Category: Science and Tech

Rainbow Physics

By Anupum Pant

There’s much more to a rainbow than it is usually told to us in our basic science classes. There are double rainbows, complete circular rainbows and what not. Physics girl explains…

For example, have you noticed that the sky above the rainbow is darker, while under it the sky is brighter. I didn’t know that! There’s complex combination of reflections and refractions taking place inside droplets which causes this. I can’t even explain it in text.

It doesn’t stop at double rainbows. Did you know, if it wasn’t for the sun;s mighty glare, you might have been able to see tertiary and quaternary rainbows too. Stacker rainbows are for some other time…

This Way Boarding a Plane Could be Much Faster

By Anupum Pant

It always seems like boarding a plane could be a much more efficient process. Normally it takes too much time, even when airliners are always trying to make it better by doing the back to front board. Or are they?

Of course, business class boards first. And then, the most common, seemingly optimized, way of boarding used by most airliners is the back to front. That means, all the people who’re allotted the last third of the seating are asked to board. Next the middle third goes in and then the front seating guests. It’s as if there’s no way boarding process could take lesser time. After all experienced airliners must be spending so much to find the best way to save time (money) here.

Turns out, this method which most airliners choose to adopt is the worst, and takes more time than possibly any other boarding process. Even guests boarding in a random order would take a significantly lesser amount of time. So why don’t airliners try to do better here?

boarding times

Probably because if they did, no one would buy their express boarding upgrade for an extra $20 to $30. Making the boarding process seem long actually makes them money, not lose.

The WILMA technique. Which means window seats board first, next middle seats and then the aisle seats. It’s logical that this would be quicker and is actually much quicker. That is because the people seated in aisle seats don’t have to get up and go to the aisle to let the window seat people go in – like it happens in the above technique.

To find out what works better. And which one is the most effective method, watch the simulation below.


via [Mythbusters]

Golf Balls and Their Dimples

By Anupum Pant

A golf ball is full of those cute dimples. Wouldn’t it have been better if they were clean and smooth with none of those tiny little bumps on their surface. Do these tiny bumps even really serve a purpose? Turns out, they do!

On a normal golf strike, a smooth golf ball would have reached 130 yards at most. Whereas a dimpled one travels more than twice as much – About 300 yards. What makes the difference? The dimples, of course. Aerodynamics!

A smooth ball has no lift. A dimpled one on the other hand is able to create a turbulent flow around it which provide it with a significant amount of lift. Such a ball can easily reduce the drag created by the air around it and is able to fly for longer.

The size, shape and number of dimples on a golf ball affect the amount of drag force it can reduce. So, different manufacturers have different parameters for their golf ball dimples. The more number of dimples you have, the more number have to fit on the ball’s surface and more desirable it is to reduce the drag. That means, each dimple has to be small and a point is reached where there are so many dimples that the ball is effectively a smooth one. So a sweet spot needs to be hit in order to optimise the flight of the golf ball.

The sweet spot lies somewhere in between 300 – 500. So, any ball with number of dimples less than 300 or more than 500 is not optimised for performance. So, most manufacturers have around 350-450 dimples on their golf balls. 336 dimples is believed to be a totally optimised number. Others believe that it has to be more than 380.

Back in the day when people did not really know about this, they had smooth balls and the flight of such a ball was something they weren’t impressed by. So now they had scratched golf balls, and then we had balls with dimples.

Breaking Spaghetti

By Anupum Pant

If you hold a long piece of dry spaghetti from the ends and bend it till it breaks, something unusual happens. Almost always the strand breaks into three pieces. Sometimes even four, and more. Statistically, very rarely it breaks cleanly into two parts.

The answer to why this happens has troubled physicists for a long time. Still not much is known about this phenomenon. Richard feynman had his own theory explaining why this happens. Until now, it was believed that the vibrations from the first fracture cause the second fracture. But that doesn’t seem to be the mechanism if you see it at very high frame rates. Because the second fracture happens much before the vibrations from the first reach it. [Paper]

This work of spaghetti breaking also lead to the 20006 IG nobel Award.

Smarter everyday, a youtube channel, to find out how this happens, decided to delve deeper into this and did an experiment that has never been done by any one else. The host captured it in slow motion at quarter million frames per second.  Before this, people had gone upto 4000 frames per second. 4000 FPS doesn’t really give you a lot. But when the frame rated is kicked higher, the mechanism sort of starts becoming clearer.

Both fractures, if it braeks into three, takes place with a very small interval in between. And now, thanks to this extreme slow motion video, it is believed that the first fracture triggers the second fracture.

Finding if There’s Juice Left in a Battery

By Anupum Pant

It’s hard to tell a dead battery from a good one. Or is it? Like you can find out if an egg is spoiled by dropping it in water, a bad battery can be spotted by simply dropping on a hard surface. If a battery bounces more and fails to stand up, it certainly is a bad one. But if it doesn’t bounce as much and stands up on the hard surface, if dropped from a small height, it is a good one. But how does this really work. Or does it?

Yes, it sure is a good test to find your bad alkaline batteries. According to a popular theory, this works because gas gets collected inside a battery which makes it pressurized, so it starts bouncing more as the juice goes out. This has been tested, and not found to be true.

Instead, what makes this work is pretty different from that theory. In a good battery, the inner part of it is very mushy – or, not firm. That is mostly due to the presence of Manganese dioxide, which is added to prevent the gas from collecting inside a battery. So, this mushy matter inside it contributes to an anti bounce mechanism.

As the juice gets used up, the manganese dioxide changes to a more firmer manganese oxide, and a relatively hard core is left inside a finished battery. So, when it is dropped, it bounces more than the battery that has mushy stuff inside it.

The following video tests it –

The Role of Wind in a Tree’s Life

By Anupum Pant

Remember the biosphere 2? In short, it’s a miniature version of our planet, now owned by the university of Arizona, constructed for scientists to study how the planet’s living systems actually work. Learnings from this tiny planet enabled scientists to innovate and come up with new ideas related to growth of plants etc. Or that is what they thought when they planned to make this biosphere.

The major discovery from it was something they had never expected. The most interesting thing they learnt from it was the importance of wind in a plant’s life. Who’d have thought!

In the biosphere 2, they had trees growing faster than they would grow in the wild. Also, they found that these trees wouldn’t completely mature. Before they could, they used to collapse. Later it was found that this was caused by the lack of wind in the biosphere. And it turns out, wind plays a major role in a trees life. The presence of wind makes a tree stronger, it is thus able to mature and not fall down due to its own weight.

When plants and trees grow in the wild, the wind constantly keeps them moving. This causes a stress in the wooden load bearing structure of the tree. So, to compensate, the tree manages to grow something called the reaction wood (or stress wood). This stress wood usually has a different structure (in terms of cellulose or lignin content and more) and is able to position the tree where it’d get the best light, or other optimum resources. This is the reason why trees are able to contort towards best light and still survive loads in even awkward shapes. A contorted building like that would easily fall. The tree is able to grow in a more solid manner – thanks to the reaction wood.

If there’s no wind, like in the biosphere 2, the trees end up being much weaker and aren’t able to survive for long. This happens in homes too. Plants grown indoors, without any kind of wind hitting them on a regular basis tend to become weak. So, before they are planted outside in the wild conditions, their structure has to be strengthened by causing stress.

Remember, stress is what makes a tree strong enough to sustain the wear and tear that it’d face later in life.

Calvin Klein’s Obsession to Lure Jaguars

By Anupum Pant

Traditional field observations do not always do the job, especially when researchers are dealing with elusive nocturnal animals. So, camera traps are a great way for biologists to gather information about the behaviours of these shy animals. These traps (not really physical traps to capture animals) basically consist of a camera, and an infrared sensor to trigger the camera when an animal is detected  at night. These remote camera can also be kept running throughout, day and night.

Jaguars, the solitary nocturnal cats, which are hard for humans to spot in the wild, are one of the best suited animals for such camera traps. But, the areas jaguars cover in the wild can reach up to several tens of kilometres. So, researchers have to find new methods to get the Jaguar to come to the camera and get captured. For this, they use a technique you won’t believe is actually used.

Calvin Klein’s Obsession – a “compelling, potent and powerful” fragrance – does the job. Obsession is an “intensely provocative  scent” meant for men to use, and a 4 oz vial of it sells for $71. Coincidentally, jaguars seem to like it too. Or is there a deeper reason why they like it?

Ordeñana, a Bronx Zoo researcher tried on several other perfumes in order to find the one that best calls a jaguar. All you need to do is spray some of it somewhere near the camera trap and a jaguar often comes up.

It works because it has civetone in it – A chemical compound that comes from these small nocturnal mammals called civets. Instead of troubling little civets for this, it’s mostly synthesized in the laboratory. It is believed that this compounds seems like a territorial mark to the jaguar and it comes to mask it off with its own scent. Thereby marking the territory as its own.

So, the next time you go camping in the woods, you’d would want to use any scent in the world other than the ones that have civetone in them. Clearly, wearing Calvin Klein’s Obsession is just out of question for any kind of camping in the wild.

via [Scientific American] and [Washington Post]

Electrons Faster than Light. No.

By Anupum Pant

The Rutherford-Bohr model or simply the Bohr model described the structure of an atom. In it, the nucleus consisted of protons and neutrons, and was positively charged due to the presence of protons in it. Electrons revolved around the nucleus in circular orbits. It was a very simplified description of an atom and served as a good introductory means to teach the structure of an atom. However, several decades back this model was superseded by the Shrodinger model of atom which described the structure of an atom using quantum theory.

The Bohr model fails on many levels – these have been listed here. [Link]

Richard Feynman, using the postulates of Bohr model, argued that the last possible element that could possibly exist would be the one with the atomic number 137. That is to say, no elements greater than atomic number 137 could exist. This argument comes from a simple analysis.

When you consider the Bohr model, and keep filling the nucleus with protons, a point reaches when the charge inside a nucleus becomes very high. In order to maintain a stable orbit around such a high atomic number element, the electrons in the lowest level (having the smallest radius of orbit) would have to move really fast. Or they’d simply crash into the nucleus. When the atomic number reaches more than 137, the calculations using the Bohr model tell you that the lowest electron (1s electron) in such an atom would have to revolve around the nucleus with a speed that would analytically end up being larger than the speed of light – which of course isn’t possible because nothing travels faster than light. So, the element 137 just cannot exist, or so argued Feynman.

Goat Menace in the Galapagos Islands

By Anupum Pant

Just two of the many remote archipelagos of the Galapagos islands in the Pacific ocean are home to some of the most magnificent creatures here on earth – The Galapagos tortoises. These are giant tortoises that can weigh up to 300 kg and usually go on to live for more than 100 years, even up to 170 years in rare cases.

Only thing, their existence is now threatened. About 1,500 exist today. Back in the day, some hundreds of years back, it is estimated that there used to be as many as 250,000 such tortoises living in the Galapagos archipelagos. But thanks to the passing sailors of the yore, these beautiful reptiles  got massacred for oil and food. That caused a massive decline around the 70s and now we have the results.

That’s not all these sailors did. They also introduced several non native species into the islands. Goats were one of them – the most relevant ones in this context. These goats multiplied like wild fire and soon there were tens of thousands of goats finishing off vegetation in the islands. In the islands they were never even supposed to be in the first place. This corrupted the ecological balance and proved to be a menace for the existence of giant tortoises. As if we already had too many to lose.

Concerned conservationists wanted to fix this. For that they devised a not very pretty technique to accomplish the task. Goats had to be gone.

Sharpshooters were brought in from New Zealand. Judas goats, with GPS collars were prepared and released into the island. While these spy goats were searching for a pack of goats to socialize with, the sharpshooters were being flown in helicopters, tracking the judas goats to the pack of goats. Packs were located this way, sharpsooters individually shot each one of the pack members and let the GPS equipped goat go away to find them another such group of goats.

The video below is not for the weak hearted. Also, there’s a one hour long radiolab episode which talks in detail about this situation, attached below the video.

[Video] Contact Lens Origins

By Anupum Pant

Did you know? The first contact lenses were something you wouldn’t want to wear – They were made of glass, covered the whole eye (yes, even the white part) and were as thick an average slice of bread! So, you couldn’t wear it for more than a couple of hours.

Adolf Fick, born in Germany began researching the contact spectacle in Zurich. He used rabbits and human corpses to conduct his studies.

Plants Can Grow Within Human Bodies

By Anupum Pant

Yes, plants can grow inside human bodies. Here’s what happened about 4 years back. And it’s just one of such many instances where plants have been found growing in human bodies.

A 75-year-old man from Massachusetts, Ron Sveden had been experiencing short breath for a couple of months. And then his condition started deteriorating. He started coughing incessantly one day. That was when he knew it was something serious. 911 was called and he was rushed to the hospital.

Doctors took the X-ray. They found that one of his lungs had collapsed and a tiny spot was seen on the X-ray. Sveden was now sure that he had cancer. He just waited for the doctors to speak.

The test for cancer turned out to be negative. Doctors instead found a pea plant growing from his lungs. A pea must have gone down the wrong hole some time, doctors theorized. Apparently the warm and moist conditions inside the lung had made it a perfect place for the pea plant to grow.

After a fairly simple surgery the 1.25 cm pea plant was removed from his lung and Sveden was sent back home.

Amazing Cephalopods

By Anupum Pant

The brain of an octopus is the size of a walnut – Significantly smaller than that of us. Or I’d rather say the main brain of an octopus is of that size. That is because only a third of the total neurons in the body of an octopus are in its main brain. Rest of them are distributed in its eight arms.

This is the reason the arms of an octopus are not completely its own. They sort of have a mind of their own. They have the ability to do their own thinking, or at least basic coordination, problem-solving and reaction.

Even when an octopus is killed and its arms are separated from its main body, they still are able to react to stimuli, and more. That is like a severed human arm reacting to a hot kettle. The thing is, even with a walnut sized main brain, it can do so many things that our complex human brains allow us to do.

These creatures are also pretty astounding when it comes to sensing their environment with their arms (skin) and creating camouflage. They are colour blind, and yet they are able to do some amazing texture and colour replication on their skin (as seen in the video below). They can literally see using their skins. Some cephalopods like cuttle fish have the photoreceptor protein in their skin (as well as eyes). We and everything that has an eye have it only their eyes.

Radioactive Bananas and Most Radioactive Places

By Anupum Pant

Although radiation would be last of your worries, but eating 20 million bananas would kill you due to radiation poisoning, if not due to anything else. That is because bananas emit ionising radiation which is bad for you. But, as the amount of radiation dose you’d get if you eat a banana would be almost the same that you’d get from the background radiation while sitting in your balcony for an hour, you shouldn’t really worry.

Bananas are slightly radioactive because they contain potassium. The element decays and emits radiation which can kick electrons out of atoms – ionising radiation. In fact, everything emits trace amounts of radiations.

Beer with Foam on it

By Anupum Pant

Think about this. You have a glass full of water, with water nearly till the rim and then you have a mug full of beer, with its foam almost reaching the edge. Carrying the glass full of water in your hand from one end of the room is clearly more difficult than carrying the mug of beer that has foam in it. I have always thought that this must be due to the difference in viscosity of both the fluids. But what if one had beer with no foam and other had beer with foam in it?

Turns out foam plays a big role in determining if the liquid spills on shaking the container, or not. It’s much easier to spill beer with no foam on it or even a glass full of water, or a glass full of coffee (with no foam of course). But when you have foam on your drink it is much harder to spill it.

That is because walking with a liquid that has no foam on it lets the waves propagate easily, without any resistance. However with a liquid with foam on it has to go through the resistance from the foam to propagate waves on its surface. This makes it harder for the liquid to spill.

Some researchers at Princeton university are studying the actual physics involved in this “anti-sloshing mechanism” of foam on liquids by studying the motion of foam bubbles using a high speed camera.

Stainless Steel Soap

By Anupum Pant

How in the world would a piece of metal be used as soap. I never knew something like that could be used to clean your hands. But it does and there’s a fairly scientific hypothesis explaining why it works.

Stainless steel soaps are real and you can buy them in stores. These soaps apparently help to remove or neutralise strong odour from your hands after you cook – like the smell of garlic, fish or onions. Although not everyone agrees that there is a solid scientific explanation for it, but it does work and you can try it at home. Even if you prefer not buying a soap to test it out right away, you could use any stainless steel surface for it.

So, when you have strong odour on your hands after cutting, say onions or garlic, you could try rubbing your hand while the water is running, on a stainless steel sink’s surface, or any other utensil made out of that alloy. This is how it is believed stainless steel soaps work.

The sulphur from stuff that causes odour to stick to your skin can bind stronger to the stainless steel surface than your skin, or that is what they believe. So, when the sulphur goes away and binds to the stainless steel surface, the odour from your hand is gone.

The exact working of this is not known. But, catalytically induced oxidation of odor molecules and an absorption of molecules on the surface of the stainless steel (especially a chemical compounding with ferrous, manganese and/or molybdenum molecules).

Onions and garlic contain amino acid sulfoxides, which form sulfenic acids, which then form a volatile gas (propanethiol S-oxide), which forms sulfuric acid upon exposure to water. – About.com

Like we all know, using only water makes it worse. Why not try it out for once.

For hardcore scientists like Dr. Bob Wolke, a professor emeritus of chemistry, this doesn’t seem to work. Granted he didn’t conduct a perfect scientific study. Probably if he did, he might something. Well, it does work for people, if it works for you too, great. How does it matter.

via NPR