Couch potatoes date back 7,000 years

Thought couch potatoes are the product of a modern lifestyle? They may have evolved 7,000 years ago!

Thought couch potatoes are the product of a modern lifestyle? They may have evolved 7,000 years ago!

A new Cambridge study has shown that couch potatoes have a history that stretches back 7,000 years when humans first picked up the plough.

Research into lower limb bones shows that our early farming ancestors in Central Europe became less active as their tasks diversified and technology improved.

Cambridge University anthropologist Alison Macintosh found that this drop in mobility was particularly marked in men.

Macintosh shows that after the emergence of agriculture in Central Europe from around 5300 BC, the bones of those living in the fertile soils of the Danube river valley became progressively less strong, pointing to a decline in mobility and loading.

Macintosh suggests that male mobility among earliest farmers (around 7,300 years ago) was, on average, at a level near that of today's student cross-country runners.

Within just over 3,000 years, average mobility had dropped to the level of those students rated as sedentary, after which the decline slowed.

Macintosh laser-scanned skeletons found in cemeteries across Central Europe.

The earliest skeletons she examined date from around 5300 BC and the most recent from around 850 AD - a time span of 6,150 years.

Using a portable desktop 3D laser surface scanner to scan femora and tibiae, she found that male tibiae became less rigid and that bones in both males and females became less strengthened to loads in one direction more than another, such as front-to-back in walking.

These findings all indicate a drop in mobility. In other words, it is likely that the people to whom the skeletons belonged became, over generations, less intensely active and probably covered less distance, or carried out less physically demanding tasks, than those who had lived before them.

"My results suggest that, following the transition to agriculture in Central Europe, males were more affected than females by cultural and technological changes that reduced the need for long-distance travel or heavy physical work," said Macintosh.

"This also means that, as people began to specialise in tasks other than just farming and food production, such as metalworking, fewer people were regularly doing tasks that were very strenuous on their legs," Macintosh said.

Researchers reveal theory behind creation of Earth’s tectonic plates

Starting roughly four billion years ago, cooler parts of earth's crust were pulled downwards into the warmer upper mantle, damaging and weakening the surrounding crust. The process happened again and again until the weak areas formed plate boundaries.

"Over a much longer period, the same process could have created many tectonic plates. We have got a physical mechanism to explain how it could have happened," study author David Bercovici from Yale University explained.

The process began about four billion years ago and caused complete fractures some three billion years ago.
To investigate how the plates formed, Bercovici and Yanick Ricard of University of Lyon in France developed a computer model of earth's crust as it may have existed billions of years ago.

The model included a low-pressure zone at the base of the crust which caused a piece of the crust to sink into the upper mantle - mimicking conditions thought to have occurred early in the earth's history.

As the process repeated over time, it created a large tectonic plate with an active subduction zone.
Prior studies suggested the age of the plates - based on evidence of subduction gathered from minerals - preserved in ancient rocks.

In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate and sinks into the mantle as the plates converge.

The oldest such specimens are four-billion-year-old zircons found in the Jack Hills of Australia that appear to have formed at temperatures and pressures that are indicative of subduction.

"The subsequent movement of the plates has erased much of the evidence of their origin," said Paul Tackley, a geophysicist at Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland in a report published in Nature.

According to Robert Stern, a geologist at University of Texas in Dallas, there is no firm evidence of plate tectonics earlier than one billion years ago, but the new mechanism behind plate formation is "the first interesting example of how it might have occurred".

Who 'invented' the sound bar speaker?

Back in the day, budget-priced 5.1-channel home theater-in-a-box systems ruled, but that was before sound bars totally obliterated that product category.

The classic home theater setup -- with front left, center, and right, surround speakers, and a subwoofer -- was the de facto sound standard. High-end home theater buyers still use multichannel systems, but the multichannel home theater-in-a-box system is almost dead. Up until recently, I reviewed 12 or more home theater-in-a-box systems every year for CNET, but now sound bars are the most popular solution.

Altec-Lansing introduced the very first sound bar/subwoofer system -- the Voice of the Digital Theatre -- in 1998. Even today, it still looks like a fully contemporary design, but as far as I can tell, Altec didn't follow up with other models. I recently chatted with Zvox founder Tom Hannaher about the history of the category, and he recalled the Cambridge SoundWorks TVWorks 250 'bar from the late '90s, but that one also flopped.

SoundMatters introduced the MainStage in 2003, and when I reviewed it I wasn't terribly impressed with its sound. Another company, Niro, made a few 'bars starting in 2003. They were very expensive and sounded pretty good, but Niro dropped out of sight after a few years.

Home theater-in-a-box systems were big sellers, so the market wasn't ready for a single speaker solution in the early 2000s. A lot of HTIB owners of the era lined up their five tiny satellite speakers in a row, making do-it-yourself sound bars!

The first 'bar to eventually catch on was the $199 Zvox 315, and in 2003 that speaker sounded amazing. It was a breeze to hook up; bass power was so good a sub wasn't required; and dialogue intelligibility was excellent. Sales were slow, so Hannaher's startup faced rough times early on. But since he was the company's only employee, and he wasn't drawing a salary, Zvox stayed the course. Looking back, you might wonder why it was so hard -- all of the 5.1 channel HTIBs came with a bunch of wires, and hooking up those systems was always a time-consuming ordeal.

Zvox went on to introduce a range of sound bars that were favorably reviewed here at CNET and elsewhere. Zvox is still in the game, and still making superb 'bars.

In retrospect, it looks like it was Zvox's winning combination of easy setup and excellent sound that separated its speakers from the competition's. I'm amazed that, even today, most TV buyers put up with the lousy speakers built into their sets. And thanks to the market's insatiable appetite for ever skinnier TVs, their built-in speakers are worse than ever. Apparently buyers never choose TVs based on sound quality, so manufacturers have zero incentive to make better-sounding displays.

I'll credit Altec with inventing the sound bar, but Zvox was the first to perfect it. If you have memories of early sound bar systems, share them in the comments section.