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+ - Which Is More Scalable, Nuclear Energy Or Wind Energy?-> 1

Submitted by mdsolar
mdsolar (1045926) writes "Summary: Empirically, wind energy is much more scalable than nuclear energy.

China is the true experiment for maximum scalability of nuclear vs wind. It has a tremendous gap between demand and generation. It can mostly ignore democracy and social license for nuclear. It is building both wind and nuclear as rapidly as possible. It has been on a crash course for both for about the same period of time. It has bypassed most of the regulatory red tape for nuclear.

So how is it doing?

        China turned on just over 16 GW of nameplate capacity of wind generation in 2013 according to the Global Wind Energy Council.

Over the four years of 2010 to 2014, China managed to put 4.7 GW of nuclear into operation at the Qinshan Phase II, Ling Ao Phase II, Ningde, Hongyanhe and Yangjiang plants. This is not their stated plans for nuclear, which had them building almost double this in 2013 alone and around 28 GW by 2015, but the actual plants put into production. The variance between the nuclear roadmap and nuclear reality in China is following the trajectory of nuclear buildout worldwide: delays, cost overruns, and unmet expectations."

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Comment: Pair Instability Super Novae (Score 2) 46

by mdsolar (#47728345) Attached to: The Star That Exploded At the Dawn of Time
The instability that causes the collapse of a stellar core and subsequent explosion comes from turning gamma rays into pairs of electrons and positrons. This turns energy into matter and cuts the pressure that the energy provides. It turns out that these explosions may make observing the early universe easier. One of the most important abundance ratios is the interstellar medium is the ratio of oxygen to carbon. The strength of the carbon monoxide bond is so strong that these two really pair up. Whichever runs out first determines the remaining chemistry to a large degree. Mass losing carbon rich stars produce carbon rich dust, while mass losing oxygen rich stars produce silicate dust for example. But, primordial Pair Instability Super Novae may produce lots of oxygen with little carbon or silicon to combine with. So the very early solid phase of the ISM may be mostly water ice. This happens to increase the far infrared emissivity of this solid phase making early objects brighter in the red-shifted sub-millimeter. Thus very early object may be easy to find in surveys at that wavelength.

Comment: Re:Why can't hydrogen cool? (Score 2) 46

by mdsolar (#47728129) Attached to: The Star That Exploded At the Dawn of Time
The universe cools as it expands. Once the background radiation is cool enough then the heat of contraction can dissipate. Initially, growth of structure in the universe happens only in dark matter because the normal matter smooths out destiny fluctuations. But after recombination, the normal matter begins to catch up.

Comment: Re:Why can't hydrogen cool? (Score 1) 46

by mdsolar (#47727767) Attached to: The Star That Exploded At the Dawn of Time
You've got this right. Rotational transitions are the important ones (aside from atomic carbon). For molecular hydrogen, these are at higher energy so the most abundant molecule does not contribute much to radiative cooling normally. It does become important in primordial gas, but then the gas has to be warmer to excite those transitions.

+ - The star that exploded at the dawn of time->

Submitted by sciencehabit
sciencehabit (1205606) writes "To probe the dawn of time, astronomers usually peer far away; but now they've made a notable discovery close to home. An ancient star a mere thousand light-years from Earth bears chemical elements that may have been forged by the death of a star that was both extremely massive and one of the first to arise after the big bang. If confirmed, the finding means that some of the universe’s first stars were so massive they died in exceptionally violent explosions that altered the growth of early galaxies."
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