Problem with Facebook – On Facebook Everybody Loses

By Anupum Pant

I had to say this a couple of weeks back. But, now I think, I’ve gravely been irritated by Facebook to let it out. So here goes a post on how Facebook is repeatedly trying to make you confirm your own  pre-conceived notions and is basically making you an ignorant person everyday, is hurting page owners, and they are doing all of this to make short-term money for themselves. It is evil. That, is the problem with Facebook.

Almost every good thing you want to see is hidden from you on Facebook

Okay, let us start with my Facebook page. I know it is a small one, with just 446 likes (as of today). That said, I can tell you one thing for sure, I never forced any one of these people to like my page, nor have I ever advertised my page on Facebook to amass likes. All, or may be most of the people who like my page wished to clearly subscribe to my content and my views. Clearly, they wanted to be updated on the things I was posting. But Facebook tells me, that isn’t happening, unless I pay them the money.

Now take a minute to look at the screenshot below:

Facebook page insights
Look at the total reach.

See the first post in that list. Of all the 446 people who’ve subscribed to the page, this appeared on only 15 news feeds. Moreover, the chances are high that all of these 15 people must have not even scrolled down to see the loaded post. So, probably 10 of the 15 loads were just useless loads. 5 of them who actually saw the post, decided (probably subconsciously) to not engage – that is understandable. Even if all the 15 people did see this post, how is that fair? Continue reading Problem with Facebook – On Facebook Everybody Loses

Train Wheels are Not as Simple as They Seem

By Anupum Pant

I’m pretty sure not many of you know this about train wheels, neither did I.

Look at the picture and answer this: What do you think keeps a train moving on the track? or Which part of the wheel do you think it is that keeps the train from careening away from the track at turns?
Applying general logic, I thought that flanges at the end of the wheels  kept a train from going off rails at a turn. Turns out, I was wrong!

In fact, flanges at the end of the wheels are just a safety mechanism to keep the train on its track only if the main mechanism fails. And what is that main mechanism?

The problem with cornersTrain wheels are conical in shape. That means they have a varying diameter at different points of contact. Now, suppose the track turns right. The train’s left wheels now have to travel more than the right wheels because at the turn the track on the left is longer.

So how do the left wheels travels more than the right wheels without a differential?
Since the wheels are conical in shape, the whole wheel-set shifts a bit to the left, if the track curves right. Now the point of contact of the left wheel is at a larger diameter of the cone. While the smaller wheel Correction from the toptouches at a point where the diameter of the wheel is lesser. Therefore, if the left wheel now makes one circle it travels further than the right wheels and the train moves along the curve smoothly.

The whole beauty of this system is that the amount of shift of the wheel-set happens automatically, makes the train move on turns smoothly and keeps the train on track.

Look at how you can try this at home using 2 plastic cups and 2 similar pipes. [Experiment]

If I couldn’t explain it properly, probably the best physics teacher ever – Richard Feynman – will explain it to you better. [Video]

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Concrete Cloth – Makes Durable Shelters Within Hours

By Anupum Pant

Today we have something which civil engineers would be extremely proud of – A recent innovation in concrete technology that has an immense life-changing potential – The concrete cloth; certainly a splendid engineering marvel.

What is it?

It is material which feels like a very thick canvas and has a three-dimensional fiber matrix. This piece of thick cloth is impregnated with a specially formulated concrete mixture. Once it is completely wet with water, it hardens into a thin, strong, fire-resistant and water-proof material, within a few hours. Commercial variants either have a hydrophobic coating on the outer surface or a PVC lining from the inside to make it completely impermeable to water.

Concrete Cloth

Since it just a thick piece of canvas impregnated with concrete, it can be transported fairly easily and can be made into various shapes to be used for different applications. For instance, it can be used for rapidly deploying hardened concrete shelters for people in need. It works like this:

  1. You carry a huge concrete canvas balloon with you in a truck.
  2. Place it wherever you need the shelter to be deployed.
  3. Pump water into it.
  4. Quickly start inflating it using a pump.
  5. Pull it around using, say a truck.
  6. Wait for it to harden.

Advantages:

  • To erect a shelter with concrete canvas, it only takes a fraction of the time taken to construct a shelter using tradition building techniques.
  • Unlike cloth tents, this one is extremely durable and can last for about 10 years. Moreover, it protects the residents from any form of extreme weather outside (Thermally insulated).
  • Construction material is light enough to be transported by a small pickup truck.
  • Requires just 2 people and can be deployed to a ready state within 24 hours – Within these 24 hours it gains about 80% of its full strength.
  • Can be tailored as required with the help of staples, cuts and nails / screws. In fact cutting it before hardening is not much different from cutting a thick piece of cloth.
  • Does not burn and is water-proof.

[Read more]

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Fascinating Gear Videos + Moving Gear Fixed in Concrete

By Anupum Pant

Almost everything that has something spinning, probably has, one or a system of gears hidden inside it. Open up a CD drive, or anything that spins, and you’ll see. Mechanical engineers spend a good amount of time learning about traditional gear systems in their courses. I’ve compiled a few gear videos here, that are probably not covered in any educational institution’s syllabus. (please inform me in the comments section if you have them in your course)

1. Crazy shapes: While, It is popularly believed that gears have to be circular to work properly, it should be noted that gears can literally bear any shape and work fine, as long as they are designed well. In the following video we can see how carefully designed gears in square, oval, spiral, fish shapes, and any other out of the ordinary shapes, can be made to work together perfectly. [video]

Some other artistic wooden gear sculpture can be seen in the link here. Engineering meets art [Here]
Build at home: Turns out, with computers in every home these days, designing these gears isn’t rocket science. Enterprising engineers can use this fairly detailed 5-minute video tutorial to cut out weird gear shapes at home. The process of designing can be automated by using jerry’s script. [video]

2. Unpredictable moves – Gears can sometimes work together to provide a mechanical advantage in a system and can end up moving in a pretty unpredictable manner. The following video is a perfect example of how gear ratios can mess with the heads of non-engineers. The guy calls his machine – under the ruler faster than the ruler – watch it and you’ll understand why. [video]

It isn’t magic. If it still confuses you, here is a great post that explains a similar phenomenon that uses gears to build a “faster than wind cart (DDWFTW)“.

3. Reduction gear system with a fixed gear in the end: I wanted to keep this craziest reduction gear system for the end. It is the one that blew my mind. And the ones who think the number 1 and number 2 are ordinary systems they meet everyday in the lab, they need to check this one out.

This system designed by Arthur Ganson transcends engineering and moves into the realm of art. It consists of a motor that spins at 212 revs per minute. To the motor are attached twelve 50-1 reduction gears in series.

The most incredible part – the last gear in this series appears as if it is fixed, but it actually turns. It moves so slow, that it has been sealed into the wall using concrete. Even when the motor is turned on, it appears fixed with rest of the system moving continuously. It is estimated that if it wasn’t fixed, the gear would have taken 2 trillion years to make a complete revolution. In fact the third and the gears after that in this system don’t appear to be moving too.

Nuclear Powered Pacemakers for the Heart

By Anupum Pant

Heart and Pacemakers

Your heart is a complex device. It comes with its own sophisticated electrical system that controls the rate and rhythm of your heartbeats. The electrical system is responsible to make the heart contract and as a result pump blood into your body. It is required to keep a proper rate and rhythm. There is a whole lot to learn about how the human heart works. But that is for some other day. Or, you can read it here – [Link]

As years pass, like any other electrical system, even the heart is prone to electrical faults. Faulty signals can make the rhythmic beating, non-rhythmic. This can make life difficult for a person. Enter pacemaker…

Pacemakers are small devices that are placed in the chest. They use low energy pulses to maintain the rate and rhythm of your heartbeats by overcoming the faulty electrical signals. Sometimes Permanent pacemakers have to be used to control long-term heart problems. For this, they are required to run for a long time without replacement. Who’d want their chest dug every two months to replace the pacemaker battery?!

Nuclear powered

Nuclear batteries work due to a nonstop radioactive decay of certain elements. They can last for incredibly long times. Due to their extremely long lives and high densities they are used in space devices and other underwater systems; basically, in systems where replacement of batteries is not an option. So, scientists from the past thought – why not use them to power pacemakers too!

In the 1960s, scientists at the Los Alamos Scientific Laboratory in New Mexico began exploring the feasibility of being able to use nuclear power for pacemakers. The idea was to develop a penny sized battery that could be used with a pacemaker and could be implanted in a human body. It was made. And they decided to call it an atomic battery or Radioisotope battery or simply a nuclear battery.

Despite bearing the name “nuclear” battery, they were not really little nuclear reactors as they didn’t use chain reactions to produce energy. So, there was no danger of a meltdown. They were safe devices. No radiation related issues were ever reported.

The Problem

Agreed these batteries were costly and weighed a lot, but that was not the problem. The big problem was that they contained hazardous material which had to be recovered once a patient died. There were several instances when a person had died; the living relative had returned the nuclear battery, but the Nuclear Regulatory Commission never received it.

However, later in the year 1988 last of the nuclear batteries were used. Now they were being replaced with long lasting (~10 years) lithium batteries.

Even today Los Alamos National Laboratory has a fact sheet on their website that mentions what to do in case you find a nuclear battery.

The Underwater Optical Man-hole

By Anupum Pant

Agreed, sometimes, when you find yourself being interrogated in a room covered with one-way mirrors, you can’t see the people who are observing you; Instead, you see yourself in the mirrors. Otherwise, If you can see something, it seems normal to assume that the thing can see you too.

A trout’s window to the outside world is something similar to what a person in the interrogation room experiences. However, unlike the person, a fish can actually see things that are out of the water, but the view is very limited.

The Snell’s Window

When a fish looks up from water, it sees only a circular window of light, from under the water surface. Everything that lies outside of this circle is darker. This darker area of vision is replaced by the reflection of the sea/lake bed (where there is no source of light to illuminate it). This effect isn’t due to any limitations of a fish’s eye. In fact, even human divers see only a circle of light when they are under water. This circle is called the Snell’s Window or the optical man-hole.

Irrespective of the fish’s visual acuity, some physical properties of water and air get together and have a great effects on what a fish can see. It sees a circle with diameter calculated by the Snell’s equation.
In short, the window is about 2.3 times as wide as the fish’s depth. So, a fish can see more if it goes deeper. At a depth of 1 meter, it can clearly see things on a circle that is 2.3 m wide on the surface of water.

So, even if you can see a fish in water, it will be foolish to assume that the fish can see you too. Some times it can’t. It looks something like this from under water:

In Wikipedia’s words:

Snell’s window is a phenomenon by which an underwater viewer sees everything above the surface through a cone of light of width of about 96 degrees.

Why does it happen?

It happens due to a simple optical phenomenon called the total internal reflection.
The physics behind this phenomenon can be read here. [Read here]

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