Md Jahedul Islam

Earth has a geographic North Pole and a South Pole. Due to geographical location both poles have no seasons other than winter and summer. In winter the sun does not reach the polar regions. In summer the opposite is true, i.e. the sun does not set in the polar regions. But in the polar regions the sun does not rise much above the horizon. When it's winter at the North Pole it's summer at the South Pole. Due to the slight tilt of the earth in its orbit the sun cannot be seen at the two opposite poles at the same time.

Apart from the geographic north and south poles the earth has two more poles. These two are the Earth's magnetic poles. That is like a magnet the earth also has two poles. Earth acts like a magnet. Surrounding the Earth is an invisible magnetic field known as the Earth's magnetosphere. The solidification of molten iron in the Earth's interior creates a strong magnetic field. It is under the influence of this magnetic field that the needle of the compass moves and indicates the direction. A compass needle is also a magnet. The south pole of the bar magnet faces the north pole of the Earth's magnetic field.

The reason for this is that two magnets attract with opposite poles and the opposite happens with equal poles i.e. repulsion. The location of Earth's magnetic north and south magnetic poles is completely different from the geographic north and south poles. There is a considerable distance between these two poles. The magnetic north and south poles are not fixed in the same place as the geographic north and south poles. Earth's magnetic field extends quite a bit into space. Earth is a powerful magnet floating in space.

This magnetic field is constantly protecting the earth from harmful cosmic rays. Without this magnetic field the planet Earth would not be habitable for life. This protective ring is constantly protecting the earth from the harmful rays of the sun. This magnetic field shields the Earth from the intense rays of the Sun and other harmful rays from space. Without this ring it would not be possible to imagine biodiversity on earth. Without the magnetic field the Earth's atmosphere would have been destroyed by the solar wind.

The intense radiation of the sun hit the earth. Then humans have need to build concrete shelters under the earth's crust to live. So it is scientifically proved that the role of this magnetic field is very important for our living. The Earth rotates on its axis once every 24 hours and the molten iron at its center rotates creating a magnetic field. However the Earth's magnetic poles change regularly and this change happens about once in two to three million years. At the center of the earth is a sphere of superheated solid iron.

Its temperature is about 5 thousand 700 degrees Celsius. Surrounding the central solid sphere is a relatively low-temperature liquid. The components of this liquid are mainly iron and nickel. Hotter and less dense material escapes to the outer layer due to temperature pressure and compositional differences. Similarly dense substances in the outer layer move to the inner layer. Basically it is an ongoing process. It's happening all the time. However, due to the high pressure of the Earth the very center sphere cannot be liquid.

The Earth is constantly rotating on its own axis from west to east in its orbit around the Sun. It takes the earth 23 hours, 56 minutes, 4 seconds to complete one rotation on its axis. As a result of this rotation of the Earth like the sun rises in the east and the sun sets in the west every day. That is as a result of this motion there is day and night on earth. This is the instantaneous speed of the earth. This rotation causes the Coriolis effect (apparent deflection of moving objects) at the center. Due to this a kind of vortex is created in the center liquid.

As a result electric current is generated. Because of this electric current an invisible magnetic field is created. An electric current is created due to the magnetic field when the electrically charged metal rotates in the liquid core. Magnetic field is created due to electric current. This cycle continues continuously.

As a result it can be felt that the energy at the center of the earth seems to be continuously generated without any outside help. The matter is actually a completely different form. This electric and magnetic energy is generated in the center from the rotational force of the Earth rotating at high speed due to the Sun's attraction. There is also the active influence of the internal energy of atoms and the thermal energy stored in the Earth's interior. So there is no danger of the earth's magnetic field suddenly disappearing. But what could profoundly affect the future of Earth and mankind—is the reversal of Earth's magnetic poles. Although this is a completely natural process. But the resulting dangers can be devastating and catastrophic. Such a dire situation can pose a serious threat to the existence of mankind.

According to researchers, when the Earth's magnetic pole reverses it can cause a terrible danger for Earth's fauna. Whis is known as 'mass extinction' (a situation where a natural disaster or an asteroid hitting the Earth's surface can cause the extinction of many species) could wipe out a large part of the Earth's biodiversity. Because the weakening of the magnetic field makes it impossible to protect the Earth from the sun's harmful rays. These rays can be fatal to animals. The last magnetic pole reversal occurred about 780,000 years ago. Meanwhile modern research has shown that since the 1980s, the Earth's magnetic field has begun to weaken unusually. In particular in a region called the South Atlantic Enum the magnetic field has become almost useless. This region covers one-fifth of the Earth's surface. Because of this weakness researchers believe that the Earth's magnetic pole may reverse in the next few years.

Meanwhile without the Earth's magnetic field the catastrophe would have been triggered by electromagnetic interference and radio-wave interference. As a result the earth's radio waves would have become ineffective. Wireless communication would have been destroyed. In this situation the birds lost their direction would fell from the sky to the ground. Plane will went out of the control. In the meantime the world's electricity supply would have stopped. The free flow of the solar wind would have destroyed the Earth's atmosphere. There was a time when there was no air to breathe in the world. Currently the Earth's magnetic field keeps high-energy particles from the Sun and the solar wind out of the Earth's atmosphere.

Because of this auroras are seen at the North and South Poles. Also if the Earth's magnetic field were to disappear then the atmosphere would be depleted. As a result the atmospheric pressure of the earth will also decrease. As atmospheric pressure decreases sea water will evaporate more rapidly. At some point air and water will disappear completely into space. Earth will become a desert like Mars without air and water. At this time even if a person is alive on the surface of the earth cancer will appear in the body due to the effect of the sun's radiation. Due to the lack of radio waves the artificial satellites that were once in the orbit of the earth will also start falling to the earth. Natural disasters like earthquakes, landslides, eruptions can also occur in the world.

Electrical appliances, circuits, power grids and communication systems will be severely damaged. As a result satellites, mobile phones, the Internet—nothing will work. In such a situation mankind will return to a dark age. Where modern technology will not exist. In a word if the magnetic field disappears, extreme disaster will descend on the earth in a very short time.

According to recent research results this mystery of reversal of the Earth's magnetic pole may be a new challenge for mankind. The results of this study will become more clear in the near future. Natural disasters are happening all over the world. There is also no shortage of cosmic dangers. Amidst everything we have to play the biggest role in keeping the world beautiful and livable. We should take special attention for protecting the nature and life.

The writer is a, Network Technician (ICT Cell) Jagannath University, Dhaka.