thanks: Times of India
dedicated by: Kavignar Thanigai.
- The satellite was selected through a competition called ‘Cubes in Space’, jointly organised by NASA and ‘I Doodle Learning’
- This will be the first time an Indian student’s experiment – a 64 gm satellite – will be flown by NASA
The satellite, called KalamSat, will be launched by a NASA sounding rocket on June 21 from Wallops Island, a NASA facility. This will be the first time an Indian student’s experiment will be flown by NASA.
What can we say. This is something simply extraordinary. The Prime Minister of India should take notice of this boy’s intellectual ability and provide him all necessary support to continue his appeti…
Speaking to TOI from Pallapatti, Rifath said it will be a sub-orbital flight and post-launch, the mission span will be 240 minutes and the tiny satellite will operate for 12 minutes in a micro-gravity environment of space. “The main role of the satellite will be to demonstrate the performance of 3-D printed carbon fibre,” he explained. He said the satellite was selected through a competition called ‘Cubes in Space’, jointly organised by NASA and a organisation called ‘I Doodle Learning’.
The main challenge was to design an experiment to be flown to space which will fit into a four-metre cube weighing exactly 64 grams. “We did a lot of research on different cube satellites all over the world and found ours was the lightest,” he said. Rifath said the satellite is made mainly of reinforced carbon fibre polymer. “We obtained some of the components from abroad and some are indigenous,” he said.
Question Corner: Why is a large part of an iceberg under water though ice is lighter than water?
Ans: R.JAGANNATHAN .Luminescence Group CECRI Karaikudi, Tamil Nadu. The Hindu May-23,2013
Ice floats in water because it is lighter (less dense) than water, the medium in which it floats but with most part of the solid ice under water. This is simply because ice and water differ in their densities only in a small way. Water in liquid form at normal room temperature has a density of 1 gm/cc while in solid form as ice has a density 0.92 gm/cc. That is , ice is lighter than water only by about 8 %. Turning to explain the extent of immersion /flotation, we need to invoke the law of flotation which states that any solid floating in a liquid displaces equal weight of the liquid over which it floats.
Any solid object placed over a liquid starts sinking and displaces liquid with the volume of liquid it displaces equal to the volume of the solid it is immersed in. Depending on the densities of the solid and the liquid, the extent of immersion -sinking varies. Because, the displaced liquid generates an upward force called buoyant force eventually determining the extent of immersion which is responsible for keeping afloat solid object(s) in liquid(s).
As the solid object is put in a liquid, the solid starts sinking/immersed. This process of sinking or immersion goes on until weight of the solid equals the weight of the displaced liquid. At the point of equalizing their weights., it starts floating. So in the case of ice by virtue of its density being lighter the sinking process can go on up to the point when 92 % of its volume is immersed in water while the remaining 8 % floats because 92 % of water displaced will equal the weight of the solid ice floating. Hence this makes only smaller part of 8 % (tip) of the iceberg float while the rest gets immersed in water. Interestingly when the same ice is placed in sea-water, it will float slightly more because sea water is more dense than normal/river water.
THIS PROCESS WILL KEEP THE ROOT WET ENOUGH THROUGHOUT THE DAY WITH MINIMUM QUANTITY OF WATER Madurai: Next time when you discard used plastic bottles think twice before doing so. They may be of some use to you. These pet bottles, which often add to the garbage, can turn a saviour of smaller plants that need water to withstand the summer. An agriculture officer K. Arumugam of Chokkikulam uzhavar santhai has developed a simple drip irrigation model using such bottles. “This is a simple method. We have tested at our uzhaar santhai. All that one needs to do is to fill the bottle with water and use fibre of coconut sheath, instead of caps, to seal its mouth. Make a small hole on the ground closer to the root of the plants and put the bottle upside down.”
The District Police Office premises near Surveyor Colony here have put the system into use. Scores of used water bottles half-buried upside down on the ground are ‘feeding life’ to the plants around the dry tank in front of the building housing the office of Superintendent of Police. A closer look will reveal that the bottles are ‘breathing’ with bubbles coming up through the water inside.
“The water will seep through the fibre drop by drop and directly feed the root. This process will keep the root wet enough throughout the day with minimum quantity of water. The quantity of water which is consumed in a day in conventional way of watering the plants can last for nearly a week,” the Superintendent of Police, V. Balakrishnan, a post -graduate in Agriculture, said. For the police who ware trying to find some solution to keep these saplings alive, this has provided some relief.
People who want to go away to enjoy summer vacation can use this system (use a two-litre bottle) to keep their plants alive for week, Mr. Arumugam said. “Besides, the used plastic bottle is put to good use,” he added. Report : The Hindu April:23-2013, S. Sundar. Dedicated by: Kavignar Thanigai.
How did coffee become more popular in south India and tea in north? History appears to give the reason. Legend has it that in the late 16th century while Haji Baba Budan was returning from Haj through Yeman, he found people boiling coffee beans in water and enjoying the “decoction”. He then smuggled a handful of the (forbidden to export) beans with him and planted them on the Chgikamgalur Hills in Karnataka and the locals took to it with elan. Soon , coffee plantations appeared in Kodagu and the Nilgiris, and we all were hooked on to the morning coffee. Tea , on the other hand was introduced later (early 19th century) by the colonial British who copied it from the Chinese and planted it in Assam and Darjeeling. This colonial drink soon became popular among the subjects entrants into the Indian taste buds.
But why are we hooked on to coffee and tea? The answer comes from science, which tells us that they both contain the mood-altering and addictive drug caffeine. While this is a proximal answer, the ultimate question is why at all do these plants go tothe trouble of making the molecule in the first place. After all, it takes metabolic energy to do so. The answer appears to be “to deter herbivores”, or as a defence chemical. Note that the raw bean or leaf is bitter to taste, and the animal would shy away, leaving the plant alone to grow and flourish.
Recent findings add another dimension to the tale. It has been found the caffeine is found not only in the bean or the leaves but also in the nectar that the plant produces and packs a drop or two in its flowers. And why it would do so and what this stored caffeine does in the flower nectar has been investigated by a group of researchers from U.K and published in the March 8, 2013 issue of Science.
They note that while plant-derived drugs like caffeine and nicotine (the drug n the tobacco plant ) are lethal in high doses, they do generate pleasant effects when taken in very low doses. But then why in the floral nectar? Is it in order to”hook on” bees and other pollinating insects? To understand this, the researchers first measured the levels of caffeine in the nectar of three plants, Coffee arabica, C.liberica and C,canephora, to which bees make a bee-line for (pardon the pun), and found the amounts to be less than a thousand-fold that of the sugar present in the bean just a teasing touch.
They hypothesised that the caffeine in the nectar could affect the learning and memory of the foraging pollinatiors. Could it be that they would come to these flowers, enjoy the nectar and in the process take away and dispense the pollen, thus breeding these plants in preference to those that do not store caffeine in their nectar? In order to test this, the researchers took the trouble of training individual bees to associate a floral secent with sugar reward. In one set the bees would go to the containers with sugar solution, and in another set the sugar solution spiked with a bit of caffeine. And they found that the bees would consistently return to the caffeine sugar scent even three days later. In other words, caffeine acted as a memory enhancer. The bees were hooked on to caffeine.
The researchers went further ahead and investigated the biological mechanisms behind the mode of action of the caffeine. The bee brain contains what are called projection neurons or nerve cells that have protein surface (a receptor) that normally binds to the molecule adenosine. When these nerve cells are adenosine -bound, the behaviouur of the bee is one of quiet and calm. However when caffeine is brought in, it kicks out the adenosine and attaches itself to the receptors at the end of the sensory neurons. The effect is to stimulate the neurons, increase memory, and wake up and excite the insect.
In effect then caffeine has two roles in the plant. One is defence against the predator goats and cows, while the other is to entice the pollinating insect by drugging it and tweaking its memory so that it pollinates this plant in preference to other pants that do not pack the drug in their nectar. The researchers conclude by stating that “our experiments suggest that by benefits arising from enhanced pollinator fidelity”.
In plainer English, one can say that the trick the coffee plants play is another example of the ‘selfish gene ‘idea, namely , use any ruse to help propogate my genes over other competitiors, and do so for generations; and if it takes caffeine to entice and tweak the memory of the pollinator , so be it.
Excerpts:Thursday April:18.2013. written by :D.Balasubramanian.
Dedicated by:Kavignar Thanigai.
AMAZING BUT TRUE: BIRD BRAIN
Because of something called imprinting, some birds may be confused about exactly who their mother is. Imprinting, a term first used by Austrian zoologist Loren Eisley, refers to a period of time in a bird’s life when it bonds with its mother. Usually this occurs shortly after a bird hatches. Once the bond is established, it is very hard to wipe out – and it affects the way that baby birds learn social and survival skills.
Imprinting is strongest in animals that leave the nest immediately after hatching, such as ducks or chickens. For this reason, it seems that nature has developed this way to keep the young, defenseless birds from wandering too far from their mother’s protection.
After a baby duck or chick hatches and opens its eyes, it considers the first moving object it spots to be its mother. It will follow that creature or thing around, imitating it and learning its behavior, such as how to find food and greet other animals.
In wood ducks, the bond from imprinting is especially strong. Because of imprinting, the babies recognize their mother’s call. These birds nest high in trees. The mother waits for her ducklings to hatch and then flies to the ground where she calls up to her babies. One by one, they drop out of the nest, plummeting up to 50 feet (15m) to the ground where they trust they will join their mother.
Scientific tests show that if their biological mother isn’t around during the imprinting period, some birds will bond with other things – a puppet held by a human, a dog, or even a little girl, as is the case for geese in the 1996 film Fly Away Home.
sources: Discovery channel
Dedicated by: Kavignar Thanigai