The magic of Aurora lights

For those planning a holiday to the Arctic, there is plenty to look forward to; the incredible frozen landscapes and rich cultures that inhabit them, and the wildlife that is like nothing else on Earth, are more than enough to make anyone fall in love with our planet's northernmost regions. And that is without mentioning one of the most awe-inspiring elements of polar expeditions: the aurora Lights.

What are aurora lights?

The aurora or polar lights have intrigued those who see them on polar expeditions since time immemorial, appearing as a brightly colored light in the Arctic night sky. These lights are caused by the collision of charged electrons with atoms in our atmosphere. These electrons come from the sun on solar winds and are then redirected by the Earth's magnetic field, which acts as a buffer against those solar winds. So in essence, the beautiful flow of light across the sky is in fact a visual effect of the planet's in-built defences against solar radiation. The varying colors of the lights depend on the kinds of atoms they encounter as they flow through the magnetosphere and into the upper atmosphere: oxygen causes green and red lights, while nitrogen causes blue and purple lights. The contour and flow of the aurora lights is caused by the continual shifting of these forces and elements.

When Can You See Northern Lights?

The best time to see the lights is in the winter months. The reason for that is that the sky is its darkest in the winter and no other lights appear in the sky to distract from the beautiful show.

The area that has the most views of the aurora lights is the arctic or the antarctic. You can see them almost every other night if the sky is clear. The truth is that you can see the lights in the regions south and north of the aurora zone as well.

Why are aurora lights important to us?

Auroras are essentially geomagnetic or electromagnetic phenomenon. They Auroras are capable of producing high electrical impulses, and can easily meddle with the electric fields on the earth. Sudden disrupting of electric power supply occurs due to interference with the power grids.

Telegraph lines have been reported to be affected and rendered totally useless during the occurrence of these Auroras.

The Auroras have also been known to affect the weather, but precise and exact information seems to be missing. Yet it can be firmly said that the occurrence of the Auroras have been found to accelerate the storms originating in the North pacific, as compared to other times.

The temperature has also been known to be affected by these Auroras. People living in the areas which witness these polar lights often report the air to become quite crisper and chilly during the Auroras.

Astronomers are trying to discover methods aimed at predicting the occurrence of these Auroras, in order to gain control over their effects on the earth in a more better way.

How Does An LDR Work And What Are Its Applications

The LDR (Light Dependent Resistor) is also known as a photoconductor, photo resistor, photoconductive cell or simply photocell. However, it is typically called by the term photocell at present. The LDR is utilized as an inexpensive photosensitive element and has a wide usage in various applications at present. In the subsequent paragraphs, we will throw some light on how LDR functions and also some of its uses.

How does it work?

The fundamentals of the working principles of an LDR can be easily understood by virtually any person without any need to enter into complex details. First of all, one must comprehend the fact that an electric current is actually the movement of the electrons within a particular material. There are lots of free electrons in the good conductors and the actions of a potential difference are responsible for moving them in a specific direction.

Since there are not many free electrons in insulators having a high resistance, it is quite difficult for current to flow by drifting them. As a matter of fact, a Light Dependent Resistor is made out of any type of semiconductor material having a high resistance.

The number of free electrons which are able to move is quite less and therefore it has a high resistance; most of the electrons are not able to move since they are locked into the crystal lattice. Consequently, there is a high LDR resistance in this particular condition. The lattice absorbs the light photons when light falls on the semiconductor and this results in the transfer of energy to the electrons. In this way, some of them are able to break free from the lattice by getting energized and this enables them to conduct electricity.

Thus, the semiconductor's resistance along with the overall LDR resistance gets lowered. An increasing number of electrons get released as more light falls on the semiconductor which enables them to conduct electricity and therefore there is further lowering of resistance.

Usages

Due to its simple structure, low price plus tough features, the LDR is nowadays used in lots of electronic circuit designs. In fact, it is appropriate for many applications despite the fact that it lacks several features which are present in the phototransistor and the photodiode. It has got a wide usage in circuits like smoke or flame detectors, card readers, burglar alarms, and photographic meters and so on.

Hopefully, this article has provided you with adequate information regarding what exactly is an LDR, its working principles as well as its applications. In case you have further queries, just go online and get the necessary information from the web.

Three Japanese Blue LED Inventors Awarded Nobel Physics Prize

The 2014 Nobel Physics Nobel Prize was awarded to three Japanese scientists who invented the very first efficient blue LEDs (Light-Emitting Diodes) in the mid-1990s. This was a game-changing breakthrough that made blue LED lighting possible.

The prize worth $1.1 million was awarded to Hiroshi Amano, Islam Akasaki, and Shuji Nakamura “for the invention of highly efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources.”

Reports say that the magical breakthrough “triggered a fundamental transformation of lighting technology.”

Before the Blue LEDs Invention….

Before the 1990 invention, only red and green light-emitting diodes were being used. You would find them in modems, VCRs, TVs, displays, and other electronic devices. Manufacturers were also mainly focused on indicator lights in toys, and for automotive and industrial applications.

At the end of 1990, everything had changed as the blue LEDs were now being used on almost every electronic gadget. Every gadget maker was now keen on installing these lights in their products. Blue light LED products were increasingly becoming popular too.

The Game-Changing Invention

In the 1990s, the three physics geniuses discovered that gallium nitride GaN (an exotic material used in light-emitting diodes since 1990s) had great capability in creating highly efficient and super-bright blue LEDs.

The invention also utilized indium-gallium-nitride (InGaN) quantum which was found to not only improve the efficiency of the LED lamps, but also allowed for tuning of the light frequency.

Years later, blue LEDs have become even more efficient and the fact that all LEDs are based on solid-state electronics, with technological advancements, we expect to see more efficient and brighter lamps in just a few years.

Great Future Improvements Economically

A statement given by the Royal Swedish Academy of Sciences said that LED lamps would improve the life quality of over 1.5 billion people around the world- people who lack good access to electricity grids as thanks to their low power requirements, the lamps can be powered by cheap local solar power.

The statement also pointed out the environmentally friendly properties of blue LEDs which include low energy and material consumption.

William Rhodes also pointed out that the invention created more than 250,000 jobs including a $17.7 billion market. It was without a doubt a huge boost to the economy.

It’s a game-changing invention that has greatly improved the lives of many people around the world and the economy as well. The three geniuses triggered a revolution in the lighting industry and without a doubt, they so deserved the Nobel Physics Prize.