Notebook

Humans

50 years ago, scientists debated when humans first set foot in North America

In 1973, archaeologists debated when people first arrived in the Americas. Mounting evidence suggests its much earlier than they thought.

Life

A new metric of extinction risk considers how cultures care for species

Conservation efforts should consider relationships between cultural groups and the species important to them, researchers argue.

Chemistry

These chemists cracked the code to long-lasting Roman concrete

Roman concrete has stood the test of time, so scientists searched ruins to unlock the ancient recipe that could help architecture and climate change.

Genetics

50 years ago, scientists sequenced a gene for the first time

Within five decades, scientists went from sequencing a single gene to sequencing the entire human genome.

Space

Humans haven’t set foot on the moon in 50 years. That may soon change

In 1972, the era of crewed missions to the moon came to an end. Fifty years later, a new one has begun.

Health & Medicine

How much water should you drink a day? It depends on several factors.

A study of more than 5,000 people in 23 countries finds that individual water need varies widely depending on physical and environmental factors.

Physics

50 years ago, physicists found the speed of light

In the 1970s, scientists set a new maximum speed limit for light. Fifty years later, they continue putting light through its paces.

Health & Medicine

50 years ago, a ‘cure’ for intoxication showed promise

In 1972, vitamin and chemical injections reduced the amount of time that rats fed alcohol spent drunk. The science has yet to pan out for people.

Animals

A clam presumed extinct for 40,000 years has been found alive

The reappearance of living Cymatioa cooki clams places it among a group of back-from-the-dead creatures dubbed the Lazarus taxa.

Archaeology

50 years ago, Stonehenge’s purpose mystified scientists. It still does

In 1972, scientists thought Stonehenge may have been a calendar. Today, we still don’t know its purpose, but we have gained insight on its origin.

Earth

50 years ago, scientists found a new way to clean up oil spills

In the 1970s, researchers added chemicals to the list of oil spill cleanup methods. Soon, they may add microbes.

Earth

50 years ago, scientists dug into Pangaea’s past lives

In 1972, scientists wondered whether Pangaea was Earth’s only supercontinent. Fifty years later, we know it wasn’t the first and it won’t be the last.