Category Archives: Natural Life

How Magnets Work

A magnet is any object that has a magnetic field. It attracts ferrous objects like pieces of iron, steel, nickel and cobalt. In the early days, the Greeks observed that the naturally occurring ‘lodestone’ attracted iron pieces. From that day onwards began the journey into the discovery of magnets.

These days magnets are made artificially in various shapes and sizes depending on their use. One of the most common magnets – the bar magnet – is a long, rectangular bar of uniform cross-section that attracts pieces of ferrous objects. The magnetic compass needle is also commonly used. The compass needle is a tiny magnet which is free to move horizontally on a pivot. One end of the compass needle points in the North direction and the other end points in the South direction.

The end of a freely pivoted magnet will always point in the North-South direction. The end that points in the North is called the North Pole of the magnet and the end that points South is called the South Pole of the magnet. It has been proven by experiments that like magnetic poles repel each other whereas unlike poles attract each other.

Magnetic Fields

What is a magnetic field? The space surrounding a magnet, in which magnetic force is exerted, is called a magnetic field. If a bar magnet is placed in such a field, it will experience magnetic forces. However, the field will continue to exist even if the magnet is removed. The direction of magnetic field at a point is the direction of the resultant force acting on a hypothetical North Pole placed at that point.

Magnetic fields are produced by the motion of electrical charges around an electrified wire.

How is a magnetic field created?

When current flows in a wire, a magnetic field is created around the wire. From this it has been inferred that magnetic fields are produced by the motion of electrical charges. A magnetic field of a bar magnet thus results from the motion of negatively charged electrons in the magnet.

Magnetic Lines Of Force

Just as an electric field is described by drawing the electric lines of force, in the same way, a magnetic field is described by drawing the magnetic lines of force. When a small north magnetic pole is placed in the magnetic field created by a magnet, it will experience a force. And if the North Pole is free, it will move under the influence of magnetic field. The path traced by a North magnetic pole free to move under the influence of a magnetic field is called a magnetic line of force. In other words, the magnetic lines of force are the lines drawn in a magnetic field along which a north magnetic pole would move.

The direction of a magnetic line of force at any point gives the direction of the magnetic force on a north pole placed at that point. Since the direction of magnetic line of force is the direction of force on a North Pole, so the magnetic lines of force always begin on the N-pole of a magnet and end on the S-pole of the magnet. A small magnetic compass when moved along a line of force always sets itself along the line tangential to it. So, a line drawn from the South Pole of the compass to its North Pole indicates the direction of the magnetic field.

Properties of the magnetic lines of force

  • The magnetic lines of force originate from the North Pole of a magnet and end at its South Pole.
  • The magnetic lines of force come closer to one another near the poles of a magnet but they are widely separated at other places.
  • The magnetic lines of force do not intersect (or cross) one another.
  • When a magnetic compass is placed at different points on a magnetic line of force, it aligns itself along the tangent to the line of force at that point.

These are just some of the basic concepts of magnetism. One cannot possibly grasp the depth and appreciate the versatility of magnets without reading more about the uses of magnets, the Earth as a huge magnet and electromagnetism among other things.


The Jungle Eagle

The harpy eagle (Harpia harpyja) is a neotropical species of eagle. It is the largest and most powerful raptor found in the Americas,[4] and among the largest extant species of eagles in the world. It usually inhabits tropical lowland rainforests in the upper (emergent) canopy layer. Destruction of its natural habitat has caused it to vanish from many parts of its former range, and it is nearly extirpated in Central America. In Brazil, the harpy eagle is also known as royal-hawk.

Deep Sea Fish Farming

In this episode of Upgrade, Motherboard goes to Baja California, Mexico to get a firsthand look at these free floating pods, and to get an understanding for why we need better ways to cultivate our future food sources.

Whether it’s found on a plate of sushi, grilled in our backyard, or thrown on pasta, seafood is a staple for many diets around the world, and demand is growing. And as the commercial seafood industry booms, fish stocks worldwide face perilous declines.

We’ve surpassed our capacity to sustainably fish wild caught fish, shrimp, and mollusks from the ocean, and so we’ve turned to aquaculture, or fish farming, as a strategy to meet demand for our growing appetites for water-borne critters. The aquaculture industry is growing fast. According to the FAO, per capita production of seafood from aquaculture has increased 6.9 percent annually since 1970.

Unfortunately for us and for our Earth, current methods of fish farming often involve crowded, tethered pens, which can have poor water circulation and contribute to the spread of disease, and put large amounts of environmental stress on the surrounding waterways.

This is where Steve Page of Ocean Farm Technologies comes in. Taking inspiration from naturally-occurring schools of fish and Buckminster Fuller’s geodesic domes, Page co-designed the Aquapod, a free floating, untethered deep ocean fish habitat which reduces overcrowding, and creates less stress on surrounding environments due to its unique ability to change location with the ocean’s current.

Portable River Turbine

These turbines for rivers and canals allow for the introduction of a base load supply, providing a complete renewable energy solution for the best cost-benefit possible. This proprietary technology is standardized and easily scalable. Although qualifying as “green”, these products are positioned as the best alternative for decentralized electrification along rivers.

The Smart Hydro Power turbine was developed to produce a maximum amount of electrical power with the kinetic energy of flowing waters. Because it is powered by kinetic energy instead of potential energy, it is known as a so-called “zero-head” or “in-stream” turbine. As such, no dams and/or head differential are necessary for the operation of this device; the course of a river remains in its natural state and no high investments in infrastructure are required. Because the amount of kinetic energy (velocity) varies from river to river, a greater amount of energy is generated with a higher velocity of water flow.