Maxwell's equations introduced "displacement current" theoretical hypothesis, which stated that a changing electric field could induce a changing magnetic field in a vacuum. Furthermore, Maxwell extended Faraday's law of electromagnetic induction from metal circuits to vacuum, and theoretically concluded that a changing magnetic field could induce a changing electric field in a vacuum. Then, Maxwell predicted the existence of "electromagnetic waves" in a vacuum and claimed wireless communication could be achieved by "electromagnetic waves". This study reinterprets Hertz's "electromagnetic waves" verification experiment and reveals that Hertz’s experiment did not prove the existence of "electromagnetic waves", but rather proved that wireless communication was achieved by independent electric field waves. Based on Coulomb's law and mathematical derivation, this paper proves that Maxwell's "displacement current" hypothesis is inconsistent in theory, and directly demonstrates through experiment that the "displacement current" hypothesis is not true, that is, a changing electric field cannot induce a changing magnetic field in a vacuum. In a modern wireless broadcasting system, there are only electric field signals without magnetic field signals. Wireless radio signals are the transmission, propagation, and reception of independent electric field waves in the air. In the application of microwave technology, when a microwave oven is turned off or on, the energy density of the electric field wave and the energy density of the magnetic field wave are not equal, which violates the principle of energy conservation. In EMC engineering testing, a magnetic field probe cannot directly detect magnetic field signals in a changing electric field environment. Based on theoretical analysis and experiments, this study proves that Maxwell's "displacement current" hypothesis is incorrect and denies the existence of "electromagnetic waves," which will have a profound impact on modern scientific discoveries and technological advancement.