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?

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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….]

Does antimatter fall up or down?

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Does antimatter fall up or down?

From NOVA Nature of Reality:

There are two kinds of matter in the universe: ordinary matter, which makes up all the stuff of everyday life, and antimatter, a sort of mirror image of matter. When the two meet, they annihilate in a flash of energy. It’s our good fortune that, in the early Universe, there was just a tiny bit more matter than antimatter, leaving us with a cosmos almost empty of stuff that could destroy us. Otherwise, we wouldn’t be here to ask what, exactly, antimatter is.

Here’s what we know: Anti-electrons, known as positrons, are nearly identical to electrons, but instead of being negatively charged they are positively charged. The same goes for other antimatter counterparts: antiprotons are negatively charged and made of the antiquarks corresponding to the quarks in normal protons.

But physicists think that the other properties of the particles should be the same. [Read more at NOVA…]

This metal plate is perforated with holes, each of which lines up with a galaxy or quasar. The BOSS survey maps the position and distance to a huge number of galaxies using many masks such as this. [Credit: moi]

This metal plate is perforated with holes, each of which lines up with a galaxy or quasar. The BOSS survey maps the position and distance to a huge number of galaxies using many masks such as this. [Credit: moi]

Far from being invisible, black holes are among some of the brightest objects in the Universe. The black holes themselves aren’t emitting light, but the matter they draw in heats up and much of it shoots back out in powerful jets. When that happens, the black hole is known as a quasar, and it can be visible from billions of light-years away. For that reason, mapping the distribution of quasars can help cosmologists understand the expansion rate of the Universe in an earlier era — and constrain the behavior of dark energy. My latest story in The Daily Beast explains:

If dark energy will be the same in billions of years as it seems to be today, the future will be dark and empty, as galaxies continue to move apart from each other at ever-faster rates. If dark energy comes and goes, though, maybe the rate of expansion will slow down again. All of this is a long time from now—trillions of years after the death of the Sun—but we might see hints about it today. We hope to see signs of what is to come by looking at how dark energy behaves now, and how it has acted in the past. Similarly, if dark energy is stronger in some parts of the cosmos, then certain pockets of the Universe would grow faster than in others. That also has implications for how the future cosmos looks. [Read more…]

Using Black Holes to Measure Dark Energy, Like a BOSS