On Its Way to Interstellar Space, Voyager 1 Explores the Magnetic Highway

This image shows NASA's Voyager 1 spacecraft exploring a new region in our solar system called the "magnetic highway." Image credit: NASA/JPL-Caltech

When NASA launched its Voyager 1 and 2 spacecraft 33 years ago, the probes' primary mission was to explore Jupiter and Saturn. But the two satellites have performed above and beyond their original duty: As of March 2012, Voyager 2 was 14.7 billion kilometers away from Earth, in the heliosheath—the outermost layer of the heliosphere where the solar wind is slowed by the pressure of interstellar gas—and yesterday, at the American Geophysical Union meeting in San Francisco, scientists reported that Voyager 2 has entered a new region at the edge of our solar system, which they believe is the final area the spacecraft has to cross before hitting interstellar space: a magnetic highway for charged particles.

Scientists call this region a magnetic highway because of the connection between our sun's magnetic field lines and interstellar magnetic field lines, which allows lower-energy charged particles from our heliosphere to zoom out into interstellar space, and higher-energy particles from outside to come in. Before Voyager 1 entered this region for the first time on July 28, the charged particles bounced in all directions, "as if trapped on local roads inside the heliosphere," according to a NASA press release. The region ebbed and flowed toward Voyager 1 several times before the craft entered it again on August 25; the environment has since been stable. The magnetic highway is still inside our solar system, scientist believe, the because the direction of the magnetic field lines haven't changed. (The Voyager probes are sending data back to NASA's Jet Propulsion Laboratory through the Deep Space Network, or DSN.)

"Although Voyager 1 still is inside the sun's environment, we now can taste what it's like on the outside because the particles are zipping in and out on this magnetic highway," said Edward Stone, Voyager project scientist based at the California Institute of Technology, Pasadena. "We believe this is the last leg of our journey to interstellar space. Our best guess is it's likely just a few months to a couple years away. The new region isn't what we expected, but we've come to expect the unexpected from Voyager."

So what's it like on this magnetic highway? Voyager 1 reports back that solar winds have slowed to zero, and the magnetic field is about 10 times more intense than before the termination shock, which it crossed in December 2004.

Here's a fun animation, courtesy of NASA, of Voyager 1 on the magnetic highway:

Can You 'Hear' These Silent GIFs?

GIFs are silent—otherwise they wouldn't be GIFs. But some people claim to hear distinct noises accompanying certain clips. Check out the GIF below as an example: Do you hear a boom every time the structure hits the ground? If so, you may belong to the 20 to 30 percent of people who experience "visual-evoked auditory response," also known as vEAR.

Researchers from City University London recently published a paper online on the phenomenon in the journal Cortex, the British Psychological Society's Research Digest reports. For their study, they recruited more than 4000 volunteers and 126 paid participants and showed them 24 five-second video clips. Each clip lacked audio, but when asked how they rated the auditory sensation for each video on a scale of 0 to 5, 20 percent of the paid participants rated at least half the videos a 3 or more. The percentage was even higher for the volunteer group.

You can try out the researchers' survey yourself. It takes about 10 minutes.

The likelihood of visual-evoked auditory response, according to the researchers, directly relates to what the subject is looking at. "Some people hear what they see: Car indicator lights, flashing neon shop signs, and people's movements as they walk may all trigger an auditory sensation," they write in the study.

Images packed with meaning, like two cars colliding, are more likely to trigger the auditory illusion. But even more abstract images can produce the effect if they have high levels of something called "motion energy." Motion energy is what you see in the video above when the structure bounces and the camera shakes. It's why a video of a race car driving straight down a road might have less of an auditory impact than a clip of a flickering abstract pattern.

The researchers categorize vEAR as a type of synesthesia, a brain condition in which people's senses are combined. Those with synesthesia might "see" patterns when music plays or "taste" certain colors. Most synesthesia is rare, affecting just 4 percent of the population, but this new study suggests that "hearing motion synesthesia" is much more prevalent.

[h/t BPS Research Digest]

The Surprising Link Between Language and Depression

Skim through the poems of Sylvia Plath, the lyrics of Kurt Cobain, or posts on an internet forum dedicated to depression, and you'll probably start to see some commonalities. That's because there's a particular way that people with clinical depression communicate, whether they're speaking or writing, and psychologists believe they now understand the link between the two.

According to a recent study published in Clinical Psychological Science, there are certain "markers" in a person's parlance that may point to symptoms of clinical depression. Researchers used automated text analysis methods to comb through large quantities of posts in 63 internet forums with more than 6400 members, searching for certain words and phrases. They also noted average sentence length, grammatical patterns, and other factors.

What researchers found was that a person's use (or overuse) of first-person pronouns can provide some insight into the state of their mental health. People with clinical depression tend to use more first-person singular pronouns, such as "I" and "me," and fewer third-person pronouns, like "they," "he," or "she." As Mohammed Al-Mosaiwi, a Ph.D. candidate in psychology at the University of Reading and the head of the study, writes in a post for IFL Science:

"This pattern of pronoun use suggests people with depression are more focused on themselves, and less connected with others. Researchers have reported that pronouns are actually more reliable in identifying depression than negative emotion words."

What remains unclear, though, is whether people who are more focused on themselves tend to depression, or if depression turns a person's focus on themselves. Perhaps unsurprisingly, people with depression also use more negative descriptors, like "lonely" and "miserable."

But, Al-Mosaiwi notes, it's hardly the most important clue when using language to assess clinical depression. Far better indicators, he says, are the presence of "absolutist words" in a person's speech or writing, such as "always," "constantly," and "completely." When overused, they tend to indicate that someone has a "black-and-white view of the world," Al-Mosaiwi says. An analysis of posts on different internet forums found that absolutist words were 50 percent more prevalent on anxiety and depression forums, and 80 percent more prevalent on suicidal ideation forums.

Researchers hope these types of classifications, supported by computerized methods, will prove more and more beneficial in a clinical setting.

[h/t IFL Science]


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