A spectroscope is a device which measures the spectrum of light. Early spectroscopes were simply a prism with graduations marking wavelengths. Modern spectroscopes generally use a diffraction grating, a movable slit and some kind of photodetector[?], all automated and controlled by a computer.
... their energy level to a higher level using a second solar photon. The highly excited electrons are transferred to the primary acceptor protein, but this time ar ...