Curiosities: Why do we feel that The Moon is following us when we move?

May 29, 2017

By Eddy Montilla.

When I was a child, rather than playing with gadgets individually as children do today, my friends and I used to play together or with nature. I remember that we used to race against The Moon and we, of course, always won. Years later, this situation made me think about this curiosity: Why is The Moon behind us when we are walking? Why is The Moon following you when you are seeing it from a moving vehicle?

To start with, the truth is that The Moon is not “following you”. This wrong perception comes from a fact that can be explained with one word: Distance.

When you are moving, there are many objects close to you and inside your visual angle. These objects are used as parameters to judge distance and that’s why you are well aware that you walk past a particular object and it is then behind you. Besides, when an object is near you, it can be seen from different angles, which lets you know its position clearly. This situation does not happen with The Moon for two reasons: First, The Moon is an average of 238,855 miles (384,400 km) away from you without other things to be compared with it for size reasons and second, you cannot see it from different angles because of distance. These two factors give us the wrong impression that The Moon remains in one spot and begins to move right along with us when we move.

Copyright 2017 All rights are reserved.

Curiosities: Are there birds that cannot fly?

May 7, 2017

By Eddy Montilla.

Thanks to the Wright brothers, Orville and Wilbur, today we can take a plane and go from one country to another. They invented successfully the first airplane, which was piloted by Orville in 1903. But with all respect that these two American inventors really deserved, I think we should give credits to birds first, since it was Wilbur’s interest in the observation of birds what made possible the Wright brothers’ flying machine. Human beings, therefore, have always associated the idea of flying with birds, and now the question is can really all birds fly?

The answer is no. The ostrich, kiwi, emu and penguin are examples of birds that cannot see the ground from the air.

Copyright 2017 All rights are reserved.

Curiosities: What is the characteristic that makes from a seahorse a unique animal on Earth?

April 22, 2017

By Eddy Montilla.

Judging by their common name (seahorses) and physical appearance, both ideas lead many people to think that hippocampus (their scientific name) are mammals. Actually, they are not.

Seahorses are fish, and therefore, they lay eggs. They look cute and swim gracefully, but when it comes to eating, I do not recommend you to be at their side if you are a crustacean (a creature with soft body divided into sections, like shrimps, for example), especially a Myside shrimp since you might be sucked up by their long snouts. Seahorses eat dozens of times per day (40 times or more) and at the end, the number of shrimps they eat can be counted by hundreds or thousands of them (3,000 brine shrimps). Their eyes play an important role in this task because both eyes work separately, that means a seahorse can look forwards and backwards simultaneously.

Until now, the explanation is very simple. What is difficult to understand for human beings is that seahorses are monogamous and only mate for life. And if you are a male seahorse, be ready to be a mom! How come? Well, the female will put their eggs into your pouch and after that you have the responsibility to carry them until they hatch. They are the only animals on Earth with this characteristic.

Copyright 2017 All rights are reserved.

Curiosities: How long do your nails grow per day and why?

April 10, 2017

By Eddy Montilla.

If you have children, you have noticed how often you cut their nails and, on the contrary, you cannot remember the last time you cut yours. That means age plays an important role when it comes to nail growth. But it is not the only one: health conditions, good diet, and other factors are involved too. In general, nails grow 0.01 millimeter per day in adults. This process, however, is not homogeneous. For example, fingernails grow faster than toenails and, if you are left-handed (as I am), your nails on the fingers of your left hand will grow faster and vice versa.

As for the second question (why?), observe your nails. The visible part of them are on the skin, but the growing part is coming out from under it. The root of the nails is located in a place called matrix (it bears no relation with the movie at all). Your fingernails and toenails are both basically composed of cells, to be more specific, of keratin, which is a protein that forms not only your nails in this case, but also feathers, hair, horns, etc. In the matrix, cells are born, grow and dye by the time you see them as nails (this explains why you do not feel pain when cutting them.). Since cells are growing there constantly, new cells push out the old ones that finally get packed and come out, turning into those nails that a lot of women usually treat with the utmost care.

Copyright 2017 All rights are reserved.

Curiosities: Why do people want to urinate (wee) when they see water flowing?

March 1, 2017


By Eddy Montilla.

It seems that there are no scientific reasons to explain why we need a wee when we see water flowing or listen to the sound of it. Then, why does that happen?

     Because of psychological reasons: Conditioned reflex and association of ideas.

     A reflex is an action o movement that we do and it happens naturally in response to something. Typical examples are to try to grasp something that goes directly to the palm of your hand or to close your eyes when something is about to cause it any harm. A Russian psychologist called Ivan Pavlov observed his dog’s saliva when his pet was eating or about to eat, a natural reaction indicating that the animal was hungry. Later, Pavlov noticed that the dog began to salivate even when he did not have food in front of him. Then, he made an experiment: He fed his dog and rang a bell. After several repetitions, the dog was salivating whenever he heard the bell with or without food around him. This observation (or perhaps it would be fairer to say this dog!) revolutionized the realm of psychology because we learned that besides natural reflexes, there are others that can be conditioned (conditioned reflex).

     When you see the flow of your urine (wee) coming out of body and listen to the pee sound or the sound made by the toilet after flushing it, this image and sound remain inside your brain. Then, when you turn the faucet on, the water you see flowing and its sound evoke them, provoking the sense of urgency you feel to go to the restroom.

Copyright 2017 All rights are reserved.

Curiosities: Why do your stomach and intestine growl (grumble) when you are hungry?

February 12, 2017


By Eddy Montilla.

It is almost midday; my students are taking an exam and silence reigns in the classroom. Then, a very familiar sound tells me that the time for the exam has finished. The clock? No. It is one of the student’s stomach growling. His classmates cannot contain their laughter and I think about it: Why does your stomach rumble when you are hungry?

     To understand the answer better, three myths should be dispelled. First, your stomach does not growl only when you are hungry. It may happen even when you are satisfied after eating. Second, the rumbling noise is not coming from your stomach only, but from your intestines too. And third, it is not true that your stomach is absolutely “empty” when you are hungry. In fact, you have gas, gastric juice and other liquids and they are (combined with the walls of the gastrointestinal tract that contract and relax) the responsible for those rumbling sounds that usually embarrass all of us in front of other people.

Copyright 2017 All rights are reserved.

Curiosities: Why does your body shiver when you are cold?

December 5, 2016

By Eddy Montilla.


I could not use my bicycle last night because of the rain, so I decided to go home by bus. While waiting at the bus stop, I noticed two things about the girl who was in front of me: One, she was wearing a miniskirt and boots despite a temperature between three and four degrees. Second, she was shivering.

     “Social conventions and male chauvinism dictate cruel rules sometimes” I thought. “If you are a young girl, people expect you to show your legs even in winter and extend the length of your skirt some centimeters annually as you are getting old until the day comes when you cannot even see your feet.” Then my thoughts went back to the second observation: Why does your body shiver when we are cold?

     On very cold moments, your body temperature drops from its normal parameters (from 36°C to 37°C) to lower values that can lead to hypothermia, a dangerous condition because of a long exposure to cold. After moving or running for a while, you take your coat off as soon as you feel hot, right? And you do that because friction and movements produce heat. Sometimes, we do not remember this fact, but our body does, and that’s why it shivers: As an attempt to protect you by raising the body temperature.

Copyright 2016 All rights are reserved.