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Comment Re:T-Mobile UMA (Score 1) 289

by alfredw (#32724360) Attached to: Best Phone For a Wi-Fi-Only Location?

+1 for this suggestion. I have a T-Mobile Blackberry 9700, and the UMA calling is its killer app.

With UMA, the phone contacts T-Mobile over WiFi whenever that's available. That means that you can get T-Mobile service on your campus in exactly the way you would if you were talking to a T-Mobile tower: voice, SMS, Blackberry Email, Data Services, etc.

It's also amazing for roaming. Are you overseas? Connect to a WiFi network and all of the sudden you're in the U.S. as far as the phone company is concerned. I travel very frequently, and this feature plus a Boingo Mobile plan and Google Voice allow essentially limitless talk for +$8/mo on top of the ordinary phone bill.

For T-Mobile UMA, you do NOT have to buy HotSpot Calling as an option. (I don't think it's offered anymore anyway.) If you don't have the HotSpot option for $x/mo, you can still use UMA, but all minutes come out of your regular voice time (note free evenings/weekends still apply). If you have the extra option, then all minutes on WiFi are free.

Comment Re:Wow (Score 5, Informative) 153

by alfredw (#31660204) Attached to: A User's Guide To the Universe

For the record, I submitted the review without any sort of link to the publisher (per the Slashdot book review policy). The /. editors add in those links.

And no, I don't work for the publisher. I genuinely read the book and enjoyed it.
Books

Submission + - Book Review: A User's Guide to the Universe

Submitted by
alfredw
alfredw writes: "[NOTE TO EDITORS: Disclosure: I am a graduate student in the same department as one author (Goldberg). I've taken his Cosmology and Graduate Electricity and Magnetism class. He's not my academic advisor, nor is he on my thesis committee and he has no determination of my grades or future performance. I also shared an office with the other author (Blomquist) for about a week in 2008, when I was joining the department and he was leaving. We're casual acquaintances only.

Please publish only my obfuscated email address.

I have chosen to review this book because it was released recently (end of Feb, 2010).]

Have you ever wanted to buttonhole a physicist at a cocktail party? Do you have the burning desire to sit down with a professor and ask a laundry list of "physics" questions about time travel and black holes? Do you want to know more about modern physics, but want to do it with pop culture experiments instead of mathematics? If you answered "yes" to any of those questions, then you're in the target audience for A User's Guide to the Universe: Surviving the Perils of Black Holes, Time Paradoxes, and Quantum Uncertaintym

A User's Guide to the Universe (hereinafter "A User's Guide") is the physicist's answer to Phil Plait's Death from the Skies!: These Are the Ways the World Will End.... What Goldberg and Blomquist have created is a fun, light read about interesting areas of modern physics that will entertain while it educates. The book assumes very little scientific background on the part of the reader. Those with some knowledge (this is Slashdot, after all) will find the explanations of well-known concepts (the double slit experiment, for example) lucid, direct, brief and entertaining.

A User's Guide covers topics like relativity, time travel, the Standard Model of Particle Physics, and alien life. It does so with a very tongue-in-cheek sense of humour, and footnotes that act as the authors' very own peanut gallery. While this humour lightens up what could otherwise be a few dry areas of discussion, the littering of the text with pop-culture references is bound to make the book feel a bit dated in years to come. For now (March 2010), though, A User's Guide is so fresh you might call it ripe.

Unlike Death from the Skies, this book is well illustrated. The pen-and-ink cartoons are omnipresent, and serve to both illustrate the text, and to take every opportunity for a joke (cheap or otherwise) that presents itself. Overall, I felt that the cartoons were a strong addition to the book, as they can provide a needed laugh in a serious section, or can eliminate the proverbial thousand words when describing an experiment or concept.

The chapter on time travel is a stand-out. It presents several "practical" designs for time machines, which use black holes, cosmic strings or wormholes as components. I am an avid reader of pop-sci books, and I found designs that were new to me. The discussion of the Grandfather Paradox (if you go back in time and kill your grandfather, then you were never born and could never have committed murder) and ways around it are very helpful and present a solid physical framework for thinking about these issues. When the Grandfather Paradox is reformulated using pool balls, instead of thinking humans, it becomes clear that the issues are physical and not metaphysical. Also, the authors helpfully include a chart ranking sci-fi shows and movies for their time travel savvy.

You'll also find a strong and entertaining treatment of inflationary cosmology, including discussions of the evidence behind the theory and a look at some consequences. This book avoids both a heavy technical treatment and a historical look at the development of the theory (see, for example, Alan Guth's The Inflationary Universe for that) and instead dives right in to the juiciest parts. This style is well-suited to the reader who wants the funs bits without all of the baggage.

If you're curious about quantum mechanics, the second chapter contains a one of the best introductions in the field. By asking questions like "can we build a Star Trek transporter?" the authors drive a quick and satisfying tour through the weirdness of the microscopic world. This "evil genius hands-on" approach is this book's most important contribution to pop sci literature, and its most endearing feature. You'll start by looking at Star Trek, but end with the mysteries of the double-slit experiment, wave-particle duality and the uncertainty principle.

Finally, at the end of the book, the authors helpfully include two sets of references: one to the pop sci literature, and one to the technical literature. Many of the best pop physics books of the past are listed, and the bibliography could serve as useful direction to more depth for the interested.

Overall, A User's Guide accomplishes what it sets out to do. It combines a hands-on, question-driven approach to physics with a tongue-in-cheek, pop-culture-based sense of humour. And then it throws on a layer of great cartoons to make the entire package something that most science books aren't: enjoyable. This book is fine, and you may well learn something in the process."
Space

Submission + - Hubble Builds 3D Dark Matter Map (discovery.com)

Submitted by
astroengine
astroengine writes: "Dark matter can't be spotted directly because it doesn't interact with electromagnetic radiation (i.e. it doesn't emit any radiation and reflects no light). However, its gravitational influence on space-time can bend light from its otherwise straight path (a phenomenon known as "lensing"). Using a sophisticated algorithm to scan a comprehensive Hubble Space Telescope survey of the cosmos, astronomers have plotted a map of "weak lensing" events. Combining this with red shift measurements from ground-based observatories, they've produced a strikingly colorful 3D map of the structure of dark matter."

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