The phase velocity is the speed at which a wave of a single wavelength moves, and is typically about 1.5 kilometres per second for sound waves in water. Waves moving in a dispersive medium are described by a phase velocity and a group velocity. In simulations Mobley has shown that ultrasound pulses could move at 'superluminal' speeds when they enter water that contains thousands of tiny plastic beads. Webinars Tune into online presentations that allow expert speakers to explain novel tools and applicationsĬan sound waves travel faster than the speed of light? Yes, says Joel Mobley, a physicist at the University of Mississippi in the US.Video Watch our specially filmed videos to get a different slant on the latest science.Podcasts Our regular conversations with inspiring figures from the scientific community.Audio and video Explore the sights and sounds of the scientific world.Supercool physics Experiments that probe the exotic behaviour of matter at ultralow temperatures depend on the latest cryogenics technology.The science and business of space Explore the latest trends and opportunities associated with designing, building, launching and exploiting space-based technologies.Revolutions in computing Find out how scientists are exploiting digital technologies to understand online behaviour and drive research progress.Nanotechnology in action The challenges and opportunities of turning advances in nanotechnology into commercial products.#BlackInPhysics Celebrating Black physicists and revealing a more complete picture of what a physicist looks like.Artificial intelligence Explore the ways in which today’s world relies on AI, and ponder how this technology might shape the world of tomorrow.Collections Explore special collections that bring together our best content on trending topics.Innovation showcases A round-up of the latest innovation from our corporate partners.Projects and facilities Follow the latest progress at the world’s top scientific experiments.

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Speed of sound in water