Posted in Science & Nature

Centre Of The Universe

We often meet people who act as if they are at the centre of the universe. These egocentric people behave as if they are the most important people in the world and that their words and actions are more meaningful than they actually are, while assuming that they play an important role in other people’s lives. This is a common belief in children who are still learning to differentiate the world and other people from their own minds, but in adults, it is almost pathological.

Speaking of which, where is the centre of the universe?

In ancient times, the concept of “universe” was very different. Many cultures imagined the universe as consisting of the Earth where we lived, plus the heavens and the underworld (often supposedly where the good and bad end up after death respectively). These worlds would be connected by a central axis mundi, or world axis. An example of this is the mighty Yggdrasil, the World Tree, found in Norse mythology. It is said to be a gigantic tree that connects the Nine Worlds and is the centre of all life.

As the science of astronomy developed, we realised that we are not at the centre of the universe. Geocentrism – the model where Earth is at the centre of the world with the Sun, Moon and planets orbiting it – eventually gave way to heliocentrism – the modern model where the Solar System orbits around the Sun.

It took brave scientists such as Nicolaus Copernicus, Johannes Kepler and Galileo Galilei challenging the Church and Aristotelian science establishments to show that our understanding of the universe was wrong, despite pressure and punishment. Through scientific observation and inquiry, it was shown that we are not at the centre of the world, but the Sun is.

But as we discovered more about the heavens, we realised that the universe is far vaster than the Solar System. With the advent of the Big Bang Theory, we realised that the universe is expanding, with every object moving away from each other in all directions. This is an extremely difficult concept to visualise, but because the universe is expanding infinitely in all directions, it technically has no centre.

On a final note, the concept of the universe being infinite may not be relevant to us because we cannot observe the infinite universe. Instead, we often talk about the Observable Universe, which is the portion of the universe that we can physically observe with our eyes, telescopes and other instruments. The centre of the observable universe, like anything observable, is the observer.

Therefore, in some sense of the phrase, you are technically at the centre of the universe.

Posted in Life & Happiness

Shoot For The Moon

A common saying goes:

“Shoot for the moon: even if you miss, you’ll land among the stars”.

The saying was coined by author Normal Vincent Peale, who was a minister famous for his books and work on the power of positive thinking. He was also widely criticised by many psychologists and mental health experts, who noted that his style of positive psychology was not founded in evidence and realism, but in naive optimism.

The saying sounds lovely at first, because it seems to be a beautiful metaphor for trying your best at everything. It says that whatever happens, you will land on another beautiful opportunity and good things will happen.

But of course, life does not work that way. As important as it is to make an effort to try and take action, you will not always be positively rewarded for it.

As it is with everything, science can help us break down the flaws with the philosophy of this saying.

Firstly, the Moon is 384,400km away from Earth. It took brilliant scientists and mathematicians with a significant amount of NASA budget 6 years on the Apollo program to put astronauts on the Moon.

Dreams are certainly achievable, but we cannot ignore that sometimes we have to pour in much time, resources and energy to achieve them. When we look upon someone’s success, it is important to consider how much effort they may have put in. Furthermore, it is paramount that we be realistic with our goals and dreams, in that we need to be patient and accept that it could take a series of failures, sacrifices and heartbreak for us to land on the Moon.

Secondly, space is unimaginably massive. If you shoot for the moon and you miss, there is a very high chance that you will float along the lonely, vast emptiness of space for the rest of eternity in a vacuum before you hit anything else (realistically, you will die of suffocation, thirst, starvation or being frozen first). The nearest star to us is the Sun, 150 million kilometres away. The second closest star – Proxima Centauri – is about 4.24 light years away. This means that even if you travelled at the speed of light, it would take 4.24 years, covering a distance of 40 trillion kilometres.

This fact teaches us that we have to be prepared for the fact that when we chase our dreams, there is a chance of things catastrophically failing. That is just life.

Lastly, even if by some miracle you survived the journey and landed among the stars, it would not be what we expect. As romantic as it sounds to land and live on a star like the Little Prince, in reality, stars look much like the Sun – a gigantic, glowing ball of fire. You will be incinerated even before you land on it.

And there is our final lesson from this saying: even if you achieve your goals, the end result may be completely different to what you expected. You may not even be happy with the outcome. So avoid pinning all of your hopes and happiness on achieving a single dream. Make sure to diversify your goals and identity.

As factually wrong as the saying may be, we can still learn valuable lessons from it, albeit completely the opposite message. But perhaps this is the more important truth in life: sometimes, we fail to achieve our dreams.

That said, we must continue to try for our goals and dreams, just with realistic expectations of how life can go. Had NASA given up after the tragic fiery accident of Apollo 1, we may have never been able to experience the glorious moment of humanity setting foot on another celestial body.

Shoot for the moon, but maybe have a backup plan. And if you fail, don’t lose heart and give up, but instead try again and try new, different things constantly.

Posted in Science & Nature

Constellation

To our ancestors, the night sky was not only useful for navigation and telling the seasons, but also for entertainment. Using the mind’s eye, they connected the dots to form a skeleton of a picture – a constellation.

Constellations became the basis of numerous tales and legends. The ancient Greeks told stories of mighty hunters fleeing from scorpions, of fair maidens chased by satyrs, and of noble animals who helped a hero in their quest. In the Far East, they tell a story of lovers who are punished by being placed on separate stars, only being allowed to meet once a year. Similar stories based on constellations can be found in almost every culture around the world.

Constellations are fascinating as they just look like a collection of bright dots to us, but in reality, they represent a spread of stars throughout the cosmos, unimaginably far from us and each other. Even though the stars may appear to be right next to each other, one star may be thousands or millions of light-years further from us than the other.

This is because a constellation is a two-dimensional picture representing three-dimensional space, meaning that depth is ignored. Because of the great distance, entire worlds appear to be simple points, while the vast emptiness of space flatten out to short gaps.

Mythologies and stories based on constellations teach us many pearls of wisdom, but perhaps this is the most valuable lesson the constellations have to teach us. When we look at something from a distance, we lose the fine details. Even the awe-inspiring beauty and size of the cosmos can be reduced down to a simple line drawing in the sky.

The same principle applies to people.
When we judge a person, we reduce a complex life full of stories, experiences, thoughts, feelings and circumstances down to a single stereotype, letting us objectify, criticise, belittle and dismiss people easily.
When we comment on a historical event, we focus only on big events and try to simplify the narrative to a few cause-and-effect stories, while conveniently forgetting the individual lives affected or the broader context that led up to that point.
When something bad happens in the world, we try to find meaning or something to blame, instead of trying to understand the numerous variables that factor into the situation.

Constellations are beautiful, but they don’t tell the full picture. If we want to truly understand the world we live in and the people we share that world with, we have to learn to consider the details and look at things from different points of view.

Posted in Science & Nature

Kessler Syndrome

When we imagine catastrophes, we think of disasters involving mass destruction such as volcanic eruptions, tsunamis and nuclear war. But there are so many creative ways the future of humanity can go awry. For example, there exists a possibility of humanity losing the ability to launch anything into space for the foreseeable future.

This interesting hypothetical scenario was described by astrophysicist Donald J. Kessler in 1987. Earth is currently surrounded by many layers of orbiting satellites. Unfortunately, satellites eventually break down and its components can end up as space debris. Since there is nothing in the vacuum of space that will degrade them, space debris stay in an endless orbit around the Earth unless they fly low enough that they get caught by air resistance and burn up in the atmosphere.

Kessler proposed the following problem: what happens when debris collide and set off a chain reaction? Although we think of orbital objects as slow moving or even geostationary, orbital objects are travelling at extreme speeds – at least 8km/s (or 28,800km/hr). When two objects collide at such incredible speeds, there is a huge amount of energy released in the form of shrapnel.

If the orbit is dense enough with debris, it is theoretically possible that these shrapnel will hit another piece of debris and set off another reaction. If the chain reaction can sustain itself long enough, soon the entire orbit will be littered with high-speed shrapnel, obliterating any object trying to cross the orbital layer.

The implication of the Kessler syndrome is that it would essentially make it impossible for us to launch any new satellites or rockets into space. This would stop us from exploring the depths of space and dash any hopes of interstellar travel and space colonisation. Scientists are already working on policies to reduce further space debris and experiments on how to clear up debris. But without awareness of the issue, no change would happen.

With climate change becoming an increasingly pressing issue, it is ironic that our littering of space could potentially ruin our chances of escaping and finding a new home if the need should arise.

Posted in Science & Nature

Zero Gravity

With the development of technology, we are now at a point in history where there is an abundance of video footages taken in space. Thanks to this, the general population can visualise the strange phenomenon that is the lack of gravity in space. We are able to see videos of objects and astronauts gently floating and even strange phenomena such as tears simply pooling around a person’s eyes rather than streaming down the face. Most of these scenes are from places such as the International Space Station which is in orbit around the Earth, as there has been no expeditions leaving Earth’s orbit since the last moon landing in 1972.

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However, the common misconception is that objects in space stations are in zero gravity conditions. Objects in orbit are still under the influence of Earth’s gravity, which is why they do not fling out into the depths of space. So why do astronauts in space stations look like they are not under the influence of gravity? The reason is that an object in orbit is travelling incredibly fast.

The International Space Station is about 420km above the surface of the Earth. Here, it experiences about 90% of Earth’s surface gravity, meaning that theoretically, it should fall straight back. However, the ISS is travelling at 8km/s (27600km/h) sideways at the same time – the orbital speed. Because of this, the ISS is falling back to Earth at the same rate as it is travelling tangentially away from Earth. This makes it travel at a blistering speed in a circle around the Earth.

Not only is the ISS free-falling around the Earth, but so is its contents. Therefore, the astronauts inside look like they are in zero gravity, but are in fact simply in free-fall, much like a skydiver. In this state, they experience no “weight” as the g-force becomes zero and the astronauts accelerate at the same rate as the ISS. Ergo, the astronauts are “weightless”, not in “zero gravity”. This condition can be simulated on Earth in the so-called “Vomit Comet” – an airplane designed to fly up and down along a certain path, to produce a weightless, free-fall when it falls.

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Posted in Science & Nature

Voyager

In 1977, NASA launched into space two unmanned probes named Voyager 1 and 2 respectively. These probes were designed to study Jupiter and Saturn and were not expected to function past this point. The original Voyager mission officially ended in 1989 when Voyager 2 did a close flyby of Neptune. However, as of 2014, both Voyagers are still travelling ever onward into interstellar space, sending back crucial data about our solar system and what is inside it, along with beautiful photographs of the planets.

The two Voyager probes greatly outlived their expected lifespan and exceeded what they were expected to do. Thanks to the Voyager program, we now have a far better understanding of our own Solar System, such as the fact that it is asymmetrical, or that Neptune had three rings. Voyager 1 is now the most distant man-made object from Earth – with its closest neighbour, Voyager 2, being billions of kilometres away from it. Yet it continues to strive onwards into the unknown, exploring the depths of space all alone.

The Voyagers also carry a golden record on which scientists recorded pictures, sounds and music (such as Bach and Mozart) that represented scenery found on Earth. It also includes various languages, mathematic formulas, a representation of our Solar System and our DNA, anatomy and reproduction. It is meant to be a time capsule of Earth, for our future descendants or whatever else may be out there.

Posted in Science & Nature

Space Pen

According to a popular legend, it is said that during the height of the Space Race, NASA was hard at work trying to develop a pen that could be used in space. The standard ball-point pen relies on gravity to pull the ink to towards the ball, allowing it to write. Obviously, this design does not work in space. NASA reportedly spent $1.5 million (some sources say $12 billion) and finally developed a space pen. This pen could write upside-down or in zero-gravity, on almost any surface and would work even at temperatures below freezing or over 300°C.
The Russians were faced with the same dilemma – they used a pencil.

As entertaining the story of overthinking Americans is, it is a complete urban myth. Both US and Russian astronauts used pencils in the early stages of the Space Race, but there were many flaws with pencils. Firstly, it was deemed unsafe to write important official documents using an erasable writing tool. Secondly, wood is combustible and fire is potentially disastrous on a space mission. Lastly and most importantly, pencil lead is made of graphite and broken tips and graphite dust are commonly released when using a pencil. Graphite is an extremely conductive material and if the dust were to go into an electrical circuit, it could easily cause a short-circuit and spark a fire.

To solve this solution, Paul C. Fisher – founder of Fisher Pen Co. – invested his own funds (not the US government’s) to create a pen that used pressure-loaded ink cartridges, making it perfect for zero-gravity use. NASA approved of the pen’s effectiveness and not long after, even Russia imported about a hundred of these space pens for their own use.

Posted in Philosophy

The Significance Of You

We are often reminded of how insignificant we are as individuals (or even as a race for that matter) in the grand scale of time and space in the universe. We are but a tiny, invisible dust particle on the map of the universe and we make up a sliver of time in the history of everything. This is a reminder that we should be humble, that no matter how great we think we are, we are nothing in the eye of the universe.

Then again, sometimes it is nice to remember that we are significant. Consider this. For you to have been born, generations after generation of couples have had to produce a child. You are the product of 4 billion years of evolution. 4 billion years of unbroken lineage, from the primordial ooze to bacteria to fish to amphibians to reptiles to rodents to primates. If even a single couple in that chain decided not to have an offspring, you would not be here reading this. Of course, this also puts you under the pressure that you may be the last one in that 4 billion-year chain not to reproduce, but let us ignore that for now.

Now consider the stars. When you look upon the night sky and see the twinkling of a star, what is happening is that photons (light particles) are hitting your retina and triggering a signal that is sent to your brain and interpreted as twinkling. Those photon generated by the star you see have travelled light years through the vast universe until your retinas rudely interrupted its journey. The closest star to us (excluding the sun) is Alpha Centauri, located 4.37 light years away. 1 light year (distance travelled by light in a year) is just under 10 trillion kilometres, meaning that those photons you blocked had travelled at least 41 trillion kilometres – or 41,343,392,165,178,100 metres. All you had to do was exist in a certain location and look up at the sky.

Some might say that you are puny and insignificant compared to this astronomical scale. But another way to think of it is that you effected real change in the universe (even if it was blocking a particle of light). No matter how small you are, no matter how short your life is compared to the history of the universe, you are not insignificant. Chaos theory (better known as the butterfly effect) dictates that even the smallest change in initial conditions can lead to unpredictable, widely diverging outcomes. For all you know, your existence is the difference between the existence of life on a distant planet somewhere.

So never say that you are insignificant. And if evolutionary biology and astrophysics is not enough to convince you, then look around you. The people you have met and interacted with throughout your life are affected by you in one way or another. For example, a compliment you paid in passing might completely change the person’s day. A simple act of kindness you thought nothing of could be recorded in someone’s life book as a life-changing event. Even a smile can make a difference. You are significant.

“If you could only sense how important you are to the lives of those you meet; how important you can be to the people you may never even dream of. There is something of yourself that you leave at every meeting with another person.” ~ Mr. Rogers

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Posted in Science & Nature

Hammer And Feather

What would happen if you dropped a 1kg ball and a 10kg ball at the same time from a high building? Most people would think that the 10kg ball would obviously fall faster and thus hit the ground faster, but the truth is they would fall at exactly the same time. The reason for this is that the force that accelerates a falling object is gravity, which on Earth is constant at 9.81ms-2. This means that no matter how heavy the object is, they will always accelerate by 9.81 metres per second per second. This was hypothesised by Galileo Galilei, who came up with the thought experiment of dropping two balls of different mass from the Leaning Tower of Pisa (there is debate as to whether he actually performed the experiment). The theory was later solidified by a certain Isaac Newton, who devised the laws of universal gravitation and the three laws of motion.

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However, if the two balls were dropped from an extremely high place, they may land at different times as mass affects the terminal velocity – when the force of gravity equals the force of drag caused by air resistance, leading to a constant velocity. A heavier object will keep accelerating to a greater velocity than a lighter object, which would have reached terminal velocity before the heavier object.

One place where this will not happen is in a vacuum where there is no drag force. To prove that the hypothesis that two objects of different masses will fall at the same time in the absence of air resistance, Commander David Scott of the Apollo 15 moon mission took a hammer and a feather with him. Once he landed on the moon, he dropped the hammer and feather in front of a live camera, showing that the two landed at exactly the same time. He thus proved that Galileo’s conclusion from two hundred years ago was in fact correct.

Posted in Science & Nature

Units

In September of 1999, NASA ambitiously launched a Mars weather satellite. But the satellite did not even reach its destination, instead exploding in the atmosphere soon after launch. Why was this? The reason was so stupidly simple. The failure was because of units.

The satellite that was designed by Lockheed Martin was designed using the imperial system (pounds, feet and yards), whereas NASA’s systems used the internationally-used metric system. Because of this simple error, the pride of the USA space program fell to the ground and an astronomical amount of money was burnt to ashes in the air.

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