The Earth is Round, huh?

How was the cartoon characters' invasion of Facebook profile pictures, this December? Every profile you land onto, would have shown you Dexters, Popeye, Scoobies, Tin Tins and several other stalwarts from the Cartoon World, letting us know how people loved (and would love) to revert to their childhood. You do, I bet. Perhaps, for this reason, these kind of high school queries pop up in my mind, then and there. :) Apparently matured science-freaks, stay away. ;)

Flat Earth Model

Is the Earth round? Why shouldn't it be flat as it was assumed to be, centuries ago? What bothers the Flat Earth Model? Let me put forth, a few.

The Flat Earth:

Early astronomers, (most of them are actually travelers) who spent most of their time on sea, assumed that the Earth was flat, though their assumption wasn't blind enough to be criticized. 

1. Out of hundreds of ships that start their journey from the same spot, a few were found missing, as they lose their way, get stranded on the sea and die off. This made the other travelers assure, "The horizon is always seen as a straight line bordering the sea and the sky; The ships cross the horizon and fall off the earth into the space", which proved the possibility that the Earth is flat.

Since the earth is flat, ships that cross the horizon(border) fall off the earth into the space and get lost.

2. "According to the Aether Wave Theory, aether- a massless substance pervades all matter and even space(vacuum). If so, it would eventually resist the high pace of revolution of the spherical Earth round the sun; Being a sphere, aether resists its motion", the flat-earth nuts say.

The Spherical Earth:

On the contrary to the Flat Earth model, evolutionary philosophers like Eratosthenes posed a strong contradiction to the pre-existed model. Some of the solid and substantial proofs are as follows.

Lunar Eclipse

1) We all agree that Lunar eclipse occurs only because the shadow of the Earth darkens the Moon, as the earth comes in between the Sun and the Moon. If not the Earth were spherical, the shadow observed would not be a "curve". This affirms that the Earth must be round, i.e, spherical.

2) Mast of Ships coming from a far distance is always seen before the hull. This proves that the Earth is round.

3) A stick casts shadows of different lengths at different places, at a time only because the Earth is round, spherical. If the Earth were flat, the stick would cast shadows of same length everywhere.

4) The geometric shape with minimum surface area is sphere. Every matter, especially liquids tend to get spherical to minimize their surface area. In analogy to this fact, spherical Earth must favor it formation.

5) Pole star(Polaris) is seen straight above the sky when observed from the North Pole, where as it is seen lower in the sky when observed from the Equator. This proves that the earth must be round.

Modern Approach:

Though, these points validate the spherical shape of the Earth, one need a fool-proof experiment to confirm its shape. 

Every satellite image of the Earth, taken from the space or from the moon, show that the Earth is round. Also, the invention of three-dimensional imaging system and geosynchronous satellites add yet another proof to the Spherical shape of the Earth.

Satellite image of the Earth

Also, the weight of an object as measured at the Poles appeared to the greater than that of the Equator. Since, the weight (gravitational force) varies inversely as the distance, heavier weight implies lesser distance. Therefore, the Poles must be relatively nearer to the center of the Earth, than the Equator. Therefore the shape of the Earth must be a sphere compressed at its poles. This shape, known as "Oblate spheroid" is widely accepted as the shape of the Earth. :D

gotcha??

Why is the night sky dark?

Sitting beside a sea, comforting on the beach sand with legs stretched, relishing the cool sea breeze, peeping at the dark clear night sky pondering something is really exciting, yeah?? 

Ever got such a kinda situation to bask the beauty??

Yeah? But halt here....! Why is night sky always "dark"??? Ever wondered? 

Why, at first look, you might say, "This is too fundamental. Too simple and obvious". But it isn't so simple as it seems to be! This is a famous and not so easy paradox called as "Olbers' paradox" which has just been solved to some agreeable extent.

"Why night sky appears dark, huh?"

When you put forth this question, you are likely to get the most probable explanation, "During night, the sun is on the other side of us. So, we feel the sky dark."

But it is not quite convincing, for we aren't high school kids anymore. Smarter children, who have a good sense of intelligence would pose a contradiction to this explanation, which goes, "Science says that there are over 200 billion stars in our galaxy - the Milky Way. So, what about the light emanating from those stars? Wouldn't they light up the sky??"

If light from almost every star reaches the earth,
 the sky would look like this.

This question has a salutary logical point. There are almost uncountable number of stars on the sky(in the Universe). These stars, being self-luminous, would definitely give off light which should reach the earth. If this is true, the sky would look at least like this:-(see the image on the right)

But in reality this doesn't seem to be holding good. What has happened to the light rays which have been emanating from these stars? What is preventing them from reaching the earth?

The most expected answer is "Stars(other than the sun) are excessively far from the earth and therefore, the rays exhaling from them suffers an appreciable loss in intensity. So, the night sky is dark". This explanation would render us a little better view on the topic. But what is that which is exactly responsible for such a loss in intensity??

Picture describing Oblers' paradox.

One might say that every galaxy contains more number of planets and other dust particles, than the number of stars. So, these plants, asteroids, comets and dust would simple block "some" of the light rays from the distant stars from reaching the earth. But remember, they block only "some".

Also, the distribution of stars is not uniform, but they hide behind one another so that it solves the paradox to a little extent.

But the main and more accurate answers are as follows:

1)The Universe is expanding. So, light from the distant stars are "red-shifted" to obscurity.

2)The Universe is young. Light from distant stars hasn't even reached us yet!(may sound funny for beginners)

Speaking about the first explanation, the Universe is said to be expanding frantically. The Big Bang Theory supports this view. So, distant stars which are moving at a considerably high speed will be "red-shifted". To elaborate, as these stars are moving at a high speed relative to the earth, the wave-length of the visible light emitted by them would be shifted towards red.(red-shift) 

But some physicists put-forth a counter-argument that light of lower wavelength like gamma rays, x-rays and UV-rays would also be red-shifted to "visible region" and this would compensate the former.

Whatever be it! But the second point has a good significance. The Universe is young and degenerate. So, we only see the part of Universe less than 15 billion light years away. Objects which are more than 15 billion years old are too far away for their light to reach us. 

Thus, Oblers' paradox is somewhat resolved. Contradictory thoughts are welcomed. Cheers......!

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(pictures are taken from the web. and link courtesy - wikipedia)

Jupitor's stripe plays Hide and Seek game with Skywatchers!

Yeah. I am sure, I'm not kidding. But you have to believe that "One of the two equatorial belts, a thick stripe that encircles the Jupiter has played "hide-and-seek" game with astronomers and sky-watchers".

Figure showing the lower equatorial belt missing.(right)

Any amateur sky-watcher, if witnessed the giant planet through an astronomical telescope for the first time, could identity it only after confirming the presence of those two deep wide stripes that encircle the planet. They call it as "the equatorial belts". These belts usually contain fast moving jet stream of gases that fill up the planet's atmosphere. 

But what has happened on the previous may storms the sky-watchers and astronomers. Yup. One of the two dark stripes on the Jupiter was found missing!!!

Even a side-line sky watcher with a small telescope on his garden could distinguish the difference since, the stripe plays a significant role in the planet's physique. The absence of the stripe on the planet gave the a different view to the cosmologists.

"WTH?? Even we play x-box, play-station games and it's been ages we forgot the old hide and seek game", said the member of "Game-geek kids' association". :D

"So, my science teacher was correct. The Jupitor must really be very old. Now I can understand it from the fact that it plays 'hide-and-seek" games", says the head of the Game-geek kids' association. :D

Where it could have gone?? This perplexing question made most of the sky-watchers stir up their minds in search of the reason. But some geeky, well informative, intelligent, resourceful and clever Astrophysicists never showed any feeling of being surprised. "The planet has lost this stripe before, most recently in the 1970s and the early '90s. So far, the stripe has always reappeared", they said.

Whatever be it. But what is the reason behind this strange occurring? Scientists are  stumped for a complete explanation of this incident. Some amateur cosmologists put forth their view that the stripe, a part of the Jupiter's atmosphere could have moved somewhere. But that is not completely possible in the Jupiter.

Unlike the earth's atmosphere, Jupiter's atmosphere cannot move much distance, on account of the planet's iron clutching heavy gravity. The reason for this weird happening was anyway figured out after a month by Hubble Space Observatory.

"The Jupiter's atmosphere, the largest planetary atmosphere of the Solar System is mainly composed of molecular hydrogen and helium with a trace amount of ammonia, hydrogen sulphide and methane", wiki says.

The images captured and published by the Hubble Space Observatory reveals the mystery. "The stripes are hidden behind the white ammonia ice crystal clouds, which are present in the atmosphere obscuring the view", says Hubble Space scientists.

The team has also predicted that the cloud which is obscuring stripes should clear out in a couple of months. I'm sure their prediction will obsoletely be perfect.

Err..I want Hubble to set up a new crew for finding a better place to live! This old spoiled Earth is already stinking up, with all kinds of pollution and frantically increasing population. Seriously we need an alternate. Do you know any?? :D ??


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Data and image courtesy: wired science, wiki, national geographic news.

A Massive Star Revealed

Giant stellar nursery surrounding the new star NGC 3603

A team of astrophysicists, under the leadership of Paul Crowther, has revealed to the world, two young cluster of stars, NGC 3603 and RMC 136a. The twins are found fit to be called the "Super-heavy weight champions" of the observable parts of the Universe.


The crew of astronomers has used European Southern Observatory(ESO)'s Very Large Telescope(VLT) as well as archival data from the NASA/ESA Hubble Space Telescope to analyse the different parameters of the newly discovered stars. The statistically verified data put forth by the crew about the masses and luminous intensity, surprises the astronomers all over the world.

Out of the two, the star NGC 3603 seems to be a cosmic factory from where a cluster of stars frantically emanate, from the nebula's extended clould of gas and dust, located 22,000 light years from the Sun.

The Massive star clusters on Large Megallanic Cloud.

It's counter-part RMC 136a(fondly called R136) is found to be another cluster of hot and massive stars, well located inside the Tarantula Nebula, in the large Megallanic Cloud, at a distance of 165,000 light years from the sun. It is also noteworth that this Megallanic Cloud, is one of the neighboring galaxies of our Milky way.

The team has also put forth a sum-up data of the images captured by the ESO's VLT which reveal that these stars weigh 265 times the mass of the sun. This data has traumatized several scientists and astronomers who reckoned that the most massive of all stars would not weigh more than 150 solar masses.

To their surprise, the birth masses of these two stars, estimated by the crew is close to 320 solar masses.

"Unlike humans, these stars are born heavy and lose weight as they age" says, Dr.Paul Crowther, Astrophysicist. Yup. It makes a point, though seems to be funny.

"Being a little over a million years old, the most extreme star R136a1 is already 'middle-aged' and has undergone an intense weight loss programme, shedding a fifth of its initial mass over that time, or more than fifty solar masses", added Dr.Paul Crowther.

What if such a massive star be taking the place of our sun?? Mind-blowing, isn't it??

"Its high mass would reduce the length of the Earth's year to three weeks, and it would bathe the Earth in incredibly intense ultraviolet radiation, rendering life on our planet impossible," says Rapheal Hirschi from Keele University, who was one among the crew members.

Not just this discovery, but the team has also predicted how massive a star could be, withing this cluster. "The smallest stars are limited to more than about eighty times more than Jupiter, below which they are ‘failed stars’ or brown dwarfs," says Olivier Schnurr, from the Astrophysikalisches Institut Postdam.

As the Indian Astrophysicist Dr.Subrahmaniyan Chandrasekhar quoted, less massive stars, having their masses less than 8 solar masses would shed enough mass, eventually become white dwarf. He has also added that more massive star of masses close to 150 solar masses would ultimately become either neutron-star or a black-hole. This theory is well known to the world as "Chandrasekhar's limit". Now the question is about the stability and existence of these lately discovered stars which weigh almost 300 solar masses. This fact poses the previous theory, a contradiction, which would be solved soon, I guess.

But the sad part about these stars is that they will "die soon". Yup. But don't panic. In astronomy, 3 million years is really short. And that could be the clue. Small life-span of these stars could be the reason why such massive stars are not being witnessed then and there. These are rare and are found only on densest clusters of the Universe. 

But, what is the use of these stars being several times luminous than the sun?? People of this generation never show any interest in comprehending  these kind of stars. Instead, they show a huge craze on cine-stars and pop-stars. Cheers. \m/

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Image and data courtesy: European Southern Observatory(ESO) 

The Mystery of Force Fields!

The day was little breezy. Professor Govind was busy soldering the transistors on his new invention. The television was switched on and Sheela was there easing on the sofa, watching an episode of "Star Trek". It was indeed a nice episode. An asteroid was heading towards the small space ship in terribly high speed. The crew felt the danger of the asteroid hitting the space ship. Everyone was puzzled.

The captain shouted "Shields up!"

No sooner he shouted, than a thin bluish layer enclosed the space ship. It shattered up the asteroid into pieces then.

"Phew!, that's the end", exclaimed Sheela in amazement. "Professor, what actually is a force field?"Sheela's question attracted his attention. He started then, 

" Force fields are thin impenetrable barriers which could destroy or reflect everything that fell on them. Be it a stone, metal piece, water or even laser."

"Just have a look at this photograph. It looks like this", he showed her.

"The principle behind this force field is a simple theory. You might have seen your Plasma television screen. The same goes here- the principle of isolating air from vacuum", he paused to take out something from his junk box.

"Oh!, But Professor,what is that we call "plasma"? interrogated Sheela.

"I'll rather show you off", said Prof.Govind and took a hollow glass sphere, in which a metal electrode is inserted. He said, "Sheela, this glass bulb contains a mixture of Helium and Neon gases at very low pressure," while connecting its terminals to 5000V a.c. supply of high frequency(about 35 kHz). The bulb started glowing and violet streaks started appearing in it.

"Wow!" wondered Sheela.

He said, "Before the matter inside the bulb were in gaseous state. But, as soon as we started applying electric potential, the gases will be ionized completely. And this state in which gases are completely ionized is called "Plasma state" the forth state of matter" and touched the glass bulb. White streaks appeared from the filament to the point where he touched the bulb.
"Is there any chance that I get shock while touching this bulb, professor?" asked Sheela."Actually the glass here behaves are dielectric between the ionized air inside and my hand(both being a conductor, this setup behaves like a capacitor). 
Leaving this setup intact, he took a strong horseshoe magnet and placed it near iron filings. Sheela smiled and said, "I knew that magnets attract charged bodies already in my grade-5". 
"That's the matter. So we have ions that are charged, haven't we? Just imagine that this magnet attracts these ions completely to one side thereby creating vacuum at the center.We get a plane of ionized gases on the corner." 
The same principle is used in plasma windows.


"This plasma window can be used in combination with a series of laser curtains and carbon-nanotubes to generate a powerful force field around us. But to stop laser, one must deal with photochromatics", said Prof.Govind.
"Photochromatics?" interrogated Sheela.
"Yeah. It is the science based on the fact that certain materials can exist in two different forms. Say your sunglasses. How does it become black on exposure to the sun?" puzzled professor Govind.
"How?" asked Sheela. 
The glass is coated with a thin film of photochromatic materials which when exposed to radiations like UV rays becomes dark(colored) due to a change of state. Similarly, specially designed material has to be used to selectively stop lasers or else, you'll go blind on dark while you're in force fields."


"Hmm. That was interesting!" exclaimed Sheela. "Anyway, it's time for the dinner. Thank you professor. I must go now." 
"It's been a great time explaining you about this. Pleasure!" said the professor and got back to his workshop.

Anti-gravity

One day, Sheela wanted to ask some doubts on superconductors. She decided to approach prof.Govind in his laboratory. To her surprise, he was floating in mid-air defying gravity. She was astonished and ran out of words. She forgot why she'd come there and asked," Professor, How could you do that??!!!".

He jumped from mid-air and smiled at her. "Well, If a magician could do that, why can't I?"

"A magician performing anti-gravity trick"

"Super-conductive magnetic levitation is a wonder science which has made a remarkable mile-stone in the history of Science. There are two notable changes that occur when a material changes into a superconductor, namely

#1. Electrical resistance becomes zero.

#2. Magnetic lines of force are excluded from the material.

And these all happen for certain metals at low temperature only.Hope you might have heard about "Meissner effect".

When a superconductor is placed in a weak magnetic field, the field penetrates only a small part of the material(order of few micrometers). Just look at these pictures depicting Meissner effect", said Professor Govind.

"Meissner effect is a state of perfect diamagnetism in which, the magnetic field within the material of the superconductor is zero(B=0). This leads to the condition that the magnetic susceptibility is -1.

Whenever a magnet is brought near diamagnetic materials, they themselves become magnetized so as to oppose the external magnetic field. This is extreme in this case. You might be knowing that water is diamagnetic and this fact has helped scientists to levitate a frog applying a high magnetic field of "15 tesla", added him.

"That sounds interesting", exclaimed Sheela.

"Just watch what I'm doing. I'm pouring liquid nitrogen which boils at -196 degree Celsius so as to bring this metal piece to its superconduction state. It's always pleasure to watch how it levitates.

By now you could have understood the secret of anti-gravity and how I was floating in mid-air earlier", asked professor Govind.

"Hmm..That's true..and interesting too."

Ghost Busted # 1

2nd Sunday, Houston, TN: 

"It was like a glimpse of fire; It was like the air fired around; see, we were very frightened and ran away home in a hurry", says two young students of the Houston High School who had witnessed an ANGEL ORB on a cloudy night. They seem to be frightened of the scene and never agree to come to the place again. They show their evidence, a photograph showing the angel orb in front of a statue with clear-cut image of that Orb that frightened them. The digital camera has been analyzed by specialists to check out the troubles, if any. "Perhaps it may be the spirit of the student who has just passed by", said the others.

Sheela was reading this news aloud and said, "Wow! Brilliant! What you say about this professor?"

Professor Govind said, "Well, Orbs caught in photographs! Might be some optical phenomenon".

Sheela, "What? Professor, But they have an evidence. See this photograph showing the angel orb. "

"Hmm. Am very sure that this is not an angel orb. Nor a devil spirit too! Just try to understand Sheela, this is just an optical phenomenon.

The human eye has the power of perceiving only a narrow range of the spectra of the Universe. So, we cannot see things which are transparent to visible spectra. But digital camera which perceives and records a wide range of spectra including Infra-red and ultra-violet. So, this picture must have been taken from such digital camera.

Orbs are nothing but some objects which are transparent completely to the visible spectra and so we humans cannot see such bodies. They are mostly gases and rarely liquids and solids. For instance, we cannot see the water vapors on the sky, which an Infra-red picture can show clearly those things with diverse colors shades so as to distinguish their density", said Professor Govind.

"So, you say it's not the angel orb. Yeah?" asked Sheela. 

"Well, even water drops on the lens, dust particles and stuff like these can even cause such abnormal perception. Hmm, to be more exact, it's paranormal. See, we have only witnessed optical phenomena like diffraction, interference and polarization of visible spectra. We should never forgot that even invisible spectra undergo these phenomena whose result , we cannot perceive with our eyes. Still digital IR cameras and other devices can record these patterns, which frightens us. To say that a terrible demon just now had a cup of coffee with me sounds more of a comedy than of a mystery."

"Hmm. Usually I've seen skeptical listeners who just argue that angels and demons never exists but they could not give a perfect scientific reason for the non-existence of the puzzling happenings like this one", said Sheela with inquisitive eyes.

That's what for I am here," said and smiled professor Govind.

A Seed to Strepulsion Physics

One fine evening, Professor Govind was enjoying the cool breeze on his sea side walk. He smiled at the young and charming students who were busy building their sand-castles on the coast. Every time when the tides washed away their feet, they rejoiced. It was a full moon day of the Spring. The professor wanted to caution them and said, "Children, enjoy the scenario; but never go into the coast. These Proxigean Spring tides are dangerous, you know? They occur once in every 1.5 years only and are dangerous; Be careful". 

"What? Proxigiiii?, well what’s that? " asked one of the children.

"Yes. Proxigean Spring tides are very high tides that arise when the moon is at its proxigee, i.e, the closest distance(perigee). The moon's gravitation pulls the ocean water to it’s direction which is counteracted by the earth's gravitation and rotation to give rise to these kind of high tides", said Professor and pointed out a high tide along the coast.

"So, are you saying that all these tides are the action of the moon's gravitational pull?" asked one of the students in an inquisitive voice. "Yes. Of course, every body in this universe attracts every other body, as given by Newton, isn't it my child?" asked the professor.

"If every object in this Universe attracts every other objects, then the universe would be a condensed mass of ball and there will never be any distribution of matter as now; there won't be any planets, any stars, any asteroids, blah, blah, blah. The entire matter(mass) of this universe would stick together making a pile of matter, isn't it?" asked a bright student.

Everyone laughed and made fun at him. "Do you mean, Newton is wrong? Or the entire scientific society which's been following his theories were fools? WTH!" asked a boy in a sarcastic undertone.

"Listen my boys. Don't laugh at him. His question makes a sense. Please don't disregard anyone's knowledge". The boys stopped laughing at him, obeying professor's words. They were all anxious to listen to what the professor is going to say.

"Your name, my boy?" asked Professor Govind.

"Venkat Ram" said the inquisitive fellow with a shivering voice of guilty and shame.

"Good. I should appreciate you first. See, although we have everything established by our preceding society, the observations made by some of us are constantly offering some new concepts and corrections to the preceding theories. And one such is the "Strepulsion Physics" the branch of physics that's popped to explain the question that you put forth."

It was Dr.NavinChandra Shah and his associates who have proposed a new theory called "Stellar Repulsion Force Theory" in 2003. It is yet to be accepted world-wide. According to their postulates, it is repulsion and not gravitation(attraction) that dominates the Stellar Universe.

Two stellar bodies(stars) never attract each other. Newton's law of gravitation is bound to non-stellar bodies(planets, satellites, asteroids, celestial bodies other than stars) alone. No wonder, his apple fell down due to the earth's attraction, but his concepts aren't applicable in case of stars.

If not the stellar repulsive force exists, the whole world would be a condensed mass as you said. The universe is balanced by both attraction and repulsion, and the planets revolve due to retraction force which is the resultant of stellar repulsion and non-stellar attraction. Two planets attract, two asteroids attract, even a star attracts planets, but two stars never attract, but repel. He's put forth some argument which correct Newton's theory of Gravitation, Galileo's astronomical concepts and Einstein's General Theory of Relativity", said Professor Govind.

"Interesting.." said Venkat Ram, the one who initiated the talk. "Where can I get the further information about this Sterpulsion Physics, sir?" asked him.

"Hmm. I've a book with me. Also you can try downloading the e-books from either of the sites, http://strepulsion.org/index.htm or http://www.strepulsion.com/theory.htm " said the professor.

"Oh! It's time. See I forgot that I got some work in my laboratory. Feel free to ask whatever you need, children. Bye. Take care", said the professor and got back to his lab.

Power from Fruits!

One fine day, Professor Govind was doing some experiments on Quantum teleportation. Sheela entered his lab and found some cut fruits on the table. She thought that Govind must have cut the fruits for his breakfast. She asked, "Professor, the law is the same for all, isn't it?

"Yes, no doubt" said professor Govind.

Sheela sarcastically asked him, " Haven't you shouted at me not to eat something in the laboratory?? Then, what these freshly cut apples and lemons have to do in your laboratory?" 

Govind smiled at her and said, "Oh! These fruits are the food for these multimeters and LED's."

"Food for them!" screamed Sheela. "But how?", she asked.

"Well, I can explain you. Different types of fruits have different electrolytes(ions) in them, especially, lemons and grape fruits have acids like ascorbic acid, citric acid, ions and NADH(Nicotinamide Adenine Dinucleotide Hydride generates cellular energy). When electrodes are inserted into them, these ions migrate to the appropriate electrodes generating current.

He took an apple and inserted two electrodes, a copper electrode(cathode) on one of the sides and a Zinc rod(anode) on the other side. He connected these rods to a multimeter and it was found working. Then he replaced multimeter with an LED(Light Emitting Diode) and showed that it lit up. But the light doesn't last long. It was slowly becoming dull and finally stopped glowing.

"Oh! So, fruits produce current that won't last for even 5 minutes, yeah?? Then what's the use professor?" asked Sheela. "Hmm. Nothing, I suppose. They produce only a few current(about 2 volt) and stops as soon as all the electrolytes have been used up completely. However few more lemons connected in series can serve as our regular batteries. Also potatoes produce a few more volts than fruits. So, this is a bit economical than ours", said Professor.

"Economical?? Well, what do you mean? Don't you know that these lemons cost more than a common battery? Sound that you haven't been to the city markets, right?" laughed Sheela.

"Hmm..I didn't make a note of it. Err, I think it would help a lot in any village in an under-developed countries, where there's no availability of neither electricity nor batteries", said Govind.

Invisible Liquid!

It was 28th of February, the National Science Day. Sheela was wondering what could she present on the eve of Science exhibition arranged in her school. With no other thought, she decided to approach professor Govind. No sooner she opened the laboratory, she was puzzled. Professor was inflating some balloons. 

She asked him whether he's turned a baby with sarcastic undertone.He welcomed her and asked what can he do for her.She explained her situation and requested him to guide her with a science fair project.

He asked, "Why shouldn't you do this?"

"This!! Professor, I'm sure that I ain't a baby," shouted Sheela.

Govind said, "Hmm, say that you're familiar with helium balloons".

"Professor, I know that helium is lighter than air and hence a balloon inflated with helium floats to the top; what's new with this??" asked Sheela desperately.

Now professor didn't speak anything and went to the junk box and took an empty glass fish tank. Then he started doing something. "Professor, I was asking about my science project, please", Sheela said. Professor never uttered any words and was keen in his job. Sheela watched what he was doing.

(watch the video)

Sheela
could not speak for a moment."Woww!Invisible liquid" she exclaimed.
"So, how about you doing this for your science fair, Sheela?" asked
professor. 

"This is excellent professor. Explain me how it works", asked Sheela.

"The principle is nothing but what you explained me earlier. Density matters..." smiled Professor.

He
continued,"I just closed this tank with a wooden board and filled it
with Sulphur hexafluoride gas. Sulphur hexafluoride is roughly 5 times
denser than air. Lighter gases tend to displace heavier gases downwards.

Hence SF6 displaces air upwards".

"Thousand thanks for you professor," greeted Sheela.

"But be careful.This gas is much poisonous and also a green house gas", explained Professor.

Spiderman - No more a fiction

Have you ever wondered that you would climb up walls? Have you ever tried grabbing the roof? It's not that tougher as you think. Just give it a try.Yes. Professor Paul Steen and Michael Vogel of Cornell University have paved way for a new world where people climb up walls like lizards! They have invented a new palm-sized device that adheres on all surfaces through electro-osmosis flow process.

They say that they were inspired of Florida beetle which can grab a leaf firmly with a force of 33 mN which is about 60 times its own body weight, yet can detach at any instant.

Thanks to the beetle and another forerunner who's given us a great concept of adhesion to walls and roof. She's none other than Gecko(lizard) which can climb up the walls and stay upright grabbing the roof throughout its life. But there is difference between the adhesion mechanisms followed by the lizards and the beetle. Geckos(lizards) possess millions of minute hair like structures called setae. And each setae contains numerous micro-fibrils which use van der waal's forces to cling to various surfaces.

In 2006, Stanford researchers developed a robot with synthetic setae which enabled it to climb up walls and even to walk on the roof.

But beetles use liquid mechanism to gain the control over adhesion and instantaneous detachment. They use the surface tension and capillarity phenomena of the tiny droplets on their legs to stay attached to leaves for longer time.

Having studied the various mechanisms that enables these creatures to stay grabbed lead the researchers devise a new palm-size instrument that creates a similar effect.

The device consists of flat plate with numerous holes, each of size few micrometer. A bottom plate serves as a fluid reservoir and there is a porous plate in the middle. An electric field is applied by a common nine-volt battery which pumps water through the device causing the water droplets to squeeze through the top layer.

The surface tension of the water droplets enables the device to stick on various surfaces. 

The prototype model with 1000 holes each of 300 microns grabbed 30 gram which is more than 70 paper clips.

This is the same principle why two wet glass plates stick together. But the magnitude of the force is increased in this by increasing the number of pores and decreasing the size of each pore on the plate. For instance, one square inch device with millions of 1 micron holes can hold more than 15 pounds. 

To turn adhesion off, the electric field is simply reversed thereby pulling the water droplets again to the reservoir.

The device can be of great use in the future, where people climb up buildings to reduce on street pedestrian traffic. Also, this can technology can be coupled with robots and other machines which need high rigidity and grabbing capacity. These devices can also be fabricated on shoes and gloves for better performance.

Note: Goal keepers are not to try this on their gloves during their sessions! Strictly!

A boon to Paraplegics

Shankar is a 12 years old boy. Having got much interest in the field of computer technology, he used to participate various competitions involving computer presentations and software program designing. He wins the competition every-time he participates, leaving his parents to wonder how he had learned those programming languages. He used to learn everything about technology from the net through his PC. One day, he was riding on his motor-cycle at break-neck speed. It was a bad weather for him and his parents. Unfortunately, he got stuck beneath a container lorry which smashed both of his hands and caused severe other complications. Also, he lost his speech. Even after recovering from the serious injury, he felt like hell as he could not operate his computer, which bagged him good conduct, appreciations and knowledge. But he never lose hope. Now, he operates his computer well again, not by his hands, but by his eyes. Thanks to Wolfgang Beinhauer and Fabian Herman of Fraunhofer Institute of Industrial Research, IAO, Stuttgart.

Yes. Those researchers have developed a new technology that enables one to access the computer menus through eye movements. A sensor device tracks the eye movements from 1 to 1.5 metre and transmits the co-ordinates of the area viewed to the mouse pointer of the monitor. The sensor device comprises IR-LEDs(Infra-red Light Emitting Diodes) and a micro CCD CAM(Charge Coupled Device Camera) which sends the tracked information to a computer through wires.

"Calculating the motion was comparatively easy while clicking presented a real challenge", says the developer.

In order to click any button one need to stare at the button for half a second.

A special software was designed by Fabian Herman which makes certain areas sensitive such that it can be activated by fixing the eyes on them for a certain length of time. The Graphical User Interface(GUI) measures this interval and decides whether the user wants to click the button or the user is just reading the menu text. Also, there's a drawback that if one takes more than half a second to read a text, the software decides it as a click.

To improvise this, the button changes color twice before it goes, "click". 

But still, there was a drawback. Our eyes make miniature jerky movements called microsacchades. While this involuntary jerky movements happen, the pointer dashes around all over the monitor. But this is overcame by using micro-filter software which suppresses theses micro-sacchades and then determines the main direction of movements.

This system is a great boon for differently-abled persons as it satisfies the cyber-thrist of such people without any hurdles. Soon we'll have an entirely different eye-controlled world!

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(Thanks to Fraunhofer press release)