Tardigrades Could Live on Earth Until the Sun Dies

Jasper Nance
Jasper Nance

In considering the relative brevity of human existence, astronomer Carl Sagan once wrote, "We are like butterflies who flutter for a day and think it is forever." The same could not be said of the microscopic animals known as tardigrades, which, scientists are now predicting in the journal Nature, could stick around on Earth until the Sun dies. 

The tardigrade, also known as the moss piglet or water bear, is an admirably durable little monster. It superpower is a sort of half-death state called cryptobiosis. When hard times come around, the tardigrade simply curls up, dries up, and mostly stops living, only to re-inflate and rejoin the world when conditions are more comfortable. Studies have shown that tardigrades can survive scorching heat, blistering cold, starvation, desiccation, radiation, and even the vacuum of space.

That's just on the individual level. There are more than 1000 different tardigrade species [PDF], and all have already been around for a long, long time. Scientists estimate that the first tardigrades appeared on the planet around 600 million years ago—about 370 million years before the first dinosaurs. The dinosaurs disappeared. The tardigrades kept on trucking. 

And according to the authors of the new paper, the moss piglets could just keep on trucking for another 10 billion years.

"A lot of previous work has focused on 'doomsday' scenarios on Earth—astrophysical events like supernovae that could wipe out the human race," co-author David Sloan of Oxford University said in a statement.

But humans are far from the toughest kids on the block. ("Human life is somewhat fragile to nearby events," as the researchers diplomatically put it.) Why not try to find out how sturdier species would fare in those same scenarios? To do so, the researchers calculated the effects of three doomsday events—an asteroid strike, a nearby supernova, and a gamma ray burst (another type of stellar explosion)—on tardigrades' environment and physiology.

You can probably guess what they discovered.

"Although nearby supernovae or large asteroid impacts would be catastrophic for people, tardigrades could be unaffected," Sloan said. "Therefore it seems that life, once it gets going, is hard to wipe out entirely. Huge numbers of species, or even entire genera may become extinct, but life as a whole will go on."

Co-author Rafael Alves Batista, also of Oxford, said his team's findings should expand the scope of what we might consider a "habitable planet."

"Tardigrades are as close to indestructible as it gets on Earth, but it is possible that there are other resilient species examples elsewhere in the universe. In this context there is a real case for looking for life on Mars and in other areas of the solar system in general. If tardigrades are Earth's most resilient species, who knows what else is out there."

Archaeologists Uncover World's Oldest Known Brewery in Israel

People have been knocking back beers for 13,000 years, according to new archaeological findings out of the Middle East. As Science magazine reports, evidence of wheat and barley-based beer was found inside stone mortars carved into the floor of a cave near Haifa, Israel.

The Raqefet Cave was used as a burial site by the Natufians, a group of semi-nomadic hunter-gatherers who were also responsible for the world’s oldest known bread, which was discovered in Jordan in July. These findings challenge previous evidence that traced the origin of beer back just 5000 years.

Beer was also previously believed to be merely a by-product of bread-making, but archaeologists say that isn’t necessarily the case. Instead, researchers believe beer may been served during ritual feasts “to venerate the dead and/or to enhance group cohesion among the living,” researchers wrote in their paper, published in the Journal of Archaeological Science: Reports.

Remarkably, the Stanford University researchers who made this discovery weren't even looking for evidence of alcohol. “We did not set out to find alcohol in the stone mortars, but just wanted to investigate what plant foods people may have consumed because very little data was available in the archaeological record,” Li Liu, a professor of Chinese archaeology at Stanford, said in a statement.

Researchers theorize that beer brewing may have inspired the Natufians to cultivate cereals in the region, but it’s not currently known whether beer or bread came first. The mortars dug into the cave floor were reportedly used for storing and pounding wheat and barley, as well as brewing beer.

The beverage wasn’t exactly what we know as beer today, though. According to the BBC, the prehistoric beer was “gruel-like” and similar to porridge. It was likely weaker than modern beer, too.

[h/t Science]

Newly Uncovered Galileo Letter Details How He Tried to Avoid the Inquisition

Galileo Before The Papal Tribunal by Robert Henry. Hulton Archive, Getty Images
Galileo Before The Papal Tribunal by Robert Henry. Hulton Archive, Getty Images

Galileo Galilei was one of the Roman Catholic Inquisition’s most famous targets. As a result of his outspoken support for the theory that all the planets, Earth included, revolve around the Sun, the Catholic Church charged him with heresy and he spent the last years of his life under house arrest. Galileo was well aware that he was on the Church’s hit list, and a newly discovered letter shows that at one point, he tried to tone down his ideas to avoid persecution, according to Nature and Ars Technica.

The letter in question, written in 1613, solves a long-held mystery for Galileo scholars. It was found in the library of the Royal Society, where it has been for at least 250 years.

Galileo’s beef with the Catholic Church came about because of his support for heliocentrism—the idea that the solar system centers around the Sun—as advocated in Nicolaus Copernicus’s book De Revolutionibus. Galileo’s scientific writings clearly endorsed Copernicus’s theory of the world, including in personal correspondence that was widely disseminated, and in some cases, he directly questioned the scientific merit of Biblical passages.

In 1613, Galileo wrote to a friend and former student named Benedetto Castelli who was then teaching mathematics at the University of Pisa. The letter was a long treatise on Galileo’s thoughts on Copernicus’s ideas and religion, arguing that science and astronomy should not be overpowered by religious doctrin . (He would later expand this into his Letter to the Grand Duchess Christina.) As with many of Galileo’s writings at the time, the letter was copied and disseminated widely, and eventually, a friar named Niccolò Lorini forwarded it to the Inquisition in Rome in 1615.

This is where things get tricky. Galileo claimed that the version of the letter Lorini sent was doctored to be more inflammatory. He sent a less controversial version of the letter to a friend, saying that it was the original document and should be forwarded to the Vatican, essentially to clear his name. But scholars have never been able to be totally sure if he was telling the truth about the letter being doctored.

This newly discovered letter suggests that he was lying, and that he himself was looking to tone down his rhetoric to appease the Catholic Church and keep authorities from quashing the spread of heliocentric ideas. The original copy found in the Royal Society archives shows changes to the wording in what appears to be Galileo’s handwriting. The seven-page letter, signed “G.G.,” includes changes like swapping the word “false” for the more slippery “look different from the truth,” changing “concealing” to “veiling,” and other edits that seek to tone down the rhetoric that inflamed Church leaders. The wording and handwriting corresponds to similar writing by Galileo at the time. Based on this finding, it seems that Galileo did seek to make his ideas more palatable to the Catholic Church in the hopes of escaping persecution by the Inquisition.

Discovered on a research trip by science historian Salvatore Ricciardo of Italy's University of Bergamo, the letter may have been overlooked in the Royal Society archives because it was cataloged as being dated October 21, 1613 rather than the date it actually bears, December 21, 1613. However, it’s unclear how it came to the Royal Society in the first place. The document is the subject of a forthcoming article by Ricciardo and his colleagues in the Royal Society journal Notes and Records, according to Nature.

The minor changes Galileo made did not successfully hold off the Church’s crackdown on heliocentrism. In 1616, the Inquisition ordered Galileo to stop teaching or defending the theory, and several of his books were subsequently banned. He would stand trial again almost two decades later, in 1633, on suspicion of holding heretical thoughts. He was found guilty and sentenced to house arrest, where he remained until his death in 1642.

[h/t Ars Technica]

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