Why is the planet Mercury so hot? Mercury spins very slowly on its axis when it travels around the sun. This means that a point on its surface is exposed to the sun for almost six months (as on Earth) at a time. This makes...
Why do hippos wallow in the mud? Hippos are found near swamps and rivers. They like to spend time in the water and even remain immersed underwater for hours at a time. Wallowing in the mud is a favourite activity of hippos. This cools the...
Which birds are good talkers? Many birds can be taught to say some words. But some can be taught to talk long sentences. Among birds, the best talkers are parrots, mynahs, ravens, jackdaws, crows, and some jays. The African parrot and the Indian mynah are...
Why is gravity stronger on earth than in space? Gravity between two objects is less when the objects are separated by a vast distance. Though the moon, earth, and other objects in space have great mass, they are separated from each other by vast distances....
How do people explore the ocean depths? Vehicles called submersibles help to explore the ocean depths. Such vehicles have mechanical arms and hands. They can be remote controlled from land or piloted in the water. The air pressure in the submersible will be the same...
Why does a hologram appear three-dimensional? To create holograms, a beam of laser light is split into two beams which travel through an arrangement of lenses and mirrors. One beam bends toward the object. The other travels toward the holographic film. Then the beams meet...
Why do cats have rough tongues? The tongues of cats, big (lions) and small, are like sandpaper. They have tough bits of flesh or papillae, which stick up from the middle of the tongue. They function like the bristles of a hairbrush. When the cat...
What is Stonehenge famous for? Stonehenge is in England and was built around 5,000 years ago. It features standing megaliths or big stones which were arranged to mark the midsummer sunrise and midwinter moonrise. It is speculated that Stonehenge might have been a religious meeting...
Which is the biggest planet? The biggest planet is Jupiter as it has more mass than the combined mass of all the other planets. It is 11 times bigger than Earth and spins 30 times faster than Earth spins. It takes a little less than...
What are star signs? From Aries to Pisces there are 12 star signs. Depending on the month and date of birth, people have different star signs. The sun, according to astrologers, moves through the stars in the heavens, during the year, passing through the 12...
