President Trump said his uncle, Dr John Trump, had “invented radar” when speaking to reporters on October 24 after early voting in Palm Beach, Florida.
A clip of the president’s remarks was shared on X by journalist Aaron Rupar where it swiftly received a community note, approved by other platform users, stating that “Donald Trump's uncle did not invent radar."
Trump’s claim is incorrect, though his uncle was heavily involved in U.S. radar research during World War II.
Newsweek contacted the White House press office for comment on Sunday by email.
Trump’s Claim
Trump made the radar claim on Saturday when speaking to reporters in Palm Beach about all the Iranian equipment he said had been destroyed by American forces during the Iran war he launched in February.
Referring to the U.S. military he said: “They’ve knocked out all of the, actually some of the things my uncle invented, the radar.
...
“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. I knocked out all of the different things and the only thing they have going for them right now is inflation.”
After Rupar shared a shortened clip of Trump’s remarks on X a community note was added stating: “Donald Trump's uncle did not invent radar. The ‘first practical radar system’ was patented by Sir Robert Watson-Watt, who built on the work of others such as Heinrich Hertz and Christian Huelsmeyer.”
Who Invented Radar?
A large number of people played a role in the invention of radar, something admitted by British radio engineer Sir Robert Watson-Watt, widely regarded as one of the key figures in the process.
In his 1958 memoir ‘Three Steps to Victory’ Watson-Watt wrote: “It has become habitual to call me ‘the father of radar’. The genealogical tree is cluttered with legitimate grandparents, great-grandparents and great-great grandparents of radar.”
The existence of electromagnetic waves, which form the basis of radar, was proved by German physicist Heinrich Hertz in a series of experiments conducted between 1886 and 1889.
In 1904 another German physicist, Christian Hulsmeyer, patented a device that could detect ships using radio waves and was widely seen as an early form of radar.
In 1935 Watson-Watt, working at the UK’s National Physical Laboratory in Teddington, produced a device that was able to consistently locate aircraft. This led to the creation of Chain Home, a series of radars across the U.K. that played a key role in defending the country from the German air force during the 1940 Battle of Britain.
Dr. John Trump
While Dr Trump, the younger brother of President Trump’s father Frederick, didn’t invent radar he did play an important role in establishing the American radar research program and getting the technology in use with the U.S. military.
Dr Trump became an assistant professor of electrical engineering at MIT in 1936 and worked on radar research. In 1942 he became secretary of the US National Defense Research Committee's Microwave Committee which gave him a role overseeing radar research across the country.
From February 1944 Dr Trump worked alongside Watson-Watt and other key UK scientists while heading the British Branch of MIT's Radiation Laboratory.
Trump’s Previous Claims
Trump has a track record of making claims about his uncle that struggle to stand up to scrutiny.
Speaking in Pennsylvania last year the president said his uncle taught Ted Kaczynski, also known at the Unabomber, during his time at MIT and found him to be a “seriously good” student. However in response MIT said “we have no enrollment record or information that Ted Kaczynski ever attended MIT.”
Trump’s uncle also died in 1985, 11 years before Kaczynski was publicly identified and arrested in 1996.
Contact Newsweek editors on this story: Matthew Robinson and Trevor Davies