This Month in the Archives

Dive into 174 years of groundbreaking research

This Month in the Archives

Dear Reader, In the Northern Hemisphere, the sun reaches its highest point in the sky during the summer solstice on June 21. To calculate the altitude and zenith of the sun, our ancestors used observatories and sundials, sophisticated instruments (unlike the useless decorative ones we put in our gardens) that have fascinated our editors for decades. And if all that bright summer daylight is keeping you awake, take a look at some of these stories on sleep—why it exists, what it is, and how it evolved. Unrelatedly, but in the news: measles. Outbreaks such as the one happening now in the U.S. have been a problem for a long time. I hope you enjoy the journey! Dan Schlenoff, editor of “50, 100 & 150 Years Ago” Keeping Track of Time with the Sun Very accurate—for a sun clock. August 1935. Sundials are one of the oldest scientific tools humans use. Up to a couple of centuries ago they were the best way to keep track of time. December 1925: The Mayans kept remarkably good track of time using “the largest sundial in the world.” February 1934: “Sundials and Their Construction”—part 1 of a nine-part series that will tell you everything there is to know. August 1935: Quibbles about useless decorative garden implements aside, here’s an article on highly accurate “sun clocks” for garden use. August 1991: “What in Heaven Is a Digital Sundial?” Our “Mathematical Recreations” columnist Ian Stewart explains it all.   Sleep: It’s Important The sleeping brain is an active organ. October 2015. More daylight—or less—doesn’t affect the amount of sleep we need. But what is sleep anyway, and what happens during slumber? May 1878: In this old article, lack of sleep causes “softening of the brain, insanity, and death.” Funny! Except that psychosis and death are both possible. February 1967: REM was discovered in 1953; the different stages of sleep were untangled over the next few years. November 2003: Why did evolution design us to sleep? Isn’t it a waste of time? Here the enigma starts getting unravelled. October 2015: Mental deficits from lack of shut-eye show the neurological benefits of sleep.   Measles and Epidemics A tribesman takes the symbolic blame for a measles epidemic in Vancouver Island, Canada, reported in 1908. Nature is a force that doesn’t bend to internet memes or political pressure. Infectious organisms have evolved to be successful in a variety of situations. December 1908: Native American tribes on Vancouver Island used a “Measles Cannibal” ceremony to attempt to halt an epidemic of this disease. February 1916: The spread of diseases in a school: now we are all too familiar with this disease “vector.” April 1984: A century of measles epidemics in Iceland: awful but a great opportunity to study the spread of this disease in an isolated population. March 2000: Vaccines are safe. We said it then, we say it now. But yeah, nobody likes getting injections.   Current Issue: June 2019 The “Cambrian explosion” describes the widespread evolution of complex animals. But some careful sleuthing has uncovered fossil evidence that shows multicellular organisms were evolving millions of years earlier than we had thought. Plus: Some animals have evolved the ability to sleep with half their brain awake. One vaccine, properly developed and administered, might protect against a multitude of diseases. Here’s something else we don’t know: Where do protons and neutrons get their mass from? For more highlights from the archives, you can read June's 50, 100 & 150 Years Ago column.       Follow Us   To view this email as a web page, go here. You received this email because you opted-in to receive email from Scientific American. To ensure delivery please add news@email.scientificamerican.com to your address book. Unsubscribe Manage Email Preferences FAQs Terms & Conditions Privacy Policy Contact Us