This is a device that can precisely measure the wavelength of light, and can for example distinguish light emitted by a hydrogen atom from light emitted by helium.
Many telescopes are designed to primarily capture visible light, which represents only a sliver of the spectrum of light emitted by stars and other celestial objects.
Bohr's atomic model resolved several unanswered questions, including the stability of atoms and the reason behind spectral lines observed in the light emitted by heated elements.
Although this is slower than the speed of the light and materials emitted by solar flares, coronal mass ejections can have much more dramatic effects on Earth.
The thing about this, it's not anymore about perceiving the light emitted from a screen but now traveling inside the light, traveling inside the scene.