Tag: object

First Man-made Object in Space – A Manhole Cover?

By Anupum Pant

Edit: The first man-made object to cross the boundary of space (100 km above the sea level, or the karman line) a Nazi German V2 rocket on October 3, 1942. – As mentioned by Scott and Adolf in the comments.

Background

Odd, I know. Teachers would say Sputnik was the first ever man-made object to orbit earth, but there is a slight possibility that Sputnik might not have been it – it could have been a humble manhole cover (not so humble, read on).

Back in the year 1956 (or summer of 1957, but definitely before the launch of Sputnik which happened on 4th October 1957), scientists at Los Alamos were learning to contain a nuclear explosion. To find out, they decided to do a much much larger version of the fire-cracker-in-a-can trick…
I’m not sure if they were doing it out of a desire to loft objects in space using a novel nuclear bomb propulsion, or it was something else, it sure was madness.

The mad experiment

In a 500 feet long and 4 feet wide vertical cylindrical tunnel, they put a nuclear bomb. The top of this tunnel was sealed using a 4 inch thick man hole cover (on steroids). The lid weighed about 2 tons! They were sure that even the 2 ton lid would blow off like feather due to the nuclear explosion. However, they weren’t sure on exactly how fast it’d travel up. To measure the speed, high-speed cameras were placed near the opening.

The bomb was detonated. Some say that the high speed cameras were only able to capture the image of the lid in a single frame. Which by the way could also contribute to an enormous error margin in the speed calculation. Nevertheless, the speed was of the lid at which it flew up in the air was calculated to be 41 miles per second – approximately 6 times the escape velocity! Never before had any man made objects moved at that speed inside the earth’s atmosphere. The lid went. It was never seen again. No one knows where it is now.

It’s highly likely that the lid was burned up and never reached Space. Or, may be it did reach some place and then dropped back. Again, must have got burnt during re-entry. Nothing can be said for sure.

Another thing that could have happened is that the lid went on and started orbiting the earth – highly unlikely, still. It’s probably still floating up there. And if things weren’t worse already, think of this – the first man-made object ever to orbit the earth was a manhole cover? Or, the fastest man-made object ever to travel inside the earth’s atmosphere was a manhole lid? Damn!

[Source 1] [Source 2]

Klein Bottle – A Bottle That Contains Itself

By Anupum Pant

To appreciate the beauty of mathematics and nature there is no escaping without learning about a Klein Bottle. A three-dimensional representation of a Klein bottle looks like this – [image]

There are number of phrases you can use to describe (not exhaustively) it. A few of them are as follows:

  • An object with no boundaries.
  • An object with no inside or outside.
  • One sided surface.
  • Non-orientable surface

Wikipedia describes it as:

The Klein bottle is a non-orientable surface; informally, it is a surface in which notions of left and right cannot be consistently defined.

Simplifying things: A Möbius strip is a simpler example of a non-orientable object. That means it has no inside or outside. Add another aspect – having no boundaries – to it, it gets more complex and you end up with a Klein bottle.
If you haven’t heard of Möbius strips, to understand such surfaces, you can make one for yourself now.

  1. Tear off a strip of paper.
  2. Hold it horizontally, straight with both of the short edges in your hands.
  3. Now, twist one of the edges by 180 degrees and join the two short edges. You’ll have something like this in your hands – [image]

Test the surface and edges: On this object you just created, move your finger along the surface. You’ll find that your finger comes  back to the same place eventually. There is no inside or outside for this object, there is just one surface.
The same thing happens with its edge (try moving your finger along the edge). Here is a Music box playing a Harry Potter theme continuous – forward, inverted, forward and so on – manner; Relevant video: [video]

Now spin it (the Möbius Strip) fast. You can NOT practically do it. I mean, spinning it like you spin a circle and get a sphere. There! You have a Klein bottle. It is better than a Möbius strip in a way that it (Klein Bottle) has no boundaries.

Klein bottles cannot actually exist in our three-dimensional worlds, the ones that look like them (Klein Bottles) are just 3D representations of a 4D object. Like a two-dimensional drawing of a 3D cube. These models are available for you to buy. Interestingly, in spite of having no inside or outside, they can be filled with a liquid. But, given the opposing force of air, they are pretty tough to fill. It is important to note that the 3D representation of a 4D Klein bottle has an intersection of material, this doesn’t happen in 4D. It is like the intersecting edges of a 3D cube in the 2D representation.

You’re thinking 3D? At MIT (and other places) 4D printing is already happening.

If you are having a tough time imagining this 4D object, the following 4D animation might help (or leave you perplexed) – [video]
[Extra reading for math geeks] as if they already didn’t know about Klein bottles.

Gomboc – An Object That Never Falls

By Anupum Pant

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There’d be hardly anyone among us who hasn’t played with a roly-poly toy during their childhoods. If you know it by some other name, you could think of it as a toy that never falls, no matter how hard you hit it, and sells in variants which look like this. That isn’t exactly what a Gomboc is, but you get an idea about what it does – It does not fall. For more, read on.

What is a Gomboc?

A Gomboc (Gömböc) is a mathematical 3-D shape which has only one position in which it can stand and is made up of a single material  of uniform density. If you try to make it stand in some other way, or try to knock it down, it moves back to that single stable position, gradually. When placed on its side, it starts rocking magically, gains momentum, straightens itself and gradually comes to rest in that single position. Here is a video of a Gomboc doing its thing.

A Gomboc is an object surrounded by a number of complex curves, it takes an immense amount of accuracy to get the surfaces right. An accuracy of  the orders of around 1/10th of a human hair’s thickness is required for it to work properly. For better, people have started 3D printing these complex shapes.

The world’s largest Gomboc was displayed in China in the year 2010 which measured around 3 meters in all directions.

Terrestrial tortoises, who use a similarly shaped shell to get on their feet when turned upside down, were using it long before humans had found a way to construct it. The first time we made it, was in the year 2006. Evolution got there first!

How is it different than a Roly-Poly toy?
A roly-poly toy usually has an internal counter weight made up of a heavier material. But a Gomboc is made up of a single material.

Uses: Use it as a paper weight or to gift it to your friend who is a math geek. Tortoises use it to save their own lives.

Where can I buy one?
You can get one for yourself from an official website of the inventors – Here.