Science, Tech, Math › Science Scientific Definitions of Current Share Flipboard Email Print MirageC / Getty Images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated January 15, 2020 In science, the word "current" refers to the flow of a medium. The specific definition depends on the context: Definition (Electricity) Current is the rate of flow of electricity. The unit of current is the ampere (A) which is defined as 1 ampere = 1 coulomb per second. Definition (Fluid) Current is the flow of a fluid, such as a gas or liquid. Air currents refer to air, while ocean currents and rip currents refer to water. A typical unit is meters per second (m/s). Definition (Quantum Mechanics) In physics, a current may refer to a probability current, which is also called a probability flux. This is a quantity that described the probability of flow in terms of unit time per unit area.