French physicist Pierre Curie defends his thesis on magnetism, which includes his experimental findings regarding the effect of temperature on paramagnetism and states what is now known as Curie's law.
During experiments with cathode ray tubes, German physicist Wilhelm Roentgen discovers a previously unknown form of electromagnetic radiation, the x-ray.
The first large-scale hydroelectric power plant, located in North America at Niagara Falls, begins delivering power.
A German-American electrical engineer, Charles Steinmetz, applies the mathematics of complex numbers to the analysis of AC circuits.
Pieter Zeeman, a student of Dutch physicist Hendrik Lorentz, demonstrates that a magnetic field can split the spectral line of a light source into multiple components with different frequencies (the Zeeman effect).
French physicist Antoine-Henri Becquerel first observes natural radioactivity.
Italian-Irish inventor Guglielmo Marconi receives a patent for the radio, a device that enables the wireless transmission of electromagnetic waves.
German physicist Karl Braun invents the cathode-ray oscilloscope, a means of visibly displaying graphical representations of electromagnetic signals. The cathode ray tube that the device contains eventually evolves into other types of electronic displays, including the receiving screen of the television.
German physicist Wilhelm Wien determines that the so-called “canal rays” discovered by his compatriot Eugene Goldstein in1886 are the positively charged equivalent of cathode rays.
Valdemar Poulsen, a Danish engineer, invents the telegraphone, an early magnetic recording device designed to record telephone conversations.
Ernest Rutherford, a physicist from New Zealand, determines that the rays that Becquerel discovered to be emitted from uranium (1896) are composed of two discrete forms of radiation, which he terms alpha rays and beta rays.
Waldmar Jungner of Sweden develops the rechargeable nickel-cadmium battery.