The Messier Catalogue

By Anupum Pant

This might be a prevalent piece of information but like so many other very common things I do not know about, the Messier catalogue, I found, was just one of them. Ignore this if you know what it is…

I realized not knowing about the Messier catalogue, when a friend of mine asked me what the M with a number beside it signify in his Google sky app. We some how collectively chose to blindly predict that this was the way stars are named, with no knowledge whatsoever on the fact why only M was used.


Boy, we were wrong! Of course, M was used because of the “Messier catalogue”.  But it wasn’t for stars.

Charles Messier was a French astronomer who had a decided on a mission for his life. He was to search and find as many comets he could, in his lifetime. He went on to find 15 of them – quite extraordinary for a single man to have done that.

While doing this search for comets Messier, to keep the comets separate from other cloudy objects he discovered, he started keeping a journal of non-comet objects. This came to be known as the Messier catalogue of deep sky objects.

As time progressed, objects were added one by one to the list. Their names on this catalogue start with the letter M – denoting “Messier  objects” (not stars, but nebulae, star clusters and galaxies.). There are a total of 110 objects in this catalogue and is a nice thing for amateur astronomers to do the Messier marathon. This involves watching all of the objects at night spotting the sun rises.

The last object, M110 was added by Kenneth Glyn Jones in the year 1967.

All of these objects have other names too. One other name is the one that comes from the New General Catalogue (NGC). And hence the names are like NGC 1952 for M1.

More information about each one of the 110 objects can be found here [Link]


A Check Valve for Light

By Anupum Pant

Here’s a cool effect you can achieve with just light, olive oil and a few turns of copper wire (or really strong magnets with a larger section of the magnetic field where the magnetic field lines are parallel). This is called the Faraday effect and the physics of it is complicated to be explained on a blog. Not that I know how it exactly works, but it still is cool to just watch a stream of light get influenced by nothing but just a strong magnet!

One interesting application of this effect is faraday rotator, or basically check valve for light – that is to say, a device through which light passes in one direction and not in the other. So, it is transparent if you look at it from one side and opaque from the other side. The video explains this too…

Faraday rotation is an example of non-reciprocal optical propagation. Unlike what happens in an optically active medium such as a sugar solution, reflecting a polarized beam back through the same Faraday medium does not undo the polarization change the beam underwent in its forward pass through the medium. This allows Faraday rotators to be used to construct devices such as optical isolators to prevent undesired back propagation of light from disrupting or damaging an optical system.

Pneumatic Mail Systems

By Anupum Pant

Inherently, the telegraph system had a short coming. Messages had to be transcribed into text and the then the messages ultimately had to be delivered by hand. And like any form of communication, a time had come for telegraph too. It was no longer fast enough.

pneumatic mail system

Then in big cities like London, Boston, New York City, Philadelphia, Chicago, and Saint Louis a new system of sending across messages started to develop, somewhere in the 1890s. This was the pneumatic tube mail.

The system consisted a network of several miles of subterranean pipelines which were big enough to carry a cylindrical box  full of physical messages across the city. The canisters could travel at about 35 miles per hour with the help of compressed air. It was fast. But then it was an expensive way of communication too.

Nevertheless, it had become a full blown emergency system to carry mail in the aforementioned large cities. This sounded like medivial sci-fi or something taken off a cartoon series. I had no idea these things were real, until today.

In fact, the system was pretty successful. It was used in New York till even the 50s. In Paris the system was used until the 80s!

For further reading – [Source 1] [Source 2]

Even today, much advanced cousins of this system are being used in a wide range of workplaces like hospitals, supermarkets and banks.

Hospital installations are not just pipes from A to B, but networks with junctions and computer-controlled switches. Some are vast: Stanford Hospital in California has 124 stations…

The major advantage of using these in a hospital for instance, is that the canisters, besides just physical letters, can also carry various other objects like blood samples,  specimens, medicines etc. Following is a video explaining the Stanford hospital’s pneumatic mail system…

Thanks to the relatively new developments in extreme sports videography, we can have a first person view of these canisters while they are travelling through one of these tubes.

Little Deep Beauties of Nature – Butterflies

By Anupum Pant

If you have ever handled a butterfly, you must have noticed that the wings of a butterfly leave a kind of dust on your fingers. If you look closely, using a scanning electron microscope of course, you’ll find that these dust like things are in fact scales! Butterfly has scales on in wings. Whatever purpose it serves to the butterfly.

The name Lepidoptera means “scale wing” in Greek.

The scales, so tiny themselves, have much tinier grooves on them. The grooves are so evenly spaced that they match the wavelength of a particular colour of light and that is what gives them their distinctive colour. May be some of it comes from the pigment too, but most of the colour comes only from the grooves, the topology of it. The colour comes from the nano-structure on the surface of a tiny tiny scale. Amazing!

We indeed have a lot to learn from the world around us.

This is clear when you fill the grooves using a liquid like propanol. The colour disappears as the grooves are filled with the liquid. Once the liquid evaporates, the colours come back to life.

These colours that come due to the topology of the scales serve various purposes like camouflage, warning, attracting mates, absorbing heat by looking darker and deceiving predators.

Paper Armour was Real

By Anupum Pant

It has been said that several hundreds of years ago, during the 600 BC, the Chinese had developed a method to construct a battle armour using just paper. Sounds like an implausible myth. But turns out, after a good amount of testing by mythbusters, it can be said that paper armour probably was real.

By folding paper multiple times, and by layering it with shellac or resin like it used to be done in the old days, or even without any kind of resin in between, paper becomes considerably strong and can stop attacks from arrows, stabs etc, just like an armour is supposed to do. In fact, an armour made of paper is much lighter than its steel counterpart and would have added agility to the warrior’s movements. So, technically it outperforms a steel armour.

paper armour


Image source: PDF

However, when a paper armour gets wet, like we all know, it becomes heavy. It actually becomes heavier than the steel armour. So, it wouldn’t have been a good choice for the Chinese if the battle was being fought on a rainy day, or if a river had to be crossed.

The paper armour made by the mythbusters team was made up of small fragments of folded paper, each of which were about half an inch thick. While just 1mm thick steel did the trick.

The paper did as well as steel in the sword and arrow tests, failing only the blunt-force test, so the team built a full suit of paper armor to match against a period-accurate steel counterpart. – [Mythbusters wikia]