Crazy as it might seem, there was a time when the U.S., the Soviet Union, and other countries tested nuclear weapons by exploding them in the atmosphere. From 1945 to 1963, when such tests finally were banned by an international treaty, more than 500 nuclear bombs were detonated, releasing radioactive fallout that spread far and wide across the planet, causing harm to the environment and human health. For example, everyone born in the U.S. 1951 has been exposed to nuclear fallout, and for some, it's resulted in an increased risk of thyroid cancer, according to the U.S. Centers for Disease Control and Prevention (CDC). The tests caused what's known as the 14C bomb pulse because of the spike in the atmospheric concentration of carbon-14, a carbon isotope that also occurs naturally. The excess carbon-14 was distributed throughout Earth's atmosphere, peaking in 1963 when the test ban went into effect. That radioactivity, which has gradually been declining since the 1960s, has been absorbed by plants, animals and people, creating a sort of time stamp that's enabled researchers to measure when things occur - from the longevity of white sharks to the growth of human knee cartilage and even brain cells. Post h as been generat ed with GSA Content Genera tor DEMO!
It's also enabled forensic investigators to estimate the age and year of death for human remains with much greater precision than previously possible. Using the bomb pulse is an advance upon conventional radiocarbon dating that uses naturally occurring 14C, according to Thomas D. Holland. He's a research professor and director of the Forensic Institute for Research and Education at Middle Tennessee State University. Holland explains via email. 14C in the atmosphere almost doubled the normal level," Holland explains. "Viewed on a longitudinal chart, the total amount of 14C present in the atmosphere shows a dramatic pulse in late 1963, followed by a gradual decline of approximately 4 percent a year as the 'artificial' bomb-created 14C is absorbed out of the atmosphere by living things and the ocean. But if there's evidence of the bomb pulse's effects, it's possible for 3475&po=6456&aff_sub5=SF_006OG000004lmDN forensic scientists to determine that the bones belong to a person who died sometime between 1950 and the present. By examining organic tissues with different growth and "turnover" rates, such as fingernails and hair relative to bone, scientists can estimate where on the bomb pulse downward slope the sample falls and speculate an age. Carbon-14 levels in fingernails, for example, can help scientists determine the year of death with 91 percent accuracy, according to a 2022 study published in Journal of Forensic and Legal Medicine. But the bomb pulse isn't just useful for dating human bodies. Thure E. Cerling, chair of the department of geology and oral geophysics and a distinguished professor in both biological sciences and geology and physics at the University of Utah, used the bomb pulse in this 2016 study on poaching in the ivory trade. Cerling explains via email.
Felix, a slave in Pompeii, is already tired, even though it's only midday. He's been hard at work in the midsummer heat, the clear blue sky offering no shelter from the blazing sun, save for the occasional breeze off the Mediterranean Sea. However, he has a rest period, so he and a few other slaves trudge back to the center of Pompeii along the Via dell'Abbondanza. The rich smell of baking bread fills the air, so he buys some, then purchases dried nuts and fish at a nearby thermopolium, where food comes ready to eat in clay jars. The handful of asses (ancient Roman coins) he uses to pay for his meal comes from the meager wage his master provides, but it's worth it on a day like today. Because it's a day unlike any other, as he'll soon realize. It is Aug. 24, 79 C.E. The earth rumbles beneath his feet, and some of the older people who've lived in Pompeii for nearly 20 years shake their heads.
The mountain has been unquiet before. But never like this. Before long he joins a growing crowd fleeing the city. Ash and shards of hot rock are falling from the sky. Looking back, he can see thick drifts of ash collecting on roofs and filling the streets. Pompeii is dying before his eyes. This is the true story of the Roman city of Pompeii and the people who lived there. It's also the story of the city's sudden destruction, love and the eventual rediscovery of ruins that offer an incomparable window into life in the Roman Empire 2,000 years ago.C.E. Pompeii began to grow into a city around 600 B.C.E., settled by the Oscans, an ancient people of Campania. It was home to a mix of cultures from around the Mediterranean, but the Oscan influence remained strong until the day the city was destroyed. The ruins of Pompeii also reveal that the inhabitants revered Greek culture.
The temples, statues, public buildings and decorations in the villas all reflected a high degree of Hellenistic influence. Pompeii was not the most important city in the Roman Empire, or even in the Campania region in southern Italy, but it was a particularly wealthy city. Before its destruction, Pompeii sat on the coast of the Bay of Naples near the mouth of the Sarno River, making it a trade hub for the region. The waters of the Sarno and the volcanic soils deposited by Mount Vesuvius combined to give the area rich farmland - volcanic soils are notably high in nutrients and the river provides a ready source of irrigation. And the limestone, called tufa, used to build the large public buildings and the villas and mansions of Pompeii's richest citizens was likely quarried from the Monti Lattari mountain range just south of the city. Among Pompeii's more impressive buildings were temples to Jupiter, Venus, Augustus and others; an amphitheater that could hold 20,000 people (Pompeii's entire population at its peak); elaborate public baths; public parks and gymnasia; an entire theater district; and a sporting arena.