Theories about the Earth’s core are altering fast. For a long time scientists believed that, the Earth’s core was pure molten iron. However, new research shows that along with a large amount of molten iron, there are other elements within the core, for example, there is between 5% and 15% nickel at the Earths core. The same research by Oxford University (UK), California University, and The Swiss Federal Institute of Technology Zurich, shows that the composition of the Earth’s core is fundamentally different to the cores of the Planet Mars and the asteroid, Vesta. This could explain much about the differences between Earth and other planets in the solar system, scientists believe that their findings may soon explain why life emerged and evolved into sophisticated forms here rather than on Mars.
Scientists cannot experiment on the Earth’s core nor can they reproduce core conditions in the laboratory, because of the pressure and temperatures involved. Scientists study the core by observing how seismic waves travel through the core, and studying iron rich meteorites, and using computer simulations and models. Advances in digital technology have led to new scientific understanding of the Earth’s core.
The Earth’s core contains much iron; it is very hot and creates magnetic fields as radiation within the core decays. These spread out from the earth’s centre, and surround the two poles. Every few million years these reverse, scientists do not yet understand how or whether this affects life on Earth, what causes it, or when the next reverse will occur. It is possible that reversal weakens the field and some scientists think that a temporarily weak magnetic field could have something to do with evolution and may have caused conditions that led to the mass extinction of the dinosaurs. However, the Earth’s core is still maintaining the magnetic field. The Earth’s magnetic field protects the Earth and the life living upon it from dangerous particles in solar winds.
However, the Earth’s magnetic fields affect animals directly in their everyday lives. Some animals sense the Earth’s magnetic field and use it to guide them to food and on their migrations. Scientists know that turtles and bats find their way using the Earth’s magnetic field, although they are not certain how. Magnetite, in tiny amounts, has been found in animal brains and zoologists believe the magnetite is crucial in this natural Global Positioning System. Experts have long known that birds use the Earth’s magnetic field on their amazing migratory flights across the Globe. They now know that birds’ eyes have particular light reflective molecules in their eyes, meaning that they can see the magnetic field. These molecules connect with their brains and form a natural compass. Herd animals also lie in a magnetic north/south or south/north direction and bacteria align themselves in a similar way. Whales and Dolphins also use the magnetic field to navigate and experts believe that whales and dolphins may beach themselves when there are tiny disturbances within the field.
There has been much speculation as to whether the magnetic field affects humans. It is likely that, as with other animals, the magnetic field affects humans but nobody is sure how. Some people believe that mobile telephones, telephone masts, emit electro-magnetism. However, others believe that electro-magnetic therapy may help scientists understand the human brain. Fluctuations within the Earth’s magnetic field help animals detect Earthquakes, Tsunamis, and other geological disasters before humans. Humans are animals and if magnetic fields and fluctuations with those fields affect animals, why not humans and their health. Experts are unsure whether magnetic fields and fluctuations affect growing human brains, i.e. children’s brains.
The Earth’s core and its magnetic field may affect affects life on the surface in many ways. It may have triggered the dinosaurs’ great extinction. It certainly does affect animal navigation and migration, bird experts have known for a long time that bird migration used the field. Research on the connections between Life on Earth and the Earth’s magnetic field continue to inform scientific understanding of how the Earth’s core affects all life on Earth from bacteria to very complicated life forms. Scientists know that the Earth’s core affects life on Earth and they are learning how it does so. Understanding of this interesting and intriguing scientific area is growing constantly and it is likely that further research will lead to further revelations.