Einstein's The Fish Puzzle

Albert Einstein is the founder of the Theory of Relativity and is considered the most important scientist of the 20th century and of all time. The impact of Einstein's discoveries regarding the nature of space and time continues to be a central subject of scientific research in physics, cosmology, and mathematics, while his surname is often used as a designation of high intelligence. His theories were essentially a profound revision of the old Newtonian Physics and were a revolution for scientific and philosophical research.
Professor Puzzle puzzles honor Albert Einstein with a new series of metal and wooden puzzles, each based on the theories of the leading scientist.

The Fish Puzzle

"Each of us is smart. "But if you judge a fish by whether or not it can climb a tree, it will spend its whole life believing it is stupid." Although Albert Einstein probably never uttered this famous phrase, it reflects the great scientist's thought that intelligence cannot be measured by such narrow and rigid criteria. Exercise your brain with the original fish puzzle and try to separate and then reconnect the fish from the metal rod.