Owner: The SciTech Journal URL:http://thescitechjournal.blogspot.com/ Join Date: Thu, 03 Jan 2008 13:58:12 -0600 Rating:0 Site Description: The SciTech Journal is a richly informative project. As its name and the catch line suggest, it attempts to answer various questions arising in common man\\\'s mind relating to science and technological phenomena. Site statistics:Click here
Pressure Cooker and Quicker Preparation of Food 2008-04-19 12:39:00 Q. What does pressure have to do with quicker preparation of food in a pressure cooker?A. Apart from pressure, water and steam also have their roles to play. Ultimately, though, it is the pressure that matters. Here’s what result in quicker cooking. Ordinarily, water boils at 100° Celsius. The temperature rarely rises higher because escaping steam carries excess heat away. If a container of boiling water is sealed, however, the heat is trapped and pressure starts to rise. This force pushes down on the surface of the liquid, preventing water molecules from breaking apart from one another to create steam. Thus, far less heat is dispersed from the container and, eventually, from the food.The result of all this is the temperature of the water greatly exceeds 100° Celsius, cooking the food Read more:Pressure
Active Volcanoes 2008-04-24 12:40:00 Q. How many active volcanoes are there in the world? Which country heads the list?A. Including those which are submarine (under the surface of the sea), there are 1,343 active volcanoes. Indonesia, which comprises over 13,600 islands, has 76 historically active volcanoes. About 80% of them erupted in the 20th century. There have been 1,171 eruptions in recorded history of Indonesia. Japan, however, has witnessed 1,274 eruptions.More Reading:Volcano (Wikipedia) Read more:Active
Water drawn from Faucet 2008-04-30 13:05:00 Q. Hot water often appears milky white as it is drawn
from the faucet. Water from the cold water pipe seldom appears that way. What causes this?A. The seemingly foamy appearance of water issuing from hot water faucet is due to the air that is dissolving in the water. The heat tends to make the air come out of any solution and form bubbles. This is true in case of water also. But the pressure of the water within the pipe prevents air’s escape until the faucet is opened. Once the faucet is opened, it reduces the pressure and thus permits the bubbles to form which give the water its milky-white appearance. In a few minutes the bubbles escape and the water is again clear. Read more:Faucet
Highest Mountain in the Solar System 2008-05-04 11:45:00 Q. Which is the highest mountain in our solar system? Is it Mount Everest?A. No, howsoever tall Mount Everest stands, it doesn’t stand a chance on this count. The highest as well the largest known mountain in the solar system is Olympus Mons on the planet Mars. (see photo) It rises about 79,000 feet (24,000 meters) above the surrounding plains. The Mount Everest, on the other hand is only 29,028 feet above sea level. It has about 100 times the volume of our terrestrial champion. The base of Olympus Mons is 600 kilometers across. The volcanic crater at the summit is over 64 kilometers across, large enough to accommodate about eight cities like Mumbai. If Edmund Hillary had set out to climb Olympus Mons at the same pace as he climbed Everest, it would take him 130 days – almost three tim Read more:Mountain
, Solar
, System
Sloth and its Survival 2008-05-07 13:52:00 Q. How does the sloth, being such a lethargic animal, survive in the wild where norm is survival of the fittest?A. The sloth’s extreme sluggishness works to its advantage. This primitive mammal which sleeps 18 hours out of every 24, expends so little energy that it eats much less than its more advanced relatives. This is one reason for its success. It survives on a few calories, so it doesn’t have to move about much for forage and the leaves it eats are abundant.The sloth’s laziness in grooming helps its natural camouflage. Its coarse hair, rarely tended, is practically an ecosystem by itself, harbour two species of blue-green algae. The growth of algae turns the sloth’s hair greenish, making it almost invisible in the trees. It is far from conspicuous to its predators. With its he Read more:Sloth
Wisdom Teeth 2008-05-11 14:30:00 Q. Why do we have wisdom teeth? Why are they sometimes painful?A. Humans have 20 primary and 32 permanent teeth. The primary teeth’s shedding begins about age 5 or 6 and is finished by the age of 13. Wisdom
teeth grow after adult dentition has replaced the first primary (milk) teeth, bringing the total complement to thirty-two.Our ancestors, the early hominids, had large powerful jaw (see pictur
Most Poisonous Snake 2008-05-11 05:55:00 Q. Which is the most poisonous snake in the world?A. There are 2,400 kinds of snakes, but only about 100 of them are considered dangerous to human. Most naturalists believe that the taipan snake of Australia, found in a remote area of Queensland, is the deadliest and produces the most toxic venom, which is 50 times as powerful as that of the king cobra. In one bite the Australian taipan snake rele Read more:Snake
White Powdery Coating on Grapes 2008-05-12 23:00:00 Q. Often a white powdery coating is seen on green as well as black grapes. Which substance is it? Is it pesticide?A. It is true that in some regions maximum quantity of pesticides are sprayed on grapes. However, white powdery coating on grapes is not pesticide. It is yeast, a type if fungi. Originating as microscopic single cell organisms from grape vine, these cells reproduce in large numbers by Read more:White
, Coating
Largest Egg 2008-05-18 00:30:00 Q. Which bird lays the largest egg?A. The elephant bird of Madagascar would have topped the list had it not become extinct. Its egg measured 33 centimeters long with a diameter of 24 centimeters.Presently, the record goes to ostrich, which lays a number of eggs (see photo). The large-sized would be 20 centimeters long, 15 centimeters in diameters and weigh about 1.75 kilogram equivalents to hen’ Read more:Largest
Bullets Fired into the Air 2008-05-19 08:54:00 Q. Are bullets fired into the air lethal?A. It is not just police officers who pull trigger while pointing their pistols towards the sky. Jubilant troops often fire bullets into the air to celebrate victory. At the end of the Gulf War, however, Kuwaiti troops were warned of the dangers of this practice by American officers. They claimed that the returning bullets still traveled fast enough to kill Read more:Bullets
, Fired
Time Zone in Antarctica 2008-05-22 00:52:00 Q. Among the 24 time zones, which applies to Antarctica
where all time zones meet?A. There is no specific time zone for Antarctica and neither could there be any. There are many research bases scattered throughout this continent. Some of them set their clocks in accordance with the southern city closest to them, such as Christchurch, New Zealand. But most prefer to follow the time zone of their na Read more:Time Zone
Physical Evidence of Asteroids on the Earth - Craters 2008-05-27 00:03:00 Q. Is there any physical evidence that asteroids struck our planet in the past?A. While most asteroids maintain orbits within those of Mars and Jupiter, smaller groups are known to have more eccentric paths. Occasionally, asteroids large enough to survive the plunge through the atmosphere become meteorites. They can be quite destructive. Most of their impact craters have gradually wiped out by nat Read more:Evidence
, Asteroids
, Earth
World’s Most Successful Passenger Aircraft 2008-05-30 23:48:00 Q. Which has been the world’s most successful passenger aircraft so far?A. It was DC-3, popularly known as Dakota, manufactured by Douglas Aircraft Company of USA. Powered by two 1,200 hp propeller engines, it had a cruising speed of 300 kilometers per hour and had accommodation for 28 passengers, with a flight crew of 2. It was introduced on commercial routes in 1936 and its first domestic flig Read more:World
, Passenger
Gold in the Seawater 2008-06-08 06:41:00 Q. How much gold is there in the seawater and is it possible to reap it?A. Besides hydrogen and oxygen, there are 44 elements in the oceans. Gold is one of them but not as much as most people would like to believe. There is only 1 gram of gold for every 100 million tonnes of seawater. The presence of gold in the oceans has been known since 1872 and since then many people have made futile attempts
Smallest Breed of Dog, Chihuahua 2008-06-10 03:58:00 Q. Which is the smallest breed of dog?A. The unbelievable record is claimed by Chihuahua
(pronounce chee WAH wah) which originally comes from the Mexican province of the same name. Having slender bodies and disproportionately large ears, Chihuahuas have been classified as toy dogs. Newborn pups average 100-125 grams and when fully grown they weigh anything from 1 and 1.5 kilograms.More Reading:Chi Read more:Breed
Person’s Weight at Different Places on Earth 2008-06-12 00:24:00 Q. Does a person weigh the same at all places on our planet?A. No, he doesn’t. The reason, plain and simple, is that the Earth
bulges slightly at the Equator and all places there are nearly 13 kilometers farther away from the planet’s centre, i.e. centre of its gravity. As you move away from it, the force of gravity is reduced in inverse proportion. A 75 kilogram person living in London would Read more:Weight
, Places
Hippopotamus and its Pink Colored Sweat 2008-06-13 23:58:00 Q. It is said that hippopotamuses have pink colored sweat. Is it true? What could be the reason for it?A. True! But ‘sweat’ is a misnomer. A hippo (to call by its informal name) does not have sweat glands underneath its skin for release of excess heat of the body. It spends a large part of the day in water which keeps it cool and also takes much of its three tonnes weight off its squat legs th Read more:Colored
, Sweat
Mouse, Pointing Device for Computers 2008-06-17 13:25:00 Q. Why the pointing device used for computers is called mouse?A. The computer mouse was invented by an American scientist named Douglas Engelbart (see photo) in 1963 – and this was before the personal computer complete with keyboard and monitor was introduced in 1977.The pointing device got the name ‘mouse’ because Engelbart had joined its cord at the back, like a tail. Before he realized th Read more:Mouse
, Pointing
, Device
RSS Feed 2008-06-21 03:11:00 Q. What is RSS feed?A. RSS stands for 'Really Simple Syndication' or 'Rich Site Summery'. It is a format for delivering regularly changing web content. Many news-related sites, web blogs and other online publishers syndicate their content as an RSS Feed
to whoever wants it.RSS solves a problem for people who regularly use the web. It allows you to easily stay informed by retrieving the latest cont
Birds and Electrocution 2008-06-20 01:18:00 Q. Why a bird perched on a high tension power line does not get electrocuted?A. High voltage itself is of little consequence so far as there is no flow of electricity from one point to another. Instead of high voltage it is the high voltage difference that matters.When a bird, hopefully a small bird, lands on a transmission cable it acquires the same voltage as the cable, so there is no potential Read more:Birds
Tortoise and Turtle 2008-07-06 03:27:00 Q. Are the words tortoise and turtle names of the same creature? Or, are they different species?A. Those which live on land are called tortoise (photo 1) and those which live in sea, rivers or ponds are called turtle (photo 2) by the zoologists. Both are different species. Turtles have broad legs which serve as flippers. A species of sea turtles known as leatherback can weigh up to 800 kilograms, Read more:Tortoise
Jerking Tail of House-lizard 2008-07-02 03:24:00 Q. Why does tail of a house-lizard jerk and toss about for some time even after detaching from the body?A. Would it not be discriminatory on the part of Nature to provide many hunting capabilities to predator animals and birds without providing in equal measure of self-protection to the animals and birds which are preyed upon? Without an even handed distribution of skills and abilities the fate of Read more:House
Costliest Postal Stamp 2008-06-27 09:58:00 Q. Which country has issued the costliest postal stamp?A. World record is held by Kenya, Uganda and Tanganyika. Out of these three countries Tanganyika does not exist as a separate country. In 1964 Tanganyika and Zanzibar merged to form United Republic of Tanzania. Situated 35 kilometers away from mainland Tanganyika and hardly 2,650 square kilometers in area, Zanzibar’s Arab minority government Read more:Postal
, Stamp
Driest Place on the Earth 2008-07-20 00:37:00 Q. Is there a place on the Earth
where it doesn’t rain at all?A. The record of being the driest place on our planet clearly belongs to the 1,40,000 square kilometer Atacama desert in Chili, South America. It hasn’t experienced rainfall since last 450 years or so and it seems that the dry spell may have begun much earlier.Atacama is the oldest desert. It was formed about 10 million years ago. S Read more:Place
Unsolicited E-mail, Spam 2008-07-16 00:51:00 Q. Why the unsolicited e-mail sent out to large number of people at the same time is called spam?A. The term is derived from Monty Python’s Flying Circus, a British TV comedy. The word ‘spam’ was sung therein repeatedly and loudly, drowning out conversation.The e-mail spam works much the same way, since it creates a great deal of clutter and chaos in the internet traffic. It is also known a Read more:Unsolicited
Popping of Popcorn Kernel 2008-07-12 08:17:00 Q. Why does a popcorn kernel ‘pop’ when it is roasted?A. There are six main kinds of corn such as flour corn and sweet corn, but only pop corn would pop when subjected to proper heat.A pop corn kernel is sort of a sealed container the outer coating of which encloses a layer of hard starch as well as core of soft moisture-laden starch. The amount of moisture is 13.5% to 14%, considered optimum Read more:Popping
The SciTech Journal publishes portable e-book! 2008-07-12 08:00:00 Now carry The SciTech Journal
where ever you go. Read it off-line. Email to a friend. Being empowered now gets easier!The SciTech Journal publishes
its first e-book issue in portable document format. In this e-book you will read more than 50 general knowledge questions and answers, i.e. everything that is published so far on the Journal!So what are you waiting for? Click here and download it now.
Greenhouse Effect and Rising Sea Levels 2008-07-10 07:25:00 Q. To what extent the sea level would rise if all the icecaps in the world melt due to the global warming?A. No one knows for sure, but some estimates have been made and they are largely focused on Antarctica. The Arctic on the other end is not a major cause of worry, because there is no icecap as such and its ice floats on the Arctic Ocean. If it is melted, the sea levels would not be affected. I Read more:Rising
Manufacturing Technique in Striped Toothpaste 2008-08-07 10:23:00 Q. Some toothpastes are colorfully striped. What is the technique employed in manufacturing it?A. Manufacturers give colorful stripes to toothpaste by using a two-in-one like tube within a tube. The main tube is filled with white paste. Another tube within the main tube is filled with colored paste. This type of design prevents white and colored pastes from mixing. A few holes are made on the uppe Read more:Manufacturing
, Toothpaste
Conversion of Mass into Energy by the Sun 2008-08-01 04:55:00 Q. How does the Sun convert its mass into energy according to Einstein’s famous equation E=mc2?A. To keep the calculation simple, let’s consider the conversion of 1 kilogram of the Sun’s hydrogen into helium. The conversion produces only 0.993 kilogram of helium. This means the missing 0.007 kilogram of matter or mass is transformed into energy. The equation is E=mc2 in which m denotes quant Read more:Conversion
, Energy
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