Posted in Psychology & Medicine

Motion Sickness

Why do we get motion sickness when we are riding a moving vehicle?

Our sense of balance relies on an elaborate system. Our eyes give us visual information about head position and if it is moving in relation to our surroundings. Our inner ear contains delicate tubes (vestibular system) that act as gyrometers, indicating if our head is tilted or moving. Our brain synthesises the data from these two systems to know where we are in three-dimensional space and how we are moving within it.

The problem is that these two systems give conflicting information sometimes. For example, when you read in a car, your vestibular system senses that you are moving, but your eyes tell your brain that you are still. Conversely, when you watch a fast-paced action movie or playing a virtual reality game, your eyes will sense movement but your head will feel no movement.

When your brain receives conflicting information, it becomes confused; which information should it trust? The brain assumes that one of them must be wrong, possibly because you have been poisoned. The sensory mismatch results in nausea and you may start to vomit because the brain tries to get rid of whatever “poison” may be causing the problem.

In essence, motion sickness is caused by a mismatch between what the brain perceives and expects versus the reality.

Similarly, we can experience a form of “mental motion sickness“. Our brains are designed to predict the future, but the side effect of this is that we tend to form idyllic, simplified expectations. A good example is our tendency to hang our happiness on a future moment.

When we are unhappy or going through a hard time, we are prone to thinking that changing something will result in happiness. Some people change jobs or escape to another city (the “geographic solution“). Some people eagerly await for a holiday or for a deadline to be over. Some people start or end a relationship. We expect a drastic change in the future, even though the reality is that most things in life take time to change and happiness is not a switch you turn on, but a steady state that you build up to.

Eventually, when we realise that we are still unhappy, our brains become confused why reality is so different from our expectations. It makes us nauseated and want to reject our reality, frustrated that we are still miserable. But reality will not change just because we will it to.

The only solution is to manage our expectations. We need to accept that change happens gradually and that changing our environment will not necessarily change our headspace and perspectives. Our miseries will not disappear without us trying to improve our wellbeing. Instead of expecting a magical fix, we need to be mindful of our reality and find peace with the fact that it is okay not to always be okay.

We have evolved to improvise, adapt to and overcome changes and challenges. So instead of wallowing in self-pity that things did not turn out as expected, we must accept that things are as they are and keep fighting on to find our inner peace and happiness.

Posted in Philosophy

Achilles And The Tortoise

In 450 BC, a Greek philosopher named Zeno thought of the following paradox. Let us imagine that Achilles and a tortoise were to have a footrace. Achilles, obvious being faster than the tortoise, allows the tortoise to have a head start of 100 metres. Once the race starts, Achilles will quickly catch up to the tortoise. However, within the time he took to cover the distance, the tortoise would have travelled some distance as well (say 10 metres). When Achilles runs the 10m to catch up again, the tortoise has once again toddled on another metre. Thus, whenever Achilles reaches somewhere the tortoise has been, he still has farther to go. Because there are an infinite number of points Achilles must reach where the tortoise has already been, theoretically the tortoise will be ahead of Achilles for eternity.

According to this thought experiment, motion is paradoxical and theoretically impossible. However, we know for a fact that motion happens. So how can we break Zeno’s paradox?

The main flaw of Zeno’s paradox is that he uses the concept of “eternity”. If we record the story mathematically, the time taken for Achilles to run the footrace is (if it took him 10 seconds to run 100m): 10 + 1 + 0.1 + 0.01 + 0.001… = 11.111… Ergo, the tortoise is only ahead of Achilles for less than 11.2 seconds (rounded). After 11.2 seconds pass, the time passed exceeds the sum of the infinite series and the paradox no longer applies.

Although it is a flawed paradox, the story of Achilles and the tortoise teaches the concept of geometric series – that something finite can be divided an infinite amount of times. For example, 1 = ½ + ¼ + 1/8 + 1/16… ad infinitum. This principle is a crucial part of mathematics and has significant implications in the field of economics. For example, it can be used to calculate the value of money in the future, which is necessary for working out mortgage payments and investment returns. Perhaps it is because of this mathematical principle that it seemingly takes an infinite amount of time to pay off a mortgage.

Zeno’s paradox teaches us that one should not take the concept of infinity for granted.