When another old cave is discovered in the south of France, it is not usually news. Rather, it is an ordinary event. Such discoveries are so frequent these days that hardly anybody pays heed to them. However, when the Lascaux cave complex (群) was discovered in 1940, the world was amazed. Painted directly on its walls were hundreds of scenes showing how people lived thousands of years ago. The scenes show people hunting animals, such as wild cats or dogs. Other images, picture birds and, most noticeably, horses which appear in more than 300 wall images by far outnumbering all other animals.

Early artists drawing these animals finished a meaningful and difficult task. They did not limit themselves to the easily accessible walls but carried their painting materials to spaces that required climbing high walls or going into narrow passages in the Lascaux cave complex. Unfortunately, the paintings have been exposed (暴露) to the harmful action of water and temperature changes, which easily wear the images away. Because the Lascaux caves have many entrances, air movement has also damaged the images inside.

Although they are not out in the open air, where natural light would have destroyed them long ago, many of the images are in bad condition and are hardly recognizable. To prevent further damage, the place was closed to tourists in 1963, 23 years after it was discovered.

A group of scientists is gathering today in the U. K. to discuss a thick piece of ice that’s cracking in Antarctica, which is of the size of Delaware.

The ice shelf is called Larsen C, and it now has a 90-mile crack running through it. The big rift (裂缝) is slicing the ice shelf from top to bottom. But this is not just another sad climate change story. It’s more complicated. “A lot of things are going on deep inside the ice,” says Adrian Luckman, a glaciologist.

Luckman says climate change is certainly influencing this region. Larsen C used to have two neighbors to the north, Larsen A and Larsen B. As the air and water warmed, those ice shelves started melting and then disappeared in 1995 and 2002. But the crack in Larsen C seems to have happened on its own, for different reasons.

Larsen C has many cracks. All ice shelves do. This particular crack has been around since at least the 1960s. The unusual part is that in 2014, this crack — and only this crack — started growing quickly. Why?

“Well, that is a little bit of a mystery and that's why it drew itself to our attention,” says Luckman. One puzzling aspect is how it managed to cut through areas of softer ice that bind (连接) the ice from neighboring glaciers into one giant sheet. Starting in 2014, that soft ice did very little to slow down this rift.

Scientists are split on how important this crack is for the stability of the whole ice shelf. Some say if this giant section breaks off, it won’t make a difference. Others disagree.

“Ice shelves are the gates of Antarctica in a way, and the gatekeepers of Antarctica. The ice shelves are already floating, so if they fall apart it does not immediately affect sea levels. It’s what they hold back -water from all the inland glaciers — that could be problematic. If all the water packed in those glaciers made their way to the sea, it could significantly raise global sea levels,” says Ala Khazendar, a geophysicist.

The Biggest Stadiums in the World

People have been pouring into stadiums since the days of ancient Greece. In around 8 A.D., the Romans built the Colosseum, which remains the world’s best known stadium and continues to inform contemporary design. Rome’s Colosseum was 157 feet tall and had 80 entrances, seating 50,000 people. However, that was small fry compared with the city’s Circus Maximus, which accommodated around 250,000 people.

These days, safety regulations—not to mention the modern sports fan’s desire for a good view and a comfortable seat—tend to keep stadium capacities (容量) slightly lower. Even soccer fans tend to have a seat each; gone are the days of thousands standing to watch the match.

For the biggest stadiums in the world, we have used data supplied by the World Atlas list so far, which ranks them by their stated permanent capacity, as well as updated information from official stadium websites.

All these stadiums are still functional, still open and still hosting the biggest events in world sport.

● Rungrado 1st of May Stadium, Pyongyang, D.P.R-Korea. Capacity: 150,000. Opened: May 1, 1989.

● Michigan Stadium, Ann Arbor, Michigan, U.S. Capacity: 107,601. Opened: October 1, 1927.

● Beaver Stadium, State College, Pennsylvania, U.S. Capacity: 106,572. Opened: September 17, 1960.

● Ohio Stadium, Columbus, Ohio, U.S. Capacity: 104,944. Opened: October 7, 1922.

● Kyle Field, College Station, Texas, U.S. Capacity: 102,512. Opened: September 24, 1927.