Tag: plane

Posted in Science & Nature

Bird Strike

Posted on by Jinavie

An airplane flying across the sky faces many dangers. But a very common yet not well-known type of accident is the bird strike. Just as the name suggests, a bird strike is when a plane collides with a flying bird. This may not sound so dangerous, but considering a plane typically flies at 800~900km/h, the energy from the collision is quite significant. If a plane flying at 800km/h collides with a 5kg bird, the energy generated is 92 tonnes. This is not only enough to instantly kill the bird, but also enough to damage the plane.

The most common type of bird strikes is when a bird collides head-on with the windshield or gets sucked into the engine. The latter can cause severe damage to the engine and even cause it to fail. For example, in 1960 a plane flying above Boston collided with a flock of starlings, leading to all four of its engines failing and causing it to crash, killing 62 passengers. Since birds typically fly below an altitude of 9000m, bird strikes most often occur during take-off and landing. However, there are case reports of much higher altitude crashes, with the record being held at 11300m.

According to statistics, the most common type of bird involved are waterfowls and gulls, with 15% of bird strikes being severe. Bird strikes cause $1.2 billion worth of damage annually worldwide and has cost 200 lives since 1988. The first bird strike occurred with the invention of the airplane, as recorded by the Wright brothers (inventors of the modern airplane). As bird strikes cause so much damage, airports place many countermeasures to prevent them. The most frequently used methods are driving away birds from runways by using scarecrows and other methods, or modifying the plane and engines to be more bird-resistant.

Posted in Science & Nature

Dimensions: Flatland

Posted on by Jinavie

As we live in a three-dimensional world, it is difficult to imagine that there are higher dimensions. To illustrate this, the thought experiment of the hypothetical “Flatland” can be considered. Let us assume that there is a two-dimensional world called Flatland. Here, the concept of depth does not exist. Only forwards, backwards, left and right exist; there is no up and down. Everything that happens here would look like it was drawn on paper.

Now let us interact with Flatworld. If we were to touch Flatworld with our finger, it would be like poking your finger through a newspaper. The inhabitants of Flatworld would see a circle suddenly appear out of nowhere that grows larger and larger. A person would appear as if they were being seen through a CT scanner – in sections. The concept that things can be above or below would sound crazy to a Flatlander, even though to us it appears as a simple concept.

Let us take an ant walking along a piece of paper as an example of a “2D object”. If the ant wishes to go from one edge of the paper to the opposite edge, it must walk along the 2D plane. However, with our 3D powers, we can fold the paper into a cylinder; now the ant can walk to the other point in an instant (across the fold). To another ant on the other side, the ant would look as if it teleported and suddenly appeared out of nowhere.

In another experiment, we make a Mobius strip (a ribbon is twisted once then its two sides are joined) and make an ant walk along it. Although the ant would think that it was walking in a straight line along a two-dimensional surface, it would have walked on both sides of the strip – a three-dimensional concept. If the Mobius strip concept is confusing, think of a garden hose instead: an ant walking along a straight garden hose is walking in: 1D (straight line), 2D (hose is actually a flat surface) and 3D (the ant can walk in a corkscrew pattern along the hose).

If we were to tell that ant that it had just travelled in a higher dimension, that ant would either scoff at us or be genuinely terrified of the experience. To it, we (or the giant pink circle that it sees our finger as) would look like some omnipotent being that can see everything going on in its world and teleport from one place to another. And although the concept of depth would initially intimidate the ant, it would bring the level of the ant’s understanding of the world up one dimension. For if we see what we only know, then how can anyone see anything new? The only way to truly learn and understand new things would be to jump out of the box and see everything from the outside – just like an ant seeing the piece of paper it was on from a higher ground.

Although we may laugh at the foolishness of the Flatlanders (and the ant), to a being of the 4th dimension, we would appear just as stupid and naive. By applying what we learned from the world of Flatland to our three-dimensional world, we can expand our horizon of knowledge and understand what the fourth-dimension is.

(This post is part of a series exploring the concepts of dimensions. Read all of them here: https://jineralknowledge.com/tag/dimensions/?order=asc)

Posted in Psychology & Medicine

Hysteria

Posted on by Jinavie

Hysteria is a disease that was believed until the late 19th century to be a disease unique to women due to a pathology of the uterus (hystera is Greek for uterus). The most common symptom was mental disturbance (such as extreme moods) accompanied by shortness of breath, vaginal dryness, nervousness, insomnia, oedema, faintness and many more. The treatment back then was for a physician to massage or stimulate the patient’s vagina to induce an orgasm. By the 19th century, the treatment evolved and involved vibrators and water massage machines.

This disease was first noted by Hippocrates, the father of modern medicine. Galen, another famous physician in the 2nd century, believed it to be caused by sexual deprivation. Thus, sexual intercourse was prescribed as treatment in the Middle Ages.

Modern medicine no longer recognises hysteria as a medical condition and is now referred to as sexual dysfunction (the sexual treatments described above are no longer used either). However, there is a condition called mass hysteria that indeed exists.
This is a psychological phenomenon rather than a disease, commonly occurring in closed spaces such as planes or in crowds in a state of panic. When a high tension situation arises, people easily become delusional and believe that they are suffering from a disease. The body reacts to this with actual symptoms such as a psychosomatic rash. These symptoms can be as severe as fevers, vomiting and even paralysis.

If many people are all complaining of similar symptoms and infectious disease seems unlikely, there is an easy way of diagnosing mass hysteria. Tell the patients that they have a rare disease and begin listing the symptoms they complain of. At the end, make up a false symptom (e.g. “shaking of the left hand”). If the patients all suddenly start to shake their left hands (which causes them to panic more), it is likely that their panicking brain is causing the symptoms rather than some pathogen. Symptoms subside after the patients relax.

Interestingly, mass hysteria affects women much more than men.