Credits: ESO

IN BRIEF

• Vacuum birefringence has been observed by a team of scientists for the first time ever using the European Southern Observatory's (ESO) Very Large Telescope (VLT).
• The team observed neutron star RX J1856.5-375, which is about 400 light-years from Earth, with just visible light, pushing the limits of existing telescope technology.

A LITTLE LESS STRANGE

Vacuum birefringence is a weird quantum phenomenon that has only ever been observed on an atomic scale. It occurs when a neutron star is surrounded by a magnetic field so intense, it’s given rise to a region in empty space where matter randomly appears and vanishes.

This polarization of light in a vacuum due to strong magnetic fields was first thought to be possible in the 1930s by physicists Werner Heisenberg and Hans Heinrich Euler as a product of the theory of quantum electrodynamics (QED). The theory describes how light and matter interact.

Now, for the first time ever, this strange quantum effect has been observed by a team of scientists from INAF Milan (Italy) and from the University of Zielona Gora (Poland).

Using the European Southern Observatory’s (ESO) Very Large Telescope (VLT), a research team led by Roberto Mignani observed neutron star RX J1856.5-375, which is about 400 light-years from Earth.

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Physicists typically think they “need philosophers and historians of science like birds need ornithologists,” the Nobel laureate David Gross told a roomful of philosophers, historians, and physicists in Munich, Germany, paraphrasing Richard Feynman.

But desperate times call for desperate measures.

Fundamental physics faces a problem, Gross explained—one dire enough to call for outsiders’ perspectives. “I’m not sure that we don’t need each other at this point in time,” he said.

It was the opening session of a three-day workshop, held on December 7 in a Romanesque-style lecture hall at Ludwig Maximilian University (LMU Munich) one year after George Ellis and Joe Silk, two white-haired physicists now sitting in the front row, called for such a conference in an incendiary opinion piece in Nature. One hundred attendees had descended on a land with a celebrated tradition in both physics and the philosophy of science to wage what Ellis and Silk declared a “battle for the heart and soul of physics.”

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Image credit: flickr user Trailfan, via https://www.flickr.com/photos/7725050@N06/631503428.

Ethan Siegel, CONTRIBUTOR

There are a lot of different ways to define science, but perhaps one that everyone can agree on is that it’s a process by which:

knowledge about the natural world or a particular phenomenon is gathered,
a testable hypothesis is put forth concerning a natural, physical explanation for that phenomenon,
that hypothesis is then tested and either validated or falsified,
and an overarching framework — or scientific theory — is constructed to explain the hypothesis and that makes predictions about other phenomena,
which is then tested further, and either validated, in which case new phenomena to test are sought (back to step 3), or falsified, in which case a new testable hypothesis is put forth (back to step 2)…

and so on. This scientific process always involves the continued gathering of more data, the continued refining or outright replacing of hypotheses when the realm of validity of the theory is exceeded, and testing that subjects that theory to either further validation or potential falsification.

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The idea that our Universe is part of a multiverse poses a challenge to philosophers of science.
Credit: R. Windhorst, Arizona State Univ./H. Yan, Spitzer Science Center, Caltech/ESA/NASA

A debate between physicists and philosophers could redefine the scientific method and our understanding of the universe
By Davide Castelvecchi, Nature magazine on December 23, 2015

Is string theory science? Physicists and cosmologists have been debating the question for the past decade. Now the community is looking to philosophy for help.
Earlier this month, some of the feuding physicists met with philosophers of science at an unusual workshop aimed at addressing the accusation that branches of theoretical physics have become detached from the realities of experimental science. At stake is the integrity of the scientific method, as well as the reputation of science among the general public, say the workshop’s organizers.
Held at the Ludwig Maximilian University of Munich in Germany on December 7-9, the workshop came about as a result of an article in Nature a year ago, in which cosmologist George Ellis, of the University of Cape Town in South Africa, and astronomer Joseph Silk, of Johns Hopkins University in Baltimore, Maryland, lamented a “worrying turn” in theoretical physics (G. Ellis and J. Silk Nature 516, 321–323; 2014).

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