2023届高三英语二轮复习每日阅读打卡 DAY 2 （选自National Geographic）

每日阅读打卡DAY2(选自National Geographic) Humans have spent millennia attempting to unlock the secrets of the pyramids of Giza.Built some 4,500 years ago,they contain tombs and chambers that once held the remains of early Egyptian pharaohs. But modern technology has revealed that the pyramids also contain hidden voids.In 2016 and 2017,a group of researchers known as the ScanPyramids project identified several such cavities within the pyramids.And,this week,the Egyptian authorities announced new details about one of voids:the North Face Corridor, which lies just above the entrance to the Pyramid of Khufu (the "Great Pyramid"), the largest of the pyramids on the Giza Plateau. (Learn more about the pyramids of Giza.) With the help of a technology called muon radiography-which uses cosmic ray particles to probe objects and construct 3-D models of their insides-scientists have confirmed that the North Face Corridor stretches 30 feet long and over six feet wide. Archaeologists are skeptical that these empty spaces have any ritual significance.As archaeologist Kate Spence told National Geographic in 2017,and as archaeologist Mark Lehner told the New York Times,research has shown that Egyptians likely built gaps into the pyramids to relieve pressure and keep them structurally sound. (Read about the 2017 discovery of a mysterious void in Egypt's Great Pyramid.) Still,like the pyramids themselves,these voids continue to fascinate us.So how do we know they exist-and how do scientists measure them?Here's the science behind the technology. The science of muon radiography Scientists got a better glimpse of the pyramid's innards thanks to a clever imaging technique called muon radiography,which was first tested in the field at the Pyramids of Giza more than 50 years ago. Muon radiography relies on the muon,a kind of subatomic particle very similar to the electron,except it's about 200 times more massive and lasts only a few millionths of a second.Despite their short lifespans,muons are c