Related by context. Frequent words. (Click for all words.) 62 electromagnetic waves 59 microwave radiation 58 infrared rays 57 electromagnetic pulses 57 ultrasonic waves 56 infrared radiation 55 Photons 55 infrared beam 55 Cosmic rays 55 Gamma rays 54 emitted 54 Solar flares 54 electromagnetic radiation 53 radiations 53 terahertz radiation 53 potassium ions 53 sensory nerves 52 radiowaves 52 electromagnetic 52 vibrations 51 excitons 51 nerve impulses 51 photons 51 alpha particles 51 impedances 50 ultraviolet wavelengths 50 electrochemical reaction 50 airflows 50 beam splitter 50 optical wavelengths 50 sensory stimuli 50 ionised 50 atmospheric turbulence 50 ionize 50 ionizing 50 visible wavelengths 50 microwave frequencies 50 photodetector 49 aerosol particles 49 fluorescent molecules 49 chloride ions 49 electrical currents 49 microwaves 49 Ultraviolet light 49 fluorophores 49 laser pulse 49 laser pulses 49 meteoroids 49 emit 49 resonators 49 radiative 49 wavelengths 49 silicon atoms 49 sensory inputs 48 electrons 48 millivolts 48 entangled photons 48 photocell 48 directivity 48 Nitrogen oxides 48 rubidium atoms 48 infra red 48 sunrays 48 microwatts 48 ultraviolet UV light 48 interplanetary spacecraft 48 pulsations 48 electromagnetic EM 48 electrochemically 48 laser beams 48 plasmons 47 muons 47 excitations 47 rustling leaves 47 tuning forks 47 ultra violet rays 47 vibrating 47 screeching noise 47 Earth magnetosphere 47 magnetic pulses 47 ionized gas 47 magnetic fields 47 photon 47 waveguide 47 phonon 47 ionisation 47 electromagnetic induction 47 hydrogen ions 47 water vapor 47 sensory organs 47 stimulated emission 47 chromophore 47 pulsation 47 combustion gases 47 infrasound 47 electro magnetic 47 harmful ultraviolet radiation 46 X ray beam 46 Hawking radiation 46 resonant frequency 46 infrared beams