Though it’s been around for roughly 5,000 years, yoga is more popular today than ever. The fact that you can practice it just about anywhere is a big reason why.【小题1】 That’s nearly 15 million more than the number of people who golf.

Westerners adopted yoga as a form of exercise, but at its roots, yoga is a way of life. As recorded in the Yoga Sutras, yoga is based on the idea that the mind, body and spirit are all one. The breath is said to carry a person’s life force. 【小题2】

In addition to reducing stress, yoga can improve posture and balance, strengthen bones and muscles,and keep your joints healthy. 【小题3】   For instance, downward-facing dog can relieve back pain, while plank pose is good for building a strong core (核心). For a quick break, the best choice is child pose. 【小题4】 You start out on your hands and knees and sit back, bringing your belly to the floor, with arms outstretched.

【小题5】. Globally, the industry is expected to produce $66 billion by 2027. More than 45,000 yoga studios dot the country. Despite the fact that all you really need is a mat, the average American yogi spends an estimated $62,640 over a lifetime on yoga classes and accessories.

It took Sheperd Doeleman nearly a decade to pull off the impossible. As the director of the Event Horizon Telescope(EHT), a project involving hundreds of international researchers, he spent years flying suitcases full of hard drives around the globe to coordinate(协调) observations between radio telescopes on four continents(大洲). On April 9, 2019, the coordination at last released the fruits of their labors and the world got the first image of a black hole.

The feat-which pioneering black hole theorist James Bardeen called hopeless in 1973-represented a towering achievement of astronomical technology. “It took everyone a little by surprise that they got such a good image so fast,” says Andrew Strominger, a theoretical physicist at Harvard University.

Now Strominger and other researchers are back with a wild answer, which appeared last week in Science Advances. With a distance enough telescope, the EHT coordination could see multiple reflections(反射) of light streaming from around the black hole. By sorting through the precise pattern in these rays, astronomers could study black holes and test Einstein’s theory of gravity like never before. Basically, they hope black holes will become more like stars and planets: not just objects to think about, but to directly observe.

The team did pencil-and-paper calculations using Einstein’s theory of General Relativity and some simulations(模拟) to analyze what black holes do to light. “Black holes, they’re just kind of the best at everything they do,” Lupsasca says. “And that includes bending light rays into loops(圈、环).”

As we often see on TV and magazines, flamingos are beautiful birds with bright pink or red color. Although its name includes “flame”, they are gentle ones. You might think that not much goes on in their tiny heads, but these elegant birds actually lead complex social lives. Each bird has certain other individuals it prefers to spend time with, and others it avoids. In deed, flamingos have friends.

For five years, Rose and his team observed the daily goings-on of five of the world’s six different flamingo species housed at the WWT Slimbridge Wetland Centre in Gloucestershire.

The partnerships that we see between birds are picky. The birds are choosing who to associate with. Male-female pairs spend time together, but so do same-sex pairs and even groups of three or four. And those relationships can last for many years.

“So there were some flamingos in the group that really didn’t care who their partner was for that day, they would fly lightly around... and they would have many different relationships with many different birds.” And of course there were other flamingos that were less social butterfly and more alone wolf. But even they had a few close friends. “Those birds that were least social...had more investment in a smaller number of social connection with flamingos that they knew really well.”

Rose thinks that flamingos may have evolved their social lives due to their wetland habitats-in which the resources they need are concentrated in a small area.

If flamingos know their partners, if they know that these six birds, say, are friendly, and they get on with them, they can then waste less energy quarreling with other birds that they don’t get on with.

By spending time with their friends, flamingos can more efficiently direct their limited time and energy to activities like hunting and mating.