December 2005

Lawrence Krauss on Cosmic Strings

December 31, 2005

Centauri Dreams recently examined wormholes and their possible survival from the early universe through the mechanism of a negative mass cosmic string. But what exactly is a cosmic string? Here’s Lawrence Krauss on the subject: “During a phase transition in materials — as when water boils, say, or freezes, the configuration of the material’s constituent [...]

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Closing the Distance to the Perseus Arm

December 30, 2005

When it comes to making precise observations, nothing can beat the VLBA. Short for Very Long Baseline Array, this system of ten radio antennae is dispersed over the Earth’s surface from Mauna Kea (Hawaii) to St. Croix (Virgin Islands), using 25-meter dishes to create an interferometer 5000 miles wide. The array is controlled from an [...]

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Systemic: Working with Extrasolar Data

December 29, 2005

Centauri Dreams readers will want to know about Systemic, a research collaboration led by astronomer Gregory Laughlin (University of California, Santa Cruz). Scheduled for launch in 2006, the Systemic Collaboration is a simulation that will study a catalog of 100,000 stars, some of which are surrounded by planetary systems created by the team. The idea [...]

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The Art of the Wormhole

December 28, 2005

Last week Centauri Dreams discussed the possible signature of a wormhole in astronomical data, as worked out in a 1994 paper titled “Natural Wormholes as Gravitational Lenses.” A wormhole moving between Earth and another star would show an odd but identifiable form of lensing — two spikes of light with a dip in the middle. [...]

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The Wake of a Pulsar

December 26, 2005

When a neutron star gives off pulses of radiation every time it rotates, it’s called a pulsar. The radiation, which moves along the star’s magnetic field lines, is often compared to a lighthouse beam sweeping across an ocean. Now a pulsar called Geminga has been found to leave a comet-like trail of high-energy electrons as [...]

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More on Centauri B

December 24, 2005

The recent work on the oscillations of Centauri B, discussed in yesterday’s entry, had me thinking deep into the afternoon as I dodged holiday traffic en route to the grocery. What Tim Bedding (University of Sydney) and Hans Kjeldsen (Aarhus University, Denmark) had done by coordinating the efforts of two major observatories was to explore [...]

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The Oscillations of Centauri B

December 23, 2005

Information on Alpha Centauri comes in all too slowly for Centauri Dreams, but astronomers at the Anglo-Australian Telescope and the European Southern Observatory’s Very Large Telescope in Chile have come to the rescue. They’ve teamed up to observe Centauri B, an orange K1 star slightly cooler and less massive than the Sun. In question was [...]

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How to Find a Wormhole

December 22, 2005

Wormholes make for great science fiction because they get us around the speed-of-light conundrum. Taking a shortcut through spacetime, they connect one part of the universe to another, though where and when you would come out if you went in a wormhole would be an interesting experiment, and not one for the faint of heart. [...]

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Life’s Building Blocks Found Around Another Star

December 21, 2005

The case for life around other stars, always a strong one, has become even more persuasive of late. First we found planet formation around HD 12039, a Sun-like star about 137 light years away, revealing a system that may look like our Solar System in its infancy. Now comes news based on findings from the [...]

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New Titles Highlight Research Problems

December 20, 2005

Springer’s series on astronautical engineering produces expensive books, as the 1999 publication of Colin McInnes’ Solar Sailing: Technology, Dynamics and Mission Applications made clear. There is no more thorough analysis of solar sailing in print, but the title was designed for professionals and printed in small quantity, with a corresponding pricetag. I was able to [...]

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