Tag: Physics

Serendipitous Physics Discovery

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A group of physicists attempted to use a magnetic field to influence the spin of an atomic nucleus.

Fortunately, they screwed, up, and blew up the antenna generating the magnetic field for the experiment.

In so doing, they subjected the nucleus to an electrical field, rather than a magnetic one, and when they saw the results, they realized that they had accidentally confirmed Bloembergen’s theorem, which had remained unproven for over 50 years:

A group of scientists have accidentally proven a near 60-year old theory correct, thanks to a botched lab experiment.

Nicolaas Bloembergen, the late Dutch-American physicist who won the Nobel Prize for his contributions to laser spectroscopy, previously predicted that it was possible to control the nucleus of a single atom with electric fields in 1961. His idea, however, was never experimentally proven and was left largely forgotten until now.

………

Asaad and his colleagues set about probing a single atom of antimony, a metalloid element, fabricated on a silicon wafer with nuclear magnetic resonance. To do this, the team had to place the device in a strong magnetic field. They generated the magnetic field by applying an electric current to a superconducting magnet and directed it towards the atom’s nucleus using a specialised antenna.

“However, once we started the experiment, we realised that something was wrong. The nucleus behaved very strangely, refusing to respond at certain frequencies, but showing a strong response at others,” said co-author Vincent Mourik, another postdoctoral researcher at the USNW Sydney, working in the same department.

Eventually they realised they had accidentally destroyed the antenna by cranking up the strength of the magnetic field. “What happened is that we fabricated a device containing an antimony atom and a special antenna, optimized to create a high-frequency magnetic field to control the nucleus of the atom. Our experiment demands this magnetic field to be quite strong, so we applied a lot of power to the antenna, and we blew it up!” Asaad said.

With the antenna borked, all that was being transmitted was an electric field instead. The researchers may have failed to induce nuclear magnetic resonance in the antimony nucleus but they had managed to get it to interact with just an electric field instead, proving Bloembergen’s theory. Results from the “failed” experiment have been published in research paper in Nature.

“I have worked on spin resonance for 20 years of my life, but honestly, I had never heard of this idea of nuclear electric resonance,” said Andrea Morello, a professor of quantum physics at the USNW Sydney. “We ‘rediscovered’ this effect by complete accident – it would never have occurred to me to look for it. The whole field of nuclear electric resonance has been almost dormant for more than half a century, after the first attempts to demonstrate it proved too challenging.”

I believe that Isaac Asimov once said that, “The most exciting phrase to hear in science, the one that heralds new discoveries, is not ‘Eureka’ but ‘That’s funny.”

I agree.

100 Years Ago Today

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Observations of an eclipse from multiple locations proved that Einstein’s General Theory of Relativity was correct:

On May 29, 1919, a solar eclipse forever altered our conception of gravity, rewrote the laws of physics and turned a 40-year-old, wild-haired scientist into a global celebrity — the very personification of scientific genius.

It was a very good day for Albert Einstein.

The 1919 eclipse across South America and Africa provided direct evidence for Einstein’s mind-bending theory of gravity. He proposed in 1915 that gravity isn’t a spooky force acting across space but rather is a feature of the essence of space and time. Gravity is the warping and curving of the fabric of the universe.

Einstein’s theory — the general theory of relativity — was hailed by the physicist J.J. Thomson as “one of the greatest achievements of human thought.” It has been confirmed by many more observations over the century, including the detection of gravitational waves and the first picture of a black hole just this year. He cracked a fundamental code of the universe.

………

Einstein had emerged from obscurity in 1905 with a series of astonishing papers that obliterated classical notions about time and space. But his greatest achievement came a decade later, in 1915, when he described the equations governing gravity. He’d figured out a fundamental feature of the universe, using merely the power of his brain. But was it true? What if his equations were just a mathematical fancy, something that looked nifty on paper but did not correspond to physical reality?

Einstein proposed an experimental test. A solar eclipse would block the sun’s light and allow scientists to study starlight passing close to the sun. His theory predicted that the sun’s gravitational field would displace the starlight by a certain amount compared to where they would be under classical theories of gravity.

British astronomer Arthur Eddington led an expedition to observe the eclipse from two locations, one in Brazil and one on the island of Principe near the African coast.

The stars backed Einstein.

Break out the champagne, or not, depending on how you feel about General Relativity.

Quote of the Day

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For more than three decades, macroeconomics has gone backwards. The treatment of identification now is no more credible than in the early 1970s but escapes challenge because it is so much more opaque. Macroeconomic theorists dismiss mere facts by feigning an obtuse ignorance about such simple assertions as “tight monetary policy can cause a recession.” Their models attribute fluctuations in aggregate variables to imaginary causal forces that are not influenced by the action that any person takes. A parallel with string theory from physics hints at a general failure mode of science that is triggered when respect for highly regarded leaders evolves into a deference to authority that displaces objective fact from its position as the ultimate determinant of scientific truth.

—Paul Romer, Chief Economist at the World Bank

I think that this is a good description of both the current state of economics and the string theory sect faction in physics.

They both favor mathematical elegance over a coherent model which would provide some of predictive value.

H/t naked capitalism