DAWN.COM

Today's Paper | December 22, 2024

Published 07 May, 2016 06:50am

Story Times: More astronomical parlance

Before we move further let me clarify something that should have concerned us in the past. I have purposely omitted a few words for the reason that these words, important as they might appear, would complicate and lengthen matters by far. For instance, the term ‘Electro-magnetism’, an essential portion of astrophysics or physics; or else Doppler’s (or Doppler) effect; or Cepheid variables, or optics, and some other words of equal import. This was because it was both time consuming as well as it required a sizeable length of space to do justice to the word.

I instead prefer some items that are both essential and brief too. It is a promise that I will do separate and interesting write-ups on these areas, and more in due course.

Fahrenheit: The US scale of temperature usually measured as F., named after Gabriel Fahrenheit (1686-1736), a Polish/Dutchman, who improved the thermometer by using mercury as temperature measuring (indicating) substance.

Like Celsius and Kelvin, the other temperature measuring scales, Fahrenheit has two interesting points of reference, the freezing and boiling temperatures of water, decided as 32 and 212 degrees respectively. That is water freezes at 32 degrees and boils at 212 degrees Fahrenheit (0 and 100 degrees on Centigrade scale). Kelvin scale is the same in measurement as Celsius.

In Kelvin, the temperature cannot go below absolute zero, or, 273.16 degrees, because at that temperature the molecular movement stops, and that is not possible in nature or in the lab.

Being the most popular of them all, the one most commonly used is Fahrenheit.

Centigrade or the Celsius scale is used outside the US. For astronomy and other scientific uses, generally, the scale in use is called, the Kelvin scale. It starts at absolute zero, which is -273.16 degrees and it is curiously, unattainable.

Law of falling bodies: When we drop two items from some way up in a perfect vacuum, in a free fall, (where is a perfect vacuum?) they will fall to the floor at exactly the same time, irrespective of their shapes or weights, and at the same velocity because there is no resistance at all to prevent them. But in case there is air and the presence of atmosphere, or water, the two bodies will not reach the Earth simultaneously, but separately due to resistance of the two one after the other. Interesting?

The story associated with Galileo Galilee, him having dropped two balls or spheres from the top of the Leaning Tower of Pisa is entirely incorrect, because the man never mentioned this apocryphal episode in his voluminous notes.

He insisted, quite correctly, that because the force of gravity is uniform and exact all over the place (including space, unless influenced by another force), it will affect every item uniformly, falling at the precisely same velocity.

Fibre optics: These are cables of the thickness of a human hair carrying a vast flow of information, pertaining to both the video and radio signals. Its capacity is far greater than the ordinary copper wire of telephone or television. The cable is a channel of pulses of laser light carrying information as a stream of numbers giving transmission of a much higher quality. Its capacity is great too.

Phone companies around the world are in the process of replacing copper wiring with fibre-optic wiring in homes besides industrial and heavy duty commercial units for a far better efficiency, and cost.

Nuclear fission: A ticklish issue the application of which is monopolised by the rich western nations. Our very survival depends on the understanding of this very vital issue. It is actually a nuclear reaction where nucleons previously bound in atomic nuclei are now split apart or disjointed releasing tremendous amounts of energy. This process is used in atomic bombs, besides the nuclear power plants.

Uranium, a metal, is usually used because it breaks apart easily, releases two neutrons or more, which in turn strike and break apart other uranium nuclei in a chain reaction releasing almost unbounded force.

The result is, if it is controlled, to make electricity in a nuclear power plant. The process releases tremendous amount of heat. So much that splitting the atoms in just one pound of uranium gives off as much heat as 3,000,000 lbs of coal. If the same chain reaction is abrupt and uncontrolled, an atomic bomb is the result.

Flavour: Types of quarks, an elementary particle of matter that is smallest known part of matter — a domain of particle physics. These are the basic building blocks in nature; they are much smaller than the atom. There are said to be six flavours: up, down, strange, charmed, top and bottom. Of these the top quark has yet to be discovered although it is thought to exist. Its eventual discovery would complete the set, and validate the theory. Thus far, it is going through intensive scientific investigation. The ‘top quark’ is thought to be the heaviest of them all. All told, it is more difficult to explain than appears. So, let us put it off for the morrow.

Published in Dawn, Young World, May 7th, 2015

Read Comments

Shocking US claim on reach of Pakistani missiles Next Story