 In 1925, Louis de Broglie came up with the answer for these two objections. Leveraging the recently developed light particle wave duality demonstrations, he proposed that electrons may have the same wave particle properties as light. Earlier we calculated the velocity of the electron, so like we did with electron microscopes in the previous segment, we can now calculate its wavelength. When we do, we get exactly the length of the electron orbits circumference, as enumerated by Bohr. In other words, the wavelength of the electron is exactly the length of one revolution. This would create a standing wave. A standing wave is a wave constrained to vibrate in a distance that's exactly one multiple of its wavelength. Anything more or less would create destructive interference and the wave would collapse. So the first energy shell would have to have the radius that creates the circumference that exactly fits one wave. The second shell would have to have the radius that creates the circumference that exactly fits two wavelengths. The third shell would have to have the radius that creates the circumference that exactly fits three wavelengths and so on. Here are a couple of standing waves on a string. Here's what three-dimensional standing waves look like around the hydrogen nucleus. It is these interesting geometries that give atoms their chemical properties. So the proposed answer to the question, how can an electron sit way outside the nucleus without orbiting, is that the electrons exist as standing waves that envelop the nucleus. No orbital motion is required and therefore no radiation is emitted. So it's important to remember, electrons in an atom do not orbit the nucleus. They are not like planets around the sun. They exist as stationary standing waves.