Across • Black • Bodies • Both • Celestial • Commonly • Conducting • Contact • Differ • Different • Discontinuity • Distinct • Enhanced • Equation • Evolution • Faster • Frequency • Impact • Invisible • Naked • New • Observations • Observed • Occurrence • Organisms • Particles • Phenomen • Phenomena • Play • Pressure • Properties • Psychology • Radiation • Remain • Result • Separate • Serve • Shock • Showers • Sound • Study • Substance • Systems • Temperature • They • Turn • Used • Using • Wavelength • When