Spoiler alert: We may be wrong about how the ancient Egyptians built the Great Pyramids. Decades of schoolchildren are taught the prevailing theory - the pyramids were constructed from enormous blocks of solid stone, cut by hand from far away quarries and hauled across the searing desert sands. We imagine - thanks in large part to Cecile B. DeMille - thousands of shirtless, sweating slaves harnessed to thick hemp ropes, dragging enormous square blocks of stone up steep ramps. The feat seems so incredible that some wonder whether the Egyptians had help from other planets. Always a rational voice in the room, Neil deGrasse Tyson counters, “just because you can't figure out how ancient civilizations built stuff, doesn't mean they got help from aliens.”

Figuring out how the pyramids were built has interesting applications beyond Egyptology. Today’s building materials do not have an expected lifespan anywhere near 4,000 years. And many of our modern construction processes consume so much energy and emit so much CO2 that we’re quickly destroying the very world we’re working to build. The Egyptians seemed to know something we don’t about using locally-sourced materials to construct extraordinarily durable buildings without the huge environmental footprint so common today. Did the Egyptians use their minds as much as their muscle, and if so, what can we learn from them?

The skepticism Tyson addresses comes from a logical place. Despite the common teachings of the building of the pyramids at Giza, the feat of construction seems almost implausible. The Great Pyramid of Khufu was the tallest man made structure on earth for over 3,800 years - 16 times as long as our country has existed - until the construction of the Lincoln Cathedral in England. When built, the pyramid was 756 feet long on each side, 481 feet high, and composed of 2.3 million stones weighing on average nearly three tons each. Many of the joints between block are so accurate that a human hair cannot be passed between adjoining blocks.