Screaming Coin and a Singing Spoon

By Anupum Pant

Dry ice, or Cardice – as British researchers call it, is a solid form of carbon dioxide. When carbon dioxide is cooled below temperatures of -78.5 degrees centigrade, the gas gets directly frozen into a solid form. -78.5 degrees centigrade is extremely cold, and handling dry ice without proper protection can be very dangerous – could cause frostbite / burns. The point being, it’s extremely cold.

Since it’s too cold compared to something at room temperature, even everyday objects at room temperature can make it vaporize. A simple metal coin at room temperature would feel like a hot pan to dry ice. So, when a coin is shoved into a piece of dry ice, it creates a funny sound, just like water would, on a very hot pan; or, you could say the sound be very much like a hot metal ball being dropped into a cold bath of water (the temperature difference being much less in this case, of course).

This is how it works: The metal piece at room temperature vaporizes some amount of carbon dioxide from the piece of dry ice when it comes in contact. There’s a pressure difference (Bernoulli’s principle) associated with this process and the gas tries to escape. This makes the metal vibrate very fast, creating that funny sound. This is how it sounds…

Metals work best because they have a good thermal conductivity. For the sake of trying it out yourself, if you have a piece of dry ice lying unused, you could dip a spoon in hot water and make it touch the piece of dry ice. A slightly warmer spoon will probably give you a better effect. And then the spoon will be singing…

Turning Lead to Gold

By Anupum Pant

Hunt for a process to convert a brick of lead into gold was probably the most elusive quest during the olden times when alchemy was around. However, alchemists, who were mostly dismissed as pseudoscientific quacks, actually did some good ground work to make their dream of turning lead to gold into a reality.

And then came the 20th century, when transmutation of one element to another became fairly common. In fact nuclear reactors started working on the same principle. So, besides breaking of uranium atoms and combining of hydrogen atoms to form helium, did it actually become possible to transmute lead into gold using the same process?

Sure it did. Today it is totally possible to make lead (Atomic number 82) release 3 protons to turn into gold (Atomic number 79). Not just in theory, people have actually done it successfully in laboratories. For one, Glenn Seaborg is said to have done it in the year 1951.

To do this, you’d need a particle accelerator. And if you plan to use it as a get rich quick scheme, then you are in for a bad news. Transmuting lead to gold in a laboratory consumes massive amounts of energy, even if you have to do it in extremely minute volumes. So much that the price of doing it exceeds the price of gold by a very big amount. Also, only a very minute volume of gold comes out this way.

To make a single ounce of gold this, it would cost you one quadrillion dollars. You could just buy the same amount for $1300 instead.

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.

The Old Tale of a Boiling Frog

By Anupum Pant

Background

The Frog in a pot is a very popular anecdote and you probably know about it. Still, if you don’t, it is about a frog that rests easy in a pot of water that is warmed slowly. Frogs normally won’t go into boiling water. They’ll jump out and keep themselves away from very hot water. But, if placed in a tub of water at normal temperature that is being heated slowly, according to the anecdote, they don’t react and end up getting cooked in the boiling water.

The story is used as a metaphor to tell a cautionary point about life. The moral of the frog story goes something like this – Letting small and seemingly harmless wrongs slip, could kill (or be bad for you).  It basically tells you to not be complacent about minor changes that usually seem harmless, but add up to something big/bad.

The video proof?

Scientifically, a bizarre video (not for the faint hearted) on Youtube claims to proves the frog tale. The guy in the video initially tries to put a frog in a pot full of boiling water. Of course it resists, and doesn’t go in. Later, when the frog is put into a pot full of water at normal temperature and is warmed gradually, the frog never tries to leave. It gets cooked in the boiling water. Just like the tale suggests.

Everything looks very convincing about the video experiment. Little details like placing the frog on a piece of insulator so that it doesn’t feel direct heat through the metal base, are also taken care of in the video. Also, the narrator sounds so convincing with all the science facts referring to how cold blooded animals react to temperature. They indeed do! I totally fell for it. Watch it below…

The video cuts in between and the water which was put on flame before starts boiling suddenly after the cut. Or brains tend to skip video cuts. In the boiling water is something that looks like a dead/cooked frog. If you watched it till the end, the video shows you that the dead frog wasn’t a real one. No frogs were harmed in the making of the video. Good.

But, that completely nullifies the point this experiment tries to make. A fake rubber frog being cooked in boiling water doesn’t scientifically prove the tale.

The Science

Unlike us, who maintain a constant body temperature, the frog being a cold blooded animal, its body will react to its surrounding temperature and will try to match it. But real scientific experiments have never been able to prove it. According to a very old experiment that was done in the 1800s, where water was heated at 0.002°C per second, the frog was found dead at the end of 2½ hours. Why do you think would the frog sit still for 2½ hours?

Modern scientists reject the old experiment which seems to prove it. You could place your trust in the words of a Harvard professor, Professor Douglas Melton. He says:

If you put a frog in boiling water, it won’t jump out. It will die. If you put it in cold water, it will jump before it gets hot—they don’t sit still for you.

Victor H. Hutchison, Professor Emeritus of Zoology at the University of Oklahoma also said, “The legend is entirely incorrect!”

Moral: don’t believe everything you see on the internet.

Hit like if you learnt something today.

Superfluid Helium is One Strange Liquid

By Anupum Pant

Helium can’t be frozen into a solid (at atmospheric pressure) – the very property which allows it to go from a simple liquid Helium state (warmer) at minus 269 degree C – where its boiling and evaporating quickly – to a much calmer Liquid Helium II stage (cooler).

Liquid Helium  II is obtained at a temperature lower than minus 269 degree C, at about minus 271 degree C – known as the Lambda point.

Liquid Helium II is a superfluid. Superfluid Helium has no viscosity. It behaves extraordinarily. As a summary of how extraordinary superfluid Helium is, here is a list of things it can do:

  • Superfluid Helium will leak out of solid ceramic containers which have extremely tiny pores that no other liquid can penetrate.
  • If it is taken in a container and the container is spun around the central axis, the superfluid will not spin.
  • Somehow if you manage to spin it, because it has no friction, it won’t stop.
  • It can climb walls of a container by forming an extremely thin film and defying gravity.
  • It can produce an eternal frictionless fountain.
  • It can conduct electricity better than some of the best metal conductors like Copper! It’s a big thing for a liquid to be able to do that.

Here is a summary video you can watch below.

But, I’d suggest watching the whole documentary here. It explains everything that superfluid helium can do in nice detail. Also, the researcher makes sure it is in a very simple language…

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]

Harmless Flour is an Incredibly Explosive Substance

By Anupum Pant

Background

The next time you are biting off from a bread, pizza, pancake or a doughnut, you should probably take a minute and pay a silent acknowledgement to the people who work in flour mills to bring flour to your homes. Yes, because flour, the seemingly harmless cooking ingredient can be an incredibly dangerous substance – It explodes.

Wait a minute. It isn’t a minor explosion I’m talking about. I’m talking about really big explosions. Read on to know more.

Burning Flour

Flour is almost completely starch (or carbohydrate). Since Carbohydrate is nothing but a large molecule which is essentially a couple of sugar molecules linked to each other, it burns like sugar. And everybody who has tried burning marshmallows on a candle knows how easily sugar catches fire. Agreed, carbohydrate isn’t as sweet, but it is just like its cousin sugar when it comes to flammability.

So, that is how flour can catch fire. But what is it that makes it bring down full-sized buildings?

Flour in air

Flour in your kitchen’s flour container can be a very boring thing. The fun starts when the tiny flour particles are suspended in air.

Flour particles suspended in air, or for that matter, almost anything suspended in air that can catch fire, is a dangerous thing. For example, look at one of the most hazardous situation you can have in a coal mine – There is coal dust around and accidentally there is a small sparkle around it. The whole place explodes like a bomb. This has resulted in some of the worst ever mining accidents in the history.

Such explosions happen because anything that is in powdered form and is suspended in air, has a far more surface area exposed to oxygen per unit weight, than normal lumps of the same substance. This is true for industrial stuff like powdered coal, sawdust, and magnesium. Besides that, mundane substances can explode too – like  grain, flour, sugar, powdered milk and pollen.

All it takes to cause a disaster is a suspended combustible powder and a little electric arc formed from electrostatic discharge, friction or even hot surfaces – A little spark is enough.

Such settings are common in flour mills, where there is flour floating around literally everywhere. This is what caused a giant explosion in a flour mill in Minnesota on May 2nd, 1878, killing 18 workers. But that was more than 100 years ago. Kitchens are relatively safe because you don’t have enough flour in the air to catch fire and produce great volumes of air that are enough to cause an explosion.

This happens even today. From the year 1994 to the year 2003 there have been 115 such reported explosions in food processing industries in the US.

[Source 1] [Source 2] [Source 3]

Experiment

The following is a simple experiment you can do at home (obviously with adult supervision) to understand the explosive nature of a harmless cooking ingredient. [Video]

What you need: Safety glasses, Tin can (with lid), Candle, Matches, a long Straw and fine white flour

  • Take a tin can, one with a relatively tighter lid. Make a hole at the lowest point in the side wall (just enough to fit in a straw).
  • Open it up and put in a handful of flour inside it. Now is the time to put on your safety glasses.
  • Now, burn a candle and carefully place it inside the can.
  • Close the lid, insert the straw into the hole. Now blow at the base of the can, in a way that flour stirs up inside without extinguishing the candle.
  • Watch the lid pop up 10 feet into the air.

Lucky Worms Survived The Space Shuttle Columbia Disaster

By Anupum Pant

February 1, 2003 was a sad day for science. Space shuttle Columbia, during re-entry, due to a broken piece of insulation, got completely disintegrated. With the shuttle, died all the 7 astronauts who were aboard. [Remembering Columbia]

Scientists had lost hope on all of the 80 experiments that were on board. Only several days later while sifting through the wreckage they found something interesting – at least not all was lost. A live group of lucky worms (roundworms) was successfully salvaged from the wreckage. Yes, odd, but true.

Why were there worms in the shuttle?

The space shuttle Columbia was a research flight and contained 80 experiments on board. The group of live worms, sealed in a metal container which was ensconced in a safe locker, was a part of one of those 80 experiments.

Although the particular gene experiment that had to be conducted with fresh-worms-from-space was lost because they had entered Earth several days back, the worms still proved useful for other science experiments.

From these worms scientists learned a great deal about what micro-gravity could do to animals – Like weakening of muscles and manifestation of diabetic symptoms. When in space, these are the similar things that happen to humans as well.

How did they not get killed?

Firstly, they were in a strong metal container that was nicely protected by a second layer – a reinforced locker meant to really protect things.

Since the shuttle was coming in at a speed more than 2 times the speed of sound, the locker must have hit the ground pretty hard, right? No, till the time it reached the surface, the drag slowed it down. So, the worms basically experienced just a harder-than-normal landing.

What are they doing now?

Well, as round worms don’t really live longer than 2 years usually, they must have died long back. But their descendants have been stored safely in a genetic center – lucky worms indeed. Some of these descendants were lucky enough to be sent to space during 2011 in the shuttle Endeavour.

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Hot Ice

By Anupum Pant

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For years we’ve been subconsciously conditioned to think of something cool when the word ‘ice’ is heard. But, does ice always has to be cool? How much more interesting, than water-ice, can ice be?

What is it?

The name: Hot ice isn’t solidified water, it isn’t anything even close to water. Neither is hot ice, hot. It is just a common name for Sodium Acetate Trihydrate. At room temperature, this substance looks like ice crystals and if heated, it starts turning into a transparent liquid. Since, the ice like crystals are formed at a relatively hotter temperature than water-ice, it is called hot ice.

Everything freezes. While metals ‘freeze’ at extremely high temperatures and carbon dioxide freezes at extremely low temperature, Sodium acetate freezes at 54 degrees centigrade. But, that is hardly anything interesting about it. There is more.

Touch water and turn it to ice

Think about water: Cooling water, beyond its freezing point without it getting solidified, can be done and it is called ‘super-cooling‘. This can be done by not letting water (distilled water) find any ‘nucleation points’ or simply by using an extremely clean tray to freeze it. Now, water remains in a liquid state despite being cooled under 0 degree centigrade. At such a state, if water is disturbed, say using your finger, a chain reaction starts and the water freezes almost instantly. But, doing it is tough.

Making hot ice at home – The same thing that happens with super-cooled water, can happen with sodium acetate. Touch the liquid sodium acetate and it magically turns to ice, it is indeed a fascinating process to watch (watch in the video below). And can be done fairly easily. Moreover, you are not at a danger of getting poisoned in any way. This is the reason it is used to make hot ice. It can be made at home using vinegar, baking soda and a steel vessel.

Prince Rupert’s Drop – Exploding Glass

By Anupum Pant

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What is it?

At first, a Prince Rupert’s Drop is an interesting yet harmless looking drop of glass with a long tail. It looks like a tadpole: [image]

It is no different from an annoyed person who refuses to let out his resentment – A slightest something might make him explode suddenly, but it isn’t easy to make him let it out. Confused? Read on…

Now, think of a glass drop that has immense amounts of potential energy stored inside it – It explodes (actually implodes) when the tail is disturbed, but it is impossible to hit it hard with a hammer and break it.

How?

A Prince Rupert’s Drop is formed when a drop of molten glass is suddenly dropped into a water bath. This quick cooling, solidifies the surface fast, while the inner part remains molten. Now, glass formed on the surface, being a poor conductor of heat doesn’t allow the inner part to cool quickly. When the inner part starts cooling, it tries to shrink and pulls the surface towards it. As a result, great amount of potential energy gets stored inside, in the form of stresses (stresses are seen using a polarized filter). This stored energy gets released when the tail is disturbed – It explodes into very tiny pieces of glass.

Toughened glass – a stronger variety of glass used in several places – also uses a similar technique to make strengthened glass.

On Wikipedia, a user asked about the possibility of utilizing the energy released from this explosion, being used to fire a bullet from a barrel. An interesting possibility, I must say.

The Name

Prince Rupert of Rhine did not discover the drops, but played a role in bringing them to Britain. He gave them to King Charles II, who in turn delivered them to the Royal Society for scientific study. Prince Rupert’s Drop was a widely known phenomenon among the educated during the 17th century – far more than now.

Watch it being explained better

Probably the best demonstration of this glass drop exploding is right here on the internet. Couple of months back, a YouTuber, Destin (Channel: SmarterEveryDay) posted a video demonstrating the physics behind it. He recorded  the progression of the explosive fracture using a hi-speed camera (at more than 100,000 frames per second) and calculated the speed of the fracture travelling through its tail (~ 1.5 miles per second). I’ve attached it below for you to watch.

Longest Continuously Running Experiment – 83 Years and Counting

By Anupum Pant

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An experiment so slow that a professor overseeing it, died without having seen the results for half a century! The Pitch Drop experiment, started by Professor Thomas Parnell of the University of Queensland in the year 1930, is the probably slowest science experiment and also holds the Guinness World Record for the world’s longest continuously running experiment ever.

What is the experiment?

It is an experiment designed to measure the flow of a solid looking piece (image) which is actually an extremely viscous liquid (actually a Viscoelastic Polymer) with a viscosity of approximately 230 billion times that of water. The name used for this class of extremely viscous liquids is, Pitch – Bitumen, Asphalt, Resin and Rosin are a few examples (not Glass). These things are so viscous that you can strike them with a hammer and see them shatter into sharp flakes (like glass), but it flows. The experiment is explained in detail, in the first few minutes of this radio show attached below. (the second half is pretty interesting too, but that is for some other day)

Other unbelievable materials previously covered in this series – Aerogels and Superhydrophobic surfaces.

Side note: The overseer of this experiment, Prof. John Mainstone actually lived through the drops of pitch falling three times, but unfortunately missed watching it happen every time (for 3 times in 50 years). In all, 8 drops have fallen since 1930.

  1. 1979 – He missed it because he wasn’t in the laboratory for the weekend.
  2. 1988 – Missed it because he went out for a tea break.
  3. 2000 – A camera was installed as a precautionary measure, the equipment malfunctioned; missed again!

He recently died waiting to see it in action. Since then, three web cameras have been installed as a fool proof measure to record the extremely rare event. You can watch it happening online here, although you might have to wait for several years to see it happening. (To confirm the live stream, look at that clock in in it and confirm with time here). There is also a time-lapse from 28th April 2012 – 10th April 2013 compressed into a 10-second-long video of the drop forming, embedded below.

A parallel experiment running at Trinity College, Dublin also wasn’t able to capture the rare scientific event on camera in spite of several drops falling since the commissioning of the experiment (1944). Finally, after 70 years of patient wait, on July 11, 2013 it was recorded on camera.