The second voyage of James Cook was commissioned to search for the hypothetical continent Terra Australis in the Southern Pacific Ocean. He explored the Pacific and Atlantic oceans in the process and proved there is no such continent unless it is over the South Pole itself, which we now call Antarctica.
Some sources stated that Cook traveled over 60000 miles in his second voyage. Flat-Earthers use the figure as Antarctica’s circumference and claim it as “evidence” that Antarctica is much more than a continent. In reality, James Cook explored the vast ocean and did much more than just circumnavigating Antarctica.