Void Riders



May 29, 2007 at 21:13 pm | Leave a Comment
The distribution of galaxies in the region around the Milky Way (in galactic coordinates). Each little dot represents a galaxy of typically 100 billion stars. The colors indicate the relative motions of galaxies with accurately measured distances, with shades of gree and blue indicating motions toward us, and shades of yellow to red indicating motions away from us. (For more information, see the IFA press release.

The distribution of galaxies in the region around the Milky Way (in galactic coordinates). Each little dot represents a galaxy of typically 100 billion stars. The colors indicate the relative motions of galaxies with accurately measured distances, with shades of gree and blue indicating motions toward us, and shades of yellow to red indicating motions away from us. (For more information, see the IFA press release.

We are riding on the edge of a huge void in space, hurtling along at 600,000 miles per hour. Yes, it’s true. We’re moving along with the expansion of the universe AND with the coalescence of galaxies along filaments, in clusters at places where the filaments intersect. Yet, as we go about our daily lives, we’re largely (if not completely) unaware of the ride we’re taking through space and time as part of the Milky Way Galaxy. Yet, our motion tracks with the continuing evolution of the universe.

Did that get your attention? It’s a compelling story, and one that astronomer Brent Tully is telling in his latest research into the motions of galaxies in our neighborhood of the universe. In the past, our distance measurements to other galaxies could give us some very broad information about our galaxy’s motion through space. In addition, other measurements of the Cosmic Microwave Background Radiation tell about some aspects of our galaxy’s motion. But, there’s always been a part of our motion that was unexplained—until now. Tully and a team of colleagues have done extremely precise measurements of distances to galaxies around us. Those measurements tell a great story of motion and action of galaxies through time and helped them finger a largely unexplored component of space as the culprit: the Local Void. This is a gap in space that is 50 megaparsecs across. (A megaparsec is about 3,260,000 light-years, and a light-year is the distance that light travels in a year.)

Concentrations of matter (like the filaments and clusters) are aggregates of matter that is pulled together. Concentrations of matter have gravity; they PULL on things. The Local Void, on the other hand, is empty. It seems to PUSH on things, including our galaxy. Tully explains it as the absence of a pull. If an object is surrounded by matter in all directions, except for one empty sector, then the absence of a pull from that sector is actually the same as a push. And, it can have a large effect on our region of space, in effect turning us into void riders moving along the edge of the Local Void.

It’s quite fascinating that we (all of us in the Milky Way Galaxy) should live on the edge of such a huge gap of nothingness; and, we ride along not really feeling our motion across the depths of space and time.





Stars Who Study Stars



May 28, 2007 at 3:37 am | Leave a Comment

The astronomy profession is a small community of kindred souls all focusing on dozens of different ways to understand the science of the cosmos. I go to astronomy meetings pretty frequently (well, at least once or twice a year), to catch up on the latest and greatest in astronomy research. Mr. Spacewriter has accompanied me to a couple of meetings because I wanted him to experience the science being presented, and so he could meet some of the same folks. At the opening reception of the meetings, we’ve run into many, many people I’ve worked with or went to school with “back in the day.” And, marvelled at the fresh infusion of new blood into the profession. Of course there are folks from NASA and many research institutions at the meetings, but also people like Pamela Gay and Fraser Cain, who are the main drive behind Astronomy Cast. Pamela (who is also a university professor) is doing a lot more than research and teaching in astronomy. Like me, she loves to share astronomy with the public, in any way she can.

There are also a good many very talented science writers who attend AAS meetings, reporting on the science “hot off the presses.” It’s been an honor to meet some of them, too. Where else could I have met New York Times science writer John Noble Wilford? He attended a great many AAS meetings, always asking the astute questions and subtly drawing out an education in astrophysics through his questions. Or Dutch writer Govert Schilling? Or many others who have attended these sessions over the years.

As a writer, I’ve found many outlets for the material I learn at astronomy meetings. Of course, I use the science in my documentary shows. But, for the past few years, in addition to my fulldome show production work through Loch Ness Productions, I’ve been contracted by various observatories to work as an editor and outreach person. The work runs the gamut from writing and/or editing press releases to creating exhibits. Lots of fun, and I’d love to do more of it.

And, so I shall. To wit: in a very short time, Mr. Spacewriter and I will be starting production on some vodcasts under a NASA grant with MIT Haystack Observatory. And, much of the material we’re going to talk about is from papers I’ve heard and read about at AAS meetings, as well as from direct contact with astronomers in their research settings. Through all my “productions,” I hope to excite the downloading public about the science these guys are doing. I want to show their enthusiasm and love of subject to the rest of the world, because astronomers really are as much the stars of my work as the stars they research and explore.





Preserving the Night Sky



May 24, 2007 at 12:06 pm | Leave a Comment

I’m a member of the International Dark-Sky Association. These guys are the light pollution authorities of the world. If you visit their website, you can find all kinds of information about the importance of dark skies (and not just to astronomers), as well as how to make your block, your community, your city, your state, a dark-sky site. They have a link to lighting practices and equipment that will help preserve dark skies while maintaining safety in your community. And, many of their suggestions help preserve energy expenses (an important factor).

The community I live in has some energy- and light-pollution-cutting lighting practices, although some neighbors still think it’s great to throw light up to the sky indiscriminately. In our neighborhood we managed to get our local utility to put up “screens” around the nearest streetlight so that the light shines down on the street, like it’s supposed to, and not in our bedroom window, or bathing our yard.

One of the more illustrative pages on their site is a series of links to various places on Earth, showing the light pollution from satellite’s-eye views. Check it out, and do your part to reduce light pollution, save energy, and preserve the beauty of the night skies for everyone to appreciate.





Fascinating, but Useless?



May 23, 2007 at 10:46 am | Leave a Comment

I Don’t Think So

I was browsing around at Borders Books last night, checking out the latest science books. One thing I’ve been noticing over the past few years is that the science sections in bookstores are getting smaller at about the same rate that pseudoscience, religion, and mystery book sections are growing. I don’t know that there’s a strict correlation (and I’m not saying that those three sections are related, so don’t go there), but I note the trend.

Anyway, I ran across this great little book at the counter called the Ultimate Book of Useless Information. I’m a sucker for factoids and little-known data points. So, I bought it and started browsing through it while waiting to pick someone up at the airport.

Since I’m interested in astronomy and space science, and since I’ve been doing a lot of reading on global warming and our atmosphere, a few nuggets caught my eye. First, as it says on page 61, the surface temperature on planet Earth would be 176 Fahrenheit by day and fall to 220 F by night if we didn’t have this atmosphere that sustains us. Also, as it says on page 61, Earth’s atmosphere is proportionally thinner than the skin of an apple.

Interesting facts, these. But useless? I don’t think so. They tell us a lot about our planet in just a few words. Stuff worth knowing. So, I’m not sure why the compiler of these “useless” facts dubs them so, because every fact is a teachable moment, a chance to learn something about the universe. Still, the book makes us think about these facts. It raises questions like “How do they know that?” and “Is that still true?” So, perhaps that’s the authors’ intention. Still, I don’t like seeing facts dismissed as “useless.”

Here’s another one: hot water is heavier than cold water. How do they know that? Can you prove this to yourself? How? A nice little lesson in science and fluid physics, don’t you think?

Here’s another: the human tooth has about 55 miles of canals in it. Ask your dentist about THAT the next time you’re in for a checkup (or, a root canal)!

Here’s a not-so-useless fact: a third of all cancers are Sun-related. That’s news you can use, and proof that much science data IS useful. And I think most people agree with that, once they stop to think about it.

Yet, there are those who reject science for a variety of reasons: ignorance, fear, religious misinterpretation or misunderstanding of the role of science. They may have spurred a bit of head-banging among those of us who see science as a system of knowledge and not the evil, godless practice that a few misguided souls make it out to be. In that case, I offer this last bit that I’ll mention from the book: banging your head against a wall burns 150 calories an hour.

Update: if you get this book, don’t take every “fact” in it that you read as correct. I’ve found a few “facts” that are somewhat sloppily stated, and at least one that’s flat-out wrong and could have been corrected with very simple research. With that caveat, this is still an interesting read, and now can be used as a jumping-off point to sharpen your critical thinking skills by fact-checking the “fact” mongers.





Carnival of Space



May 17, 2007 at 13:18 pm | Leave a Comment

Today Fraser Crane over at Universe Today is hosting the third Carnival of Space. Included among the blogged articles is my previous entry (below) about the Dark Matter Ring. Head on over and enjoy Fraser’s commentary and links to other great articles!





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Image of Horsehead Nebula: T.A.Rector (NOAO/AURA/NSF) and Hubble Heritage Team (STScI/AURA/NASA)

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