Slowing light to measure the creep of glaciers

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My most recent article is an interesting combination of fundamental quantum physics research — the slowing of light inside specially-designed materials — with the study of the impacts of climate change on Greenland glaciers.

How to clock a glacier

From Nautilus:

low-flying airplane buzzes along the coast of Greenland, hovering over a glacier. The belly of the plane holds a laser that bounces light off the glacier’s face. As the light beam returns to the plane, it enters a black box that slows it to a crawl, turning it into a moment-by-moment report on the glacier’s speed. Each flight, each glacier measured, allows researchers to map the diminishment of the Greenland ice cap. Similar planes skirt Antarctica and the coast of Alaska, charting the damage to the ice cover.

These airplanes and their experimental equipment don’t exist yet. But the need to measure glacier flow in real time does exist. The latest report by Intergovernmental Panel on Climate Change (IPCC) projected that melting ice may result in as much as one meter of sea-level rise by the year 2100, threatening millions of people in low-lying nations and coastal cities. Knowing how glaciers melt can help researchers predict the future. But glaciers are, well, glacial. Most of them creep roughly two to three kilometers each year, covering less distance than most of us can walk in an hour. The fastest ice flow in Greenland is the glacier Jakobshavn, which moves at the blazingly slow speed of about 16 kilometers in a year—about 180 centimeters per hour. [Read the rest at Nautilus]

A space robot arrives at a new world: Dawn at Ceres

The asteroid dwarf planet Ceres, in a view showing the intriguing two bright spots. [Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA ]

The asteroid dwarf planet Ceres, in a view showing the intriguing two bright spots. [Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA ]

Sunday is my birthday, and NASA kindly decided to give me a whole asteroid. I got to write about it for The Daily Beast.

NASA’s Dawn Spacecraft Made It to Dwarf Planet Ceres

From The Daily Beast:

When I was young, I obsessively read through a National Geographic science book called Our Universe, a good overview of current astronomy and especially the Solar System. Voyager 2 was cutting edge at the time, which gives you a hint of when this was. One chapter was devoted to asteroids, the small rocky bodies scattered throughout the inner Solar System and especially the region between Mars and Jupiter. At that time, we didn’t have clear photos of any of them, so the book had paintings of Ceres, Vesta, Pallas, and several asteroids. My mental image of Ceres for more than 30 years has been that artist’s impression: a perfectly spherical, heavily cratered object, colored a light gray.

I mention this because for the first time in history, we now have real photos of Ceres, thanks to NASA’s Dawn spacecraft. Dawn entered orbit around Ceres today, providing us with our first close-up views during its approach. [Read more at The Daily Beast…]

Of symmetries, the strong force and Helen Quinn

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Of symmetries, the strong force and Helen Quinn

From Symmetry:

Modern theoretical physicists spend much of their time examining the symmetries governing particles and their interactions. Researchers describe these principles mathematically and test them with sophisticated experiments, leading to profound insights about how the universe works.

For example, understanding symmetries in nature allowed physicists to predict the flow of electricity through materials and the shape of protons. Spotting imperfect symmetries led to the discovery of the Higgs boson.

One researcher who has used an understanding of symmetry in nature to make great strides in theoretical physics is Helen Quinn. Over the course of her career, she has helped shape the modern Standard Model of particles and interactions— and outlined some of its limitations. With various collaborators, she has worked to establish the deep mathematical connection between the fundamental forces of nature, pondered solutions to the mysterious asymmetry between matter and antimatter in the cosmos and helped describe properties of the particle known as the charm quark before it was discovered experimentally. [Read more at Symmetry…]

Weird X-Rays Spur Speculation about Dark Matter Detection

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Weird X-Rays Spur Speculation about Dark Matter Detection

From Scientific American:

Many major discoveries in astronomy began with an unexplained signal: pulsars, quasars and the cosmic microwave background are just three out of many examples. When astronomers recently discovered x-rays with no obvious origin, it sparked an exciting hypothesis. Maybe this is a sign of dark matter, the invisible substance making up about 85 percent of all the matter in the universe. If so, it hints that the identity of the particles is different than the prevailing models predict.

The anomalous x-rays, spotted by the European Space Agency’s orbiting XMM–Newton telescope, originate from two different sources: the Andromeda Galaxy and the Perseus cluster of galaxies. The challenge is to determine what created those x-rays, as described in a study published last month in Physical Review Letters. (See also an earlier study published in The Astrophysical Journal.) The signal is real but weak and astronomers must now determine whether it is extraordinary or has a mundane explanation. If that can be done, they can set about the work of identifying what kind of dark matter might be responsible. [Read more at Scientific American ]

The dark horse of the dark matter hunt

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The dark horse of the dark matter hunt

From Symmetry Magazine:

The ADMX experiment seems to be an exercise in contradictions.

Dark matter, the substance making up 85 percent of all the mass in the universe, is invisible. The goal of ADMX is to detect it by turning it into photons, particles of light. Dark matter was forged in the early universe, under conditions of extreme heat. ADMX, on the other hand, operates in extreme cold. Dark matter comprises most of the mass of a galaxy. To find it, ADMX will use sophisticated devices microscopic in size.

Scientists on ADMX—short for the Axion Dark Matter eXperiment—are searching for hypothetical particles called axions. The axion is a dark matter candidate that is also a bit of a dark horse, even as this esoteric branch of physics goes. [Read more in Symmetry Magazine]

Methane on Mars: life or just gas?

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Methane on Mars: life or just gas?

From The Daily Beast:

Methane is a familiar chemical, whether you know it by that name or not. It’s the major component of natural gas, which heats my house and possibly yours too. Methane is also a large part of human gas, which means I could start this article with a fart joke if I really wanted to. (However, it’s not the smelly part, which is provided by sulfur compounds.) Lakes on Titan are full of methane, and the chemical is a major component of the giant planets Jupiter, Neptune, and so forth.

Mars is a different case, and an interesting one: it doesn’t have a lot of methane in its atmosphere at any given moment. However, several probes—most recently the Curiosity rover—have measured methane in the Martian atmosphere. Methane on Mars could possibly reveal that the planet is more active geologically than it seems, or even that it harbors microscopic life. [Read more at The Daily Beast….]

Are comets the origin of Earth’s oceans?

[ I am reviving the Bowler Hat Science blog as a quick way to link all my new publications. Subscribe to the feed to keep up with all my stories! ]

Are comets the origin of Earth’s oceans?

From The Daily Beast:

Water, water everywhere, but where did it come from? One common explanation is that the water in Earth’s oceans was brought by comets, which bombarded the planet during its earliest period. It’s a simple, logical, and testable story.

But that doesn’t mean it’s right. A new study published last week in Science revealed that the water on Comet 67P/Churyumov-Gerasimenko doesn’t match that found on Earth. Specifically, instruments aboard the Rosetta probe measured the relative amount of deuterium in the comet’s water and found it was roughly three times higher than the amount in Earth’s oceans. Comets are chemically pristine, mostly unchanged over the Solar System’s 4.5 billion year history, so a mismatch in the deuterium content complicates the story of Earth’s water. [Read more at The Daily Beast….]