Electromagnetic waves can travel through a vacuum, as well as through various other substances and mediums. The ability of electromagnetic waves to propagate through different materials depends on the properties of those materials and the specific characteristics of the electromagnetic waves.
In a vacuum, electromagnetic waves, including visible light, radio waves, microwaves, X-rays, and gamma rays, can travel without any obstruction. This is because a vacuum is devoid of matter and does not contain particles or atoms that can interact with or absorb the electromagnetic waves.
In addition to a vacuum, electromagnetic waves can also travel through transparent media such as air, water, and glass. However, their behavior in these substances may differ depending on the frequency or wavelength of the waves and the specific properties of the medium. For example, visible light can pass through air and water relatively easily, but certain materials may absorb or scatter specific wavelengths of light, resulting in various optical phenomena.
Furthermore, electromagnetic waves can also propagate through solid materials, albeit with some limitations. Different materials have varying degrees of transparency to different frequencies of electromagnetic waves. For instance, visible light can pass through certain types of glass, while metals are generally opaque to visible light but transparent to X-rays.
In summary, electromagnetic waves can travel through a vacuum and various substances such as gases, liquids, and solids, but the interactions and behaviors of electromagnetic waves can be influenced by the properties of the medium they are passing through.