Domain: iop.org
Stories and comments across the archive that link to iop.org.
Comments · 293
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Re:Sensational!
...2599 children. Even this number is mostly meaningless as: (a) it was measured in Russia, which is pretty far from Chernobyl, while Belarus and Ukraine were the most affected; (b) thyroid cancer is only a fraction of medical problems one can get after exposure. Those who died were not the only ones who suffered.
Despite your failing argument about radiation-related health issues, I completely side with you about the need to kill the coal plants. They pollute, which creates greenhouse effect, as well as a stack of health hazards on their own. Modern nuclear plants can be built in a safe manner, with automatic shutdown-contain functions if something goes wrong. -
Re:This sounds like a sci-fi blockbuster
Believe this is the relevant paper.
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Re:So what is there of value to mine?
You are aware of things like JET? While it is still experimental for more practical usage, it still has been able to successfully preform fusion reactions. Also, the hydrogen bomb is powered by nuclear fusion.
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Re:Better article
I suggest reading the original paper. The theoretical machinery used is 4D and fully (spacetime) relativistic. If you can't cope with the physics literature, the press releases are more complete than the mangled stuff in the press (but the New Scientist isn't bad at all: http://www.newscientist.com/article/dn19727-how-to-cloak-a-crime-in-a-beam-of-light.html) Press release (Imperial) : http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_16-11-2010-9-5-43 Press Release (IoP): http://www.iop.org/news/nov10/page_45311.html . Regarding the chicken analogy, see http://www.qols.ph.ic.ac.uk/~kinsle/files/STcloak/
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Re:HOLY SHIT?
More fun facts: Some people have made carbon nanotubes from grass.
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Re:Frame of Reference Problem
> Gravitation works at the speed of light.
Um, no. Try again.
http://metaresearch.org/cosmology/speed_of_gravity.asp
http://iopscience.iop.org/0004-637X/590/2/683/57516.text.html -
Re:What's the significance?
Anyway the short version is high efficiency works, but apparently failed economically for bulk energy production. Ooops. Time for a new business plan. The purpose of yer low light camera sensor isn't to charge a battery, so its possibly useful regardless of manufacturing dollars per watt delivered.
Using femtosecond lasers for treating silicon surfaces was never going to be price-competitive for solar panel production. DRIE black silicon on the other hand, could be made competitive, if/when production scale DRIE equipment appears, specifically modified (and simplified) for black silicon forming. The strong plasma that is required, however, limits scalability. Still, not entirely impossible.
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Re:Attribution
The eight author (Philip M. Hinz) seems to work at the Steward Observatory in Tucson, AZ. The article says that the observations were done at the VLT (Very Large Telescope) at the ESO (European Southern Observatory) on Paranal mountain in Chile. However, Hinz may deserve substantial credit, since he was part of a team that actually used an APP for the first time, according to this article. That article did not look for exoplanets, but the astronomers did successfully image a faint companion for the star mu Herc A. That companion had previously only been observed spectroscopically.
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Re:They're gonna feel like...
Sure thing; as if there wasn't an avalanche of research that anyone with 5 minutes couldn't Google up for consumption. *rolls eyes*
Laury Miller and Bruce Douglas "On the rate and causes of twentieth century sea-level rise" Douglas has several seminal papers on the subject.
Permanent Service for Mean Sea Level -- if you want the raw data itself
Scientific reticence and sea level rise
The Impacts of Sea-Level Rise on the California Coast60+ references on Current Sea Level Rise @ Wikipedia (yeah, it's wikipedia; take the article with a pillar of salt and read the referenced papers and articles instead.. durrr)
With respect to the original gp post, the PSMSL dataset "defined the following criteria for selecting records from the PSMSL which were long, reliable, and avoided large vertical geologic changes:"
1. Each record should be at least 60 years in length
2. Not be located at collisional plate boundaries
3. At least 80% complete
4. Show reasonable agreement at low frequencies with nearby gauges sampling the same water mass
5. Not be located in regions subject to large post-glacial reboundSo, yah, I think the scientists took into account the obvious issues asked about by the gp: "Is the sea level rising? Or are plate tectonics lowering the land level in relation to the sea?".
Need more? Or is that enough to keep you busy reading for a little while?
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Heavy objects falling faster?
Discussion thread including math for why heavier objects fall faster because of earth gravity (normally imperceptible except with massive objects):
http://iopscience.iop.org/0143-0807/8/2/006
How quantum mechanics says that heavy objects fall faster:
http://www.sciforums.com/showthread.php?t=39234
In any case, whether heavy objects fall faster than light ones is tangential to the story. Many studies are wrong, some are pointless, but most have some relation to objective reality even if they can only simulate or deal with analagous cases. In order to meet my biological goals, I now know not to flail my arms and legs, so the study has value to me. -
Re:Science!
Common sense says that a son of an islamic black diplomat must be islamic and can't be american.
Huh? Common sense isn't supposed to be illogical.
Common sense says that heavier objects fall faster.
It depends on whether your commoner uses Newtonian or quantum physics.
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Re:Why mining?
The radiation problem is a big one, and I think the public doesn't yet realize how big of a problem it is. I mean, flight attendants and pilots are exposed to about as much or more than someone working in a nuclear power plant, so shouldn't they be wearing radiation badges? http://iopscience.iop.org/0952-4746/21/1/003 Now fast forward 50 yrs, with asteroid mining profits starting to take off. Will similar health risks get swept under the rug?
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Re:That's cool and all butFTA: "Ultimately that template can be used to replicate the pattern exactly. Next, the plan is to make a larger template from 30 blowfly corneas."
Here is a link from the article on the process http://iopscience.iop.org/1748-3190/5/3/036001 [Mass fabrication technique for polymeric replicas of arrays of insect corneas]I assume they only did a few as 30 corneas would be "larger." From the picture on the article, it looks like they used nine. However, no mention of why this is a good idea and what in particular it does for solar power.
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Re:Bit random?
The PDF (great pictures in it too) had a bit more info on why those eyes are good:
With these issues in mind, and with the objective of producing textured surfaces that could be useful, for example as reflection-reduction coatings for oblique insolation of solar cells [19–22], we decided to devise a technique for high-fidelity and mass replication of an array of blowfly corneas.
The rest of the paper appears to be all about the process, not about the eyes.
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Re:Wait a second ... relativity or quantum mechani
If you try to calculate ab-initio stuff with heavy atoms, there are approximations for relativistic quantummechanics, where the behaviour of the nucleus is approximated in a different way.
This stuff is a ways above my head but maybe this article helps: http://iopscience.iop.org/1742-6596/104/1/012025/pdf/jpconf8_104_012025.pdf. -
Actually... No.
Not solar power at all. Flettner rotors.
The only NEW thing about this plan is that they claim that they've actually received $300.000 from Bill Gates.
They have been going around with this idea for years now.
And from what I can tell - all they have to show for so far is the study linked above and this concept rendering.Looking at "estimated costs", $300.000 seems like about the amount someone with Bill Gates' money might donate to get rid of them politely.
Very few uncertainties will remain after the expenditure of the first £2 million over 2 years.
It will need perhaps £25 million and a further 3 years to complete research and development of the reliable hardware for spray vessels including the first fully instrumented, full-scale, crewed and sea-going prototype.
Once there is experience of its operation, it will cost approximately £30 million for tooling, which will allow a large number of spray vessels to be built rapidly in the event of a global emergency.About a year later...
The Copenhagen Consensus Centre, which advises governments on how to spend aid money, examined the various plans and found the cloud ships to be the most cost-effective.
They would cost $9 billion (£5.3 billion) to test and launch within 25 years, compared to the $250 billion that the world's leading nations are considering spending each year to cut CO2 emissions, and the $395 trillion it would cost to launch mirrors into space.
Is it vaporware? Not really sure.
The idea is to just spray the seawater into the air, not actually turn it into water vapor. -
Re:Good Slashdot post
Sounds like the dark galaxy called VIRGOHI 21 which might have ~1000x as much dark matter as visible matter (compare to ~10-20x for the Milky Way's ratio).
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UK catching up, only 11 years behind Denmark!
Yeah so polygons are formed in hydraulic rotating systems when you introduce a vertical jet of a different viscosity. Welcome to 1999!
Jesus this is getting ridiculous! When can Scandinavian scientists start to believe that UK/US researchers even scan their works before publishing? Its like Anders Celsius never existed!
http://iopscience.iop.org/0951-7715/12/1/001;jsessionid=B8281BB419A9613CD40649F803F5C666.c2
Full disclosure: I am not Danish -
Oh, and about the IOP? FYI:
The IOP has issued a clarification: "We regret that our submission has been seized upon by some individuals to imply that IOP does not support the scientific evidence that the rising concentration of carbon dioxide in the atmosphere is contributing to global warming.
IOP's position on global warming is clear: the basic science is well established and there is no doubt that climate change is happening and that we should be taking action to address it now. "
You going to be spreading that statement around whatever forums you post on also? After all, you seem to care so strongly about what the IOP has to say, after all.
It may also interest you to know that IOP members weren't made aware of the original statement, and in fact it was a single subcomittee of anonymous individuals who made it in the IOP's name. The Energy subcommittee at that, not the Environmental Physics subcommittee. And does anyone else find the irony delicious that the IOP is refusing to disclose who was on the committee that made the statement while demanding more openness?
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Re:Wings don't help
There is some info on deuterium bombardment of Li as well http://www.iop.org/EJ/abstract/0031-9155/23/1/003
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Re:The real problem with the glacier claims
The thousands of pages of "peer reviewed" "settled" "science" by "thousands of" "scientists" in WG1 are one pile of biased studies linked by circular references, carefully selected by a small team to obtain a desired alarmist outcome.
36,000 physicists are worried.
CAGW is dead, the deceivers are being exposed while the deceived march on, for now.
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Re:And yet the public...
Just researching La Hague, looks like a non-issue. They found an increase, but it was not statistically significant.
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Re:Slashdot did it first
Astrophysical Journal is pretty expensive.
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Re:Why would that be likely?
It's why it's entirely unlikely that you will ever see something that can be classified as life that isn't carbon-based.
Sure?
"From plasma crystals and helical structures towards inorganic living matter
Abstract. Complex plasmas may naturally self-organize themselves into stable interacting helical structures that exhibit features normally attributed to organic living matter. The self-organization is based on non-trivial physical mechanisms of plasma interactions involving over-screening of plasma polarization. As a result, each helical string composed of solid microparticles is topologically and dynamically controlled by plasma fluxes leading to particle charging and over-screening, the latter providing attraction even among helical strings of the same charge sign. These interacting complex structures exhibit thermodynamic and evolutionary features thought to be peculiar only to living matter such as bifurcations that serve as `memory marks', self-duplication, metabolic rates in a thermodynamically open system, and non-Hamiltonian dynamics. We examine the salient features of this new complex `state of soft matter' in light of the autonomy, evolution, progenity and autopoiesis principles used to define life. It is concluded that complex self-organized plasma structures exhibit all the necessary properties to qualify them as candidates for inorganic living matter that may exist in space provided certain conditions allow them to evolve naturally. "
http://www.iop.org/EJ/article/1367-2630/9/8/263/njp7_8_263.html
CC. -
Re:Not Surprised.
A huge paradigm shift is taking place lately with the realisation by humanity that "life" is not only organic - in fact organic life is simply an efficient thermodynamic machine and acts in exactly the same as inorganic "life" An excellent example is that plasma crystals exhibit the same properties as organic life http://www.iop.org/EJ/article/1367-2630/9/8/263/njp7_8_263.html Given that 99% of the universe is probably plasma as plasmas are by far the most common phase of matter in the universe, both by mass and by volume and all the stars are made of plasma, and even the space between the stars is filled with a plasma, albeit a very sparse one (http://en.wikipedia.org/wiki/Plasma_(physics)), it is most probable that organic life is simply very small part and specific type of thermodynamic machine. Nonetheless all Universe appears to be following the 2nd law of thermodynamics and humanity and organic life is simply a local iteration/mutation in the universe's attempt to obey the law, perhaps not even the most efficient one. This is the reason why we have Fermi's paradox, as we are looking to find life that is a mirror of us, whereas the universe is full of very intelligent inorganic life which even performs computations more complex than humanity at present - can you seriously stare at the remnants of Tycho's supernova with a clear mind and not think that the supernova is alive in an exotic way ? http://en.wikipedia.org/wiki/File:Main_tycho_remnant_full.jpg For the above reason perhaps the most efficient thermodynamic machines in the universe are not organically driven but inorganically driven like black holes which are the maximum entropy objects in the universe. In fact, is very possible, given the nature of humanity to create efficiencies in energy creation which however do not cover its needs but on the other hand create more needs for more consumption of energy, consistent with the 2nd law (http://www.theglobeandmail.com/blogs/jeff-rubins-smaller-world/why-energy-efficiency-means-higher-consumption/article1419515/), it is very possible that the logical progression of this trend is the creation of a black hole by humanity as the singular point of maximum entropy creation (could it be the CERN one?) In fact, the black holes in the universe may be "life" such as ours which may have "awakened" earlier than us and reached their "purpose" (see thermodynamic conclusion/limit) at an earlier time. Good stuff! Ntemis
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Nope. There was about 43.5 hours between them
Since the tsunami was west of the dateline, and TFA didn't mention the time or coordinate system used, I thought it might have been possible...
But according to wikipedia, the earthquake that caused the tsunami occurred at 2004-12-26 00:58 UTC. According to this paper, the "cosmic onslaught" hit us at 2004-12-27 21:30 UTC.
So, no. It isn't possible for the neutron star event to have caused the tsunami as it was outside of the tsunami event's light cone. -
Re:Lots of speculation.
We've got one of the best particle accelerators around (the Sun/Sol) and it hasn't managed to snuff us out yet and it's had BILLIONS of years. The LHC doesn't even come close in power levels comparatively speaking.
Actually that's not true. Basic fusion in the Sun's interior produces particles on the order of 1-20 MeV. These particles in cases when they reach the surface of the Sun can be accelerated by the Sun's magnetic fields, in extreme cases up to around 10 GeV. In comparison, the particle streams of the LHC will be colliding at energies of 10 TeV and up. That's particles with energies three orders of magnitude greater than the most energetic particles coming from the Sun.
All of that is dwarfed by ultra-high energy cosmic rays. One was observed to have an energy of roughly 3*10^8 TeV. Yes, that's almost seven orders of magnitude greater energy than what's going on in the LHC. Imagine a bunch of those whacking a neutron star for millions of years. The surface of a neutron star has a density about 5 to 6 orders of magnitude greater than iron. The interior apparently can be another 8 orders of magnitude, if our models are correct. That's as good an environment for a micro black hole as anything you'll find in nature. Yet we have neutron stars that have been around for at least 100,000 years. My bet is that with improved gravity lensing observations, they'll find more of these ancient neutron stars. -
Re:Why it's more dangerous.
Sorry, its _very_ missleading to say that cosmic rays HAVE 10^20eV. Most are many orders of magnitude lower.
Take a look here:
http://images.iop.org/objects/cern/cern/39/10/8/cernnews8_12-99.gif
A 10^20eV Cosmic Ray is a "1 per km^2 per 100 years" event.
Thats why the Oh My God particle was such an extraordinary event.
Btw, that graph is even steeper than it looks, as the Y-axis is energetic flux, not perticle flux. (thus higher energy particles are overemphasized) -
Re:It seems to me
But I don't believe you have the technology to prove said rock is going to hit the Earth in 30-40 years ; even small inaccuracies in orbital measurements and simulation could cause massive variation in the predicted position decades later.
We have demonstrated techniques for simulation of accurate orbits out to 50 Myr http://www.iop.org/EJ/abstract/0004-637X/592/1/620/ so I think even a few hundred years we can do for accurate collision calculations.
The biggest issue then is the orbital determination of the impactor. We use radar for orbit determination and we are very good at it: http://impact.arc.nasa.go/news_detail.cfm?ID=132 The article gives an example of measuring Yarkovsky effect on a 1/2 km asteroid, which changed it's orbit by 15 km over 12 years of observation.
I can not give a site, but I would estimate that inside of 6 months we can plot an important orbit to a few centimeters, and if we expect impact inside of 30 years we can predict the time to within 1 minute, which would locate the impact on Earth to within a few tens of km. -
Re:Well, now we'll know.
My apologies, but this is the last comment I can write. I'm struggling under the weight of academic deadlines, and I don't want to fail out of school because of my Slashdot addiction...
Meehl does not actually show that CO2 causes warming, he relies on the research of others to do so. In fact, while this may be a slight exaggeration, about all Meehl did here was to integrate the work of a number of other authors.
At least you're aware of the exaggeration, if not the magnitude or (more importantly) the fact that this criticism could be applied to any research that expands on previous results... which includes nearly every paper in the history of science.
This is indeed a claim made in a real journal. But it's far more controversial than you're implying. The maximum impact of this mechanism has been estimated to be responsible for no more than 23% of the 11-year cyclical variation of cloud cover.
"This is indeed a claim made in a real journal. But it's far more controversial than you're implying. The maximum impact of this mechanism has been estimated to be responsible for no more than 23% of the 11-year cyclical variation of cloud cover."
Estimated by whom? I have already shown you at least one peer-reviewed paper (although you objected to the journal's lack of reputation for "hard science") in which the estimation was far over what you state here. (Which, I admit, appears to be validly refuted for a specific period of time.) But if you are going to make an argument, as you seem to be doing here, then refute my source with one of your own, otherwise you are wasting my time.
That estimate was by T. Sloan and A.W. Wolfendale in the article I originally linked... that's the link which was originally followed by "[iop.org]" before you quoted it. Also, the paper you previously found contains similar criticisms of Svensmark 1998 on its second page.
But there are a lot of complex interactions going on here, including the fact that reflection by CO2 tends to be logarithmic... requiring a doubling of CO2 concentration to equal an incremental increase in reflection.
... Books could be written about it and probably will be.Yes, of course. The fact that CO2 absorption depends logarithmically on concentration has been known since 1900 when Angstrom and Koch first measured it in a tube filled with CO2. The absorption dropped by less than 1% when Koch lowered the pressure by 33%, which convinced an entire generation of climatologists that CO2 wasn't dangerous because it was already "saturated." In other words, they believed that adding more CO2 wouldn't warm the planet. ( Ångström, Knut (1900). "Über die Bedeutung des Wasserdampfes und der Kohlensaüres bei der Absorption der Erdatmosphäre." Annalen der Physik 4(3): 720-32. published online 308(12): 720-32 (2006) [doi: 10.1002/andp.19003081208] )
But this research is 109 years old. Books have already been written about it. As early as 1931, Hulburt used the brand-new theory of quantum mechanics to study absorption in more detail. He concluded that doubling CO2 would warm the Earth by 4C. This is still the conventional method of expressing "climate sensitivity" with respect to CO2. (Although it's important to note that this convention ignores feedback effects which very likely sum up to produce a net positive feedback effect.) His predict
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Re:Well, now we'll know.
My apologies, but this is the last comment I can write. I'm struggling under the weight of academic deadlines, and I don't want to fail out of school because of my Slashdot addiction...
Meehl does not actually show that CO2 causes warming, he relies on the research of others to do so. In fact, while this may be a slight exaggeration, about all Meehl did here was to integrate the work of a number of other authors.
At least you're aware of the exaggeration, if not the magnitude or (more importantly) the fact that this criticism could be applied to any research that expands on previous results... which includes nearly every paper in the history of science.
This is indeed a claim made in a real journal. But it's far more controversial than you're implying. The maximum impact of this mechanism has been estimated to be responsible for no more than 23% of the 11-year cyclical variation of cloud cover.
"This is indeed a claim made in a real journal. But it's far more controversial than you're implying. The maximum impact of this mechanism has been estimated to be responsible for no more than 23% of the 11-year cyclical variation of cloud cover."
Estimated by whom? I have already shown you at least one peer-reviewed paper (although you objected to the journal's lack of reputation for "hard science") in which the estimation was far over what you state here. (Which, I admit, appears to be validly refuted for a specific period of time.) But if you are going to make an argument, as you seem to be doing here, then refute my source with one of your own, otherwise you are wasting my time.
That estimate was by T. Sloan and A.W. Wolfendale in the article I originally linked... that's the link which was originally followed by "[iop.org]" before you quoted it. Also, the paper you previously found contains similar criticisms of Svensmark 1998 on its second page.
But there are a lot of complex interactions going on here, including the fact that reflection by CO2 tends to be logarithmic... requiring a doubling of CO2 concentration to equal an incremental increase in reflection.
... Books could be written about it and probably will be.Yes, of course. The fact that CO2 absorption depends logarithmically on concentration has been known since 1900 when Angstrom and Koch first measured it in a tube filled with CO2. The absorption dropped by less than 1% when Koch lowered the pressure by 33%, which convinced an entire generation of climatologists that CO2 wasn't dangerous because it was already "saturated." In other words, they believed that adding more CO2 wouldn't warm the planet. ( Ångström, Knut (1900). "Über die Bedeutung des Wasserdampfes und der Kohlensaüres bei der Absorption der Erdatmosphäre." Annalen der Physik 4(3): 720-32. published online 308(12): 720-32 (2006) [doi: 10.1002/andp.19003081208] )
But this research is 109 years old. Books have already been written about it. As early as 1931, Hulburt used the brand-new theory of quantum mechanics to study absorption in more detail. He concluded that doubling CO2 would warm the Earth by 4C. This is still the conventional method of expressing "climate sensitivity" with respect to CO2. (Although it's important to note that this convention ignores feedback effects which very likely sum up to produce a net positive feedback effect.) His predict
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Re:Well, now we'll know.
Therefore, the statement in AR4 that "It is more likely than not (>50%) that there has been some human contribution to the increases in hurricane intensity." is likely an exaggeration, not supported by the actual research.
Months ago, I was careful to say that hurricane intensity can't be linked to climate change, and that a quick look at the IPCC guidance note on uncertainty indicates that this statement is essentially the weakest statement they could make without being utterly silent. (See table 4.) In fact, I later corrected another poster who was under the impression that a clear correlation between hurricanes and climate change was in the data.
If the IPCC report had used any other qualifier from table 4, you might have a more convincing point. Furthermore, another paper in Science says "Results show that the increasing trend in number of category 4 and 5 hurricanes for the period 1970-2004 is directly linked to the trend in SST [sea surface temperature]." Dr. Landsea is a legitimate scientist, but he's not the only one studying hurricanes, and I fail to see how his claims automatically rule out those of other scientists-- especially when they're making such an weak claim given the observed trends.
And, yes, those "natural forcings" include variations in solar output, which can be measured by satellites at L1 so there's no need to search for weak correlations in sunspot data.
Please be specific. "Solar output" can mean many things.
I was quoting Meehl 2004 in that sentence, which itself quotes Meehl 2003 to show that variations in solar luminosity affect the climate. Of course, Meehl 2004 shows that this effect isn't responsible for the warming in the latter half od the century, which is shown to be due to anthropogenic CO2 emissions.
Previously, you cited luminosity data when I had clearly stated that the correlation was with period length, not luminosity.
That's because, as you now seem to agree, other correlations have been disproven by later research. I was just trying to steer you back towards the only correlation that's well-established in the peer-reviewed literature.
But the main problem with this sort of approach is that some kind of mechanism other than variations in luminosity would be needed to support your thesis. For example, in this post you claim "The sunspot activity tends to blow away the solar winds, allowing more radiation to get through to Earth's surface."
This is indeed a claim made in a real journal. But it's far more controversial than you're implying. The maximum impact of this mechanism has been estimated to be responsible for no more than 23% of the 11-year cyclical variation of cloud cover. Furthermore, there's no long term trend in Svensmark's data, which would be necessary to explain the long-term warming trend that's been observed. For more information, see chapter 7.10 of
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Self Organized Criticality
Flowing sand has been considered as a model of hydrodynamics for quite some time. They were using it in studies of turbulence when I was at the Santa Fe Institute 10 years ago. One of the effects of turbulence is the formation of vorticies that persist for much longer than one would expect from the physical characteristics of the sand. The effect was noted and named "self-organizing criticality" 20 years ago http://www.iop.org/EJ/abstract/1402-4896/1990/T33/001 . The result appears as though surface tension were involved but obviously that phenomenon doesn't apply.
I have to admit that dropping the camera to get their pictures is a neat hack.
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PS
Those natuaral variations include solar flux but not susnspots, the reason being is that there is not a scrap of hard evidence that sunspots affect Earth's climate but there is plenty of evidence they affect book sales.
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Re:It doesn't say ocean currents cause the field
The paper does not say that ocean currents cause the magnetic field. It hypothesizes that ocean currents cause secular variations in the magnetic field.
However the paper concludes with this conjecture: "If the secular variation is caused by the ocean
flow, the entire concept of the dynamo operating in the Earthâ(TM)s core is called into question: there
exists no other evidence of hydrodynamic flow in the core." So while the paper doesn't say it, the author seems to entertain the possibility that currents my be solely responsible for the magnetic field. -
It doesn't say ocean currents cause the field
The paper does not say that ocean currents cause the magnetic field. It hypothesizes that ocean currents cause secular variations in the magnetic field.
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Re:I've been reading
I think we do have a complete model of the underlying interactions that we believe would churn out the right answer if we knew how to apply it correctly. http://www.iop.org/EJ/abstract/0954-3899/31/8/E01 looked like a good overview of the issues.
I'd say that the abstract you linked to pretty much confirms what I was saying. (It's been 13 years since I did research in low-energy nuclear structure physics, and I haven't been reading the literature since then, but I have been keeping up to some extent via newspaper articles, etc. I know, for example, that there's been some encouraging success since then with applying QCD to systems with A<=2.)
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Re:I've been reading
Hmm, let me amend that a bit. I think you're right, that we don't know how to approximate the forces well. I think we do have a complete model of the underlying interactions that we believe would churn out the right answer if we knew how to apply it correctly.
http://www.iop.org/EJ/abstract/0954-3899/31/8/E01 looked like a good overview of the issues.
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Re:Environmental Research Letters?
For those too lazy to RTFA, the original research was published in Environmental Research Letters .
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Environmental Research Letters?
Is ERL for real? Is it customary nowadays for journals to charge $1900 to to publish an article?
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World's *First* X-Ray Laser? I don't think so.
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Re:Frogs
I've heard that frogs have the ability to detect single photons. This is from a cryptographer who jokingly proposed a frog-based system for quantum key distribution. But on a more serious note, what does it really mean for two people to become entangled? And does it matter that the photons are detected by a human retina? Could the entanglement just as easily happen if the photons were fired into my left butt-cheek?
Furthermore, how does one "record" it such that the data can be retrieved? Yes, I know your dumb girlfriend "saw" the flash, and can report it, but it's still subjective. It's not like saying "hmm, that photon bumped the meter to 3.2eV"
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Re:Frogs
I've heard that frogs have the ability to detect single photons. This is from a cryptographer who jokingly proposed a frog-based system for quantum key distribution.
So I'm guessing that the unit of measurement for frog-based quantum encryption is the "ribbet".
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Frogs
I've heard that frogs have the ability to detect single photons. This is from a cryptographer who jokingly proposed a frog-based system for quantum key distribution.
But on a more serious note, what does it really mean for two people to become entangled? And does it matter that the photons are detected by a human retina? Could the entanglement just as easily happen if the photons were fired into my left butt-cheek? -
Re:Not the end of the world...
Sure, at the field strength they are trying to push the NbTi magnets they lose superconductivity around 4.2K reference. That's a bad thing considering the amount of energy in the magnets!
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Re:Ugh
Even if some mini black hole is created somehow,
it will do no harm.Check this people, it has mostly arguements,
and the math are limited:http://www.iop.org/EJ/abstract/0954-3899/35/11/115004/
ps: I know you were joking.
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Re:Interferometry
Agreed, and in the interests of an intelligent thread (to which I should not be posting) I bring you "STRUCTURE OF SAGITTARIUS A* AT 86 GHz USING VLBI CLOSURE QUANTITIES" which is actually worth reading if you want to get up to date on the research into Sagittarius A*.
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Re:This is outrageous!
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Re:Want to read every single technical detail...?
Then read the abstracts.
Hint: click on the word "abstract". It's turtles all the way down. -
Re:Adsorption
I work in a group researching magnetocaloric refrigeration at room temperature. I read the Science paper, and this is about the same, except with electrical polarization instead of magnetic. It's promising in some ways, but have some potentially fatal problems.
1. 12 deg C is a really large temperature change, we have to do with 1-3C. My group would kill for a material like that, $EVIL_GENIUS_LAUGHTER. (With a design like this, it's possible to have a much greater cumulative change of temperature than what any single piece of material does, so that's how to cool from +25 to -18 C).
2. The hysteresis is not too high, look at fig. 1 in the paper. This is important, because hysteresis means you're converting electricity to heat inside your fridge. Many materials have great change in entropy and temperature when you put an electric or magnetic field on them, but it's killed for practical purposes by hysteresis.
3. You need a really high electric field. The curves in the paper are done at 100-200 MegaV/m, meaning that you need 100-200 kV to polarize a layer of 1 mm thickness. A CRT uses voltages of around 20 kV, and so it's plausible to use thin layers, or just live with the fact that you'll only get 1-2 C temperature change. (Which means it has to compete with magnetic refrigeration on an even footing).
4. It's hard to polarize and depolarize the material without electric losses. (This is a problem for ferroelectric cooling in general). You're basically charging and discharging a huge capacitor, and you'll lose the charge on the capacitor every round. This could be fixed by putting it as the "C" in an oscillating (LCR) circuit with some inductance, but it's not easy to get an inductance (L) high enough, unless you run at high frequency. This material looks to work at high frequency (the hysteresis curves are taken at 1kHz), but how do you transport the heat into/out of it? If you run at 1kHz, you'll have less than half a ms to transfer heat to the cooling fluid, which means you'll need to use a very thin layer indeed. (Incidentally this will make it easier to get a strong field gradient). Then there's the problem of moving the cooling fluid back and forth over many layers of sub-mm thickness polymer. I'm not saying it can't be done, and there might very well be smart solutions I haven't thought of, but it's not trivial. (And btw, magnetic cooling doesn't have this problem, because we can use a permanent magnet with a several cm gap, and balance material moving into the gap with material moving out.)