Astronomy originated with visible-light astronomy and what could be seen with the naked eye. As technology advanced, it became possible to observe other parts of the electromagnetic spectrum, from radio to gamma rays. Each new frequency band gave a new perspective on the Universe and heralded new discoveries.[13] Late in the 20th century, the detection of solar neutrinos founded the field of neutrino astronomy, giving an insight into previously invisible phenomena, such as the inner workings of the Sun.[14][15] The observation of gravitational waves provides a further means of making astrophysical observations.