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One family of transverse waves
Electromagnetic waves are transverse waves that transfer energy from a source to an absorber. They can travel through empty space: they do not need particles of a material to carry them. This is how energy from the Sun reaches Earth through space. All electromagnetic waves travel at the same speed in a vacuum, about 300 million metres per second. At an absorber, the transferred energy can increase temperature. A diagram showing waves travelling between objects represents energy transfer; it does not mean material travels from the source to the absorber. They also travel at approximately the same speed in air.
