Ever wonder – What Major World Cities Look Like at Night, Minus the Light Pollution

In a stunning montage of pictures, Smithsonian Magazine published an article on just about that topic. How does it look at night? Has pollution really taken away the charm of beautiful nights?

Thierry Cohen, took up the challenge some three years ago when he started on a world wide tour to take pictures of major cities minus all the light & air pollution. Cohen fears, as he recently told the New York Times, that the hazy view has spawned a breed of urbanite, sheltered by his and her manmade environs, that “forgets and no longer understands nature.”

Well, here take a look:



San Francisco 37° 48′ 30″ N 2010-10-9 Lst 20:58. © Thierry Cohen 


Tokyo 35° 41′ 36″ N 2011-11-16 Lst 23:16. © Thierry Cohen.

Tokyo 35° 41′ 36″ N 2011-11-16 Lst 23:16. © Thierry Cohen.


São Paulo 23° 33′ 22″ S 2011-06-05 Lst 11:44. © Thierry Cohen.

São Paulo 23° 33′ 22″ S 2011-06-05 Lst 11:44. © Thierry Cohen.


Paris 48° 50′ 55″ N 2012-08-13 Lst 22:15. © Thierry Cohen.

Paris 48° 50′ 55″ N 2012-08-13 Lst 22:15. © Thierry Cohen.


Los Angeles 34° 03′ 20″ N 2010-10-09 Lst 21:50. © Thierry Cohen.

Los Angeles 34° 03′ 20″ N 2010-10-09 Lst 21:50. © Thierry Cohen.


Hong Kong 22° 16′ 38″ N 2012-03-22 Lst 14:00. © Thierry Cohen

Hong Kong 22° 16′ 38″ N 2012-03-22 Lst 14:00. © Thierry Cohen




Green Nuclear Plants? You must be kidding !!

With a world besieged by global warming and the global population set to hit nine billion by 2050, sustainable energy production has become a major issue for all developing countries. In this, comes the new fangled technology dubbed as “Green Nuclear Energy”. 

In a series of TED talks, Kirk Sorensen a  former NASA aerospace engineer and former chief nuclear technologist at Teledyne Brown Engineering has been propagating the idea of “Green Nuclear Energy”.

This idea rests upon using thorium based on liquid fluoride thorium reactor.

The liquid fluoride thorium reactor is a thermal breeder reactor that uses the thorium fuel cycle in a fluoride-based molten (liquid) salt fuel to achieve high operating temperatures at atmospheric pressure.

The pro-thorium lobby, led by Kirk Sorensen claim that a single tonne of thorium burned in a liquid fluoride thorium reactor (LFTR)  can produce one gigawatt of energy. A traditional pressurized water reactor (PWR) would need to burn 250 tonnes of uranium to produce the same amount of energy. Further claims also include them producing less waste, having no weapons grade by-products, and are meltdown proof.

So, if all these claims are true then why aren’t all countries throughout the world using them ?

The answer is multi-fold and let me tell all the potential disadvantages about it which the TED talks won’t be telling you.

  1. None have been built- Yes, though the idea exists from several decades, but has never been brought to fruition.  Only a few LFTRs have actually been built; those experimental reactors had been constructed more than 40 years ago. So, this technology has is difficult to critically assess.
  2. Startup fuel– Unlike the uranium based reactors, mined thorium does not have a fission isotope.  Thorium reactors breed fissile uranium-233 from thorium, but require a considerable amount of U-233 for the initial start up. Currently there is very little of this material available. This raises the problem of how to start up the reactors in a reasonable time frame. The two alternative options for LFTR startup are enriched uranium and plutonium from reactors or decommissioned bombs. For enriched uranium startup, a quite high enrichment is needed. Decommissioned uranium bombs have a high enough enrichment, and would simultaneously dispose of weapons grade uranium, but not enough is available to start up a large number of LFTRs.
  3. Waste management –  There is still a need to manage the waste, which is still very radioactive, even though it is hazardous for a shorter period.
  4. De-commissioning costs – The costs for decommissioning a French reactor based on LFTR was  $ 130 million. As more reactors have not been constructed or experimented, it is highly unlikely the costs will decrease anytime in future.
  5. Other toxicity concerns – Other concerns include beryllium toxicity, risk of potential proliferation of radioactive salts, neutron poisoning, corrosion concerns due to tellurium buildup, radiation damage to nickel alloys used in  constructing the primary fuel salt loop.

So what now?

Various developing countries, especially India with world’s largest thorium deposit is pushing to get these LFTRs up and running. Development of thorium based reactors is merely a way of deflecting attention and criticism from the dangers of the uranium fuel cycle and excusing the pumping of more money into the nuclear industry.In a post-Fukushima world,the nuclear industry is searching for its own version of radioactive holy grail- safe reactors producing more energy for less and cheaper fuel.

With billions of dollars already spent on nuclear research, reactor construction and decommissioning costs, dwarfing commitments to renewable energy research, the thorium dream is considered by many to be a dangerous diversion.

In the end, despite the hype and pitfalls it represents i ask all of you out there, do you think it is better to spend billions of dollars to commission, research and install these new nuclear power plants or is it high enough time to invest seriously on renewable energy ?

With these thoughts, i leave you folks to read more on this:

  1.  Thorium Fuel – No Panacea for Nuclear Power, Institute for Energy and Environmental Research, 2009.
  2. Is thorium the answer to our energy crisis?, Independent, 2006
  3. Liquid Fluoride Thorium Power: Pros and Cons, Triple Pundit, 2012.
  4. Benefits of Thorium Are ‘Overstated’, UK Report Finds, Clean Technica, 2012

The undisputed legacy of Aaron Swartz


Aaron Swartz – Genius, Child Prodigy, Hacker, Activist died last Saturday and caused a media furore throughout the world. Every big media outlet posted their eulogies, postscripts about him. So, who was he and what was his legacy?


Aaron Swartz first came into limelight when at the age of 14 he helped develop the Real Simple Syndication (RSS) 1.0 specification. The RSS specification is a family of web feed formats which are used to publish works which are frequently updated—such as blogs, news headlines—in a standardized format. The Open Library, which has a lofty aim of publishing every book on earth online was also his work. As was Infogami, which later on merged with Reddit and made him financially independent and free himself to pursue various causes.


Ever since winning the  ArsDigita Prize, a competition for young people who created “useful, educational, and collaborative” non-commercial Web sites he had been associated with Open Source /Open Code movement. After the Stop Online Piracy Act (SOPA), was unleashed by the US government, he formed the group Demand Progress which was responsible for halting the juggernaut in its tracks. But, his activism and interests were not limited to open Source but ranged from health care to public policy.


In September, 2008, he used an automated program to free up nearly twenty million pages of federal court records from a government-run database. Though this act of his was on a legal borderline, but FBI decided to make a database about him. This however, was not the last such incident for some years later he used his MIT internet access to download  few million scholarly articles from JSTOR. Things became really serious after this, as he was charged by the U.S. Attorney for Massachusetts with computer fraud and other charges that carried a potential sentence of 35 years in jail and $1 million in fines. JSTOR later on, decided to drop the case, but US Attorney  Carmen M. Ortiz decided to go ahead with the trial, which was expected to begin sometime later this year.

The manner in which he was charged with and the fact that despite JSTOR dropping the case, he was still facing a court date has surfaced stories about his persecution. Swartz’s family in a statement blamed his suicide in part to the unending atmosphere of intimidation and judicial overreach.  


Aaron Swartz’s legacy would always be the Open Source/Open Web/Open Code movement he was a part of. Whatever legal disputes may have surrounded him or the clinical depression he suffered in his final days, his legend as the Champion of Open Web would grow for years to come.

Hats off, Aaron !!