Here is a classic paper on galaxy formation: http://articles.adsabs.harvard.edu/full/1977MNRAS.179..541R you can get rough timescales from there. More modern treatments include early clustering of dark matter to speed the process along. Dark matter obviates the need to worry about cooling times to some extent though consideration of lithium hydride cooling may be important before the first prompt supernovae provide some metals (most likely pair-instability SNe). You can find out more in my paper linked above.
It may be. That is about a dynamical timescale for a galaxy merger. Star formation takes much less time than 600 million years. You would not be forming a lot of earth-like planets at that time because there was very little in the way of dust early on. Most solid phase material may have been ice rather than dust owing to the early relatively high abundance of oxygen produced in pair-instability supernovae.
How soon they form depend on your cosmological simulation. Something had to be forming to reionize the universe, but it did not have to be galaxies of a sufficient size that you would notice them. But, the further the existence of quasars was pushed back, the more you needed somewhat organized bodied in which they could form even earlier so there were indications that some massive galaxies form early.
I suspect I have identified such objects from submillimeter observations http://arxiv.org/abs/0802.1666 but it is very good to see a more robust population identified here.
Engineering is a means for people who feel insecure to gain power. Personality flaws are not a real obstacle to getting a degree. I used to tutor premeds in physics and would find some pretty obsessive people, people who did not care at all about the subject, found no joy in learning it, but who covered it to get to their medical goal. But the funny thing was that I met engineering students who had just the same attitude. But physics is much more foundational to engineering that to medicine. What these students seemed most interested in were the sports cars that came along with their coop programs. I'm pretty sure that premeds who did not like medicine itself would not make it through their program while engineering students who did not like engineering would.
My experience with people who claim to be nuclear engineers here on slashdot is that they are obsessive to the point of being completely blind to reality. More than once I've said that I hoped the commenter had nothing to do with the running of a nuclear power plant because they were plainly security risks. That is on slashdot. Who know who those people really were. But there is at least an association between threats of violence and claims to be engineers. Insecure personalities could explain that association.
I've also worked with mechanical and electrical engineers who are really great people. Engineering is not a ticket to personality disorder, it just seems to attract and pass through some of that sort.
The question is: how much energy is needed to refine the silicon? That is the big cost driver for silicon right now. Use less purified silicon and costs go down. Thin film panels have energy payback times of weeks to months while silicon panels have payback time between one and three years. This mainly accounts for the cost difference.
The reduction in material use is very important for silicon. Nanosolar is at the point where its solar cells are a smaller cost component in solar panels than the glass in the panels. http://www.nanosolar.com/sites/default/files/NanosolarCellWhitePaper.pdf To compete, silicon needs to do the same. In some ways, thin film amorphous silicon does this, but the low efficiency means that you need more glass to generate the same amount of power. Crystalline silicon with low material requirements and higher efficiency than Nanosolar's material will likely deliver a lower price point than Nanosolar or First Solar's thin film technology because the cost driver will be MW/ton of glass rather than the cost of the PV material, the cost region that the thin film producers are exploring already.
Something that was a bit of a surprise about a nuclear war between Pakistan and India seems to be important here as well. Nuclear war between India an Pakistan would lift quite a lot of soot into the troposphere because of all the combustible material in cities. It turns out that solar heating of that soot causes the heated air parcels to rise into the stratosphere. That means that the soot does not fall out right away and is spread over the globe, blocking sunlight and cooling the planet enough to cause crop failure and famine around the world. http://www.planetark.com/dailynewsstory.cfm/newsid/47829/story.htm
This same mechanism is playing a similar though smaller role here by causing stronger updrafts. Interesting confirmation.
This is just a sympathy troll seeking to get more publicity for the stolen emails. There is no damage to climate science or science here, just hooligan tactics in a coordinated propaganda effort that includes break-ins around the globe. Science can't be hurt by such racketeering since it does not seek to deceive, it is another game altogether.
It is obvious that this is not a high bar since this is what we've been doing all along. The trick is to do it with renewable energy. Recently that has been what has been happening in the US and Europe with wind power especially covering much new generation. China expects to get about halfway there soon. So stabilizing emissions is going to be easy. Cutting emissions will take more effort since then we need to deal with consequences for sunk costs.
The moderator that rated this a troll ought to look at the parent instead. Only natural radioisotopes are associated with coal, not fission products found in nuclear waste.
Boy, you really pulled that one out of somewhere. Maine Yankee was hugely expensive for CMP rate payers. Why? First, it wasn't built right. Second, we didn't need the power.
For Calvert Cliffs, Turkey Point, and the South Texas Project, there is a problem with sea level rise this century since these are in tidal areas. http://pubs.giss.nasa.gov/abstracts/2007/Hansen.html So, there are environmental concerns at these sites.
Nuclear power was propaganda, "Atoms for Peace" so for a while it didn't matter what it cost. Once the cost started to matter, we saw may defaults and cancellations.
That is unique about nuclear power. For the rest, refineries, rail, bridges and sewers, we already have enough so we don't build that much new, we just maintain and replace. Refineries consolidate reaching higher capacity, rail gets bought and sold, new bridges replace old ones etc...
It might look like that is happening with nuclear power, but we are just going to see defaults. If Calvert Cliffs or the South Texas Project break ground using federal loan guarantees, it will just grind to a halt because they won't be able to get insurance against sea level rise. Taxpayers will cover the loan defaults. Nuclear power was never and will never be practical, it was political all along.
I happen to think the story is controversial as well, but because it attributes the irresponsible relicensing of nuclear plants to concern over carbon dioxide emissions when actually it appears that it has more to do with profits and a lack of concern for safety. The big issue with carbon dioxide emissions actually has to do with the opportunity cost related to new nuclear plants which, when subsidized with loan guarantees that will surely be exercised at taxpayer expense, lead to postponing the use of less costly low carbon energy generation and thus leads to an increase in accumulated emissions. We are due for another meltdown and that will reverse the relicensing that has been going on, existing natural gas generation capacity will fill in temporarily, but effort wasted on new nuclear power is a serious problem for reducing carbon dioxide emissions.
Nevertheless, the article is worth reading since it chronicle the ongoing and frequent safety violations at our aging nuclear plants. The Nation is the oldest weekly magazine in the country and has a long history of investigative journalism.
The approval of license extensions for plants with substandard and inadequate containment like Oyster Creek is the point of the article. You are making the case for Parenti.
Slashdot Mirror
Google can be your friend: http://en.wikipedia.org/wiki/Dynamical_time_scale
Here is a classic paper on galaxy formation: http://articles.adsabs.harvard.edu/full/1977MNRAS.179..541R you can get rough timescales from there. More modern treatments include early clustering of dark matter to speed the process along. Dark matter obviates the need to worry about cooling times to some extent though consideration of lithium hydride cooling may be important before the first prompt supernovae provide some metals (most likely pair-instability SNe). You can find out more in my paper linked above.
These galaxies are intrinsically blue at their rest wavelength. They have young stars and little dust.
It may be. That is about a dynamical timescale for a galaxy merger. Star formation takes much less time than 600 million years. You would not be forming a lot of earth-like planets at that time because there was very little in the way of dust early on. Most solid phase material may have been ice rather than dust owing to the early relatively high abundance of oxygen produced in pair-instability supernovae.
How soon they form depend on your cosmological simulation. Something had to be forming to reionize the universe, but it did not have to be galaxies of a sufficient size that you would notice them. But, the further the existence of quasars was pushed back, the more you needed somewhat organized bodied in which they could form even earlier so there were indications that some massive galaxies form early.
I suspect I have identified such objects from submillimeter observations http://arxiv.org/abs/0802.1666 but it is very good to see a more robust population identified here.
http://www.nytimes.com/2010/01/01/opinion/01dutton.html So all of you must be wrong.
Junk products and won't honor extended warranties they sell.
Engineering is a means for people who feel insecure to gain power. Personality flaws are not a real obstacle to getting a degree. I used to tutor premeds in physics and would find some pretty obsessive people, people who did not care at all about the subject, found no joy in learning it, but who covered it to get to their medical goal. But the funny thing was that I met engineering students who had just the same attitude. But physics is much more foundational to engineering that to medicine. What these students seemed most interested in were the sports cars that came along with their coop programs. I'm pretty sure that premeds who did not like medicine itself would not make it through their program while engineering students who did not like engineering would.
My experience with people who claim to be nuclear engineers here on slashdot is that they are obsessive to the point of being completely blind to reality. More than once I've said that I hoped the commenter had nothing to do with the running of a nuclear power plant because they were plainly security risks. That is on slashdot. Who know who those people really were. But there is at least an association between threats of violence and claims to be engineers. Insecure personalities could explain that association.
I've also worked with mechanical and electrical engineers who are really great people. Engineering is not a ticket to personality disorder, it just seems to attract and pass through some of that sort.
The question is: how much energy is needed to refine the silicon? That is the big cost driver for silicon right now. Use less purified silicon and costs go down. Thin film panels have energy payback times of weeks to months while silicon panels have payback time between one and three years. This mainly accounts for the cost difference.
The reduction in material use is very important for silicon. Nanosolar is at the point where its solar cells are a smaller cost component in solar panels than the glass in the panels. http://www.nanosolar.com/sites/default/files/NanosolarCellWhitePaper.pdf To compete, silicon needs to do the same. In some ways, thin film amorphous silicon does this, but the low efficiency means that you need more glass to generate the same amount of power. Crystalline silicon with low material requirements and higher efficiency than Nanosolar's material will likely deliver a lower price point than Nanosolar or First Solar's thin film technology because the cost driver will be MW/ton of glass rather than the cost of the PV material, the cost region that the thin film producers are exploring already.
Something that was a bit of a surprise about a nuclear war between Pakistan and India seems to be important here as well. Nuclear war between India an Pakistan would lift quite a lot of soot into the troposphere because of all the combustible material in cities. It turns out that solar heating of that soot causes the heated air parcels to rise into the stratosphere. That means that the soot does not fall out right away and is spread over the globe, blocking sunlight and cooling the planet enough to cause crop failure and famine around the world. http://www.planetark.com/dailynewsstory.cfm/newsid/47829/story.htm
This same mechanism is playing a similar though smaller role here by causing stronger updrafts. Interesting confirmation.
This is just a sympathy troll seeking to get more publicity for the stolen emails. There is no damage to climate science or science here, just hooligan tactics in a coordinated propaganda effort that includes break-ins around the globe. Science can't be hurt by such racketeering since it does not seek to deceive, it is another game altogether.
It is obvious that this is not a high bar since this is what we've been doing all along. The trick is to do it with renewable energy. Recently that has been what has been happening in the US and Europe with wind power especially covering much new generation. China expects to get about halfway there soon. So stabilizing emissions is going to be easy. Cutting emissions will take more effort since then we need to deal with consequences for sunk costs.
The strontium-90 is clearly leaking from the power plant though and is entering the ground water and the Hudson River http://www.clearwater.org/press-releases/clearwater-files-new-indian-point-environmental-and-public-health-contention-2/
The moderator that rated this a troll ought to look at the parent instead. Only natural radioisotopes are associated with coal, not fission products found in nuclear waste.
Boy, you really pulled that one out of somewhere. Maine Yankee was hugely expensive for CMP rate payers. Why? First, it wasn't built right. Second, we didn't need the power.
And strontium-90 leaks must be stupid as well? http://www.nukewatch.com/quarterly/2009spring/cover.pdf
For Calvert Cliffs, Turkey Point, and the South Texas Project, there is a problem with sea level rise this century since these are in tidal areas. http://pubs.giss.nasa.gov/abstracts/2007/Hansen.html So, there are environmental concerns at these sites.
But that makes no difference since we will never use those. Meanwhile the new EPRs make matter worse. http://www.greenpeace.org/international/press/releases/new-nuclear-reactor-s-waste-is
Nuclear power was propaganda, "Atoms for Peace" so for a while it didn't matter what it cost. Once the cost started to matter, we saw may defaults and cancellations.
That is unique about nuclear power. For the rest, refineries, rail, bridges and sewers, we already have enough so we don't build that much new, we just maintain and replace. Refineries consolidate reaching higher capacity, rail gets bought and sold, new bridges replace old ones etc...
It might look like that is happening with nuclear power, but we are just going to see defaults. If Calvert Cliffs or the South Texas Project break ground using federal loan guarantees, it will just grind to a halt because they won't be able to get insurance against sea level rise. Taxpayers will cover the loan defaults. Nuclear power was never and will never be practical, it was political all along.
I happen to think the story is controversial as well, but because it attributes the irresponsible relicensing of nuclear plants to concern over carbon dioxide emissions when actually it appears that it has more to do with profits and a lack of concern for safety. The big issue with carbon dioxide emissions actually has to do with the opportunity cost related to new nuclear plants which, when subsidized with loan guarantees that will surely be exercised at taxpayer expense, lead to postponing the use of less costly low carbon energy generation and thus leads to an increase in accumulated emissions. We are due for another meltdown and that will reverse the relicensing that has been going on, existing natural gas generation capacity will fill in temporarily, but effort wasted on new nuclear power is a serious problem for reducing carbon dioxide emissions.
Nevertheless, the article is worth reading since it chronicle the ongoing and frequent safety violations at our aging nuclear plants. The Nation is the oldest weekly magazine in the country and has a long history of investigative journalism.
The approval of license extensions for plants with substandard and inadequate containment like Oyster Creek is the point of the article. You are making the case for Parenti.
Actually, coal plants produce zero nuclear waste.
While the post says I wrote that, your edits are a big improvement.
"Rube Goldberg" is a substantive criticism. Also, RTFA. Breeders won't work.