The following quote is from a physical geology textbook about magnetite:
Many organisms, including human beings, create magnetite within their skull cases. Some researchers believe that birds and whales exploit the properties of this mineral to assist them in migratory navigation (Why do we make magnetite in our own heads?)
I wanted to know more about this topic, so I searched phrases like “magnetite brains” and came up with some unusual google results. I have found very little actual information as to why magnetite is produced in our brains, but I did find a lot pseudo-science and fraudulent claims for the benefits of ingesting it. Magnetite is an iron oxide which some people eat believing that it will increase their iron levels. I’m not even sure if the body absorbs that type of iron because most supplements given as prescriptions are iron sulfates. An individual can only absorb about 100mg of iron per day while the rest passes through the system. There are several pills, powders and potions that advertise the main ingredient as magnetite. It is touted as a miracle drug which the manufacturers claim can be used as a cure for restlessness, tremors, convulsions, irritability, dizziness, vertigo and blurred eyesight. The “magic magnetic pills” can act as a stimulant like coffee but also have the ability to calm the spirit. It is said to balance the hemispheres of the brain. Nutritional reasons and homeopathic remedies are not the main reason for the product, though. There is a belief that magnetite supplements increase telepathic and psychic abilities.
I have never been able to understand why anyone would want the ability eavesdrop on the thoughts of others. I don’t want to know the uncensored things that people think. What goes on in my mind is confusing enough. Do you want to know what goes on in my mind the majority of the time? Repetitive thoughts and phrases.
Electricity and magnetism are really two forms of the same thing. A strong magnetic impulse can change the electrical signals in our brain. A relatively new technology called Transcranial Magnetic Stimulation (TMS) uses a powerful magnetic pulse to control a person’s motor skills. The neurobiologist uses a map of the brain and then places the powerful magnet over a particular area of the skull to manipulate a specific body part. The video I watched showed how the pulse could make a man’s fingers or toes move. It even has an effect on someone’s speech. For example, a man was counting and his speech became slurred when the magnetic pulse was placed over a specific part of the skull, but immediately after it was removed his speech returned to normal. The clinical use of TMS is used as a possible treatment for psychiatric illnesses such as depression and also to control physical pain.
I read an article from livescience which stated that a protein found in the human retina, when placed into fruit flies, has the ability to detect magnetic fields. It is thought that many animals sense magnetism through proteins called cryptochromes.
This is from the livescience article:
They placed the fruit flies into a T-shaped maze, with each arm equipped with a coil wrapped in such a way that when a current was sent through it, the coil became magnetized. The team varied which side was magnetized and its strength, which went up to eight times that of Earth’s magnetic field.
The flies with the human cryptochromes showed sensitivity to the magnetic fields – either avoiding them as they might naturally do if not acclimated to the magnetism, or showing a preference for the magnetized arm of the maze when trained with sugar rewards to go toward the magnetic field.
The human protein only worked in the blue range of light, the researchers found.
Personally, I would have liked to have been a fly on the wall when this experiment was being carried out. I have worked with a number of fruit flies in biology lab, but I’m not exactly sure how one goes about training a fruit fly to do anything. The study also used an unnatural level of the Earth’s magnetic field, so the findings are not particularly useful in actual conditions.
There are other studies which suggest that birds might also be able to see the Earth’s magnetic field. Many migratory birds travel only at night. (As I was writing this post, a bird flew into directly into the window in my living room. It’s OK and flew off seemingly unharmed. ) A scientist who studied this phenomenon said,
“Birds also use the sun and stars to navigate, but we’re not certain how,” Mouritsen said. “How do they compute all of this information and end up with a direction to fly in? There are so many steps in this process we simply don’t know about.”
Do you see what he said? “Birds also use the sun and stars to navigate, but we’re not certain how.” I think that birds navigate more by the sun, stars and landmarks than by magnetic fields. If birds relied solely on magnetic fields, then it wouldn’t matter if they traveled during the night or day. Sea turtles are also said to use the Earth’s magnetic field to navigate, but I find that somewhat doubtful. When sea turtles hatch, they will try and walk toward the light of the moon reflected on the surface of the ocean. If there are street lights nearby, then they will walk toward those. The baby sea turtles are relying more on their sense of sight and not using the Earth’s magnetic field to find the ocean.
I don’t think humans use the power of magnetism as a main source to navigate, either. Think about it a little bit. If you have a GPS, how often do you pull out a paper map to use for directions? If you only have a paper map, how often do you use the sun or stars to assist you in navigation? If you can use the sun and the stars for navigation, how often would you rely on a slight “magnetic feeling” in getting where you need to go? Some might argue that it would be useful to have an internal compass which could assist in physical orientation and give the most direct route. I grew up in the mountains and so north-south-east-west have little bearing on how direct a route is. If you want to go directly north, but a large mountain range is in the way, then it isn’t the most efficient way to go north. Maybe if we were magnetotactic bacteria, then the Earth’s magnetic forces would be our only and most useful way to navigate through our environment. Luckily, we are not magnetotactic bacteria :)