A Simple and Elegant Cloaking Device

By Anupum Pant

In the year 2011, UTD NanoTech unveiled their carbon nanotube invisibility cloak, making us move one more step closer to realizing a piece of magical cloth which fictional characters often use to turn themselves invisible. And then there was a 3D printed invisibility cloak too.

A few researchers at the University of Rochester have now created their own elegant version of an invisibility cloak. It’s, in principle, a fairly simple optical device which uses just four lenses to cloak objects behind it, keeping the image behind it still visible.

In fact, whatever it does, it does it in 3 dimensions. That means, the viewer looking through the device can actually pan to change the viewing angle and can still see the image of the background, undistorted, as if there were no lenses in between, in real-time. And it is probably the first ever cloaking device to be able to do that.

The device has a blind spot (sort of). In a way that It doesn’t cloak anything that lies in the axis of the lens system. The cloaking area is in the shape of a dough nut. Any part of the object that accidentally enters the axis area becomes visible and conceals the background. The device is simple and cheap enough to be easily scaled to cover greater area, as long as lenses of that size can be made. The video explains it better.

via [Quarks to Quasars]

Best Explanation of Quantum Entanglement

By Anupum Pant

I don’t know a lot about Quantum entanglement, but I still think it is very interesting. So much that a PC game which contained of this concept, immediately landed on the list of my most favourite games. Yet, it sure is a tough thing to get into your head.

Fear not. Associate Professor Andrea Morello of  University of New South Wales (UNSW) is here to explain it to you, in this video which people have started calling – “The best explanation of quantum entanglement so far”. I have to admit it, I am still not sure if I really understand what the professor tries to explain in the best explanation ever video.

In very simple words entanglement works like this. If two objects are entangled with each other, and if you separate them by any distance (even place them at the opposite ends of the universe), then they’d still remain connected very peculiarly. Entangled particles even separated by a massive distance would still be connected – as in, whatever you did to one of the particles would instantly happen to the other particle at the other end.

The instantaneous reflection of changes done on the first particle to the other particle happened faster than light. And Einstein didn’t like that, he called it “spooky action at a distance”. Tom me, this video explains it better…

Liquid Nitrogen Experiments

By Anupum Pant

Short of time and keeping up with a busy schedule, I looked around for something interesting to learn today and I found this cool video of very interesting experiments that were done with liquid Nitrogen on ScienceDump. There are 11 such experiments that are shown in the video…

The first one is a Liquid Nitrogen explosion, something like this professor did some time back. To demonstrate his students how Liquid Nitrogen expanded, he blew up a container of Liquid nitrogen to toss 1,500 ping-pong balls. [Video]

Is an Aeolipile, or a rocket styled jet engine made using liquid nitrogen A.K.A Hero engine. Liquid nitrogen heats up inside a container, expands and comes out of tiny orifices to create a jet that makes the container spin. A simpler version of it can be done using a ping pong ball (again). [Video]

The third one simply is a demonstration of what happens when you eat a biscuit dipped in Liquid Nitrogen.

Fourth one again is something you’ll have to see to get really impressed by what some solids at very low temperatures can do. A nice demonstration of something similar is done on this video. [Video]

Fifth one! Oh, the Leidenfrost effect. We’ve talked enough about it already. [Here]

Others are all pretty interesting too. The eight one probably takes the cake – brings back a dead creature to life, or does it…. But I won’t spoil them for you. Watch the video now…

A Few Amusing Physics Phenomena

By Anupum Pant

Veritasium has always amused us with very interesting physics phenomena over the years. And now, as always, the channel has asked its users to send their answers to these 5 interesting physics mystery.  Here have a look at them…

Do leave a reply on his channel if you think you know why these happen.

For all of the 5 things, I do have my own theories but I’d rather wait till the next week when Derek will release the solution video. I do not want to publish my haphazard theories, which might be wrong.

However, I’m quite sure about one thing. Why does cereal get attracted by a magnet?

That is mostly because it has iron in it. By iron I mean real iron in its pure form. In fact, you can even extract iron from cereal. The best part is that it is not even difficult. All you need is cereal, a neodymium magnet, water, a bowl and a resealable bag.

A 2-Minute Exercise to Do Better in Interviews

By Anupum Pant

Is there a job interview or a public speaking gig coming up for you? Well, you don’t have to worry as much as you are doing right now because Amy Cuddy is here to save you.

Amy Cuddy, a social psychologist at Harvard Business School, talks about a power pose – a 2-minute pose – you could strike before going into an interview which has been proven to have a significant difference in your performance at anything that requires confidence (like an interview).

She introduces this concept in the a very convincing TED talk that I’ve attached below. If you do not need much convincing, you could skip watching the talk and just do this before you go into an interview or go to the stage for something.

  • Find a quiet place where no one will see you and make fun of you.
  • Strike a superhero pose. If you don’t know what that means, stand like this. For 2 minutes. Done! Otherwise, here is a nice infographic based on Cuddy’s research. [Link]
  • If you don’t, at least do not stoop and close your shoulders while waiting in the lobby because it certainly affects you negatively.

Apparently, according to an experiment by Amy Cuddy and Dana Carney of Berkeley, 86% of those who posed in the high-power position (the superhero pose) opted to gamble, while only 60% of the low-power posers (closed poses) felt comfortable taking a roll of the dice.

Moreover, a significant difference was found in the saliva samples of both the high-power pose people and the low-power pose people. Who’d have thought that a simple 2 minute pose could make chemical differences in your body!

On an average, the high-pose people saliva showed an 8% increase in the testosterone level, while the ones who did the low-power pose had a 10% decrease of the same. That is phenomenal, if you ask me.

Also, the hormone related to stress, Cortisol decreased by 25% among high-power posers and increased 15% among low power posers. (A decrease in cortisol levels is better for activities like interviews)

It’s So Easy To Make A Speaker At Home!

By Anupum Pant

While doing a random experiment with the ordinary motor, a youtuber Andy Elliott who runs the channel mist8k (known for his awesome videos) mistakenly touched the 3.5 mm jack of a speaker cable to the motor’s wires.

This resulted in something very interesting. The sound being transmitted through the cable started coming from the motor. And consequently, he invented the very basic speaker. Then he made a video of him explaining how to make a speaker at home using just a copper wire, magnet, tape, jacks and a disposable plastic cup.

I first saw this on Gizmodo and I thought it deserved a mention in the engineering section of this blog. I can’t wait to try it myself and probably improve the “very basic speaker” to make a nice iPod dock in the future…

Here is what he does –

  • Uncoils a copper wire from a component of an old PC, turns it into a small circular coil of the size of the circular magnet and then tapes it to the back of a disposable plastic cup.
  • Then, makes a larger coil by winding it around a bottle cap and tapes it on top of the smaller coil.
  • Connects one end of the larger coil to the tip of the 3.5 mm jack and the other end of the coil to the base of the jack. The other end of this wire having the 3.5 mm jack is also a 3.5 mm jack, which goes into the computer’s (or any player’s) speaker plug.
  • Places a strong neodymium magnet on top of the coils and plays the music. That’s it!

The computer turns the sound signal into an electric current. This current flows into the jack and then into the coil. Thus, the coil produces a magnetic field of its own. This varying magnetic field coupled with the static magnetic field of the neodymium magnet makes the coil move. Which in turn moves the back of the cup (as it’s taped on it) and makes the air vibrate. As a result, sound is created.

Here’s the video where he teaches how to do it…

Popping a Pimple Can Actually Cause Death

By Anupum Pant

Never ever try to pop a pimple on your face, especially if it is in the danger triangle of the face (explained below).

You wouldn’t believe me if I told you that popping a pimple coming out in a certain area of your face could be lethal. If not lethal, it can cause facial paralysis or meningitis. Of course the chances aren’t that high, but it’s 100% true. If you don’t trust me, or you think Wikipedia is not always right, you could go and ask your physician about the “danger triangle of the face“. For real recorded cases of grave problems caused due to popping of pimples, you could check this link. To quote one…

A moderately stout man of 20, scratched the head off a pimple on his lip six days before admission to the hospital and died 36 hours after admission.

Recent example of a serious problem caused due to popping of a single pimple.

The danger area: The danger triangle is sort of a triangle, more of a rectangle on your face which covers the eyes (and eyebrows), the nose and the upper lip. The diagram is not completely accurate. Pimples in this area of the face should be left untouched.

Why? This area of the face covers something called the Cavernous sinus. In simple words, it is a cavity at the base of the brain which drains deoxygenated blood from the brain back to the heart. Unfortunately, the facial veins which circulate blood to the danger part of the face can drain blood directly drain into this cavity, the same cavity which has a direct access to the brain. Also, since there are no check valves, the blood can flow in any direction in these parts.

Now, if pimples are popped, the bacteria from these pimples can flow back and ultimately reach the brain. Imagine noxious pus flowing into your brain. That’d definitely be dangerous. But it is highly unlikely. Still, there is a chance.

Be careful. Don’t use your hands to pop pimples. Leave them alone.

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A Thread Around the Earth

By Anupum Pant

Background

Couple of days back, I read about a puzzling geometrical conundrum, probably on Quora. It might not sound amusing to you math geeks out there, but to me, it sounded like an impossible thing at first. The sad part is, I did not save the source link in my notes. Thankfully, I did care to note down the idea. Let me call it the “Thread wound Around the Earth” puzzle.

Here is a simple question first. Try answering it without any calculation. Just guess. Be honest to yourself, don’t see the answer just below it. Scroll slow.

As BBC’s website puts it…

Imagine a piece of string wrapped around the Earth’s equator – that’s about 40,000km. How much MORE string would you need for it to sit 15cm above the ground, all the way around?

A) 1 metre, B) 1 kilometre or C) 1,000 kilometres

Thread wound around the Earth

The answer is A) 1 meter. Yes, just 1 meter of extra rope.

Suppose, you have an outrageously long thread with you. You tie it around the base of a tree, somewhere at the equator. Now, you go around the earth, along the equator, carrying the thread with you, till you come back to that tree where you started. At this point, you’ll have a thread that goes around the earth in a circle. At every point, let us imagine that the rope is taut and touching the ground (there are no mountains or valleys in between). It’s a perfect circle (assume).

Suppose, you still have an extra meter of the rope left now. So, you break the wound rope at one point and add the extra meter to it. That of course slackens the wound rope. For this rope to be taut again, it has to be lifted up by some amount. What do you think that distance would be from the ground? Assume that the rope still makes a huge circle just above the ground and lifts by equal amount at every point along the equator.

Just the extra meter of rope, causes the rope to rise by ~15 cm all around the earth (actually 15.9 cm). For a single meter of rope added to a 40,000 km of rope, that sure seems like a huge lift! But that isn’t all…

rope 15 cm above earth

The most amazing part is that, no matter what the size of the circle, a meter of increased circumference will increase the radius by ~15 cm. Always!

Try tying a rope around a golf ball, or even try doing that around the sun. It’s always that – 1 meter increase in circumference, always increases the radius by ~15 cm.

The Math is so straightforward.

If you think about it mathematically, it is completely straightforward.

Radius X 2 X Pi = Circumference

That means, the Radius is directly proportional to the circumference of a circle. Everyone knows that. So, the amount of change in the radius is reflected proportionally in the circumference, the magnitude of radius can be anything, really. So it’s pretty natural that just a single meter of rope is required to lift the rope by 15.9 cm around any circle. The size doesn’t matter. But practically thinking, the above question makes it seem impossible.

Please hit like if you learnt something from the article.

Talk by Arvind Gupta Will Make You Salute Him

By Anupum Pant

Background

We are all born scientists. Young kids have an inborn talent of thinking and learning by interacting with their environment – just like scientists do. Their everyday play is a type of experimentation and the toys they use, are their scientific equipment.

But unlike the children of developed countries, in India, a major chunk of little kids are not fortunate enough to cross ways with these fancy toys. In a place like India where 70% of the nation’s population still resides in backward villages, a man like Arvind Gupta is doing some really incredible work that deserves a salute. He’s popularizing science among kids by showing them quirky ways to convert trash into useful toys.

The Story of Mr. Gupta

He is the Indian Bill Nye – the Indian science guy – Arvind Gupta.
Arvind Gupta calls himself a toy maker (I think that is a very humble name he gives himself) and he has been doing it for the last 30 years! During the 70s when Mr Gupta was studying in IIT – Kanpur, he lived through a period which came with a revolution that aimed at revitalizing primary science in the village schools. Later, he went to the US, studied at Caltech, came back, worked at the top research laboratories in the country, and yet he wasn’t satisfied.

He somehow felt that the cutting-edge research he was doing, its effect on the major part of the Indian people wasn’t directly visible to him. This was when he started a village sized program to popularize science among the rural kids. He continues to do this even today. His way of doing it – Teach them to convert trash into toys. It was a beautiful idea.

I still remember watching Arvind Gupta on Doordarshan, teaching us science. We never noticed we were learning –  by touching, feeling, cutting, sticking – pulling things apart and putting things together.

His toys

He can turn anything into a toy that explains a basic science principle in a very interesting way to children. For instance, his way of sticking match sticks together to make objects as simple as 2 dimensional angles to objects as complex as bucky balls, is just amazing. But that’s not all.

Go to his YouTube channel you’ll find a number of tutorials to create amazing little devices from trash, which even adults will enjoy. Besides that, to cater to the linguistically diverse population of India, his videos come in languages like Hindi, English, Tamil, Bengali etc…

Watch his talk below. In a 15 minute breathless talk you’ll watch him demonstrate everything from simple mathematical, biological, chemical and physical principles with match sticks and rubber tube parts, to at least twenty other plain yet ingenious toys. Watch him make it all, right there at the talk! You can’t miss it.

The one I like the best is the slate he makes, using wool and velcro, for blind people. The second best toy in my opinion is the incredibly simple whistle made by cutting a straw. The crank generator made of trash is impressive too! What do you like to most? Let’s discuss in the comments below.

Every kid would love science this way.

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Build an Autonomous Toothbrush Robot in Minutes

By Anupum Pant

Background

If you are looking for a cool little science project, I think your search should end right here because today I’m sharing with you an awesome way to transform your toothbrush into an autonomous toothbrush robot. This one is just autonomous enough to move around on its own, hit obstacles, turn around and continue. But remember, since it is a fun project that can be completed within minutes (in under $5), you can’t expect a lot out of this basic bot.

Also, I did not invent this thing. I happened to stumble upon a video by Evil Mad Scientist on YouTube that taught me the basic idea of how this thing works. So, cheers to him. However, since my supplies were constrained, I felt a need to find some alternative methods to construct a similar bot. I’ve shared the original video and my own alternatives (in text) under it… You can skip reading the next two sub-headings and watch the video below them.

Here is what you’ll need:

  • A toothbrush (preferably, one with angled bristles)
  • A cellphone vibrator motor
  • Some double side tape
  • and a Button cell

Here is what you do:

Firstly, do not worry if you don’t have the exact materials mentioned above, I’ve suggested some alternative ideas after the video.

Stick on motorCute but unstable

  1. Grab the toothbrush and carefully cut off the handle, we’ll just need the head. Now, this part can be the most difficult because the plastic at the neck can be pretty tough sometimes. If you are not confident, take help from an elder.
  2. Use the double side tape to stick the motor on top of the head in a way that the rotating shaft of the motor doesn’t touch the bush.
  3. Connect the button cell to the terminals of the motor. If the whole bot starts vibrating with the motor, It’s done. Place it on the floor and watch moving…

[Video]

Alternatives

  • Suppose you don’t have a brush with angled bristles. You can just take any other toothbrush and keep it under your mattress for a day to get pressed. The straight bristles turn into angled bristles. I had to do this, so I know.
  • Now, if you don’t have a cellphone vibrator motor, you can use one of these common motors too. All you’ll have to do is stick a piece of clay or tape on the shaft to make a counter weight so the motor vibrates when it rotates. You don’t want it rotating smoothly here.
  • To make the bot turn away better from obstacles, I stuck 3 toothpicks on top of the brush in a way that one of them was sticking out in the front and the other two were pointing out from the sides to form wing like structures.

It hardly takes any effort to try it out and then you’ll have your own bot moving around on the floor of your house. It feels great to watch it move like that! If you can, try making a huge variant. Use a bigger brush, pencil batteries and a bigger motor.

[See this for more details]

The Simple Difference Between Venom and Poison

By Anupum Pant

Venom and Poison are both toxic substances. Still, some animals are called venomous and others are poisonous. The only difference between being called poisonous or venomous is in the way these animals deliver the harmful substance.

Venom: When animals like snakes use their sharp fangs to bite into the flesh and let the toxic substance move into the body of their prey,  through the punctured skin, they are called venomous animals. To deliver venom an animal has to use tools like fangs or stingers.

Poison: Poison is something that can get inhaled, ingested or seeped into the skin directly. For example, if you accidentally touch a brightly colored poison dart frog, you will transfer the toxins it secretes from its skin, to your own skin. And then the poison will seep into your blood stream.

The same substance can be Venom + Poison: Some substances can be both venom and poison depending on how an animal delivers it. eg: Tetrodotoxin – an extremely toxic substance – is found in both puffer fish and in a blue ringed octopus. It is poisonous in a puffer fish and venomous in a blue ringed octopus.

The same animal can be both venomous and poisonous: One example for this is the pelagic sea snake – a snake related to cobra. It has a poisonous flesh and its bite can also deliver a venom.

Non-poisonous Venom: There are some venoms which can be ingested without experiencing any ill effects because it was not designed to survive the acids present in the stomach. These types of venoms won’t get a chance to get absorbed in the blood stream. Before they try that, they might get digested. This is the reason a snake doesn’t die when it swallows its own venom. That doesn’t mean you can try drinking snake venom.

So you can happily go around telling everybody that most snakes aren’t poisonous, because most snakes use fangs to deliver venom, not poison. [Video]

 

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