## Galileo’s Paradox

###### By Anupum Pant

Here’s an image of a contraption. It is basically a long stick hinged at one end and is free to move about the other. At the end of it rests a ball. Near the ball there’s also a cup fastened to the stick. The big stick is lifted up high and is temporarily supported by a small stick.

Now, what do you think would happen when the temporary support is removed? Normally, it would be very intuitive to think that the cup and the ball would fall at the same speed. In other words, nothing fascinating would happen. Both would fall and the ball would roll away…no?

However, something very unexpected happens when the support is removed. Something that, in a jiffy demonstrates some very important concepts of physics like centre of mass, torque and acceleration.

The big wooden stick (with the fastened cup) falls and it falls faster than the ball. Actually it falls and also rotates. As a result of the swing, the cup comes under the ball just before ball reaches it and the ball ends up inside it.

Under the influence of the same gravitational force, irrespective of the mass, the cup and the ball must have fallen at the same rate, as predicted by Galileo? What really happens? The video explains…

## Cutting a Round Cake on Scientific Principles

### Background

For years the phrase “cake cutting” has conjured up just one image in my brain – A triangular section of the cake. This way of cutting a cake is so normal that even the tools (especially the spatula) that are made for cake cutting are made in a way that’d work with best when you are making that traditional triangular cut. Turns out, this method of cutting a cake which we’ve all know for years is totally wrong.

### Why is it wrong?

It’s wrong mostly for mathematical loners. People who, on their birthday, have no one around to share the cake with, and cannot finish off the whole cake. For them and the ones who have to store the cake after cutting it, are extremely careful about how moist the edges remain when they next eat it, this right way to cut a cake might be of great importance.

The way we’ve always know is “wrong” because when you cut off, say a single section of the cake and decide to store the larger piece in the fridge, some internal part of the cake remains exposed and it dries off. So, the next time you cut off a piece near the area where you started, you’d get a freshly cut moist wall of cake on one side, and a repulsively hard dried up wall on the other. That, some think, is extremely unpleasant.

### What’s the Right way?

About 100 years back, a brilliant Polymmath (and a mathematician), Sir Francis Galton, faced a similar annoyance. So, instead of cursing others for having invented an absurdly inefficient way to cut a cake, he decided to develop his own. He ended up developing a very simple and efficient cut which helped him keep the cake wall relatively moist. Here’s how the cut works. (Cut along the dotted line)

Describing his new way of cutting cakes, he got an article published in the Nature magazine (dated December 20th, 1906). “Cutting a Round Cake on Scientific Principles

Alex Bellos from the Numberphiles describes it in a video below:

## A Bizarre Weight Loss Story – Year Without Food

### Background

What this grossly obese man did in the year 1965 is probably one of the most stupidest things you could emulate to lose weight. Doctors, and I would advice you totally against it. Yet, I felt that it’s good to know a stupid thing once in a while, in order to avoid it (maybe). Luckily, the man who did it, ended up fine and also lost several dozens of kilograms in the process. Here’s what happened…

### Story time

A man who weighed 207 kg decided to go on a fast to lose weight. His fast lasted for 382 days. For the whole 1 year and 17 days, this man ate nothing. He only consumed “non-energy-containing fluids”, multi-vitamin tablets and potassium tablets. It’s important to know that he whole thing was monitored closely. It’s probably the longest reported fast. (A much much longer claimed fast – which they say lasted more than 70 years – is probably fake and pretty interesting too)

By the end of his fast, the man had lost around 126 kg of weight. That’s about 61% of his initial body weight! For the whole time, his body had used up the stored fat to power him. It was incredibly lucky for him that he did not face any adverse conditions while he was doing this. A slightly gross thing to know is that, since he wasn’t eating anything, he felt a need to use the bathroom only once in 40-50 days.

### The Science of it

Normally if you don’t eat for a couple of hours, the human body is able to extract energy from the glucose in your bloodstream and liver. After about 8 hours, you no longer have any of the glucose left in your body.

Once the glucose is finished, the body starts burning a bunch off glucose molecules stuck together – known as glycogen, stored in muscles and liver. This source finishes off in about 2 days’ time. After that the body starts breaking down muscles. But that can be avoided by taking up a few defined exercise routines.

Next the body starts using up fat molecules into glycerol and free fatty acids. Everything in your body can run from this good source of energy. And that is how the fat gets lost. Surely, you don’t want to do that because you’ll end up sick, weak, depressed and cranky. You might even die if you try this.

[Source]

### Bonus

Here’s an account of a person, who recently tried fasting for 11 months. Below is an image of what the fast did to him. Yes, he’s the same person (with a gap of 11 months of course). It was clearly a very bad experience. [Link]