Intermediate

For centuries, women in Sweden called their cows home with a sound called kulning. Now, kulning has been embraced by many, including universities as a form of art. But from medieval times until the mid-20th century, the sound could be heard every summer, ringing across the mountains. Reaching up to 125 decibels, kulning can be heard over 5 km (1 mi) away. Since cattle tend to wander off, they needed to be able to hear the herdswomen calling them.

It was traditionally women who went up the mountains with the herd in the summer. They each lived in a small settlement, tending the animals. They milked the cows, made cheese and spent hours doing all the rest, like cooking, knitting, mending, making brooms, etc. It was hard work, but the women also had a lot of freedom without men around. They could do whatever they wanted up there.

According to Executive Sushi Chef Kazunari Araki, sushi is not originally Japanese.

He says the combination of rice and fish began in the 3rd century along the Mekong River in Southeast Asia. It was cleaned, gutted and finally covered in a salt and rice mixture for several months in order to preserve it. When the fish was ready for consumption, the rice would be thrown away as it would have become too salty to eat. 

By the 12th century, this process had spread to China, and subsequently Japan, where it was called narezushi. According to Araki, things changed in the 16th century, vinegar replaced salt, which was key to the development of sushi. This also led to the name sushi—which translates to “vinegared rice”.

Consumers are becoming more interested in sustainability and want to know for sure where products come from. One way to do this is to use DNA. For example, a supplier in the US grows organic cotton. The cotton is then sprayed with a unique DNA combination. This makes it easy to find out if a final product is made from that cotton. No one can substitute cheaper, non-organic cotton anywhere in the supply chain.

Another concern is labor practices. Consumers want to be sure the workers who produce the goods are treated well. The US has established new rules requiring companies to prove that imported goods were not made with forced labor. If they can't, then the goods are seized at the border. From January to March in 2023, border officials seized almost $1 billion worth of shipments.

In 1939, the typical Japanese person only ate 4 grams of meat per day. Today, the average person eats 130 grams, and their favourite meat is pork, not fish as one might expect. One of the reasons for this significant change was the rise of Western influence in Japan.

Japan was known as a vegetarian country in medieval times. The national religions, Buddhism and Shinto, are both in favor of plant-based eating, but the Japanese couldn't eat meat mainly because of a shortage of arable land. As a way of dealing with this problem, Japan’s rulers banned people from eating meat.

With the arrival of the Dutch in the eighteenth century, things changed. The Japanese came to associate the meat-loaded diets of the Europeans with societal success. And in 1872 Emperor Meiji ate meat in public for the first time, automatically lifting the meat-eating ban.

Nothing smells better than freshly-baked bread. Take it out of the oven, let it cool a little, and cut into it. A puff of steam comes out and fills your house with that amazing aroma.

I've been baking bread for nearly 10 years. I started with a technique called the French knead, or the aptly-named "slap and fold". You pick up the dough then slap it onto the counter. Then turn it, pick it up, and slap it down again. The process is noisy, exhausting, and you end up with tiny bits of dough flying around your kitchen. They stick to the walls and are hard to scrape off. The bread tastes good, but I'm not sure if it's worth it.

Fast-forward to last month. I've refined my process to near perfection. You just put the ingredients in a bowl, stir them for a minute, cover them, and leave them all for a full day. The bread comes together perfectly. There's no mess, it's dead simple, and it tastes amazing.

The world population has increased for most years over the past 120 centuries. Some notable exceptions were the Mongolian invasions, which reduced the world population by as much as 11 percent in the 13th century, and the Great Plague in the following century, which reduced it from 475 million to about 350 million.

During the early 18th century, advances in science and the beginning of the Industrial Revolution allowed the world population to skyrocket, as child mortality rates plummeted and life expectancy at birth increased gradually.

Have a look at the chart below and discuss what you see with your teacher.

I once took a trip to Yellowstone National Park in America with my dad. The park was incredible—especially the wildlife.

We were driving into the entrance and saw a lot of cars parked on the side of the road so we just parked behind them and looked around. In the distance, a couple of bison were grazing. They look like cows, but with massive heads with fur on top that looks like an afro. They were majestic, like something from a bygone era. 

A little while later, we were walking along a path through the hills. A park ranger was there to keep people moving because some bison had decided to hang out right next to where people were walking. Up close, they were even more impressive. 

When I was growing up in the 1960s and '70s, things were made to last. My husband and I have a waffle iron that belonged to his grandmother—it's about 80 or 90 years old and it still works! My father loved to fix things and taught me to love it, too. So repairing things seems natural to me.

However, these days things are made to break down. It's called "planned obsolescence". Manufacturers make sure their products will stop working after a few years. Some obsolescence is natural as new products are added and technology advances. But planned obsolescence becomes a problem when the manuals and parts for repair aren't made available. Consumers are forced to discard products and buy new ones, creating huge amounts of waste. And small repair shops can't stay in business, hurting local economies.

When I was a kid, my father would drag us out of bed in the wee hours of the morning to watch a rocket launch, on our fuzzy little 9" black-and-white TV. They were momentous occasions. When I was 7, the Apollo 11 mission took us to the moon. I saw that happen! It was awesome.

For years after that, my father would point out satellites as they traveled across the night sky. It was amazing to see them out there. But that was about 50 years ago. Today there are so many satellites that you almost always see one. And with the new mega-satellite arrays being developed, that number is going to explode. SpaceX alone plans to launch more than 30,000 in the near future. While this will make huge advances possible in various technologies, it will also add to a new problem—satellite pollution.