The knowledge that electromagnetic waves travel through space and not just through matter is based on experimental evidence and a deep understanding of the nature of electromagnetic radiation.
Here are a few key points that support the understanding that electromagnetic waves can travel through space:
Vacuum Propagation: Electromagnetic waves can propagate through a vacuum, which is a space devoid of matter. This was demonstrated by James Clerk Maxwell's equations, formulated in the 19th century. These equations describe the behavior of electromagnetic fields and predict the existence and propagation of electromagnetic waves in empty space.
Speed of Light: The speed of light, which is approximately 299,792 kilometers per second in a vacuum, is a fundamental constant in physics. It has been measured and confirmed through various experiments. The fact that light, which is an electromagnetic wave, can travel across vast distances through space at this constant speed supports the understanding that electromagnetic waves propagate through vacuum.
Astronomical Observations: Astronomical observations provide further evidence that electromagnetic waves travel through space. We receive and analyze electromagnetic radiation from distant stars, galaxies, and other celestial objects. These electromagnetic signals have traveled through the vacuum of space for vast distances before reaching our telescopes and detectors.
Wireless Communication: The practical applications of electromagnetic waves in wireless communication, such as radio waves, microwaves, and satellite communications, rely on the ability of electromagnetic waves to travel through the atmosphere and space. The successful transmission of information over long distances without a physical medium between the transmitter and receiver demonstrates that electromagnetic waves can traverse space.
Based on these observations and experimental results, scientists have established that electromagnetic waves can propagate through space, independent of the presence of matter. This understanding forms the foundation of many fields, including astrophysics, telecommunications, and modern physics.