Rapider than Rapids

After second thoughts, is an afterthought: this also means boats and other river craft don’t require to be powered by engines, sails, paddles, rowers etc going downstream and only need it going upstream.

E4

Consider a mountain stream. It flows. It flows because the place where it originally started from as a geyser, spout, fountain, lake, spring, headwater or whatever the heck else, is located even higher up in the mountain somewhere, and so, obviously, acted on by gravity, that out-gushed stuff starts flowing down — as opposed to upwards. Clear so far, right? Now we come to where the stream has become a big fat river and is flowing more languid and lazy but it’s still flowing, otherwise it’s not going to get anywhere in a hurry. Simple again, isn’t it?

Well, what I am coming to is that if it’s flowing then it’s going from a higher place to a lower one, which must mean that the surface of any river is actually a slope. And things which are put on a slope — for instance, a ball or a car — tend to roll downwards. If you still have no questions till now because everything I’m saying is lucid up to here, then I have one. Can something roll down the slope of a river? In other words, can a free-floating object in a river float with a velocity that is greater than that of the river? It should, no? If not, why?

And here, after second thoughts, is an afterthought: this also means boats and other river craft don’t require to be powered by engines, sails, paddles, rowers etc going downstream and only need it going upstream.

DEAR MS

(The problem was: “How can the insides of an egg be got out without breaking the shell?” — MS)

Eggsactly-That-Dept:

First, wash the egg with soap and water. Take a thick pin and push it gently into the egg on the long end. Make a hole on the other end of the egg. Leave one hole very small and make the other a little larger. Take the needle and put it into the hole and break the yolk. Blow hard into the smaller hole with your mouth to get the egg to come out of the larger hole and into a bowl. Once the whole egg has been blown out of the shell, gently wash the shell in warm soapy water.

•Narayana Murty Karri, k_n_murty@yahoo.com

(However, nobody got the first part of the question which was how to get an egg inside a bottle with its shell intact. Answer: immerse it in vinegar till the shell becomes soft and then use the same method as for getting a hard-boiled egg inside the bottle without its shell. Meanwhile, the other problem was: “Although all solid stuff feels solid, it’s not. Meaning, matter is comprised chiefly of nothing. So why don’t we fall through the floor?” — MS)

Matter-Of-Falling-Dept:

Adhesive and cohesive forces hold molecules together to form solids; so do chemical bonds. Think of it as why we don’t fall through a mesh when we stand on it. Though it is full of holes, it still supports us. Solids are 3D meshed at a microscopic scale.

•Dr Shyam, orthoshyam@gmail.com

All solid stuff comprises atoms that further form molecules of matter, which are held together making strong bonds of complex chemical structures. These molecules also generate electromagnetic forces to form an electrostatic field, building up a strong force field preventing matter from falling through. Thus, we do not fall through the floor.

•Shashi Shekher Thakur, shashishekher@yahoo.com

The basic force preventing you from falling through your shoes 
and the floor or the ground you stand on is the electrical repulsion between the atoms in each set of adjacent surfaces that are in contact with one another.

•Alan D’Souza, iamaland@gmail.com

ENDGAME(S)

1. If you are a swimmer then you know that you can see much better underwater if you wear goggles. Why?

2. If you try to pull a reel of thread that’s rolled under a piece of furniture by pulling the thread horizontally the reel rolls out easily. But try pulling the thread at an angle and the reel rolls even deeper under the furniture. Again, why?

(To get in touch with Mukul, mail him at mukul.mindsport@gmail.com)

• Mindsport