Year: 2018

Universe Got Its Bounce Back

Universe Got Its Bounce Back

Humans have always entertained two basic theories about the origin of the universe. “In one of them, the universe emerges in a single instant of creation (as in the Jewish-Christian and the Brazilian Carajás cosmogonies),” the cosmologists Mario Novello and Santiago Perez-Bergliaffa noted in 2008. In the other, “the universe is eternal, consisting of an infinite series of cycles (as in the cosmogonies of the Babylonians and Egyptians).” The division in modern cosmology “somehow parallels that of the cosmogonic myths,” Novello and Perez-Bergliaffa wrote. In recent decades, it hasn’t seemed like much of a contest. The Big Bang theory, standard stuff of textbooks and television shows, enjoys strong support among today’s cosmologists. The rival eternal-universe picture had the edge a century ago, but it lost ground as astronomers observed that the cosmos is expanding and that it was small and simple about 14 billion years ago. In the most popular modern version of the theory, the Big Bang began with an episode called “cosmic inflation” — a burst of exponential expansion during which an infinitesimal …

America’s declining relevance and China’s gains in the South China Sea

America’s declining relevance and China’s gains in the South China Sea

At a top regional security forum on Saturday, US Defence Secretary Jim Mattis said China’s recent militarisation efforts in the disputed South China Sea were intended to intimidate and coerce regional countries. Mattis told the Shangri-La Dialogue that China’s actions stood in “stark contrast with the openness of [the US] strategy,” and warned of “much larger consequences” if China continued its current approach. As an “initial response”, China’s navy has been disinvited by the US from the upcoming 2018 Rim of the Pacific Exercise, the world’s largest international naval exercise. It is important to understand the context of the current tensions, and the strategic stakes for both China and the US. In recent years, China has sought to bolster its control over the South China Sea, where a number of claimants have overlapping territorial claims with China, including Vietnam, the Philippines and Taiwan. China’s efforts have continued unabated, despite rising tensions and international protests. Just recently, China landed a long-range heavy bomber for the first time on an island in the disputed Paracels, and deployed anti-ship and anti-air missile systems  to its outposts …

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 …

Our Time Has Come - Alyssa Ayres

Our Time Has Come – Alyssa Ayres

How India is Making Its Place in the World Publisher –Oxford University Press     Release Date –Jan 2018   Pages –336    ISBN 978-0-190-49452-0 Over the last 25 years, India’s explosive economic growth has vaulted it into the ranks of the world’s emerging major powers. Long plagued by endemic poverty, India was hamstrung by a burdensome regulatory regime that limited its ability to compete on a global scale until the 1990s. Since then, however, the Indian government has gradually opened up the economy, and the results have been stunning. India’s middle class has grown by leaps and bounds, and the country’s sheer scale—its huge population and $2 trillion economy—means its actions will have a major global impact. From world trade to climate change to democratization, India now matters. While it is clearly on the path to becoming a great power, India has not abandoned all of its past policies: its economy remains relatively protectionist, and it still struggles with the legacy of its longstanding foreign policy doctrine of nonalignment. India’s vibrant democracy encompasses a vast array …

Genetic Engineering to Clash With Evolution

Genetic Engineering to Clash With Evolution

In a crowded auditorium at New York’s Cold Spring Harbor Laboratory in August, Philipp Messer, a population geneticist at Cornell University, took the stage to discuss a powerful and controversial new application for genetic engineering: gene drives. Gene drives can force a trait through a population, defying the usual rules of inheritance. A specific trait ordinarily has a 50-50 chance of being passed along to the next generation. A gene drive could push that rate to nearly 100 percent. The genetic dominance would then continue in all future generations. You want all the fruit flies in your lab to have light eyes? Engineer a drive for eye color, and soon enough, the fruit flies’ offspring will have light eyes, as will their offspring, and so on for all future generations. Gene drives may work in any species that reproduces sexually, and they have the potential to revolutionize disease control, agriculture, conservation and more. Scientists might be able to stop mosquitoes from spreading malaria, for example, or eradicate an invasive species. The technology represents the first …

Finding links between the Standard Model of particle physics and the octonions

Finding links between the Standard Model of particle physics and the octonions

In 2014, a graduate student at the University of Waterloo, Canada, named Cohl Furey rented a car and drove six hours south to Pennsylvania State University, eager to talk to a physics professor there named Murat Günaydin. Furey had figured out how to build on a finding of Günaydin’s from 40 years earlier — a largely forgotten result that supported a powerful suspicion about fundamental physics and its relationship to pure math. The suspicion, harbored by many physicists and mathematicians over the decades but rarely actively pursued, is that the peculiar panoply of forces and particles that comprise reality spring logically from the properties of eight-dimensional numbers called “octonions.” As numbers go, the familiar real numbers — those found on the number line, like 1, π and -83.777 — just get things started. Real numbers can be paired up in a particular way to form “complex numbers,” first studied in 16th-century Italy, that behave like coordinates on a 2-D plane. Adding, subtracting, multiplying and dividing is like translating and rotating positions around the plane. Complex …

Discovering gravitational waves from neutron stars

Discovering gravitational waves from neutron stars

Rumours have been swirling for weeks that scientists have detected gravitational waves – tiny ripples in space and time – from a source other than colliding black holes. Now we can finally confirm that we’ve observed such waves produced by the violent collision of two massive, ultra-dense stars more than 100m light years from the Earth. The discovery was made on August 17 by the global network of advanced gravitational-wave interferometers – comprising the twin LIGO detectors in the US and their European cousin, Virgo, in Italy. It is hugely important, not least because it helps solve some big mysteries in astrophysics – including the cause of bright flashes of light known as “gamma ray bursts” and perhaps even the origins of heavy elements such as gold. As a member of the LIGO scientific collaboration, I was immediately in raptures as soon as I saw the initial data. And the period that followed was definitely the most intense and sleep deprived, but also incredibly exciting, two months of my career. The announcement comes just weeks after three scientists were awarded the Nobel …

Time to look closer to home

Time to look closer to home

Immigration is at the heart of the Brexit debate. It’s a large reason why economic arguments have failed to sway voters. Despite warnings of the high economic costs of leaving the EU (warnings supported by a majority of economists), immigration has continued to have a powerful influence – and is perhaps the major reason why the opinion polls have become so close in recent weeks. The immigration debate is quite polarised. On one side, the Remain campaign either ducks the issue or focuses on the benefits that immigration brings to the economy as a whole. On the other side, the Leave camp focuses on its costs and plays into fears (often in a cruel and cynical way) that migrants are putting pressure on public services that are already at breaking point. At least among Labour supporters intending to vote leave, immigration also appears to be a key issue. The need for a more even-handed assessment of the costs and benefits of immigration is sorely needed. While immigration brings undoubted benefits, it also places pressures on particular communities. It also feeds a sense of …

Trying to understand perception by understanding neurons

Trying to understand perception by understanding neurons

When he talks about where his fields of neuroscience and neuropsychology have taken a wrong turn, David Poeppel of New York University doesn’t mince words. “There’s an orgy of data but very little understanding,” he said to a packed room at the American Association for the Advancement of Science annual meeting in February. He decried the “epistemological sterility” of experiments that do piecework measurements of the brain’s wiring in the laboratory but are divorced from any guiding theories about behaviors and psychological phenomena in the natural world. It’s delusional, he said, to think that simply adding up those pieces will eventually yield a meaningful picture of complex thought. He pointed to the example of Caenorhabditis elegans, the roundworm that is one of the most studied lab animals. “Here’s an organism that we literally know inside out,” he said, because science has worked out every one of its 302 neurons, all of their connections and the worm’s full genome. “But we have no satisfying model for the behavior of C. elegans,” he said. “We’re missing something.” …

Challenges of keeping the masses moving

Cities worldwide face the problems and possibilities of “volume”: the stacking and moving of people and things within booming central business districts. We see this especially around mass public transport hubs. As cities grow, they also become more vertical. They are expanding underground through rail corridors and above ground into the tall buildings that shape city skylines. Cities are deep as well as wide. The urban geographer Stephen Graham describes cities as both “vertically stacked” and “vertically sprawled”, laced together by vertical and horizontal transport systems. People flow in large cities is not only about how people move horizontally on rail and road networks into and out of city centres. It also includes vertical transport systems. These are the elevators, escalators and moving sidewalks that commuters use every day to get from the underground to the surface street level. Major transport hubs are where many vertical and horizontal transport systems converge. It’s here that people flows are most dense. But many large cities face the twin challenges of ageing infrastructure and increased volumes of people flowing through transport …