This post is part of a series about quick questions and answers about the Virgo experiment and the science of gravitational waves. Do you have a quick question yourself? Tell us and we will reply!
“Are gravitational waves different from electromagnetic waves?”
Yes, the nature of these two kinds of waves are completely different, even if the generation “mechanisms” are similar. Gravitational waves are ripples in spacetime produced by accelerated masses, while electromagnetic waves are ripples of the electromagnetic field caused by accelerated electric charges, for instance when a current is flowing in an antenna. In addition to their different origins, these two kinds of waves act on completely different physical entities: gravitational waves act on the geometry of spacetime, whereas electromagnetic waves act on electric charges. Furthermore, gravitation is much weaker than electromagnetism, so the effect of gravitational waves on Earth is expected to be extremely small. This is why complex dedicated instruments like Virgo are required to detect them.