Trump says his uncle invented radar; fact-checks say he did not

Centre · 2President Donald Trump said his uncle, Dr John Trump, "invented radar" while speaking to reporters in Palm Beach, Florida, on 24 October after early voting. 1 2 Centre · 1Newsweek reports he made the remark while talking about Iranian equipment he said US forces had destroyed in the Iran war, which Newsweek says he launched in February. He said: "My uncle invented radar can you believe it. From MIT Dr John Trump. I mean he'll probably be angry at me but I knocked out their radar." 1 Centre · 2A clip shared on X by journalist Aaron Rupar received a community note saying Trump's uncle did not invent radar. Newsweek quotes the note as saying the "first practical radar system" was patented by Sir Robert Watson-Watt, building on Heinrich Hertz and Christian Huelsmeyer. Hindustan Times quotes a note saying John G. Trump contributed to WWII radar development and deployment at MIT's Rad Lab but did not invent it. 1 2

Centre · 1Newsweek says radar had many contributors. Hertz proved the existence of electromagnetic waves in experiments between 1886 and 1889. Hulsmeyer patented a ship-detecting device in 1904. In 1935 Watson-Watt produced a device that could consistently locate aircraft, which led to the Chain Home network used in the 1940 Battle of Britain. Watson-Watt himself wrote in his 1958 memoir that the "genealogical tree is cluttered" with earlier contributors to radar. 1 Centre · 1John Trump, younger brother of the president's father Frederick, did have a real role in radar. Newsweek says he became an MIT assistant professor of electrical engineering in 1936. In 1942 he became secretary of the National Defense Research Committee's Microwave Committee, overseeing radar research across the US. From February 1944 he headed the British Branch of MIT's Radiation Laboratory, working with Watson-Watt and other UK scientists. 1 Centre · 1Hindustan Times describes him as a professor of engineering and physicist specialising in high-voltage phenomena, who designed X-ray generators for cancer therapy. It says the FBI had him examine Nikola Tesla's papers and equipment after Tesla's death in 1943, and that he died in 1985. It adds that MIT posted about him in June, calling him "the president's uncle" and a "MIT legend". 2

Centre · 2Both outlets note that Trump has spoken about his uncle before. Hindustan Times cites a 2024 New Hampshire rally and a 2016 New Yorker article on earlier mentions. Newsweek recalls that Trump said last year that his uncle taught Ted Kaczynski at MIT, which MIT disputed, saying it had no enrollment record of Kaczynski. Newsweek also notes the uncle died in 1985, before Kaczynski was identified in 1996. Newsweek said it asked the White House press office for comment, and the coverage shows no response. 2 1