Telephone: The invention of the telephone is often attributed to Alexander Graham Bell, but another inventor named Elisha Gray also independently developed a similar device around the same time.
Calculus: Both Sir Isaac Newton and Gottfried Wilhelm Leibniz are credited with independently inventing calculus in the late 17th century. Although their approaches differed, both made significant contributions to the field.
Television: Philo Farnsworth and Vladimir Zworykin separately developed electronic television systems in the early 20th century. Farnsworth's system eventually became the basis for modern television technology.
Steamboat: While Robert Fulton is often recognized as the inventor of the steamboat, John Fitch actually built and successfully demonstrated a steam-powered boat several years before Fulton's design.
Airplane: The Wright brothers, Orville and Wilbur, are known for inventing the first successful airplane in 1903. However, there were other inventors, such as Gustave Whitehead and Samuel Pierpont Langley, who also made attempts at powered flight around the same time.
Typewriter: Christopher Latham Sholes is often credited with inventing the typewriter in the late 19th century. However, prior to Sholes' design, there were several other inventors who developed similar writing machines, including Charles Thurber and John Pratt.
Radio: Guglielmo Marconi is widely recognized for his contributions to the development of radio communication. However, Nikola Tesla also made significant advancements in wireless communication and held several related patents.