It is a term used in grafting of plants. For the whip and tongue graft, similar cuts are made on the stock and scion. These are made with a single draw of the knife and have a smooth surface so the two can develop a good graft union.

In the theory of special relativity, the slowing down of a clock as determined by an observer who is in relative motion with respect to that clock, is called time dilation. In this phenomenon, a person finds a clock (or other time device) similar or identical to their own, ticking at a slower pace, making the observer believe that time …

Thigmotropism is the growth of a plant around a support. Tropism is a phenomena by which a plant, usually climber like money plant and ivy, responds to a stimulus. Stems of the pea plant, for instance, are weak and have coil-like structures called tendrils. When tendrils approach a support (stick), a phytohormone called auxin is released in the side of …

Yuppie flu, which is also called the shirkers’ syndrome, is a term cynically applied to those suffering from chronic fatigue syndrome. Earlier, doctors and others believed symptoms of chronic fatigue such as sleep disorders and other severe problems to be imagined. But now, scientists are linking the yuppie flu to gene mutations.

In the South Atlantic Ocean, about half way between Africa and South America, are the British islands of Tristan da Cunha. Their nearest neighbour is St Helena, another British island 2,120km (1,317 miles) away. In 1961, a volcanic eruption forced the Tristan islanders to leave for Britain. But life in crowded Britain lacked appeal and most of them went home …

A sharp rise in aerodynamic drag, occurs when a plane reaches the speed of sound. For an aircraft flying at subsonic speed, the pressure waves generated by it extend in all directions, and, outspeeding the craft, transmit the disturbance uniformly. However, for supersonic speeds, the pressure field is confined to an area extending in a Mach cone from the rear …

As you stand in the middle of a playground or while you are sitting in your class, there is an immense weight right over your head, but you do not feel it! This is the weight of the atmosphere, or air, as we know it. Composed of nitrogen, oxygen, carbon dioxide and other gases, it surrounds the earth like an …

The Venus Project is an organization that promotes and advocates American futurist Jacque Fresco’s visions of the future with the aim to improve society by moving towards a global sustainable social design that they call a “resource-based economy”. Such a system incorporates sustainable cities and values, energy efficiency, collective farms, natural resource management and advanced automation, focusing on the benefits …

Earlier, the power of a magnet was only measured in units of gauss. Gauss defines the number of lines of magnetic (flux density) per square centimetre emitted from the surface of the magnet. Today, it is measured in gauss-oersted energy units (GOe). While gauss refers to the number of lines of flux emitted from a magnet, oersted is the unit …

The uncertainty principle was laid down by Heisenberg, and is called Heisenberg’s principle of uncertainty. According to it, it is impossible to measure simultaneously the position and momentum/ velocity of a moving electron. If any attempt is made to measure both at the same instant, there will be uncertainty in measurement of either. This is because to measure the position …