Reference Terms
from Wikipedia, the free encyclopedia
Ampere
The ampere (symbol: A) is the SI base unit of electric current equal to one coulomb per second. The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross section, and placed 1 metre apart in vacuum, would produce between these conductors a force equal to 2 times 10–7 newton per metre of length. Electric current is the time rate of change or displacement of electric charge. One ampere represents the rate of 1 coulomb of charge per second. The ampere is defined first (it is a base unit, along with the metre, the second, and the kilogram), without reference to the quantity of charge. The unit of charge, the coulomb, is defined to be the amount of charge displaced by a one ampere current in the time of one second.
Related Stories
1
2
Matter & Energy News
February 5, 2026
Feb. 5, 2026 A new metasurface design lets light of different spins bend, focus, and behave independently—while staying sharp across many colors. The trick combines two geometric phase effects so each spin channel can be tuned without interfering with the ...
Feb. 4, 2026 A new optical device allows researchers to generate and switch between two stable, donut-shaped light patterns called skyrmions. These light vortices hold their shape even when disturbed, making them promising for wireless data transmission. Using a ...
Feb. 3, 2026 Researchers have found that manganese, an abundant and inexpensive metal, can be used to efficiently convert carbon dioxide into formate, a potential hydrogen source for fuel cells. The key was a clever redesign that made the catalyst last far ...
Feb. 2, 2026 A new light-based breakthrough could help quantum computers finally scale up. Stanford researchers created miniature optical cavities that efficiently collect light from individual atoms, allowing many qubits to be read at once. The team has already ...
Feb. 1, 2026 Researchers have discovered a hidden quantum geometry inside materials that subtly steers electrons, echoing how gravity warps light in space. Once thought to exist only on paper, this effect has now been observed experimentally in a popular quantum ...
Jan. 31, 2026 A strange, glowing form of matter called dusty plasma turns out to be incredibly sensitive to magnetic fields. Researchers found that even weak fields can change how tiny particles grow, simply by nudging electrons into new motions. In lab ...
Jan. 30, 2026 Researchers have found a way to make ordinary aluminum tubes float indefinitely, even when submerged for long periods or punched full of holes. By engineering the metal’s surface to repel water, the tubes trap air inside and refuse to sink, even ...
Jan. 29, 2026 Order doesn’t always form perfectly—and those imperfections can be surprisingly powerful. In materials like liquid crystals, tiny “defects” emerge when symmetry breaks, shaping everything ...
Jan. 29, 2026 Scientists have created a device that captures carbon dioxide and transforms it into a useful chemical in a single step. The new electrode works with realistic exhaust gases rather than requiring purified CO2. It converts the captured gas into ...
Jan. 26, 2026 Physicists have discovered that hidden magnetic order plays a key role in the pseudogap, a puzzling state of matter that appears just before certain materials become superconductors. Using an ultra-cold quantum simulator, the team found that even ...
Jan. 26, 2026 Researchers have demonstrated that quantum entanglement can link atoms across space to improve measurement accuracy. By splitting an entangled group of atoms into separate clouds, they were able to measure electromagnetic fields more precisely than ...
Jan. 25, 2026 Researchers have developed a technique that allows them to carve complex three dimensional nanodevices directly from single crystals. To demonstrate its power, they sculpted microscopic helices from a magnetic material and found that the structures ...
Latest Headlines
updated 12:56 pm ET
Feb. 3, 2026 Astronomers have produced the most detailed map yet of dark matter, revealing the invisible framework that shaped the Universe long before stars and galaxies formed. Using powerful new observations ...
Feb. 3, 2026 A newly detected gravitational wave, GW250114, is giving scientists their clearest look yet at a black hole collision—and a powerful way to test ...
Feb. 2, 2026 MACE is a next-generation experiment designed to catch muonium transforming into its antimatter twin, a process that would rewrite the rules of particle physics. The last search for this effect ended ...
Jan. 31, 2026 nside electrochemical devices, strong electric fields dramatically alter how water molecules behave. New research shows that these fields speed up water dissociation not by lowering energy costs, but ...
Jan. 26, 2026 For years, scientists noticed that magnetic fields could improve steel, but no one knew exactly why. New simulations reveal that magnetism changes how iron atoms behave, making it harder for carbon ...
Jan. 26, 2026 When materials become just one atom thick, melting no longer follows the familiar rules. Instead of jumping straight from solid to liquid, an unusual in-between state emerges, where atomic positions ...
Jan. 24, 2026 Scientists are finding new ways to replace expensive, scarce platinum catalysts with something far more abundant: tungsten carbide. By carefully controlling how tungsten carbide’s atoms are ...
Jan. 23, 2026 Chemists at UCLA are showing that some of organic chemistry’s most famous “rules” aren’t as unbreakable as once thought. By creating bizarre, ...
Jan. 22, 2026 A long-standing law of thermodynamics turns out to have a loophole at the smallest scales. Researchers have shown that quantum engines made of ...
Jan. 22, 2026 Scientists are learning how to temporarily reshape materials by nudging their internal quantum rhythms instead of blasting them with extreme lasers. By harnessing excitons, short-lived energy pairs ...