The best books for kids

Hilo: The Boy Who Crashed to Earth

Hilo doesn’t know where he’s from, why he fell out of the sky, what he’s doing on Earth — or why he can’t go to school in only his underwear. This series by Judd Winick is as funny as it is exciting, and tells the action-packed adventures of the boy robot who cares deeply about his human friends. Ages 5 — 12.

Who Was? and What Was? series

Think of each volume in this series as a history lesson for a child. The books cover everything from the Constitution to the Colosseum, and Paul Revere to Pelé. The already detailed series continues to add titles — your little one can read up on just about any person, place or historical event. Ages 8 and up.

Encyclopedia Brown series

A children’s version of Sherlock Holmes, this series by Donald J. Sobol satisfies curious readers through the stories of a young detective, Leroy Brown. Nicknamed “Encyclopedia” for his vast range of knowledge, he welcomes neighborhood kids to present their cases in his garage before setting out to solve the mystery. Ages 8 — 12.

Holes

One of the rare books to win both a Newbery Medal and a National Book Award, the story by Louis Sachar follows Stanley Yelnats as he fights with the curse (诅咒) that has followed his family for generations. The book with a mystery at its core is by turns funny, heartbreaking and deeply thoughtful. Ages 8 — 12.

Some whales are loud. Really, really loud. Their calls are strong enough to pass through rock beneath the seafloor, a new study finds. And the echoes (回声) of those songs bouncing off the rocks can help reveal the structure of the seafloor. Two scientists reported their findings in Science recently.

Seismologists (地震学家) Václav Kuna and John Nábělek are interested in the structure of the rock layers beneath the seafloor. The two used a network of 54 ocean-bottom seismometers in the northeast Pacific Ocean. These instruments detect waves that travel through the ground, such as those caused by earthquakes. It turns out that they can also pick up songs from a passing whale.

Underwater sounds can produce seismic echoes. When sound waves traveling through the water meet the ground, some of the waves energy changes into a seismic wave. Those seismic waves can help scientists “see” underground as they bounce off different rock layers. The way they bounce can help researchers estimate the thickness of the layers.

Kuna and Nábělek’s seismometers picked up the sound waves of a whale’s six songs, which lasted from 2.5 to 4.9 hours. Echoes from the “singer” showed the researchers that its sound waves had passed through layers of underlying rock. They revealed structural details of rock layers beneath three sites over which the whale had been singing.

The new data suggest whale songs can be effective tools to study the seafloor. Large ships may perform seismic surveys using air guns. These instruments make very loud noises that can travel long distances. But their noise can also disturb ocean life-especially the behaviors of animals that rely on sound to hunt or communicate.

Dogs can smell fear, but can they smell out the truth? It turns out, dogs are pretty good at picking up on human behavior. A team led by Akiko Takaoka of Kyoto University in Japan conducted a study which found out that dogs actually know if you’re to be believed or not.

The study involved tricking dogs in the name of science. Humans have known for a long time that if you point at an object, a dog will run to it. Researchers applied this information in their study. During the experiment, they pointed at a container that was filled with hidden food. Sure enough, the dog ran towards the container. Then, they pointed at a container that was empty. The dogs ran towards it, but found that it had no food. The third time the researchers pointed at a container with food, the dogs refused to go there. They knew the person pointing wasn’t reliable based on their previous experience. 36 dogs were used in the experiment, and every single dog wouldn’t go towards the container the third time. This experiment proves that dogs can spot a liar or that dogs have major trust issues.

In other words, if you lie to your dog, your dog forms the opinion that your words aren’t good and will behave accordingly. “Dogs have more complex social intelligence than we thought. This social intelligence evolved selectively in their long life history with humans,” said Takaoka, who was also surprised that dogs were quick when they “devalued the reliability of a human.”

John Bradshaw of the University of Bristol in the UK, who wasn’t involved in this study, says that the results indicate that dogs prefer predictability. When gestures are inconsistent, dogs tend to become nervous and stressed. The researchers plan to repeat the experiment with wolves to look into the “effects of domestication” on dogs.