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Submission + - Texas narrowly rejects allowing academics to fact-check public school textbooks (csmonitor.com)

jriding writes: AUSTIN, Texas â" Top Texas education officials rejected Wednesday letting university experts fact-check textbooks approved for use in public-school classrooms statewide, instead reaffirming a vetting system that has helped spark years of ideological battles over how potentially thorny lessons in history and science are taught.

Comment Re: It's not the Earth's fault (Score 1) 291

This is actually how we do it now, except the chalk line is measured by looking at the angular positions of various celestial bodies. This measurement determines the length of a sidereal year. We have been able to make it fairly accurately for the last 50 years or so, and extremely accurately for the last ~60, enough to know that our planet's rotation has slightly slowed during that time. But what we don't know is exactly how long a sidereal year was, say 100 million years ago. Perhaps the earth used to spin around 366 times during its trip around the sun instead of the current 365.25? It's mass and orbital period also change enough on a geologic timescale to affect this. These are problems we know about, but are difficult to solve because we just don't have the data.

Comment Re: It's not the Earth's fault (Score 1) 291

This is not necessarily true. It largely depends on how the rotation of the Earth might change over the next hundreds of thousands of years. We have only been running with leap seconds for a bit over 30 years. And we have only had the ability to measure the orbital period accurately enough to worry about seconds for about 100-150 years. Just because we have always "lept forward" in the current system, we can also leap backward. There is simply not enough collected data to know how far "off" our definition of the second is with respect to the history of the earth nor how much "jitter" we are likely to experience with an unadjusted clock. It's entirely possible that the error would never accumulate enough to be a big societal issue. If we are able to determine the average length of a year over a large time span more accurately, it's quite probable that the easiest fix might actually be simply to redefine the second.

Submission + - Morocco Plans Solar Power Mega-Project (theguardian.com)

An anonymous reader writes: Morocco, located along the north African coast, is in prime position to take advantage of solar technology, and they've committed to one of the biggest such projects in the world. The city of Ouarzazate will host "a complex of four linked solar mega-plants that, alongside hydro and wind, will help provide nearly half of Morocco’s electricity from renewables by 2020." It will be the largest concentrated solar power plant in the world. "The mirror technology it uses is less widespread and more expensive than the photovoltaic panels that are now familiar on roofs the world over, but it will have the advantage of being able to continue producing power even after the sun goes down." The first phase of the project, called Noor 1, comprises 500,000 solar mirrors that track the sun throughout the day, with a maximum capacity of 160MW. When the full project finishes, it will be able to generate up to 580MW. "Each parabolic mirror is 12 metres high and focussed on a steel pipeline carrying a 'heat transfer solution' (HTF) that is warmed to 393C as it snakes along the trough before coiling into a heat engine. There, it is mixed with water to create steam that turns energy-generating turbines."

Submission + - NASA Picks Winners for 3D-Printed Mars Habitat Design Contest (space.com)

schwit1 writes: NASA has picked the three winners in a design contest for 3D-printed habitats that could help future astronauts live on Mars.

The $25,000 first prize in NASA's 3D-Printed Habitat Challenge Design Competition went to Team Space Exploration Architecture and Clouds Architecture Office for the "Mars Ice House" design, which looks like a translucent, smooth-edged pyramid.

The design contest is the first milestone in NASA's 3D-Printed Habitat Challenge, an effort to encourage the development of technologies that could enable dwellings to be built using 3D printers and locally available resources on Mars and other locales away from Earth.

Anything cut to length will be too short.