Forgot your password?
typodupeerror

Comment: Re:Indeed... (Score 1) 110

by careysub (#47806713) Attached to: Finland's Nuclear Plant Start Delayed Again

Your post would be considerably more persuasive if you showed the price of uranium at which it became "unsustainable", and if you didn't throw out a random "well over 100x current cost" figure when your linked source only documented a 10-20 times cost using older technologies now being superseded described in the article. (Your provide no analysis to show that the even the 2007 price spike made nuclear power "unsustainable" - proof by unsupported assertion does not work)

At $130/kg the cost of uranium mining comprises a cost of 0.32 cents per kwh. So at $1000/kg this cost rises to 2.5 cents per kwh. The additional 2.2 cents is less than the estimated cost difference between advanced nuclear and more expensive future solar PV power, which I suspect you believe to be viable (I do). So the fearsome $1000/kg price still leaves nuclear power cheaper than solar. If more advanced technologies cut the cost (the normal pattern of things), and the topic of the Technology Review, this differential gets cut as well. A better article on seawater uranium extraction indicates that technologies under development should cost $300/kg, a price that drops the differential to only 0.42 cents per kwh, and making it a very minor component of nuclear power cost

Comment: Re:300 Miles context (Score 1) 110

by careysub (#47806215) Attached to: New Computer Model Predicts Impact of Yellowstone Volcano Eruption

I think you're off by a few orders of magnitude. This would be a much bigger deal than the year without a summer, which caused mass starvation. The short term damage would be a significant percentage of everything starving to death. There would be next to no crop land left in all of North America for decades, perhaps centuries.

It is worth noting that currently the world only maintains a 74 day supply of grain. A super-eruption of this kind would effectively shut down agriculture everywhere. About half of the world's grain is directly consumed as food, so if we immediately divert all grain use (feed lots, fuel and industrial use, etc.) to direct basic food use we could double that to 148 days, then we run out completely.

Of course this ideal model of even distribution is not reality: poorer places and food importers run out much faster, richer and food producing places would last longer - maybe a year? But the dramatic cooling which prevents crop production would probably last a number of years. All of the major food crops are sub-tropical species whose productivity are very sensitive to temperature. Even after the period of outright crop failure ends, productivity will be reduced. And as lgw states, the grain belt in the U.S. (~15% of world grain production) would be out of production entirely long after the direct cooling from the ash dissipated.

Another reference point is the Great Famine of 1315-1317 presumably caused by the eruption of Mt. Tarawera in New Zealand, which ejected about 6 cubic kilometers of ash, only 0.6% of a Yellowstone super eruption. The Great Famine resulted from two years of crop failure, with normal food supplies not being restored until 1325. Depending on region 10-25% of the population of Europe died. (The Black Death showed up 22 years later, the poor health of those who lived through the famine perhaps contributing to its development and toll.)

It would be safe to estimate that the majority of the world's population would die, probably a large majority.

Comment: Re:Ecosystem (Score 2) 106

by careysub (#47800711) Attached to: The Passenger Pigeon: A Century of Extinction

Their habit of long distance migration in large groups was well suited for such an explosion, exploiting all of the nut-tree resources on North America.

Unfortunately for the passenger pigeon, their favorite American Chestnut is no longer a nut-bearing species for most of its former range, thanks to the chestnut blight. So before you can re-introduce the passenger pigeon, you need to restore the chestnut -- which horticulturists have been trying, with limited success, for decades.

You are correct that restoring the species successfully (assuming we can make viable breeding PPs) is a long shot. One of the problems is their colony-style breeding behavior. The aren't solitary nesters, but live and breed in large groups. Attempts to breed them in captivity failed.

The collapse of the population to zero seems to have proceeded in phases (3, I count): loss of forest food sources from cutting, extermination efforts (hunting and simple pest-control killing) which capitalized on the dense groups that made easy pickings, but then after PP extermination was circumscribed, the population continued to collapse since they were below the natural breeding population size. In its last couple of decades efforts to save them were being made, but they were unsuccessful. The genetically documented population "bottleneck", when the breeding population dropped to 50,000, might have been a single colony.

A similar situation occurred with the cheetah, which once dropped to fewer than a dozen individuals within the last 10,000 years. There is also evidence of humans bottlenecking with populations in the low thousands within the last 100,000 years.

Comment: Re:Ecosystem (Score 4, Informative) 106

by careysub (#47800039) Attached to: The Passenger Pigeon: A Century of Extinction

The consequences would be that the ecosystem would revert to a more natural state. We don't need to have sabre tooth cats running around killing these things to keep their population in check - domestic housecats would do the job very nicely. The simple fact is, these birds were here in enormous numbers, basically a big part of the definition of the North American ecosystem, and we screwed it up....

The enormous numbers of the Passenger Pigeon actually suggest that they were the beneficiaries of an extreme environmental disruption that occurred a few centuries earlier: the sudden and dramatic disappearance on the large scale agricultural and horticultural societies of Native Americans when ~90% of the population died from successive onslaughts of pandemic disease brought by the arrival of populations from the Old World (Europeans and Africans).

European observers only ever got a look at pre-pandemic North America along the east coast, and the evidence there is of stunning change in the ecology.

Genetic studies of Passenger Pigeons have shown that the subabundance was a transient, new phenomenon. In the last million years the breeding population only averaged about 1/3 of a million, and sometimes as few as 50,000, and began a population upsurge 6,000 years ago. The enormous explosion to billions was much more recent than that.

The ecosystem for the PP were forests of nut-bearing trees, which the super-population of PPs could be seen to be damaging in their locust-like swarming and foraging, an unsustainable situation. These forests were not "natural" though, they were managed for thousands of years by Native America horticulturists who encouraged the development of large dense stands of edible nut trees.

When the Native American populations suddenly disappeared that left large stands of unexploited nut-food that allowed the PPs to break-out into the vast populations that were observed. Their habit of long distance migration in large groups was well suited for such an explosion, exploiting all of the nut-tree resources on North America.

Comment: Re:Out of the question (Score 2) 240

by careysub (#47797267) Attached to: Feds Want Nuclear Waste Train, But Don't Know Where It Would Go

You want to keep spent fuel. It's not really "waste" - the anti-nuclear lobby just likes to call it that to hype up opposition. Current light water reactor designs use only about 5% of the U-235 in the fuel rods, and only about 1% of the total energy extractable from the uranium.

Come again? Current typical PWR fuel usage is to take fuel that contains 4.5% U-235, and discharge after a fuel burn-up of 50,000 megawatt-days/tonne, spent fuel containing 1.02% U-235, which would be using 77% of the U-235 in the fuel rods, not 5%.

Also it is not clear whether your "1%" number refers to the theoretical fissile energy from the originally mined fuel (including the safely stored, easily accessible depleted uranium, which is not in the fuel rod) or just the actinides in the fuel rod itself. In the latter case, not only is U-235 burned, but a significant amount of U-238 is transmuted and burned as well (a bonus of going to higher fuel burn-ups), so about 5% of the total actinide content in the fuel is burned, a lot more than "1%".

That's why spent fuel remains "hot" for so long - the vast majority of the energy it contains is still there, and is emitted over time as radioactive energy as it decays.

Right - it is the unburned transuranics that comprise nearly all of the long-term hazard. Reburning spent fuel in specially designed reactors can extract power and keep the size of this spent fuel actinide inventory stable. Active reuse of the fuel will also prevent it from being seen as a permanent burden, eventually it will be taken away and burned.

The problem is that only heavy subsidies will build these burner reactors - they will never compete with once-through U-235 burning because the capital and fuel cost of these is lower.

Mining and enriching U-235 is actually cheaper that reprocessing spent fuel. Regular enriched uranium fuel is not "hot". It is easy to handle without special hot cells for everything. The U-235 is easier to burn. You can't even argue that eventually they will have to build them because the natural uranium will run out. It will be cheaper to extract U-235 from seawater than use transuranic fuel, in which case we will have a 10,000 year supply of once-through burning.

Transuranic burners will require government intervention to bring them into existence, to subsidize their operation in some fashion. Perhaps tying the spent fuel tax will to this is how to do it, but it looks like the tax is too low currently. If this is going to happen maybe someone should start making it happen - real development plans - now so they will actually exist in 25 years, instead of still being fiction in 75.

"OMG - this solves the nuclear waste problem! Why aren't we doing this?" Unfortunately, breeder reactors create weapons-grade plutonium as a byproduct. That's the only reason we don't do it - it's a purely political reason, not technical.

Nope they do not produce "weapons-grade plutonium" (which can only be made in low burn-up reactors, far below the burn-ups of current power reactors). It does produce extremely dirty weapons-useless plutonium*, but then it burns it too, so the net effect should be to reduce it.

President Carter banned the commercial use of breeder reactors in the U.S.

Please cite the legal vehicle through which Carter "banned" them? (You can't because this is fantasy.)

What Carter did do was veto funding for the Clinch River Breeder Reactor project one year, since it was growing into a colossal boondoggle, but the veto had no effect since it was over-ridden and the project continue unabated. The project was eventually killed by Congress in the Reagan Years (1983) because as Carter argued, it was a colossal boondoggle. The cost had grown from $400 million (with industry kicking in $257 million) to a project coasting $8 billion (with government covering all of that cost increase). That, and there was no wast processing facility to handle its fuel, that having been shutdown during the Ford Administration.

There is no "breeder ban".

*It is possible to make nuclear explosives with any combination of the transuranics, they are all fissile. But trying to make a practical munition out of the very hot (thermally and radioactively) transuranics is impossible. The weapon would require special cooling at all times, no one could service them unless using a hot cell, service life would be very short, requiring constant rebuilds.

Comment: Re:And this is how we get to the more concrete har (Score 1) 523

by careysub (#47768251) Attached to: Limiting the Teaching of the Scientific Process In Ohio

...

So that's the real end goal - to get religion - or more correctly, Christianity, back into schools so everyone becomes a "good little Christian boy".

...

Or even more correctly Evangelical Fundamentalist Christianity into schools. The Fundamentalist bloc is a political powerful sect in the U.S., but fairly unimportant in world Christianity; but has managed to misappropriate the term "Christianity" to only apply to themselves in practice. We shouldn't propagate this erroneous usage.

Comment: Re:If you don't want science... (Score 1) 523

by careysub (#47768089) Attached to: Limiting the Teaching of the Scientific Process In Ohio

Name a couple. I don't believe you understand what the church considered blasphemy to be. As for "a lot of them pretended", you cannot read minds. Especially those in the past.

What we can say is that following the trials or Giordano Bruno (executed) and Galileo (imprisoned for life, forced to recant) the Counter-Reformation shut down science where ever it held sway. Cremonini refused to look through Galieo's telescope, so afraid was he of being tainted by accusations of heresy. Copernicus's books were banned, until the 19th century. Cardano was prosecuted for heresy.

During the Age of Enlightenment that lands that languished under the Inquisition produced no important scientists. They didn't have to kill anyone else, they simply shut down critical thinking.

Comment: Re:just because the dept of ed.... (Score 2) 523

by careysub (#47767621) Attached to: Limiting the Teaching of the Scientific Process In Ohio

most of thethey do is disburse funds from the fed to the states

and this is the exact problem I have with the dept of ed. People in ny shouldnt be paying for students in cali, and people in north dakota should not be paying for students in fla. Keep the money local, and get rid of the overhead.

The portion of the Dept of Education you are complaining about, the appropriations part, comes to 65 billion dollars a year, out of total U.S. education spending of about 850 billion a year, so it is a grand total of 7.5% of that; the vast majority of U.S. education spending is already local -- exactly what you want. Happy?

And people in New York are not paying for students in California. The people in the wealthy states are, by and large, helping to educate people in poorer states, who otherwise have fewer resources with which to educate their poorer citizens (local funding has a devastating effect on education in poor counties). And what is wrong with the wealthy helping the poor?

Remember how the Constitution starts?

"We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America."

This is part of that vision thing: forming a more perfect Union by promoting the general welfare of the nation.

Comment: Re:The US slides back to the caves (Score 1) 523

by careysub (#47767361) Attached to: Limiting the Teaching of the Scientific Process In Ohio

To be fair, Europe is a continent while the United States is a country.

Let me correct that for you: Europeans like to imagine that Europe is a continent, since Eurocentric thinking is endemic to Europeans (perhaps even more than the citizens of the United States are subject to USA-centric thinking). But Europe is actually a peninsula of the Eurasian continent, with adjacent regions, and comprises only 20% of the continent, and only 15% of its population.

The United States is 40% of the North American continent, and 60% of its population, so the U.S. comes much closer to "being a continent" than does Europe.

Comment: Re:How did they build the pyramids (Score 1) 202

by careysub (#47760393) Attached to: How the Ancient Egyptians (Should Have) Built the Pyramids

Yeah, I mean Herodotus is biased, but his isn't the only account that suggests that.

It isn't that Herodotus was biased, it is that he really did not know anything at all about Khufu, who had lived 2000 years earlier. Herodotus was simply passing on the sorts of tales that travelers hear about events that occurred thousands of years earlier in a culture where historical scholarship as we think of it was unknown.

Comment: Re:They made the blocks into wheels (Score 3, Insightful) 202

by careysub (#47760329) Attached to: How the Ancient Egyptians (Should Have) Built the Pyramids

Did you read this article you linked to? It refutes this theory:

"However, even though this method is feasible and workable, it is unlikely that the GP's builders used it. The segments used by Bush had holes drilled into them to accommodate ropes which held the segments onto the block, yet none of the ancient segments found have such holes in them. How these alternative proposals fail is most clearly seen by considering the extreme case. Neither theory accounts for the movement of the fifty-ton granite slabs used in constructing the internal chambers of the GP. Considering the immense size of these monoliths, the flexible pole method would be rendered even more awkward. Forward motion would be extremely tedious--assuming that these monoliths could even be lifted by this method. Bush's idea would also be problematic. The dimensions of these slabs are not uniform, so each slab would have needed specialized circle segments. The largest monolith is about 27' x 4' x 8' at its ends.

The key failing of the cradle and the (actually extremely similar) pole theory is that it does not explain how they moved the far larger slabs that were not square blocks.

Also we have actual evidence of their methods - dragging on sledges. We have sledges, sledge tracks, and pictures of giant statues being dragged on sledges. They took the time to draw us a diagram, and people still look for other answers.

Comment: Re:So, is there any shred of EVIDENCE? (Score 2) 202

by careysub (#47760229) Attached to: How the Ancient Egyptians (Should Have) Built the Pyramids

This is very interesting, and maybe that's good enough. But isn't there some evidence of what method they might have used? Wood fragments? Tracks? Tools?

I'm asking this as a completely naive onlooker. I'm sure there is research on this spanning hundreds of years; anyone want to provide a quick summary?

How about the edges of the stone blocks that would have rotated about 500 times on their way to the pyramid? There should be systematic chipping on the edges of all of the blocks if this was used. Also, this method of movement looks suspiciously like a wheel, which Egypt did not get until many centuries after the great pyramids were constructed. In a pre-wheel culture this mode of transport might not be at all evident.

Comment: Re:Potheads assemble! (Score 1) 178

by careysub (#47675583) Attached to: Hemp Fibers Make Better Supercapacitors Than Graphene

but love science when it finds uses for hemp

Because with large scale hemp agriculture, you can always sneak in a few rows of 'the good stuff'.

No, you can't - although the belief that you can is apparently what has kept the hemp business shut down in the U.S. for 80 years (and led to Governor Arnold to veto a hemp cultivation measure in California.

The cultivation patterns are completely different. The hemp crop is grown in dense plantings that lead to tall stalks and few leaves, and then the crop is either harvested before it flowers (if an all-fiber farm) or is allowed to go to seed (if hemp seed is also harvested).

Either way there is no way that a successful drug crop, however small, can be snuck in there. (Not so drug cannabis and, say, field corn though - hiding pot among corn is an old trick).

Whenever a system becomes completely defined, some damn fool discovers something which either abolishes the system or expands it beyond recognition.

Working...