Cave Dates and Climate Estimates May Be Off

first_imgThe steady drip, drip, drip of water from stalactites should provide a way to calculate the age of cave formations, right?  Don’t be too sure.  A scientist at Florida State found that calcite deposition is a function of how the cave “breathes,” reported New Scientist.  This finding “pours doubt on ancient climate records derived from these structures.”    Climate researchers have no way of directly recording temperature for dates before about 1850.  They use “proxy measurements” from tree rings, ice cores, cave formations and written descriptions.  Tree ring measurements have come under fire lately with the Climategate scandal.  It appears the use of cave formations for estimating prehistoric climate records is now subject to question.  “Some records of ancient rainfall may be skewed, as estimates based on stalactite formation assume year-round mineral deposition,” the article said.The point to remember here, without getting into details about the extent of possible misinterpretation, is that all dating methods make assumptions.  A geologist sees the steady dripping from a stalactite, measures the calcite deposition on the stalagmite below, calculates the deposition as a function of drip rate, and then extrapolates the measurements hundreds of thousands of years back in time.  Can any geologist possibly know all the factors that could affect the deposition rate?  This article pointed out one, but there could be many others.    The estimation of ancient climate is just as fraught with assumptions.  If the geologist establishes a plausibly reliable deposition rate under current conditions, he or she might infer from slight differences in composition in a cross-section of a stalactite how the climate cooled or warmed over time.  But some factors might not correlate together.  They could counteract one another in all kinds of ways.  To show this story is not an isolated case in Florida, recall the 01/19/2006 finding in Texas about kinetic factors including the angle of the glass plate a scientist might use to collect data, or the presence of a warm human body in the cave.  South African scientists, frustrated with anomalous measurements, concluded that “the constant speleothem growth rate we assume is simplistic” (10/12/2004, bullet 4).    The unknown factors are the most worrisome.  This story points out that theory-destroying factors no one ever thought about, like cave bears, could be lurking in dark passages.(Visited 13 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

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‘Remove condom ads from buses’

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India Today Youth Summit 2011: Welcome address by Aroon Purie

first_imgWelcome address by Aroon Purie, Chairman and Editor in Chief, India Today Group at the Mind Rocks India Today Youth Summit 2011:Welcome everyone to India Today’s Second Youth Summit. A lot has changed since we last met. Last year, the mood was one of infectious optimism, of a country that had withstood a global recession. Then, one by one, the dominoes started to fall. The Commonwealth Games scam embarrassed us in front of the world. The 2G scam blew the lid off the prized telecom revolution.It was as if nothing was sacrosanct. The Army used land allotted for war widows for its own housing. One man evaded taxes worth Rs 50,000 crore. Swiss bankers started whispering about India’s best kept secret: the black money of its rich and powerful stashed away in Swiss banks.Yet, equally suddenly, there was hope, but of a different kind. That politics as we know it could change forever. That the power of the people could prevail over the power of those who had forgotten how to listen to them. That corruption may be a global phenomenon but it could have a very Indian solution.Eighteen-year-olds may have become voters in 1989 but 2011 will be remembered as the year they became citizens. It happened because of people like you.The extraordinary events of the last three months have changed the way young people are perceived. They, we were told, was the I-Me-Myself generation. I see now that they may have become the We generation.We were told modern communication tools like e-mail, SMS or Facebook would divide people. They ended up uniting your generation across cities, classes and communities.advertisementWe were told globalization would make our youth too westernized. The tricolour has instead become your favourite accessory.We were told young people were not interested in politics. But, one by one, as you converged on Ramlila Maidan in Delhi or Azad Maidan in Mumbai or Freedom Park in Banglore, with candles, slogans, and change in your hearts, you proved us and them wrong.Like a generation before you did in 1974, you were asking for accountability.The students’ revolution of 1974 threw up many of our present-day political stalwarts, from Lalu Prasad Yadav to Sushil Modi. Who knows how many of you who are Anna revolutionaries will go into politics, even though a new opinion poll we are carrying in the latest issue of India Today shows a tremendous anger against all politicians.In 1974, a man very similar to Anna Hazare, Jayaprakash Narayan, said almost the same things being said now. He too wanted to curb corruption. He too wanted to check the erosion of democracy. He too wanted changes in the electoral laws so that a “poor man’s democracy could work more honestly in a poor country”.Much has changed since then. Much has also remained the same.Two-thirds of India is under 35 – like most of you sitting in this hall. The numbers are huge. 459 million Indians are between 13 and 35. Of these, 333 million are literate.Till now, you were seen as a market. This year you proved, as you rallied behind a 74-year-old man from a hitherto obscure village in Maharashtra, that you were a democracy.As a 200-million strong voting force of 18-35 year olds in the 2009 elections, you were always seen as a swing factor. This time you proved the swing could well be a tsunami.All of you realise how you can change the rules of the game. You have every opportunity to change it further.  By 2020, just a decade from now, the average Indian will be 29 and we will have the unique distinction of being one of the youngest nations in the world. This means we would have the energy, dynamism and confidence which comes with youth.As India integrates further into the world economy, you will prove your worth on an international scale. We are already the second largest reservoir of skilled labour in the world. We produce an astounding two million English-speaking graduates, 15,000 law graduates, and 9,000 PhDs every year. And every year, the existing pool of over two million engineering graduates increases by nearly 300,000.The world awaits your ideas, your effort and your attention.When I was growing up, our horizons were limited because of our controlled, closed economy and our bullock-cart rate of growth. Today, India’s growth rate is the envy of most nations. And, far from being insulated, we have an open economy plugged into the world.Our summit this year shows us the power of great ideas. The summit is called Mind Rocks and, quite appropriately, each of our speakers today is a rock star in their own field.advertisementOur inaugural speaker, Kumar Mangalam Birla, has taken his company to new heights globally, with an empire spanning steel and cement to financial services.Chetan Bhagat is a writer who embodies the new, young, successful Indian – as much at ease in a Deutsche Bank office in Singapore as he is sitting in a sweaty set in Mumbai’s Film City.Abhinav Bindra is a thoughtful young man who used the gift of science to shoot for excellence in his sport, getting India its first individual Olympic gold medal.World Champions Yuvraj Singh and Gautam Gambhir show us what the fighting spirit is all about, while Ranbir Kapoor’s journey so far tells us that a famous surname is no deterrent to hard work.Innovative filmmaker Kiran Rao, brilliant artist Subodh Gupta, politician Kalikesh Singh Deo and Internet entrepreneur Divya Narendra will tell you: that a career is more than just a job.Zarina Mehta will tell you what goes into entertaining you. And our last speaker today, Kiran Bedi, will tell us what made her quit the police force and become a social activist who played a key role in the recent anti-corruption movement.This is a great time to be young in India. You are in the right place at the right time. The possibilities are immense and the India of the future is in your hands. To borrow a phrase, “You must be the change you want to be”.I am confident that Mind Rocks, with its mix of fun, music, intellectual stimulation and lots of career advice, will give you some pointers.last_img read more

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