For reasons of safe transportation of fruits, mangoes, bananas etc are picked before they ripen fully. Slightly green harvested mangoes are subjected to small containers of calcium carbide (CaC2) with a plastic covering. CaC2 reacts with the moisture in the air to release acetylene (or ethyne) gas, which like ethyleneis – a chemical substance produced by fruits to accelerate the …
Read More »How does an ant know its way home with no clues in a desert?
Experiments by German scientists on the Sahara desert ant, called cataglyphis fortis, have shown that the ant uses a method known as ‘path integration’ in its navigation. Path integration consists of measuring the extent of each turn, and remembering the direction of its nest, whenever the direction of its path changes, and then measuring the distance of travel in each …
Read More »How does a Submarine Work?
Even before submarines were thought about, Verne had created the blueprint of this technological marvel. Not only did he describe the machine, but he also explained, in great detail, how it worked. In fact, today’s submarines use exactly the same technology as Verne’s Nautilus did! How does a submarine float and dive under water at will? Try a little experiment. …
Read More »How does a submarine stay under water?
You may have noticed that an empty bottle will float along the surface of water, but one which is full of liquid will sink. The submarine works in exactly the same way. Each submarine has several large tanks, which can be filled with either water or air. When they were filled with air, the submarine will float on the surface …
Read More »How does a starfish open a mussel with its feet?
Have you ever tried to prise apart the shell of a mussel or an oyster? It is practically impossible to do by just pulling, so how does the starfish manage it using only its tiny feet? The secret is that the starfish again uses its feet in relays. It hunches itself over the tightly closed shell and attached its tube …
Read More »How does a starfish move?
The starfish and sea urchins creep slowly around on hundreds of hydraulically operated tube feet. If you flip a living starfish over you will see rows of these tiny feet running the length of each arm. (If you leave the starfish upside-down, time it to see how long it takes to turn itself the right way up again. Some can …
Read More »How does a snake swallow its prey?
Snakes catch live animals and eat them whole. They can swallow prey several times larger than their head. This is made possible by very loosely jointed jaws which enable the mouth to be opened wide. Backward pointing teeth grip the prey while the mouth is worked over the animal. Lots of saliva helps the meal to slip down the snake’s …
Read More »How does a sea cucumber avoid attack?
Sea cucumbers are echinoderms that have a tough leathery skin rather than a spiny one. Lying around on the sea floor in tropical and subtropical countries they look rather like long fat sausages with tentacles at one end. They feed by poking the sticky tentacles around and then placing them one by one into the mouth. All the food fragments …
Read More »How does a Nuclear Bomb differ from a Conventional Bomb?
Every now and then we hear of countries of the world carrying out heated discussions about nuclear bombs. The topics range from who has the right to own a nuclear bomb and who does not, who should use it and who must not and so on. But what exactly happens when such a bomb actually explodes? And how are nuclear …
Read More »How does a mobile vibrate?
There is a little motor fitted in a cell phone. This motor has unbalanced weight, in other words, is unevenly weighted on its output shaft. When this motor rotates, the rotating uneven weight causes the mobile to vibrate. A similar mechanism is also present in gaming devices such as the play station.
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