Light travels through space in the form of electromagnetic waves. Electromagnetic waves are a combination of electric and magnetic fields that propagate through space without the need for a medium. This means that light can travel through the vacuum of space, where there is no air or other material to carry it.
According to the theory of electromagnetism, when an electric charge accelerates or oscillates, it creates a changing electric field, which in turn generates a magnetic field. This changing magnetic field then generates a changing electric field, and the process continues, creating a self-propagating wave of electric and magnetic fields, known as an electromagnetic wave.
In the case of light, it is an electromagnetic wave that is produced by the acceleration or oscillation of charged particles, usually electrons, within atoms or molecules. These charged particles can be excited by various means, such as by the absorption of energy or by the movement of electrons in atoms.
Once the charged particles are excited, they emit electromagnetic waves, including visible light, as they return to their original state. These waves then travel through space in a straight line until they encounter an obstacle or interact with another medium, such as the Earth's atmosphere or objects.
The speed of light in a vacuum is approximately 299,792 kilometers per second (186,282 miles per second). This speed is considered a fundamental constant of nature and serves as a universal speed limit, as predicted by Einstein's theory of relativity.
In summary, light travels through space as an electromagnetic wave, propagating through the vacuum without the need for a medium. It moves at an incredibly fast speed and exhibits both wave-like and particle-like properties, known as wave-particle duality.