Author: Jenni

A Short Guide to Hard Problems

How fundamentally difficult is a problem? That’s the basic task of computer scientists who hope to sort problems into what are called complexity classes. These are groups that contain all the computational problems that require less than some fixed amount of a computational resource — something like time or memory. Take a toy example featuring a large number such as 123,456,789,001. One might ask: Is this number prime, divisible only by 1 and itself? Computer scientists can solve this using fast algorithms — algorithms that don’t bog down as the number gets arbitrarily large. In our case, 123,456,789,001 is not a prime number. Then we might ask: What are its prime factors? Here no such fast algorithm exists — not unless you use a quantum computer. Therefore computer scientists believe that the two problems are in different complexity classes. Many different complexity classes exist, though in most cases researchers haven’t been able to prove one class is categorically distinct from the others. Proving those types of categorical distinctions is among the hardest and most important …

Americans are deeply religious people—and atheists are no exception

Americans are deeply religious people—and atheists are no exception

Americans are deeply religious people—and atheists are no exception. Western Europeans are deeply secular people—and Christians are no exception. These twin statements are generalizations, but they capture the essence of a fascinating finding in a new study about Christian identity in Western Europe. By surveying almost 25,000 people in 15 countries in the region, and comparing the results with data previously gathered in the U.S., the Pew Research Center discovered three things. First, researchers confirmed the widely known fact that, overall, Americans are much more religious than Western Europeans. They gauged religious commitment using standard questions, including “Do you believe in God with absolute certainty?” and “Do you pray daily?” Second, the researchers found that American “nones”—those who identify as atheist, agnostic, or nothing in particular—are more religious than European nones. The notion that religiously unaffiliated people can be religious at all may seem contradictory, but if you disaffiliate from organized religion it does not necessarily mean you’ve sworn off belief in God, say, or prayer. The third finding reported in the study is by …

China Rebalancing?

China Rebalancing?

I increasingly suspect my view on Chinese “rebalancing” is at odds with the current consensus (or perhaps just with a plurality of the investment bank analysts and financial journalists who watch China). In two significant ways. One. I think China’s balance of payments position is fairly robust. In both a “flow” and a “stock” sense. The current account isn’t that close to falling into a deficit (and it wouldn’t be that big a deal if China did have a modest deficit). And China’s state is back to adding to its foreign assets in a significant way. The days of “China selling reserves” are long past. And two, I think the rebalancing that has lowered the measured current account surplus is more fragile than most think. It is a function of policies—call it a large off-budget “augmented” fiscal deficit or excessive credit growth—that some believe to be unsustainable, and many think are unwise. The IMF, for example, wants China to bring down its fiscal deficit and slow the pace of credit growth, policies that directionally would …

Atomic clocks are helping physicists search for New Laws of Physics

Atomic clocks are helping physicists search for New Laws of Physics

In the late 1990s, Jun Ye, a young physicist at the research institute JILA in Boulder, Colorado, decided to dedicate much of his career to making the world’s best atomic clock. He spent some time getting to know different atoms — magnesium, calcium and barium. Eventually he settled on strontium for its internal stability. He then set to work building a laser that would tickle strontium atoms at just the right frequency. What Ye didn’t know is that he was also designing a dark matter detector. That realization came only in April 2015, when he got an email from Victor Flambaum, a physicist at the University of New South Wales in Sydney, Australia. Flambaum told Ye that according to certain theories, dark matter could subtly tweak the fundamental constants of nature, ever so slightly changing how fast clocks tick. Ye’s latest device — improved 20,000 times over his first version — was one of the few in the world sensitive enough to have a chance of picking up this faint signal. Ye is now carrying …

Social media can be used used as an evidence against you

Social media can be used used as an evidence against you

As we increasingly use social media platforms such as Facebook, Twitter, Instagram and WhatsApp to communicate with each other, many of us are unaware of the ways in which our posts might later resurface – and get us into trouble with the law. There are numerous examples of social media being used as evidence in the criminal justice system, leading to convictions and sometimes prison sentences. Peter Nunn from Bristol, England, was imprisoned in 2014 after MP Stella Creasy and feminist Caroline Criado-Perez were subjected to a string of abuse on Twitter. And after the London riots of 2011, two men were imprisoned for incitement after posting messages on Facebook inviting those who read them to meet the next day and wreak havoc in their local town. Police were able to trace the messages back to the defendants, leading to successful prosecutions. Messages and media on WhatsApp, Snapchat and the like, have been used in evidence to show that defendants have committed offences, such as selling drugs, possession of firearms(as in the case of R v Noble and Johnson, where WhatsApp messages …

Antidepressants Cause Weight Gain?

Antidepressant medications can be hugely helpful—even life-saving—for those who suffer from certain types of mood disorders. But they can also sometimes cause people to gain a significant amount of weight. Not so helpful. Studies indicate that about 25% of the people who take antidepressant medications report significant weight gain. This is seen more commonly in those who take these drugs for six months or more, but it’s not uncommon for people to report gaining 8-10 pounds within just a few weeks of starting drug therapy. Either way, it’s a bummer. You can easily imagine that frustration and negative feelings about weight gain could cancel out whatever mood elevating benefits the drugs are delivering! Are Antidepressants Worth it? There’s also some controversy over how much these drugs are really helping the millions of people who are taking them. My friend Dr. Ellen Hendricksen of the Savvy Psychologist podcast reviewed some of the research on this in a recent episode of the Savvy Psychologist. According to Ellen, studies suggest that a lot of people get little to …

Can you weigh Cloud?

Have you ever wondered how much a cloud weighs? Even though a cloud seems to float in air, both the air and the cloud have mass and weight. Clouds float in the sky because they are less dense than air, yet it turns out they weigh a lot. How much? About a million pounds! Here’s how the calculation works: Finding the Weight of a Cloud Clouds form when the temperature becomes too cold for the air to hold water vapor. The vapor condenses into tiny droplets. Scientists have measured the density of a cumulus cloud at about 0.5 grams per cubic meter. Cumulus clouds are fluffy white clouds, but the density of clouds depends on their type. Lacy cirrus clouds may have a lower density, while rain-bearing cumulonimbus clouds may be more dense. A cumulus cloud is a good starting point for a calculation, though, because these clouds have a fairly easy-to-measure shape and size. How do you measure a cloud? One way is to drive straight across its shadow when the sun is overhead at …

China tests prototype air cleaner

 A 60-metre-high chimney stands among a sea of high-rise buildings in one of China’s most polluted cities. But instead of adding to Xian’s smog, this chimney is helping to clear the air. The outdoor air-purifying system, powered by the Sun, filters out noxious particles and billows clean air into the skies. Chinese scientists who designed the prototype say that the system could significantly cut pollution in urban areas in China and elsewhere. The technology has excited and intrigued researchers — especially in China, where air pollution is a daily challenge. Early results, which are yet to be published, are promising, says the project’s leader Cao Junji, a chemist at the Chinese Academy of Sciences’ Key Laboratory of Aerosol Chemistry and Physics in Xian in central China. “This is certainly a very interesting idea,” says Donald Wuebbles, an atmospheric scientist at the University of Illinois at Urbana-Champaign, who has heard about the system but not seen it in action. “I am not aware of anyone else doing a project like this one.” The prototype, built with …

UK rejoin the European Free Trade Association (EFTA) after Brexit?

With the Brexit clock ticking ever louder, the need to plan the UK’s future relationships with not only the EU but other trading partners too becomes more urgent. One option is to seek membership of the European Free Trade Association (EFTA), the grouping comprising Norway, Switzerland, Iceland and Liechtenstein. This would provide some continuity in terms of preferential access to a not insignificant market for UK goods. EFTA accounts for 8.5% of UK exports. Membership should also, through EFTA’s free trade agreements with 38 countries, provide preferential access to a range of markets without the UK having to negotiate new bilateral agreements. Plus, securing EFTA membership would facilitate participation in the European Economic Area(EEA) if the UK wanted to pursue this post-Brexit. EFTA membership does not entail EEA membership, but only EU and EFTA member states can currently be contracting parties to the EEA Agreement. This raises the question of what is the process for joining EFTA, an organisation of which the UK was in fact a founding member in 1960 and which it only …

Is EU regulation really so bad for the UK?

Government estimates suggest that around half of all UK legislation with an impact on business, charities, and the voluntary sector originates from the EU. This is often used as an argument in favour of Brexit. But the overall costs and benefits of EU regulation are rarely scrutinised in depth. The UK government’s position since the 1980s has been that regulation in general acts as a drag on enterprise, innovation and investment, with ruinous implications for growth and employment. This thinking has long underpinned antagonism towards the EU and is lent support by numerous studies that have provided eye-watering estimates of the costs of EU regulation to UK business. Take claims made by the Leave campaign in the lead up to the referendum. Drawing on estimates produced by the think tank Open Europe, it was claimed that EU regulations cost the British economy £33.3 billion a year. The benefits of key regulations were also described as “vastly over-stated”, with more than half providing “no clear benefits”. Estimates of the costs and benefits of EU regulation, like …