We are eight, legitimately belong to the same father. I am the third and unique one amongst my siblings, and for this reason, I am an object of jealousy. I am quite big, but not as big as some of my siblings like Saturn, Uranus, Neptune, and our biggest sibling Jupiter, he is the bully. I weigh about 6 x 10²⁴kilograms^[1]. Maybe that sounds ambiguous, I weigh 2.4 trillion kg multiplied by 2.4 trillion kg. That sounds like a lot of weight, but I do not feel heavy. My name is EARTH. There a lot of reasons why I am this unique, but allow @real2josh take you on a rather awesome journey of knowledge.

🔥🔥🔥 The Earth 🌍 🔥🔥🔥

The earth as observed from the space. From pixabay

The earth is very beautiful, especially when you view it from outer space, and more beautiful are the over 8 billion humans and trillions of other living things. It is third planet away from the sun at approximately 150 million kilometers (91 million miles) ^[2] away. Not really far though, except that it will take you only 51 years, that’s if you travel with the fastest car and you don’t stop to get gas or stretch your legs or take a nap. We will see what will happen if the earth was farther or closer to the sun with as little as a million miles.

The earth is spherical in shape and rotates around its axis at a speed of about 1000 mph, way faster than the fastest car, something contrary to what scientists believe some thousand year ago. We do not feel the spin of the earth due to its enormous mass and its diameter. Despite the fast speed of rotation, it completes one revolution in about 24 hours. It however has its angle of rotation tilted a little at about 23.5^{0 [3]}. That design consideration is for a reason, we will find out.

The earth makes an amazing trip round the sun, which is completed every 365¹/₄ days, which is considered as 1 year. I believe it’s not science how we come to have a leap year every 4 years, it’s just adding up the ¹/₄ extras to give an extra day. 70% of the earth is covered by water found majorly in oceans and seas and do not fall off when the earth rotates due to the earth’s gravitational pull, something we will talk about in detail. But what constitute the large mass of the earth? What can be found deep inside the earth?

The Inside

Suppose you undertake the rather daunting task of digging the earth endlessly, what are the things you are likely to find? I have been where a well was dug, the earth was dug to a depth of about 120 ft., due to the depth of clean underground water. What did I see? There were many layers of soil, from the very hard rocky ones to the soft and coarse soil. Then there was the sharp sand just before the abundant underground water, details of which are not within the scope of this article. However, all the rock and sand and water that took weeks to dig out only forms one of the four layers of the earth, the crust.

The inner structure of the earth. Wikimedia commons under the Creative Commons CC0 License

To know what lies in the very interior of the earth, digging is not an option. Scientists have reproduced in 3D the earth’s interior, with the aid of seismic photographic data. And what have they found? First, that the earth has four layers: the crust, which is the outer layer we live on and consists of the oceans and continents, the thickness of which is about 18 miles in the case of continents or about 5 miles in the case of the ocean, containing so many beautiful rocks and elements; then the mantle which is found below the crust and has a thickness of about 1800 miles and can be as hot as 2,200⁰C at the bottom mantle close to the core. In the mantle is where you will find dense and hot rocks which can even flow, and the mantle moves, which causes movement of the earth’s plate, we’ll come to discus plate movement soon.

The next layer is the *outer core*, which consist majorly of very hot metals - iron and nickel, is also about 1400 miles thick. The temperature found in the outer core can be very enormous, such that can reach 5,000⁰C, reason why the metals found there exists in the liquid state. The *inner core* which happens to be the last layer is a ball of extremely white hot metals but do not flow like as liquids because of the high pressure present in the inner core, which keeps the metals together. Its thickness is about 800 miles and can reach a temperature of over 5,000⁰C. Its pressure which squeeze the metals together is about 45 million pounds per square inch, that is like say 4 million snake constrict a human, so enormous you would say. Why does the earth need so much iron and at this high temperature?

Magnetic field

Earth's magnetic field acting as a shield against solar flares from the sun. From Wikimedia commons. Picture made available by NASA. CC0 license

If you did a little of physics, you may easily grasp this idea. If you place a coil of wire that is electrically charged or that has electric current passing through it in between the poles of a magnet, the coil will deflect at right angle to both poles. This principle serve to protect us here on earth. How do we mean? Remember what lies inside the earth? The superhot iron? Yes! That is what generates the magnetic field around the earth. How does this field protect us? The space is full of random moving objects and rays that are very dangerous to life on earth. Particles of a cosmic ray is one of this while solar flares from the sun is another, and fortunately for us the earth’s magnetic field deflects it away, and the atmosphere around the earth also prevents random particles from getting to us here on earth. The above image demonstrates this principle.

Interestingly, the earth’s magnetic field interaction with rays from the space gives rise to what we call the Aurora Borealis - Northern light and the Aurora Australis - Southern Light. My friend @addempsea conjured a beautiful piece where he explained in details the the auroras, you can take a moment to look at it.

Earthquake

On a cool tuesday evening of January 2010, report has it that a catastrophic magnitude 7.0 earthquake struck haiti. Children were playing in the field, market women busy with their daily businesses, government workers just closing from work on their way home probably, life would have been going as usual not knowing their life was about to change on a grandeur scale, for those who would be fortunate enough to have their lives. Report has it that over 250,000 people lost their lives and many more rendered homeless. Truly a sad day in the history of the country of haiti! Things never remained the same. However where did it all start from? Why haiti?

It all began some thousands mile below the town of Ouest, close to the city of port-au-prince, the haiti capital. Remember we discussed layers of the earth and said the mantle is just below the earth’s crust, but what we didn’t really discuss is that there is a thin and malleable layer called the asthenosphere, which makes another layer called the lithosphere to move around. The lithosphere which comprises of plates called the tectonic plates, which actually slides on one another as they move inside the earth. The plates have rough edges called plate boundaries. Now here is where you may wanna pay more attention.

When these plates move, their edges often get stuck while the rest of the plate tend to move, but having moved far enough, the edges detach from each other and boom, the energy is released which ends up in what we call earthquake. To better understand this principle, try and cast your mind to a game called “tug of war”, well if you haven’t played it before, drop a comment I’ll refer you to the right person to teach you, but if you are familiar with the game, you will remember that when the chain is broken those holding on to it are likely to fall on one another, this is because energy is released.

In a similar fashion, energy stored when the plates glide over each other and the edges cling to each other is then released when they detach suddenly. The energy then radiates towards the earth surface in form of a seismic wave, and becomes what we refer to as earthquake.

Gravity

What if you play a ball up and puff it doesn’t come down, what would you do? You may imagine it not to be possible, yeah if so you’re probably right because of what we call gravity, except of course the ball can achieve escape velocity. Gravity is a cool concept and plays a very invaluable role in the existence of life. Let’s just take a few moment to look at the things that might happen suppose there was no gravity. For one there will be no water in the so called oceans and seas, because they would have all fallen away into the space. Whatever your imagination can accommodate, you will realize that it all boils down to one fact - that life would not exist without gravity. So what is the gravity?

NASA Space place defines gravity as the force by which a planet or other body draws objects toward its center.

We can say it is the force that attracts anything with mass. The idea of gravity is that any two object with mass tends to attract each other. It is the reason we feel weight. The entire idea has been elusive for many years and many great scientist have done their part in understanding gravity. However the great Sir Isaac Newton eventually described as a force, which is the product of masses of the two bodies, inversely proportional to the square of the distance between the two bodies. This what we come to know as Newton’s law of universal gravitation.

Why is gravity that important? Gravity makes the earth orbit around the sun in the same fashion from eternity to eternity, while the gravity between the earth and the moon gives the earth needed stability while completing its mandatory journey around the sun. The gravity between earth and moon is also responsible for the tides of the ocean. This same force keeps us on the earth where we are protected. No matter how much we try to jump, we still end up finding ourselves on the ground. But does that ,mean that trying to jump and not return is unachievable? Absolutely not! Thus comes the idea of escape velocity.

As the nomenclature suggests, it is the velocity a body will need to achieve if it wants fo be free of gravitational pull to another body, and such body have to move outward from the body not into the body at such speed. For a body to escape the earth's pull, escape velocity of 25,000 mph has to be attained. But is it necessary to know this principle? Yes it is! Rockets are designed to go out of this earth and the speed they must reach has to be calculated with this relationship: , where the G is the gravitational constant, M is the mass of the body to be escaped from, which is earth, and the r for the distance between the object and the body’s center of mass.

🔥🔥The Amazing Precision 🔥🔥

Why is the earth the only place in the known universe that supports life? Could that be a coincidence? Some well known scientist have come to the conclusion that certain conditions and gases came together coincidentally and formed the earth. If that was true, why hasn't there been another similar planet formed under similar conditions to support life? Let’s take a look at some important facts.

Earth's tilt: a reason behind seasons from Wikimedia commons licensed under the Creative Commons Attribution-Share Alike 4.0 International license. Author: swathiha97

Why do we have seasons over the course of the year? Some have thought it is because of the fact that our earth orbits the sun, but that is short of being right because other planets likewise orbits the sun and experience nothing of such. The amazing 23.5⁰ tilt of the earth us that variation we need. Because of this tilt the northern and southern hemisphere is such that at certain times of the year, they are either subject to more light intensity from sun as a result of the angle, which we know as summer or less light intensity from the sun, winter. This is also interesting because the seasons at both hemisphere are alternate, meaning that both parts of the earth will not experience winter at the same time.

Now let us consider the earth’s distance from the sun. We said the earth sits comfortably at a distance of 91 million miles from the sun, an amazing distance that is obviously not a result of chance. Renowned scientists have concluded that had the earth be just a million miles closer, life would not exist on earth because of the intensity of the radiation. What about a million miles farther? We would have freezed to death and all the available water on earth would have been frozen. A good question therefore would be, who measured the exact distance? And who did the heat transfer calculations to arrive at the exact distance of the earth to the sun? Definitely not me! But I suppose it would have taken more than just chance.

The solar system and the milky way galaxy is quite amazing. The earth’s solar giant, the sun radiates the exact amount of energy to support the distance from the earth. And the solar system itself sits in a position referred to by scientist as the “habitable region”. The reason is because certain elements required for the sustenance of life can be found within our solar system. Away from this, life would be destroyed by harmful radiation.

The earth’s satellite, moon is quite another fascinating aspect of this our beautiful home. It is said to be about 400 times closer to the earth than the sun, and only on earth can you actually experience a perfect eclipse of a star! The moon helps to keep the spin of the earth balanced otherwise the earth will just keep wobbling while spinning, and we will experience sporadic changes to climate.

The earth also has what I like to call the “2FP” - 2 factor protection. One of it was mentioned earlier in this article, the earth’s magnetic field which is generated from the earth's core, and helps to deflect the dangerous radiations coming towards the earth. But the earth's design is such that if peradventure the magnetic field could not deflect it, then comes into action the earth's atmosphere, which is designed to protect the earth from stray objects. So apart from the earth being designed to sustain life, it is also designed to protect those lives. This principle is similar to what we call the 2 factor authentication in our modern technological world. What would have been the probability of chance accounting for a two factor protection?

Over the past weeks I’ve read a lot of post from good authors where they have presented their science-motivated view about creation. Science has been so cool in giving logical explanation to stuffs about life, but haven't been able to explain how it actually got here. However the view of scientists, insurmountable evidences point to the fact that the earth was not a mere happening of chance.

Can you imagine what the odds are that the earth came to be the only known place in the vast universe that can support life? What is the probability of having one of the unique features of the earth happen by mere chance? What is the probability of having a planet just at the right size and position away from such a hot star as the sun in order to support life? One researcher compares it to finding a needle in a haystack!

I personally have my convictions, which I wouldn't impose on anyone. Everyone has a right to believe whatever he believes. But for a final line of thought, what if someone claims that a piece of technology, say a mobile phone existed by mere chance. That certain conditions were right at a certain time, and coincidentally, gbam, a cellphone! Would sound ridiculous, not so? How much more the complexity of life itself, which many microbiologist and life scientists, have not fully understood.

I enjoyed writing this piece, and I sincerely hope you do enjoy reading too, and join me in appreciating the masterful work put in making this earth a beautiful and conducive environment to live in. Earth is the third in the series am presently working on.

Till another time when we discuss another matter!

References

mass of the earth

How far is the earth from the sun

why earth has 4 seasons

effects of magnetic field

Science of earthquake

What is Gravity?

Planet Earth - Perfect position to support life

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