Earth's magnetic field, although generated about 2,000 miles below the surface, protects the planet's atmosphere from space radiation and the solar wind. It is essential, therefore, for life. The strength of the magnetic field, however, is rapidly decreasing; in the last 300 years alone its strength has decreased by 10%. By first exploring what the magnetic field is and where it comes from, this film is able to postulate the reasons for this rapid decline and its potential effects. The proposed ideas are largely based on expert opinions, computer simulations and physical models. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay The magnetic field works like a feedback loop; the combination of magnetism, heat and movement in the Earth's core creates an electric current. This current leads to greater magnetism, which in turn leads to stronger electric currents and so on. Ultimately, this complex process creates the overall magnetic field. Because of its magnetism, the field deflects charged particles away from Earth, thus acting as a shield from solar radiation. Without it, the atmosphere would be slowly stripped away and all life forms would be exposed to deadly radiation. The magnetic field, therefore, is part of what makes life on Earth sustainable. Having a magnetic field, however, does not make the Earth unique. Magnetic volcanic rock found on the surface of Mars shows that, until about 4 billion years ago, Mars also had a magnetic field. Its core, however, cooled and solidified, thus halting the motion that allowed its magnetic field to exist. Since there was no longer a “shield” to protect it, Mars' atmosphere was blown away by solar winds. This process suggests that if Earth's magnetic field were to dissipate, for reasons similar or different to those of Mars, the planet would also lose its atmosphere and, consequently, the life it supports. Today, scientists can tell that the strength of the Earth's magnetic field is decreasing by analyzing substances such as volcanic rock and clay pottery. Once cooled, the magnetic particles present in these substances align with the magnetic field. These particles, therefore, denote the intensity of the field at the time of cooling as well as its direction: that is, where the geomagnetic poles were located at the time of cooling. These analyzes show that it is relatively common for the strength and direction of the magnetic field to fluctuate; Current estimates suggest that, on average, the direction of the magnetic field changes every 200,000 years. The strength of the magnetic field can indicate when there will be a reversal of the North and South geomagnetic poles. The field is often weak when patches of anomalies are evident. (Anomalies are local variations in the magnetic field where the polarity is opposite to what is assumed to be based on position.) These variations cancel the polarity of the magnetic field, therefore decreasing its intensity. The anomalies will eventually begin to connect, creating larger and larger anomalies until the polarity of the entire magnetic field reverses. It is possible, therefore, that the current rapid decline in magnetic field strength that the Earth is experiencing is due to the fact that the Earth's magnetic field will reverse (relatively) soon. Due to this weakening, more radiation reaches Earth's inhabitants, thus increasing cases of skin cancer. Likewise, anomalies are currently affecting navigation, as well as inversion. Please note: this is just an example. Get a custom paper from our expert writers now. Get a custom essay The Silver Linings Playbook,.