Tag: head

Posted in Science & Nature

Car Keys

Posted on by Jinavie

There are times when you park your car, start walking away and you remember that you forgot to lock the doors. You click your remote car keys but you are already just far enough that the signal does not reach your car. Fortunately, there is a lazy way to extend your car remote’s range.

If your hold your remote against your head (such as next to your chin or your temple), you will find that suddenly, the remote works from a longer distance like magic. How can this be?

There are two explanations that factor in.

The first is very simple: height. The higher you hold your remote, the less barrier there is between you and the car, making the signal more likely to reach it. But this cannot be the only answer as the trick works when there is nothing between you and the car.

The second explanation is more technical. When you press the key to your body and click it, the electromagnetic waves that comprise the signal can cross past your clothes and skin into your body, which is mostly composed of water. The water acts as a capacitor as the signal starts to “charge” you, all the while the signal is being rapidly bounced back and forth between the remote and you. In essence, your body acts as a giant aerial that amplifies the signal, almost doubling the range of the remote.

Arthur C. Clarke once wrote: “Any sufficiently advanced technology is indistinguishable from magic”.
But even the simplest scientific principles can seem like magic until we bother looking under the hood.

Posted in History & Literature

The Oldest Trick

Posted on by Jinavie

Magic has been a great source of entertainment for the masses for thousands of years. Across the globe, under many guises, magicians have amazed audiences with seemingly impossible “miracles” using misdirection and clever trickery. The oldest recorded trick – that is to say one performed purely for entertainment and not under the guise of religion or supernatural power – dates back to ancient Egypt.

According to the Westcar Papyrus, a magician by the name of Dedi was famous for his miraculous feats. The Papyrus tells the story of how Dedi was called to put a show on for King Khufu. He proceeded to decapitate a goose, then reattach the head, bringing the bird back to life. He repeats the magic with a duck, then with a bull, wrenching its head off then bringing it back to life by reattaching the head. For his amazing performance, he is rewarded by being allowed to live in the palace. This trick is still practised by magicians to this day, thus making it the longest performed trick in history.

Posted in Science & Nature

Praying Mantis

Posted on by Jinavie

The praying mantis is sometimes considered a symbol of ultimate female empowerment. After mating, it has been observed that the female would immediately proceed to kill the male she just mated with and eat his corpse, head first.
However, one thing that is less known is that this act – known as sexual cannibalism – occurs almost exclusively in captivity. This is because in the wild, a male runs off quickly after mating to avoid a grim fate. The female, with a massive appetite after the tiring act of copulation, looks for a source of nutrients to upkeep her pregnancy. As in a captive environment the male cannot run far and the female cannot hunt easily, she opts to eat the male as this is more beneficial for her. Furthermore, as mantises have very sharp vision, it is highly likely that the observing scientists (giant, towering figures dressed in white) will intimidate the female mantis. The anxiety caused by the observation would thus make the female act more violently.

The theory that lab intervention caused sexual cannibalism was proven when mantises stopped cannibalising after being fed ad libitum (until they were full). In fact, the female would carefully observe the courtship dance of the male and decide whether he is worthy of mating. This courtship dance also has the effect of switching the female’s priorities from feeding to mating.

It has also been suggested that females may choose to eat the males they do not deem worthy (before mating), or that the males are sacrificing themselves to improve the chance of fertilisation. This is supported by evidence of decapitated male mantises copulating more vigorously and mounting the female for much longer periods. 

In other words, male submissiveness can be a factor in reproductive success.

Posted in Psychology & Medicine

Vertex

Posted on by Jinavie

The vertex, also known as the crown of the head, is the uppermost point on the human body on the top of the head. It is the part of the body that comes out first (usually) during childbirth.

There are some interesting properties regarding this anatomic location.

Firstly, if one places a cellphone on top of their head, they cannot feel the vibration when they receive a call or text message. Almost every other part of the body can feel the vibration, but not the vertex. This is because the top of the skull is not covered by any muscles, which have receptors that sense vibrations. Ergo, no vibrations can be felt.

Secondly, when one places their hand on top of their head, they experience a sudden drop in muscle strength. This applies to the whole body and can be seen through basic activities such as lifting weights or even through arm-wrestling. The degree of weakness can be up to 10~15% of the muscle’s normal strength. 

The reason for this is slightly more complicated. The nervous system remembers trauma and responds to it, such as childbirth where almost everyone (assuming they were born through vertex presentation, the most common) experiences trauma on the top of the head. For example, as labour is quite an intensive procedure, significant pressure is placed on top of the baby’s head as it tries to push out.
Because of this, when pressure or electric signals are exerted on the vertex, the nervous system responds negatively, remembering the trauma from childbirth, and “weakens” throughout the body. This results in decreased force exertion by muscles. The same effect can be achieved when a cellphone is placed on top of the head, as it emits electric signals.

Lastly, the top of the head is not sealed until a few months after birth. This makes a baby’s skull very malleable, and two fontanels, which are gaps between pieces of the skull, remain open for that time. This is seen as “soft spots” on the head which pulsates as there is no bone beneath it.