Cosmic Ray Detector at Home

By Anupum Pant

Cosmic rays are a very interesting form of radiation. They are a stream of extremely high energy particles, travelling at almost the speed of light, originating from very high energy events in our universe. It is believed that supernovae are a major source of cosmic rays. However, a lot about these particles is still a mystery.

An incredible three million of these particles, each with energy as much as a fast baseball, go through you every day. And yet, we are never aware of something like that happening. The earth magnetic field protects us from the full brunt of these rays, still a significant number of them are able to pass.

Another interesting thing about them is that when they strike the earth’s atmosphere, they form particles called pions which decay into muons. Muons have a very short lifespan. They don’t exist for more than a few micro seconds. Which means they shouldn’t be able to travel more than a few hundred meters.

Yet millions of them, travel great distances, and go through each of our bodies everyday. That is because, since they travel at almost the speed of light, relativistic effects come into play. Time is slowed down for them. So, from our frame of reference they are able to exist for a far longer time and reach us.

They are far too small to be seen or noticed. But did you know, the foot prints of these particles raining through your body can actually be seen? In fact, they can be seen using a simple $30 spark chamber constructed at home. See the video below.

[Read More]

Rivers That Meet But Do Not Mix

By Anupum Pant

Manaus is the capital city of the state of Amazonas in northern Brazil. The city is situated at about a 10 kilometre distance from the confluence of the Negro and Solimões rivers – two big tributaries of the Amazon river. While these are two names which you must haven’t probably heard of, the place where they meet is a very interesting place.

The first river, Rio Solimões is a water body full of sediments that wash down with it from the Andes mountains. Thanks to the sand, mud and silt that comes washing with it, the river looks muddy, the colour is light brown, nearly. The locals call it the white river.

On the other hand, we have the Negro river (or Rio Negro). It has significantly darker coloured water due to the presence of humic acid from incomplete breakdown of phenol-containing vegetation from sandy clearings. Although the locals call it the black river, it isn’t exactly black. The colour is very similar to a black tea concoction. However, the colour of Rio Negro is very different from Rio Solimões. Here’s how they look from up above.

encontro-das-aguas-em-manaus-9 solimoes and negro meeting

At the place where they meet, the rivers don’t mix. They leave a fairly clear boundary and flow side by side without mixing for about six kilometres. That happens because of the big difference in their flow speed, density and temperature.

While the river Solimões is a fast flowing (6 km per hour), high density (due to the sediments) and cooler river, the other river flows much slower (one third of the speed of Solimões river), is warmer and is less dense (because it is much cleaner). These differences cause the rivers to meet and not mix. Much later, about 6 kilometres later, these differences attain equilibrium and the rivers merge into the main Amazon river.

Ice Circles

By Anupum Pant

Perfect circles of ice have been seen spinning on top of water bodies for quite some time. They aren’t perfectly round most times. Recently, in the month of November last year, a huge 17 meter spinning ice disk was spotted on the river Sheyenne in North Dakota.

Several such ice disks have also been seen in the past in Canada, England and Sweden. Similar ice swirls were also seen in the Charles river, Boston. Some times they are huge, other times you see a number of tiny clusters of such ice swirls.

As always, even ice circles aren’t the work of aliens or government spies. It is completely a natural phenomena which occurs when slowly moving water moves past an obstacle creating a slow moving eddy. In due time, and due to very low temperatures, ice circles form small and keep growing as rings of frozen water on the surface of the water body keeps adding to their diameters. Here’s a video of one such big, and almost perfect, ice circle which was spotted in Rattray Marsh, Canada.

Mathematician Died on The Predicted Date

By Anupum Pant

Abraham de Moivre was a famous French mathematician who’s known even today for his  de Moivre’s formula. Besides that he’s also known for his work in  normal distribution and probability theory.

Moivre’s another area of interest involved making mortality tables. He spent a considerable amount of time connecting death with numbers and was said to have formulated a theory that could predict the day on which a person would die.

When he was 87 years old he noticed a slight change in his sleeping duration. He found that he had started sleeping for 15 minutes more than his usual duration. Each night he was sleeping 15 minutes longer. Putting the math together, he calculated that his sleeping time would add up to 24 hours on November 27th 1754. According to him, when that would happen he would never wake up again. And that is what happened.

De moivre died on November 27, 1754!

Actually, since he had predicted this, out of stubbornness and an obdurate desire to keep up his name as a great statistician, he voluntarily tried everyday to keep up with this 15 minute increase in the sleeping duration everyday. And the day when his total sleep duration added up to 24 hours, he did die. But the official cause of his death was Somnolence (or “sleepiness”).

If luck (or bad luck, if you may call it that) hadn’t favoured him, he would have slept for 24 hours and 15 minutes the other day. In reality, it was his stubbornness and probably sheer luck which put him to an eternal sleep, not math.

[Read more]

The IKEA Effect

By Anupum Pant

Believe it or not, the liking you have for something is not objectively based on just what the thing is. A great part of it comes from the amount of effort you put in it. The more effort you put in, the more you like something.

To test this out, scientists gave a group of people one sheet each, with instructions on it, teaching them how to fold an origami crane. The people followed instructions well, and did the best they could. Of course, since these people hardly had any experience with origami, their paper cranes didn’t come out too well.

The researchers then showed these cranes to a few independent evaluators and asked them how much they would pay for one of these poorly made origami crane. Evaluator obviously weren’t very interested in buying them and gave the origami cranes a low rating. However, the people who had made these cranes, on an average, rated their work much higher than what the evaluators had rated it. Also, the makers said they’d have paid nice money to buy that poorly made crane, which according to the makers was sufficiently good. [Link to the study]

Ikea is a company that sells furniture parts which buyers themselves have to assemble. Trust me, the assembly is not very easy (of course). Moreover, the instructions they supply with any piece of furniture says nothing in words. There are only illustrations of funny cartoon men putting the furniture together. You sure are able to put together the piece of furniture most times, but there are people I know who after having assembled a bed for hours get frustrated.

But then, in the end comes a strange kind of satisfaction, or a cognitive bias if you’d say, which makes the buyers value their furniture disproportionately more than what they’d have valued the same furniture assembled by someone else (or even a professional maybe).

This is called the IKEA effect.

[Read more]

Estimating the Radius of Earth at the Beach

By Anupum Pant

For centuries we’ve known that the surface of earth is curved. That means even after the sun sets on land, you could see a second sunset by somehow quickly transporting to a higher place.

Take for example the Burj Khalifa, the tallest object humans have ever constructed. It is so tall that you could watch the sunset at the base of it, at some point in time, and the sun would set about two to three minutes later for someone living on the top floor of the building. So, in theory you could see the sunset once at the base and somehow quickly go up to see a second sunset, on the same day.

But that’s not how much you need to move away from the ground to see the second sunset. You could simply lie down on a beach, watch the sun set once, and could quickly stand up once the last bit goes down, to see it go down again. In fact, if you carefully calculate the time difference between these 2 sunsets using a stopwatch, and take the length of your body into account, you could actually calculate (estimate) the radius of the earth.

All you need is a stopwatch and a trip to the beach to calculate the radius of the earth. This page explains how it’s done.

As seen on a Vsauce video at 4:52 [video]

The Most Strangest Lava on Earth

By Anupum Pant

Common basaltic magmas are red hot. Their temperatures can range anywhere from  1000 to 1200 degrees centigrade. Whereas much cooler ones like Andesitic magma and the coolest silicate magma, Rhyolitic magma, range from 800 to 1000 degrees and  650 to 800 degrees respectively. Sampling these viscous and sticky lavas can be a tough job.

But when it comes to the most strangest lava you could find on earth, things get really strange. Presently, Tanzania’s Ol Doinyo Lengai is the only volcano that erupts the strange natrocarbonatite lava – a type of igneous rock rich in carbonates such as calcite and dolomite.

This magma erupts at about 500 degrees celsius, which is almost half the temperature of those other common basalt lavas, and is cool enough to be sampled using a simple spoon. Still hot, but nothing like even the coolest silicate magmas. Unlike the other common lavas, this one is mostly black, turns white within 24 hours of eruption and is red at night. And has a viscosity lesser than that of water.

What makes it weird is its chemical composition, which unlike those common red lavas found everywhere else, is made up of calcium, sodium and carbon dioxide.

[Read more]

[Video] Measure Speed of Light Using Microwave

By Anupum Pant

Microwaves are a part of the electromagnetic spectrum. That means they travel at the speed of light. And since it’s known that most commercial microwaves use a frequency of 2450 MHz or can be found on the user manual of your microwave, the speed of light can be calculated using a very simple experiment. Involving just you, your microwave, a pizza and a ruler. You could even use chocolate or marshmallows to do this.

To find the speed of light, all you need to know the frequency and the wavelength because frequency multiplied by the wavelength of an electromagnetic wave gives you the velocity of light. The wavelength of a microwave being used to heat your pizza is fairly easy to calculate. Here’s how:

Make sure the rotation plate is stopped for this cook and then put in a large pizza on a flat microwavable dish. Start the microwave in the lowest power for a long time and keep looking inside. You’ll see that the cheese will start melting unevenly. At that moment it starts melting, switch it off and take the pizza out. Now measure the distance between the centres of molten cheese points. It usually comes to about 6 cm. Multiply it with two to get the wavelength and then finally use the frequency to find the speed of light.

Velocity = Frequency ´ Wavelength

This works because the microwave heats pizza the most, at places where there is a peak in the electromagnetic wave. All the points where the wave seems to be not moving are the places where the pizza heats the least. Turns out, the two nearest peaks (the highest point and the lowest point of the wave, where the cheese first melts) in any electromagnetic wave are separated by a distance of half the wavelength. It makes sense when you see the diagram below. This is the reason most microwaves use a rotating table to heat up your food evenly.

wavelength

How Much do Clouds Weigh?

By Anupum Pant

Oh clouds! Yes, the ones that seem like feather light cotton candies floating high up in the sky. They actually can contain huge amounts of water and can weigh as much as a jumbo jet!

Cumulus clouds which are typically a kilometre in width can contain about 500 tonnes of water, or could weigh as much as 100 elephants or 2,500 donkeys. And yet, it stays floating up there. How!?

Clouds have water distributed in form of innumerable tiny droplets across a huge space. For example, their usual density is equivalent to a teaspoon of water spread out in a volume of a small closet. Or about half gram per centimetre cube. They are so less dense that they are lighter than air. So they float up in air like a ball full of air would float on water.

Once the density of water starts increasing in a cloud, and the millions of tiny water particles start combining, they start forming relatively heavier droplets that ultimately fall out of the cloud. This comes down in the form of rain.

If you like that you’d probably also like raining frogs.

The Hot Chocolate Effect

By Anupum Pant

Have you ever tried tapping the bottom of a pan full of boiling soup? I do it all the time. And unless I hear that low hollow sound, I don’t consider the soup as cooked.

Tapping the bottom of a pan, with boiling soup in it, makes a significantly hollow sound. The frequency of sound that comes from such a tap seems to be much lower than what you’d actually hear if you tapped the bottom of a pan with same amount of cold still water. This effect has a name and is called the hot chocolate effect. Here is how it works.

Water is about 800 times denser than air. Also since air is 15,000 times more compressible than water, sound travels faster in water, than in air. Sound travelling faster in a medium (water in this case), creates a standing wave that has a higher frequency than a standing wave created in a column of some other medium which is less dense (like air).

Boiling liquid, or specifically boiling soup has a lot of air bubbles trapped in it. As a result, the average density of the liquid + air concoction decreases, and the compressibility becomes much higher. This makes the sound travel much slower in it.

So, the sound that comes from tapping the bottom of a container full of thick boiling liquid with a lot of air bubbles trapped in it makes that low-pitched sound. I find it extremely satisfying. Moreover, it is good to know that they  have a name for it!

How Fast Do Electrons Actually Move in a Wire?

By Anupum Pant

Unlike Alternating current which reverses polarity several times in a single second, direct current doesn’t do that. It is a unidirectional flow of charge. So, if you have an extremely long wire, with a switch in between, that connects a little battery in Dubai and a tiny bulb in San Francisco, how long do you think it would take the bulb to light up, when the switch is turned on?

It’d be almost instantaneous. “Almost” because it’d have a huge but finite speed. And by “it” I mean the speed at which the charge flows. Not the electrons.

The speed at which charge or electricity travels down a cable is actually the speed of the electromagnetic wave, not the movement of electrons.It is fast and depends on the dielectric constant of the material.

Electrons in an electric wire move very slowly. So slow, that it would be wise to measure their speeds in millimetres per hour. That is almost like honey flowing on a 2 degree incline. And yet, electricity is able to move across so fast because an electric wire is like a pipe filled with marbles (where marbles are electrons). When you push a marble from one end of the pipe, the marble at other end comes out, without the marble itself moving through the pipe.

Read more [Amasci]

Broccoli is Man Made

By Anupum Pant

Do you remember those massive, muscular Belgian cows? Those super cows were a result of patient selective breeding over many years. No steroids of genetic modifications were involved. Well, there’s something else very similar to how these cows came into existence, which you probably see everyday and yet never realize. Broccoli!

Several years back, probably 1000-2000 years ago, there was no broccoli. It came about in existence after some patient horticulturists selectively bred wild cabbage plants. Broccoli is actually a human innovation, which became popular in modern times only when, in the 16th century, farmers in Italy started growing it. It came to England only in 1720 and to America, much later, in the last century.

With every iteration of selection, cabbage plants with larger and tastier buds were selected and reproduced over and over again. Broccoli, to some extent, can actually be considered as a man-made food. In other words, it was invented / designed by man.

Man-made, yes. But not a genetically modified organism. So, your organic broccoli is as organic as anything else which is classified as organic.

via [PonderWeasel]

Making an Acoustic Propulsion System at Home

By Anupum Pant

Imagine you’ve got 2 PET bottles coupled to the ends of a stick and the centre of the stick is suspended using a piece of thread. Now, if you could spin this contraption, using the low frequencies from just a sub-woofer, you could give this phenomenon a fancy name – acoustic propulsion. Sounds like rocket science? It’s far from that…

Everyone must have tried making low whistles by blowing air into an empty coke bottle. The sound that comes out happens due to something called Helmholtz resonance. When you blow in air, the central column of air inside moves much faster than the air that is touching the inside of the bottle  (the air that surrounds the column of air which you blow in). This difference in velocities creates several vortexes inside the bottle, which make the air move inside in a periodic fashion. And a resonant sound frequency is generated.

I’d explain the fancy word – acoustic propulsion – like this:

In simple words, an empty coke bottle in this little sound experiment acts as a box which converts air you blow into sound. Think of it as an engine with a twist that uses heat to turn a crank. Heat being the air you blow, and the crank turning being the sound that comes out. Just that this engine also works the other way. Turn the crank and heat is generated from the other side.

Likewise, what if you put in the sound? Instead of blowing into the bottle, leave it suspended and make it vibrate with an external source of sound, a sub-woofer! If you get the right frequency, you’d generate a resonant condition inside the bottle, generate vortexes and air would come out of the bottle’s opening. This would propel the bottle further! The video below shows you how…

Why is Orange Juice + Toothpaste the Worst Idea

If you are one of those people who like to have orange juice in the morning just after they have brushed their teeth, you probably know how bad that tastes. Drinking orange juice after brushing your teeth brings about a very repulsive taste in the mouth. If you haven’t tried that, try it once. Trust me, toothpaste + orange tastes awful.

Water, fluoride, detergent and abrasives are the four major components of toothpaste. And the most common detergent (used to form foam) is called Sodium Lauryl Sulphate, or SLS. SLS has some strange effects on your taste receptors. It suppresses the receptors which help you taste sweet

Also, it destroys a compound called phospholipid – compounds meant to suppress the bitter taste. These are the two accepted reasons as to why drinking orange juice after brushing your teeth is probably a bad idea.

The Oxygen Stealing Material

By Anupum Pant

If you rely on and make your judgement on just the editorial titles being passed around on the internet, then you got to look more carefully. A few days back, when a few researchers from Denmark announced that they had developed a material, a tiny volume of which could store huge amounts of oxygen, the whole internet saw a headline floating around that said something like:

A new material, just a spoonful of which can suck up oxygen of the whole room.

That sounds like a material which every serial killer on the planet would  be waiting to get their hands on. However, the real story is quite different, from what the headlines make it look. Which is also not to say that the invention is any less remarkable.

Think about it like this – A single spoonful of this material (more like a bucket actually) sure has enough space to store the amount of oxygen that normally is available in a single room. But, unlike what headlines tell you, it can’t spontaneously pull all the oxygen from the whole room in a few seconds.

Since a tiny volume  of it can hold so much oxygen, this new material, made by tinkering of the structure of cobalt, will probably, in the near future, be a boon for patients who have to lug around heavy tanks of oxygen with them. Deep sea divers will benefit from it too, not serial killers. The video explains.