Subject: Science and Technology

What is Google’s project loon ?

Many of us think of the Internet as a global community. But two-thirds of the world’s population does not yet have Internet access.

Balloon powered Internet: Project Loon is a network of balloons traveling on the edge of space, designed to connect people in rural and remote areas, help fill coverage gaps, and bring people back online after disasters.

Then, How it exactly works ?

• Project Loon balloons travel approximately 20 km above the Earth’s surface in the stratosphere.
• Winds in the stratosphere are stratified, and each layer of wind varies in speed and direction.
• Project Loon uses software algorithms to determine where its balloons need to go, then moves each one into a layer of wind blowing in the right direction.
• By moving with the wind, the balloons can be arranged to form one large communications network.

How is the Loon designed ?

• The inflatable part of the balloon is called a balloon envelope.
• Each balloon’s electronics are powered by an array of solar panels.
• The panels produce approximately 100 Watts of power in full sun, which is enough to keep Loon’s electronics running.
• Project Loon is able to power itself using entirely renewable energy sources.

How does it connect?

• Each balloon can provide connectivity to a ground area about 40 km in diameter using a wireless communications technology called Long-Term Evolution (LTE).
• With this LTE, people will be able to access the Internet everywhere directly from their phones and other LTE-enabled devices.
• Balloons relay wireless traffic from cell phones and other devices back to the global Internet using high-speed links.

Very quickly then, what has Loon upto all this while?

• Project Loon began in June 2013 with an experimental pilot in New Zealand.
• The results of the pilot test as well as subsequent tests in New Zealand, California’s Central Valley and in Northeast Brazil were analysed.
• They were used to improve the technology in preparation for the next stages of the project.

What are Superpressure balloons?

• Superpressure balloons are made out of tightly sealed plastic capable of containing highly pressurised lighter-than-air gases.
• The concept was first developed for the US Air Force in the 1950s using a stretched polyester film called Mylar.
• More recently, Nasa has experimented with the technology and suggested superpressure balloons could one day be deployed into Mars’s atmosphere.

What’s the way forward for Google balloons?

• Google suggests that Project Loon would be a cheaper solution than installing fibre optic cables or building mobile phone masts across all of Indonesia’s islands, which contain jungles and mountains.
• Google is in talks with the Indian government to deploy this wind power project here. The company hopes to begin production by 2016.
  

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Published with inputs from Arun

Recent visit of Narendra Modi’s visit to Tesla Motors plant in San Jose, caught his attention to renewable energy technology, where the company’s CEO Elon musk introduced him to Powerwall battery technology.

<Civil service aspirants cannot afford to miss such news, as it would have caught the attention of UPSC, I hope you remember the Prelims question on NFC technology>

What is Powerwall Technology ?

• It is a wall-mountable, high-capacity lithium ion battery that can be charged using power generated through solar panels.
• Dimension – 4 feet tall , 3 feet wide and 7 inches deep.
• It stores energy for commercial or domestic use.
• It comes in two variants – 7 kwh & 10 kwh.

What is a Power Pack ?

• It is a scaled- up version of the powerwall, and can provide up to 100 kwh.
• They can be scaled to megawatt- and gigawatt-sized power solutions.

How are these batteries special ?

Currently, Powerwall technology would eliminate the need for cables & massive infrastructure, present in a conventional grid system.

CEO remarked -“The Powerwall would do to the conventional grid system, what mobile phones did to fixed line phones, eliminating the need for cables and massive infrastructure“.

What Tesla has done to Lithium-ion technology ?

• It has improved the lithium-ion technology.
• It has also integrated massive power capacities – up to 6 times the capacity of a common lead acid battery in a single powerwall in a small space.
• They are built to work for a period of 10 years, while most lead acid batteries die in 3 to 4 years.

Is there any relevance for India ?

Can they solve the problem of power-hungry rural homes!!

• Govt. has envisaged supply of 58W to each household, with 2 light point of 9W and a socket of 40W for gadgets, under its rural electrification programme.
• In this scenario, Powerwall would be good for multiple households.
• Localised micro-grids could generate electricity from solar energy for villages not connected to the main grid.

Published with inputs from Pushpendra

On 27 September, an evening remembered for skywatchers or stargazers in most parts of the world, for they were witness to a rare celestial event, aptly described by many as “once in a generation”.

An exceptional celestial treat is in store for sky gazers as the event, called the Super Blood Moon, saw the Supermoon phenomenon combine with a lunar eclipse (where the Sun, the Earth and a brighter, much larger Moon lined up together).

The result? The Moon appeared blood red in colour, nearly 30% brighter.

So, What exactly The Supermoon Is?

A Supermoon is a phenomenon that occurs when, a full or new Moon coincides with a Moon that is nearing its minimum distance (perigee) to Earth.

The Moon takes an elliptical orbit around Earth, which means that the average distance between the two changes from as much as 405,000km (its apogee) to as low as 363,000km at the perigee.

Simply put, the Supermoon occurs when the Moon is at its closest to the Earth. NASA says the phenomenon can make the Moon appear larger by nearly 14% larger than its usual visible size.

But, Why the Moon turns red during a total lunar ?

During a total lunar eclipse, white sunlight hitting the atmosphere on the sides of the Earth gets absorbed and then radiated out (scattered). That is, the atmosphere filters out (scatters away) most of the blue-colored light and what’s left is the orange and red coloured light.

This red coloured light passes through our atmosphere without getting absorbed and scattered, before the atmosphere bends it (refracts it) back out, projecting indirect, reddish light on to the Moon.

The reddish light projected on the Moon is dimmer than the full white sunlight that the Moon typically reflects back to us. That’s because the light is indirect and because the red-coloured wave lengths are only part of what makes up the white light from the Sun that the Moon usually receives.

When we see a sunrise or sunset from our perspective on Earth, sunlight is coming in at a low angle. It has to travel through a lot of atmosphere, scattering more and more blue-colored light as it goes until what is left when the light reaches us at these day/night transition times is the more reddish wavelengths that get through.
But, interesting fact is that everyone may see a Moon that is brick-coloured, rusty, blood red or sometimes dark grey, depending on terrestrial conditions.

Do you know next appearance is directly in 2033 ?

Don’t worry, we have full coverage here.

Sunday’s event was the first Supermoon lunar eclipse in over three decades. The last time the two phenomena combined was in 1982. The next such occurrence is expected to be 18 years later, in 2033. Sunday also saw the fourth instance of a blood Moon in the last two years as part of the “tetrad series” or a series of four consecutive total eclipses occurring at intervals of approximately six months.

So, is that We’re basically seeing all of the sunrises and sunsets across the world, all at once, being reflected off the surface of the Moon, How amazing it is !

Published with inputs from Arun