Category Archives: Physics World Discovery

New cosmic messengers, and what they can tell us

Bartos-multimessenger-astronomyBy Margaret Harris

Immediately after last year’s announcement that the Laser Interferometer Gravitational-Wave Observatory (LIGO) had seen its first gravitational waves, a lot of the discussion centred on what the discovery meant for general relativity.  This was understandable: getting further confirmation of Einstein’s century-old theory was (and is) a big deal.  But in the longer term, and as the LIGO detectors notch up a few more observations (they’re currently crunching data on six new candidates), the emphasis will shift away from the waves themselves, and towards what they can tell us about the universe.

The key thing to realize here is that gravitational waves are fundamentally different from other, better-studied cosmic “messengers” that travel to Earth from distant reaches of the universe.  Unlike photons, gravitational waves are not impeded by clouds of gas or dust; unlike cosmic rays, they are not deflected by electromagnetic fields. In addition, some of the most dramatic astrophysical events, such as the merger of two black holes in empty space, are “dark” or “silent” to other messengers: these events produce gravitational waves in copious quantities, but not, as far as we know, anything else.

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So you want to know about the dark universe?

Photo of Catherine Heymans, University of Edinburgh

Big thinker – Catherine Heymans is an observational cosmologist at the University of Edinburgh and author of the new Physics World Discovery ebook The Dark Universe.

By Matin Durrani

It never ceases to amaze me that we know almost nothing about 95% of the universe. Sure, the consensus is that 25% is dark matter and the rest is something dubbed “dark energy”, but beyond that our knowledge is wafer thin.

The flip side, though, is that there’s plenty for physicists to get stuck into. And if you want to get up to speed with the field and find out more about some of its challenges, do check out a new free-to-read Physics World Discovery ebook by Catherine Heymans from the Royal Observatory, University of Edinburgh, UK.

Available in ePub, Kindle and PDF formats, The Dark Universe explains the dark enigma and examines “the cosmologist’s toolkit of observations and techniques that allow us to confront different theories on the dark universe”. And to get you in the mood for all things dark, I asked Heymans some questions about her life as a research scientist. Here’s what she had to say.

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Space weather: it’s all about impact

By Susan Curtis

Extreme ultraviolet image of a tangle of arched magnetic filed lines in the Sun's corona, taken in January 2016 by NASA's Solar Dynamics Observatory.

Dangerous affair – an extreme ultraviolet image of a tangle of arched magnetic filed lines in the Sun’s corona, taken in January 2016 by NASA’s Solar Dynamics Observatory. (Courtesy: Solar Dynamics Observatory, NASA)

We all love a good disaster movie, but when it comes to real life it’s all too easy to downplay a dangerous but distant threat. Many people choose to live on active volcanoes, the citizens of San Francisco know that “the Big One” could strike at any moment, and yet they believe that the benefits of living in those locations outweigh the risk of a severe event happening in their lifetime.

The same dilemma faces the community of scientists, engineers and policy-makers who are working to understand the impacts of space weather – changes in the Earth’s environment that are largely are driven by physical processes originating from the Sun. Space weather has the potential to disrupt or even damage critical infrastructures on Earth, such as the power grids, aviation routes and communication systems that modern societies depend on, but the last notable event dates back to 2003.

That’s why Mike Hapgood, who heads up the Space Weather Group at RAL Space, part of the UK’s Rutherford Appleton Laboratory, has written a new, free-to-read Physics World Discovery ebook called Space Weather. “I thought it would be a great opportunity to highlight what space weather is really about, and to show how we are linking our scientific knowledge to a better understanding of the impacts on society,” he comments.

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Quantitative finance: what’s it really all about?

Photo of Jessica James from Commerzbank - the author of a Physics World Discovery e-book on quantitative finance

Mixing physics and finance – Jessica James is the author of the new Physics World Discovery ebook Quantitative Finance.

By Matin Durrani

Among the many joys of studying physics is that a degree in the subject can take you down lots of different paths. As our recent Physics World Careers 2017 guide revealed, they range from research and industry to education, IT and even sports, politics and the arts.

One particularly popular destination is the world of finance, which is hardly surprising given physicists’ love of numbers. Those in finance work in many different areas, with one of the most high profile – and lucrative – being the field of “quantitative finance”.

But what exactly does the term mean and what’s the field all about? To find out more, do check out the new, free-to-read Physics World Discovery ebook entitled Quantitative Finance, written by Jessica James – a managing director and senior quantitative researcher at Commerzbank in London.

As James explains in the introduction to her book, the field includes “complex models and calculations that value financial contracts, particularly those which reference events in the future, and applies probabilities to these events”. I encourage you to read her book, which is available in PDF, ePub and Kindle formats. And to whet your appetite, James has kindly answered some questions about what she does, her career to date and what the book’s about.

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Proton therapy: the benefits and the challenges

By Tami FreemanPWebook-cover

Proton therapy is an increasingly popular treatment technique that uses beams of protons to accurately target and destroy cancerous tumours. A new Physics World Discovery ebook, Proton Beam Therapy, takes a close look at the physics of this cancer treatment, its benefits and the challenges associated with bringing this approach into the clinical mainstream.

The ebook is written by Harald Paganetti, director of physics research at Massachusetts General Hospital and professor of radiation oncology at Harvard Medical School. He is a pioneer in advanced Monte Carlo dose calculations for proton therapy, and is considered the world expert on the relative biological effectiveness of proton beams.

In the last few decades, proton therapy has transitioned from research laboratories into the clinical setting – making this publication particularly timely. There are currently around 60 proton therapy facilities worldwide, and this number is increasing rapidly. “Proton therapy is becoming a standard treatment option but there are still many challenges in terms of the physics, biology and clinical use of protons, which are summarized in this ebook,” Paganetti explains.

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