limits the actual detection range.
While a marine radar with an advertised range of 50 nm will not detect vessels at that range, it is still useful and can identify higher-ground inland areas.
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An AEW&C (airborne early warning and control) system is a radar system attached to an aircraft. It can detect objects at a very long range compared to any surface mounted radar system.
The reason is that Earth’s curvature limits the range of a surface-based radar. An airborne radar system mitigates this problem.
Continue reading “Airborne Early Warning & Control (AEW&C): Mitigating Limited Radar Range Due to Earth’s Curvature”