NOVA: The Fabric of the Cosmos

NOVA's "The Fabric of the Cosmos" premieres tonight, November 2, at 9pm ET/PT on most PBS stations. Recommended for: families who aren't quite sure what relativity is, but want to find out.

Starting tonight, enjoy the four-hour series The Fabric of the Cosmos, based on physicist Brian Greene's breakthrough book. I've previewed the first episode of the show, and found it a worthy companion to the book, especially for those who aren't particularly up on physics in general: do you know what Einstein's theory of relativity really is? How about the Higgs Field (and that elusive Higgs boson) -- do you know what that actually is? How about dark energy, or the notion that the universe might be a holographic projection of a 2D version of itself? All of these are discussed in the first episode (airing tonight), which deals with the nature of "space" -- what is space, when you remove all the "stuff" (atoms and such), and how does it work? In a sense, the show is sort of "Physics for Dummies" in that it presents easily understandable metaphors for all of these questions (except the hologram thing, which still seems bonkers), and helps you to understand how physicists have thought about space over hundreds of years.

The only downside to the show is Brian Greene himself, as a host -- he doesn't quite have the spark of a Carl Sagan or a Neil deGrasse Tyson. He's good at explaining what he's talking about (and indeed he is accessible to a fault -- he often repeats simple concepts), but somehow the first hour seems a little flat -- at times I found myself wondering who the audience was supposed to be, because the show mixed extremely simple ideas (like "is space empty or not") with mind-blowingly complex ones (the universe is a hologram, projected from a 2D version of itself). In the middle there is a very easy-to-follow discussion of what Einstein really contributed to physics, and a good discussion of why space, time, and the speed of light are fundamentally kind of weird. The trick is, at times the material appears pointed at middle school students, at others it's very heady stuff.

Gather the Family Around

Because of this mixed-audience issue, I think this series makes sense for families. I can see some elementary school kids engaging with this material, though middle and high school ages seem more appropriate. There is nothing risque or dangerous in the material, and it's presented in a very friendly, engaging format. The production value is insanely high (lots of computer graphics and 3D modeling, even in static interview shots), which should make even the boring bits (or stuff that's over young kids' heads) fun to watch. And you might walk away saying, "Huh, I kinda actually do get why Einstein was a big deal." Seems worth your time, eh? Here's another video of Brian Greene introducing the series:

The first episode airs tonight, and subsequent episodes air weekly. There's more information on the Fabric of Cosmos website.

Blogger disclosure: I wasn't specially compensated to do this review. I'm a lifelong fan of NOVA, though!

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Growing Up With Headphones May Not Damage Kids’ Hearing
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A study published in the American Medical Association's JAMA Otolaryngology-Head & Neck Surgery finds no increase in child and adolescent hearing loss despite a rise in headphone and earbud use.

"Hearing impairment in children is a major public health burden given its impact on early speech and language development, and subsequently on academic and workforce performance later in life," the authors write. "Even mild levels of hearing loss have been found to negatively affect educational outcomes and social functioning."

As portable music players continue to grow in popularity, parents, doctors, and researchers have begun to worry that all the music pouring directly into kids' ears could be damaging their health. It seems a reasonable enough concern, and some studies on American kids' hearing have identified more hearing loss.

To take a closer look, researchers at the University of California-San Francisco analyzed data from the National Health and Nutrition Examination Survey (NHANES), collected from 1988 to 2010. They reviewed records from 7036 kids and teens between the ages of 12 and 19, checking each participant's hearing tests against their exposure to noise.

As expected, the authors write, they did find a gradual increase in headphone use and other "recreational noise exposure." And they did see an uptick in hearing loss from 1988 to 2008 from 17 percent to 22.5 percent. But after that, the trend seemed to reverse, sinking all the way down to 15.2 percent—lower than 1988 levels. They also found no significant relationship between noise exposure and hearing loss.

The results were not uniform; some groups of kids were worse off than others. Participants who identified as nonwhite, and those of lower socioeconomic status, were more likely to have hearing problems, but the researchers can't say for sure why that is. "Ongoing monitoring of hearing loss in this population is necessary," they write, "to elucidate long-term trends and identify targets for intervention."

Before you go wild blasting music, we should mention that this study has some major limitations. Hearing loss and other data points were not measured the same way through the entire data collection period. Participants had to self-report things like hearing loss and health care use—elements that are routinely under-reported in surveys. As with just about any health research, more studies are still needed to confirm these findings.

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Weather Watch
NASA Figures Out Why When It Rains, It (Sometimes) Drizzles
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What’s the difference between drizzle and rain? It has to do with updrafts, according to new research by NASA scientists into the previously unexplained phenomenon of why drizzle occurs where it does.

The answer, published in the Quarterly Journal of the Royal Meteorological Society, could help improve how weather and climate models treat rainfall, making predictions more accurate.

Previously, climate researchers thought that drizzle could be explained by the presence of aerosols in the atmosphere. The microscopic particles are present in greater quantities over land than over the ocean, and by that logic, there should be more drizzle over land than over the ocean. But that's not the case, as Hanii Takahashi and her colleagues at the Jet Propulsion Laboratory found. Instead, whether or not rain becomes full droplets or stays as a fine drizzle depends on updrafts—a warm current of air that rises from the ground.

Stronger updrafts keep drizzle droplets (which are four times smaller than a raindrop) floating inside a cloud longer, allowing them to grow into full-sized rain drops that fall to the ground in the splatters we all know and love. In weaker updrafts, though, the precipitation falls before the drops form, as that light drizzle. That explains why it drizzles more over the ocean than over land—because updrafts are weaker over the ocean. A low-lying cloud over the ocean is more likely to produce drizzle than a low-lying cloud over land, which will probably produce rain.

This could have an impact on climate modeling as well as short-term weather forecasts. Current models make it difficult to model future surface temperatures of the Earth while still maintaining accurate projections about the amount of precipitation. Right now, most models that project realistic surface temperatures predict an unrealistic amount of drizzle in the future, according to a NASA statement. This finding could bring those predictions back down to a more realistic level.


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