It is possible that people will be born in space and live their whole lives there. These space people will be human beings who have left Earth to live in space colonies. The colonies will be gigantic spacecraft, many kilometers across, in which there could be whole cities, together with fields and lakes. The colonies would grow their own food …

Strange as it may seem, the answer is yes. When you push or exert any king of force on something, it always exerts the same force back. You can demonstrate this by standing on a trolley or a boat and throwing something heavy away from you. The trolley or boat will move backwards. As you push on the objects to …

Yes when you ride on a very fast sledge or hear a spooky ghost story, for example. Being just a little frightened is part of being excited.

While in theory it may be possible, in practice it could be in very small amounts. In any case, tapping cosmic rays is a very complex engineering problem and the cost is very high.

If you look at a map of the Atlantic Ocean, you will see that the coastal shapes of the Americas resemble those of Europe and Africa. Might these continents have once been joined together like pieces in a giant jigsaw? A German meteorologist, Alfred Wegener (1880-1930), thought so. He wrote a book saying that, about 200 million years ago, all …

We hear a lot about ‘test-tube’ babies. These babies are not, in fact, born in a test-tube, but they do begin life in one. Medicine can sometimes help people who cannot have children. Normally, a new life begins in the mother’s womb when a sperm cell from the father fertilizes an egg cell from the mother. The two cells fuse …

Scorpion are particularly ferocious animals, even to each other, and so they lead solitary lives. They live in dry warm, areas of the world and in the wild hide themselves away in dark places, under logs or stones, for example, waiting for their prey. This normally consists of small insects and spiders. As scorpion cannot see very well they rely …

Electrical fields in theory do transmit at the speed of light. In real systems, wires have capacitance and other effects that slow the propagation. Typical propagation speeds are 0.3 to 0.7 times the speed of light, depending mostly on the wire shape and size, characteristics of wire insulation, and interactions with other conductors.

Percival Lowell, an American astronomer, thought he saw canals criss-crossing the deserts of Mars, when he observed the planet though his telescope early this century. He believed that these canals were built by a Martian civilization to bring water for irrigation from the planet’s polar caps. However, space probes have shown that the canals were simply optical illusions, and that …

Bats are not blind. Like many animals, they are born blind, but gain eyesight from the time they are seven to nine days old. Bats are night creatures. They come out only at night to hunt. Although they can see reasonably well they have no special eyesight possessed by other night creatures like the cats and owls. Instead, bats fly …