Meanderings, 14 January 2021

All week I was with a DMin class at Northern Seminary. Our class this week was about Jesus and the Pharisees as understood through a method called strategic field theory. Not long after I got home I discovered a response/review to a portion of The Pharisees, ed. Joseph Sievers and Amy-Jill Levine, was ranked in this year’s top essays for the Ancient Jew Review. You might have interests in other essays in that ranking.

Photo by Arek Adeoye on Unsplash

If you are following the “AI” developments, here’s a new app that detects AI produced writings:

Teachers worried about students turning in essays written by a popular artificial intelligence chatbot now have a new tool of their own.

Edward Tian, a 22-year-old senior at Princeton University, has built an app to detect whether text is written by ChatGPT, the viral chatbot that's sparked fears over its potential for unethical uses in academia.

Tian, a computer science major who is minoring in journalism, spent part of his winter break creating GPTZero, which he said can "quickly and efficiently" decipher whether a human or ChatGPT authored an essay.

His motivation to create the bot was to fight what he sees as an increase in AI plagiarism. Since the release of ChatGPT in late November, there have been reports of students using the breakthrough language model to pass off AI-written assignments as their own.

"there's so much chatgpt hype going around. is this and that written by AI? we as humans deserve to know!" Tian wrote in a tweet introducing GPTZero.

Tian said many teachers have reached out to him after he released his bot online on Jan. 2, telling him about the positive results they've seen from testing it.

More than 30,000 people had tried out GPTZero within a week of its launch. It was so popular that the app crashed. Streamlit, the free platform that hosts GPTZero, has since stepped in to support Tian with more memory and resources to handle the web traffic.

Wow.

Looking forward to 2066?

DENVER (AP) — Earth’s protective ozone layer is slowly but noticeably healing at a pace that would fully mend the hole over Antarctica in about 43 years, a new United Nations report says.

A once-every-four-years scientific assessment found recovery in progress, more than 35 years after every nation in the world agreed to stop producing chemicals that chomp on the layer of ozone in Earth’s atmosphere that shields the planet from harmful radiation linked to skin cancer, cataracts and crop damage.

“In the upper stratosphere and in the ozone hole we see things getting better,” said Paul Newman, co-chair of the scientific assessment.

The progress is slow, according to the report presented Monday at the American Meteorological Society convention in Denver. The global average amount of ozone 18 miles (30 kilometers) high in the atmosphere won’t be back to 1980 pre-thinning levels until about 2040, the report said. And it won’t be back to normal in the Arctic until 2045.

Antarctica, where it’s so thin there’s an annual giant gaping hole in the layer, won’t be fully fixed until 2066, the report said.

Some support, eh?!

TAMPA, Fla. (WFLA) — Security screeners spotted a scaly surprise while scanning a suitcase: a 4-foot-long boa constrictor making its way through an X-ray machine at Tampa International Airport.

In an Instagram post on Friday, the Transportation Security Administration (TSA) said security officers found the snake curled up inside a carry-on bag in December.

The passenger told officers the boa was her “emotional support pet,” a TSA spokesperson said. The agency checked with her airline, who confirmed the snake would not be allowed on the plane while loose inside a suitcase.

It would not have been the first time a snake found its way onto a flight from Tampa. In October, a garter snake startled fliers on a plane from Tampa to Newark, New Jersey, when it slithered out of a carry-on bag.

TSA said no airlines allow snakes in carry-on luggage. However, a few airlines allow snakes in checked luggage if they are packaged correctly.

Then there’s the science of walking:

FOR SOMETHING SO routine, walking is shockingly complicated. Biomechanists break a single step into several phases: First there’s touchdown, when your heel strikes the floor. Next comes the single support phase, when you’re balancing on that leg. After that, you roll onto your toes for takeoff and your leg goes into a forward swing.

All of this contains a mystery.  Researchers have long observed that when we walk, our planted leg bounces twice before swinging into the next step. That is, the knee bends and extends once when the foot first touches down, then again just before takeoff. That first bounce helps our foot absorb the impact of our weight as we hit the ground. But the function of the second bounce, a feature characteristic to human gait, has never been clear. 

In a Physical Review E paper published last month, scientists at the University of Munich may have found an answer. By modeling the physical forces that drive our double bounce, they deduced that it’s an energy-saving technique for a species that has long prioritized endurance over speed—which may be a clue about why humans evolved such an odd gait. Now, they think their model can help improve prosthetic and robotic designs, and may even lend insight into the evolutionary pressures our ancestors faced.

“The foot is the key element here,” says Daniel Renjewski, a mechanical engineer who led the study. The human foot is, frankly, kind of an oddity in the animal kingdom. People have a 90-degree angle between the foot and the leg, he continues, but few other animals do. That means most animals walk on their tiptoes or the balls of their feet, while we walk heel-to-toe. Human feet are also relatively flat, and our legs are quite heavy, both of which make staying upright while propelling the body forward a mechanical challenge. 

Our double-bounce walking pattern is distinct from the single bounce we enact when running, which is a motion that’s mostly airborne, says University of Munich sports scientist Susanne Lipfert, a study coauthor. While walking, the foot stays planted for up to 70 percent of a step cycle to help us stay balanced at slower speeds. But that comes with a tradeoff: less time to propel ourselves forward. Counterintuitively, that means your body has to work harder when walking to recirculate the leg into its next step. “It seems odd, at first glance, to aim for a gait that leaves very little time to swing your leg forward,” Renjewski says, because of how heavy our legs are: More mass requires more power.