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About the wave/particle duality: the explanation you read is extremely confused.

We know light is made of particles because it's possible to make the light source so weak that only one particle is produced every minute or so. It's possible to confirm this by detecting each individual particle. There's no way to explain this behavior if you assume that light is a wave.

But then comes the strange part: even when the particles go one at a time, we still see the interference described in the double-slit experiment you mentioned -- so the particle must be interfering with itself (since there are no other particles close to it). There's no way to explain this behavior if you assume light is a particle.

In the end, it's clear that light is really neither a simple wave nor a simple particle (and why should it be?). Still, if you insist in understanding it in these terms (and it's very useful in practice), you're stuck with this "wave/particle" duality.

Also, the exact same "wave/particle" behavior has been observed countless times with lots of different things: photons (i.e., light), electrons, atoms and even molecules as large as buckyballs (see here).

A report EFDA in preparation for ITER here. It gives shot cycle times:

• Jet: 30 minutes
• DIII-D: 14 minutes
• ASDEX: Just under 30 minutes
• FTU: 20 minutes
• RFX: 10 minutes

It even discusses replacement schedule of some equipment for ITER, with only a few blanket modules replaced per year and a complete replacement only every 10 years, for example. The time between shots is referenced as 1600 seconds here due to the limitations it places on computing requirements (so repetition rate would be ~2000 seconds since the plasma shots will be up to 400 seconds).

The introduction in the full text of the paper here discusses how HiPER will be designed with a target of 10 Hz repetition rate for a 100 full power shot sequence.

The report here mentions how the Omega laser system is designed around a 30 minute repetition rate.

3 minutes for LHD

15 minutes for NSTX

2 minutes for MST

5-15 minutes for TFTR

20-30 per working day for JT-60

Even the ones I references as being kind of slow, NIF and Z-machine, are one shot per day, not weeks and months between shots.

The smaller projects I've worked on typically ran every 2-5 minutes when cycling during a normal day, limited by them typically using underpowered, but free (due to inheriting from previous experiment) cooling system. Their run campaigns were limited by staffing, as when the handful of people were busy analyzing data, no one was left to run the machine. Larger machines I've worked on had technicians and large teams to run 5+ shifts a week, and would run for at least a third of the year. Time not running was typically spent calibrating, repairing, upgrading diagnostics, and occasionally power supplies, most of which are components a production reactor would not have. Larger machines had a much more diverse diagnostic suite, so were much harder to organize and get things ready for a full run campaign, for reasons unrelated to plasma or neutron damage. The larger machines also could run into budget reasons running for a larger part of year due to staffing (technicians assigned to more than one thing) and power costs.

Neutron damage, failures due to plasma damage, and over all maintenance costs and cycling are a MAJOR issue that fusion research needs to address before becoming commercial. But that still doesn't mean your "hours, days, and even weeks" accurate for anything currently or in the near future.

Actually on the absolute scale of temperature, all negative temperatures are hotter than all positive temperatures! I learnt this about 40 years ago, it is not exactly cutting edge physics.

The sign assigned to temperature relates to how an increase in energy affects the entropy (loosely: a measure of disorder, or uncertainty) of a system. Consider a 2 state system with a positive even number of identical particles. When all particles are in the ground state you have minimum entropy and the lowest non-negative temperature. When you have an equal number of particles in both states, you have the maximum entropy and the highest temperature. As soon as you move one more particle into the higher energy state, the total entropy of the system drops, so now the temperature is defined as negative - as now adding energy now decreases entropy!

http://prola.aps.org/abstract/PR/v103/i1/p20_1

It's a pity neither of those editorial articles mentions what the false positive rate is. This is critical.

Actually, they don't even mention whether the algorithm identifies negatives as well as positives (i.e. those who can be ruled out of any follow-up investigations etc.), and if so, what the false negative rate is. This is also critical.

The article itself in Phys. Rev. Lett. is behind a paywall. Maybe it addresses the false positive issue, and the positive vs negative issue.

The articles seem rather scant on details, and the second link seems to be a repost of the same information in the first article. My first inclination was that the story was BS - I couldn't see any way that they can accomplish what they claim to accomplish, so perhaps the news agency just really screwed up the story. After researching a few other articles about this, my judgement is that they're tracing this stuff back to the source based on listening in on messages being sent around a bunch of connected nodes. A number of nodes would need to be monitored in advance (or at least have relatively good time-frames for when it arrived at various nodes) before the information could be traced back.

More articles on the subject:
The Original Article: http://physics.aps.org/articles/v5/89
A second article with different details: http://www.ibtimes.com/articles/372537/20120810/facebook-rumor-math-terrorism-algorithm.htm

Sorry, that whole post is nonsense! OAM is a clearly defined mechanism, and the different OAM states are orthogonal. See for example http://physics.aps.org/story/v17/st15 for an explanation.

You may have suffered through traditional "higher education," but a new generation is learning a different way. Some of them are learning it better. We have made tremendous progress in many fields, why do we not study the process of academic instruction just as intensely as, say, nuclear physics?

We do. Some physics department, like the one from which I got my PhD, offers research in physics education as a PhD program. Student do research and gather data in classroom and apply the same statistical analysis techniques to asset the effectiveness of certain teaching techniques. Unfortunately, they usually do not get the same respect in the department as more traditional thesis topics. Usually there are a few (<5) faculties out of the whole department who actually care about physics education that they accept student in these topics. The APS is starting to recognize it as a specialty, but only treats it as a "special topic". We are getting there.

Khan Academy is good, a lot of people use those videos!

--cej102937

When I was TA-ing to pay my way through my degree, I recommend KA to many intro physics students. Then after talking to a lot of them, I find the result to be kind of mixed. Some find it helpful, other not and it somewhat surprised me that it did not correlated with grade. The worst case is that some thinks it's helpful when in fact it did not (and you can tell by asking conceptual questions that is only a twist of the problems covered in the video). Totally anecdotal. However, fellow students who actually engaged in physics educations research tents to agree that a one way dictation, abet using video, do not help student who lacks a good conceptual foundation to begin with. And this guy, who also did a PhD in physics education, also agree. I do think the world is better with those video than without though.

Not really sure...here is an article in Physical Review Letters by Blum about Kaons. Not sure if this is the one though.

I remember that the American Physical Society (the professional organization of physicists) studied various boost-phase missile defense schemes years ago. They found that the various options, including air-borne lasers, weren't likely to be very useful in realistic scenarios (even under otherwise optimistic assumptions).

The press release says:

The Airborne Laser currently in development has the potential to intercept liquid-propellant ICBMs, but its range would be limited and it would therefore be vulnerable to counterattack. The Airborne Laser would not be able to disable solid-propellant ICBMs at ranges useful for defending the United States.

Few of the components exist for deploying an effective boost-phase defense against liquid-propellant ICBMs and some essential components would take at least 10 years to develop, said Study Group co-chair Daniel Kleppner. According to U.S. intelligence estimates, North Korea and Iran could develop or acquire solid-propellant ICBMs within the next 10 to 15 years. Consequently, a boost-phase defense effective only against liquid-propellant ICBMs would risk being obsolete when deployed.

You can also read the full report. I don't know how the relative states of the technologies stand today.

I remember that the American Physical Society (the professional organization of physicists) studied various boost-phase missile defense schemes years ago. They found that the various options, including air-borne lasers, weren't likely to be very useful in realistic scenarios (even under otherwise optimistic assumptions).

The press release says:

The Airborne Laser currently in development has the potential to intercept liquid-propellant ICBMs, but its range would be limited and it would therefore be vulnerable to counterattack. The Airborne Laser would not be able to disable solid-propellant ICBMs at ranges useful for defending the United States.

Few of the components exist for deploying an effective boost-phase defense against liquid-propellant ICBMs and some essential components would take at least 10 years to develop, said Study Group co-chair Daniel Kleppner. According to U.S. intelligence estimates, North Korea and Iran could develop or acquire solid-propellant ICBMs within the next 10 to 15 years. Consequently, a boost-phase defense effective only against liquid-propellant ICBMs would risk being obsolete when deployed.

You can also read the full report. I don't know how the relative states of the technologies stand today.

Results like this really shouldn't surprise anyone. We have strong reasons, both theoretical and experimental, to believe that CPT invariance is an exact symmetry of the universe. To put it more simply, the laws of physics work identically forward and backward. There is no "preferred direction" of time. The fact that one direction seems to us to be "forward" reflects our local environment (we live on an entropy gradient), not any fundamental property of time. Boltzmann understood this back in the 19th century. So retrocausality shouldn't surprising.

We also have known since the 1960s that if you accept time reversibility and retrocausality, most of the "strange" features of quantum mechanics disappear: the collapse of the wave function, the uncertainty principle, entanglement, etc. All of these are just illusions created by ignoring the fact that the future is influencing the present. Time symmetric versions of quantum mechanics really should be much more widely known than they are.

I should have explained.
the research I'm talking about is this one http://prl.aps.org/abstract/PRL/v108/i9/e097403 (slashdot discussion http://science.slashdot.org/story/12/03/08/1833224/leds-efficiency-exceeds-100). those people showed that you can have an LED that you feed X energy (as electrical current), and it emits nX energy as light, where n>1. the extra energy comes from decreasing the temperature of the LED.

I was talking about the fact that if we do succeed in making a carbon neutral industry, we might go over the top and simply generate too much heat. whenever you use a steam engine to generate electricity (no matter if the heat comes from nuclear fission or fusion or from burning coal), you end up with some water that is hotter than environmental water, but too cold to use in the steam engine. people usually dump this water in the nearby stream/river, driving away the wildlife.
if we were to create all the fuel being used by cars and planes with electricity, we would probably have a lot of this water. I was pointing out that the other research allows us to solve this hot water issue as well. I'm not sure how efficient it would be to use this light for additional electricity, in the sense that you might simply be taking up too much space.

The presence of entropy in incoherent electromagnetic radiation permits semiconductor light-emitting diodes (LEDs) to emit more optical power than they consume in electrical power, with the remainder drawn from lattice heat [1,2].

Basically, the device is converting high-entropy thermal energy into even higher entropy incoherent electromagnetic radiation (light output). So, the second law of thermodynamics is not violated. Essentially, this device is acting as a way to connect thermal degrees of freedom to E&M degrees of freedom. The system, wanting to increase entropy as much as possible, tries to spread energy through all these degrees of freedom, which means creating some photons at the expense of some of the heat in the material.

It's a neat bit of physics, and will probably have implications for device efficiency and other applications.

given this:

Unpredictability and undecidability in dynamical systems

Abstract: "We show that motion with as few as three degrees of freedom (for instance, a particle moving in a three-dimensional potential) can be equivalent to a Turing machine, and so be capable of universal computation. Such systems possess a type of unpredictability qualitatively stronger than that which has been previously discussed in the study of low-dimensional chaos: Even if the initial conditions are known exactly, virtually any question about their long-term dynamics is undecidable."

So erm... under what possible conditions can carbon ever change it's atomic structure and chemical behavior to become a metal ? Short of nuclear transmutation - in which case the result is NOT carbon. Please, do explain as I would love to know.

Sure thing.

First, let's go beyond your high-school level description of what a metal is. There is no "specific set of elements" that are metallic. Rather, a metal is something that, owing to delocalized electrons, has no band gap at the Fermi level and thus is a good conductor of electricity and heat. This can be achieved in many elements, not necessarily those that are typically thought of as metals, by using fancy conditions, such as extreme pressures and/or temperatures.

Take, for instance, this report on metallic carbon in Phys. Rev. Lett: http://prl.aps.org/abstract/PRL/v102/i5/e055703
or the infamous metallic hydrogen, http://lt26.iphy.ac.cn/abstract/pdf/B1488.pdf

"Muncton also advocated that every man, woman and child in the United States should be tested monthly for AIDS and anyone detected with signs of an infection should be "permanently removed from the population". He a right-wing conservative crackpot."

Ad hominem arguments will get you nowhere.

As the article you linked to yourself says, "...eccentricity doesnâ(TM)t matter, if heâ(TM)s right about the science."

Well, apparently the American Physical Society thinks he is, at least in the case of AGW. His other exploits don't matter.

In case you still don't get it: you will have to refute his references, not his own comments, if you want to be making any kind of logical, scientific argument.

This data would seem to directly contradict what you cited.

I'm not claiming it's correct. What I am claiming is that you can't attack the person and expect others to take you seriously. It is the science that matters. Even idiots and fools can be correct now and then. Not that I am saying Moncton is either; you implied as much. You might say his credibility is low. My point is simply that it doesn't matter. It is the evidence he presents that is what you need to focus on, not his personality.

Don't take it personally. BasilBrush has proven to all that he (if he is a "he") is a True Believer in anthropogenic global warming, and he will not let mere facts or logic get in the way of his preaching of the One True Faith.

For example, he really knows how to cherry-pick his "evidence". Never mind that anybody else can do the same.

Well, let's look at the sixteen climate scientists who signed this, shall we?

Claude Allegre, former director of the Institute for the Study of the Earth, University of Paris: Sounds reasonable, though it looks like the proper name for the "University of Paris" is the "Paris VI University", or "Pierre and Marie Curie University". Unfortunately, it looks like the man is kind of a crank, and he hasn't been the director of that Institute since 1986, which makes it weird that it's the one thing they list about him.

J. Scott Armstrong, cofounder of the Journal of Forecasting and the International Journal of Forecasting: That's pretty reasonable, but forecasting and climate science aren't exactly the same thing; forecasting is the study of what's going to happen tomorrow or next week in any topic, while climate science is trying to figure out what will happen in the next year or the the next ten years with the weather. Also, Armstrong's professional background seems to be primarily in advertising, not forecasting, and he hasn't actually published any papers on climatology that I can see.

Jan Breslow, head of the Laboratory of Biochemical Genetics and Metabolism, Rockefeller University: I'm not exactly sure what he's doing on this list, since presumably it's a list of climate scientists? I mean, just because he's a researcher in one field doesn't automatically qualify him in others; it's like taking your car to ten mechanics and ignoring what they say, then asking your doctor about it and following his advice.

Roger Cohen, fellow, American Physical Society: This dude seems to be a writer for the NY Times, and I can't seem to find anyone by that name on the list of Fellows of the American Physical Society. Maybe he received his fellowship before 1990? In any case, it doesn't signify much in terms of his ability to evaluate any kind of science; those fellowships are kinda prestigious, but they're handed out for all sorts of things.

Edward David, member, National Academy of Engineering and National Academy of Sciences: What can I say? He's an electrical engineer. Would you trust him to diagnose a heart condition? An expert in one subject is not automatically an expert in all subjects.

William Happer, professor of physics, Princeton: What can I say? Damnit Jim, he's a physicist, not a climatologist! Sure, they're related - but would you trust this guy if he was talking on the way that chemists all over the world are trying to fool us about the mind control properties of fluorine? (as a side note, he's also a Fellow of the American Physical Society - why didn't they mention that?)

Michael Kelly, professor of technology, University of Cambridge, U.K.: This dude is kinda hard to Google because he shares a name with a fairly famous guitar company and a well-respected journalist (who died in 2003); however, it looks like he's done some pretty awesome work on semi-conductors. Unfortunately, that doesn't have anything to do with climate research.

William Kininmonth, former head of climate research at the Australian Bureau of Meteorology: Well, for one thing, he hasn't been the head of the ABM since 1998 (this seems to be a theme, you know?); for another, he's trained as a meteorologist, not a climate scientist. Just because they both deal with the weather doesn't necessarily mean that his word carries extra weight, but I do have to admit that he's one of the better signatories of this list.

Ric

http://physics.aps.org/articles/v5/1

They are talking about sound power sensitivity rather than sound intensity sensitivity (this detector is signicantly smaller than an ear drum).

Also, the Brownian motion pressure in water will less than in air.

But yes, the detector does see Brownian noise, and that would be the practical sensitivity limit.

See also Phys. Rev. A 78, 012336 (2008) http://pra.aps.org/abstract/PRA/v78/i1/e012336. With Holmium they get 60 qbits per atom from these "pooled states".

The articles are slightly old. K. Mølmer said during a lecture some time ago that they have found an atom suitable for 128 or 256 qbits with this method.

Within quark theory, quark/antiquark annihilation is not defined, as that has not been necessary to explain the phenomena we have observed nor does it lead to any verifiable predictions.

This is total nonsense. Quark/antiquark annihilation is perfectly well-described in standard theory. The answer to the OP's question is that the quark and antiquark do annihilate, which is why all mesons are unstable. But it takes a little bit of time for the annihilation to happen, which gives you the lifetime of the meson.

The neutralino would be a composite particle, composed of the super-partners of the guage bosons and the higgs - that is wino (w partner), higgsino (higgs parnter), bino (partner of the weak hypercharge). Since the symmetry is broken, we don't see the original super-partners, only their super-imposed forms with the same mass eigenstate.

When particles annihilate, they produce a set of particles that have a quantum number of 0. Any particles with the same mass-energy as the original colliding pair of particle and anti-particle can be produced. If mass energies are low, this means that the result will be mostly photons, because photons have no mass, and are only energy. That is, they have a low total mass energy. But any particles can be produced, so long as the result totals to 0, and has the same mass energy.

Neutralinos, as you would guess, from the term WIMP, are weakly interacting, and massive. That means that when a neutralino annihilates another, particles with greater mass energy can be produced.

In a 1994 paper Drees et al calculated neutralino decay into gluons. One of the co-authors here Kamionkowski went on to publish more on dark matter and neutralinos. There have been other papers on other possible decay products from neutralino annihilation, because, of course, if annihilation produces unstable particles, or anti-particle pairs, it can keep going until it reaches an end state of stable products. However, not all anti-particle pairs produce annihilate, and if the products are stable, they go bouncing on their merry way.

This means that anti-protons and positrons above the background, and at certain energy levels could be the signature of neutralino dark matter.

Or to roll things back: one of the few ways, other than gravity, we can detect WIMPS is from their annihilations. To determine if, and if so, what, WIMPs are composed of, we have to look at the decay products of those events. The Pamela data shows that there is an excess of positrons, however, it does not show that this excess is from WIMP annihilation. The search for this spectrum is important for both large and small reasons: large because cosmology evolves based on mass, and small because neutralinos, if detected, tell us about the final broken super-symmetrical extensions to the Standard Model, and in turn tell us about the super-partners, and, in turn, about the partners. For example, we have not seen a higgs boson, but a neutralino is an eigenstate of a higgsino fermion, which implies a higgs boson to be partnered with. Back in the 1990's Drees et al published

If you're interested, also check out this paper by Drs. A. G. Cohen and S. L. Glashow: http://link.aps.org/doi/10.1103/PhysRevLett.107.181803
That Letter discussed the implication of superluminal neutrinos and why the OPERA result were not likely to support them. Full text is open to PRL subscribers but there's a link to the accompanying free magazine "Physics" http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.107.181803

If you're interested, also check out this paper by Drs. A. G. Cohen and S. L. Glashow: http://link.aps.org/doi/10.1103/PhysRevLett.107.181803
That Letter discussed the implication of superluminal neutrinos and why the OPERA result were not likely to support them. Full text is open to PRL subscribers but there's a link to the accompanying free magazine "Physics" http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.107.181803

These guys won!

We experimentally demonstrate the fluctuation theorem, which predicts appreciable and measurable violations of the second law of thermodynamics for small systems over short time scales, by following the trajectory of a colloidal particle captured in an optical trap that is translated relative to surrounding water molecules. From each particle trajectory, we calculate the entropy production/consumption over the duration of the trajectory and determine the fraction of second law–defying trajectories. Our results show entropy consumption can occur over colloidal length and time scales.

Well his other complaint is that somehow the mass of a proton is up for question while climate science is incontrivertable. Either they're both up for grabs, or the scientific method doesn't apply to climate science.

Third option: he's a senile old git. At 82, what are the chances?

Let's look at what the APS actually has to say: "The evidence is incontrovertible: Global warming is occurring." - He's 82, what's your excuse?

This proves it! It's all a lie. Fox news is right! ;)

I don't trust Fox News, but a nobel laureate in physics at least gets me to listen.

And the other Nobel laureates that stay in the APS because they agree with this, don't. Yeah, figures.

It sounds like an interesting result, but not so practical in application...

What's worse that this: based on the abstract, all they did is to theoretically compute the composition required to lower the bandgap from 3.8 eV to a 2eV required to split the water. Since not yet realized in practice, lots of other things are not (yet) known:
1. efficiency (including the problem of keeping off the recombination of H and OH that most probably result)
2. stability to corrosion
would be the first two to pop into my mind.

http://prl.aps.org/abstract/PRL/v107/i5/e053601

Wow wow wow. Are you implying that statistics is the only kind of evidence we have for climate change ? That there is "nothing more" to climate theory than "these 2 numbers seem to be related in our datasets from the past".

In a minute you'll be saying we don't actually have confirmed experiments where increasing co2 levels causes heating in an artificial athmosphere under realistic assumptions*.
Oh wait ... we don't.

*(as in we know that moving from 0 to ~250ppm causes a bit of warming. That's cute but the 19th century is over and done with. The real question, of course, is whether what is happening now, ie 330 to 400 ppm also causes warming. spoler : It doesn't).

And another minute and you might look up that
1. Climate is chaotic, especially temperature variation
2. It is mathematically obvious that statistics are not able to predict chaotic systems

Another minute and you might ask yourself the obvious question :

There have been lots of climate predictions. Let's take those made by the IPCC. Now the judge of a theory used to be how correct those past predictions were ... So the obvious question is : given the predictions of past IPCC Assessment reports, how many were correct ?

Answer 1 out of 5 predictions is *barely* correct (and 0/5 if you count the prediction of solar output). It's also the one that was made in 2010 (in other words, the accomplishment in that is mostly correctly reading the thermometer, not actual prediction).

And let's just ignore the fact that it is basically completely impossible for anyone, even with a million dollar investment, to use the prediction algorithms and verify the results. Why ? 2 reasons, one completely damning and the other a big philosophical problem : first, the algorithms are not publicized, which used to be enough to get you kicked out of the scientific community. Second a million dollars is not enough by far. We only have the word of the scientists, and we have to blindly trust that the one experiment didn't screw up their math.

Spot on. Please, help spreading the work of Robert Adair, he's got papers on both ELF and cell phones. One of them is found here: http://pra.aps.org/abstract/PRA/v43/i2/p1039_1 There's one about cell phones too, he basically disproves the whole thing using thermodynamics and simple, fundamental physics arguments. It's more thorough than waving your jedi hand and saying "non-ionizing", too.

Since you're especially interested in physics, I'd recommend magazines like Physics Today, which I guess is accessible from decent libraries in both online and dead-tree formats. It's not a research journal and is intended for the general audience, but is somewhat more advanced than the material you usually find online. The American Physical Society also carries an on-line journal "Physics" which is free to read and provides a view into what physicists from around the globe are doing. It provides commentary and explanations to notable articles published in the Physical Review journals that are only open to subscribers.

You may also want to check some open-access journals such as the New Journal of Physics, and the upcoming Physical Review X (no content yet). But reading "real" research papers doesn't usually makes you feel it's "engaging"..

Since you're especially interested in physics, I'd recommend magazines like Physics Today, which I guess is accessible from decent libraries in both online and dead-tree formats. It's not a research journal and is intended for the general audience, but is somewhat more advanced than the material you usually find online. The American Physical Society also carries an on-line journal "Physics" which is free to read and provides a view into what physicists from around the globe are doing. It provides commentary and explanations to notable articles published in the Physical Review journals that are only open to subscribers.

You may also want to check some open-access journals such as the New Journal of Physics, and the upcoming Physical Review X (no content yet). But reading "real" research papers doesn't usually makes you feel it's "engaging"..

The definition of "unshakable" seems self-selecting, and perhaps even tautological.

It puzzles me that you submit this to Physical Review E:

Physical Review E, interdisciplinary in scope, focuses on many-body phenomena, including recent developments in quantum and classical chaos and soft matter physics. It has sections on statistical physics, equilibrium and transport properties of fluids, liquid crystals, complex fluids, polymers, chaos, fluid dynamics, plasma physics, classical physics, and computational physics. In addition, the journal features sections on two rapidly growing areas: biological physics and granular materials.

Physical Review E

Journal Article: http://prl.aps.org/abstract/PRL/v106/i24/e243602

Just $25 and no preprint on arXiv.org :(

Journal Article: http://prl.aps.org/abstract/PRL/v106/i24/e243602 fascinating, and it is important that information not travel faster than c, which entanglement hasn't been shown to violate (yet) see: http://en.wikipedia.org/wiki/Bell's_theorem

Actually, NASA launch sites may not be best suited to new launch technology. Why not use a railgun to get the initial delta-v. Navy guns have a launch velocity of Mach 7 (35% of orbital). Scale up the launch velocity (increase length to longer than a carrier), and increase the payload capacity (more power!), and you have a way to significantly reduce launch costs as well as decrease the size of the launch vehicle. A launch acceleration of 32G for 22 seconds would give orbital velocity (and a helluva ride!). That's an acceleration value used in ejection seat design. Such a launch system would be required to be 76km long (47.2 miles) and would be affected by the curvature of the earth (only 32 feet at that distance - a doable height).

I wonder if the soon to be decomissioned Tevatron has a strong enough power supply to shoot off a new shuttle. It'd be great to repurpose tech like that instead of seeing it scrapped.

Can we get this into Obama's "high speed rail" program as a rider?

Scientist code is usually a giant JUST-SO story, sufficient to derive the results they need for the task at hand.
They either don't have, or avoid putting in data that will crash the program so limit checking is not necessary.
Crashes are fine if they do nothing more than leave a trail of breadcrumbs sufficient to find the offending line of code.

Funny — this could as easily describe how physicists often write mathematics.

In this paper (the paper itself is here), Feynman notes that

The mathematics is not completely satisfactory. No attempt has been made to maintain mathematical rigor. The excuse is not that it is expected that rigorous demonstrations can be easily supplied. Quite the contrary, it is believed that to put the present methods on a rigorous basis may be quite a difficult task, beyond the abilities of the author.

Feynman's "exoskeleton" nevertheless led him to some reasonably well-respected work in quantum electrodynamics. But my point is simply that the problem isn't with "scientists," it's with intelligent people confusing 'ability, in principle to understand X' with 'actually understanding X in practice' —a fallacy that is very common in IT, and one Feynman quite consciously worked to avoid. Life is short, "all one surveys," quite long. Besides, it cuts both ways: it's not at all clear that developers who don't understand the underlying science would do a better job with scrupulous documentation, because even if they bothered to RTFM, they wouldn't have the necessary background to understand it. The net result might be a loss stemming from a "false sense of comprehension."

Finally, it is not unusual for engineers to "understand how hard it [will be] to turn [a given] exoskeleton into [the required] self-sufficient robot" only in retrospect, thus it seems quite silly to expect anyone else to understand this at the outset —here I did not say "believe one understands."

For "turning an exoskeleton into a robot," write "double-entry bookkeeping," "plumbing," "formal mathematical proof," "horseback archery," or "dating," and nothing much changes— it's hard to have a good working knowledge of something one has no experience doing.

APS Journals (1893-Present) are available free of charge for public libraries.
http://publish.aps.org/public-access-announcement

It doesn't surprise me at all that there's a huge amount of copyright violation. Here is the paywall page for a classic physics paper describing an experiment that tested a prediction of Einstein's theory of general relativity. The paper was published in 1960. They're willing to sell me the scans of this 5-page paper for $25. I teach physics at a community college, so I don't have free access to this journal online. If the price was something more reasonable, like $1 or maybe even $5, I might have considered paying. But at $25 it's not even an option. I can drive to the local Cal State campus, pull the journal off the shelf, and photocopy this paper for 50 cents. No, that's not copyright violation, because it falls under fair use.

What's really ironic is that new physics papers are essentially all available for free, whereas old ones aren't. Today, almost everyone in the field posts their papers on arxiv.org, where anyone who wants to read them can download them for free.

It also depended a lot on shape, Many flip phones because of their geometry kept the radiating part sufficiently away to be much less a concern, but almsot all smartphones today are unibody designs which means the EMF emitting body and screen is in direct contact with your head.

EMF emitting body? The plastic cover on most phones isn't the "emitting body"; the antenna is buried inside there somewhere. Breathe easily, and stay away from pickles (as someone pointed out).

The fingerprint is off:

I think you may have been confused by the blog post that you sited. You do not need to go through those convolutions to determine whether there has been polar amplification. We can just take direct measurements.

Not necessarily. We can get better at detecting floods, and also have less of them due to natural variation.

Then you have failed to account for why natural disasters are rising faster than earthquakes. You have said a lot, but failed to show anything.

I would assert that the uncertainty in a very large range, and a significant portion of that uncertainty is probably because we don't understand all of the forcings at work in our system.

Why do you keep invoking mysterious forces that are not necessary to explain any known phenomenon?

it could very well be the motion of energy from the core of the earth towards the surface, and therefore the oceans, and therefore the air.

It could just as easily be unicorns. There is no reason to believe that it is either, but I see that you are a very skeptical person who is not willing to dismiss any idea no matter how bizarre.

Known forcings being insufficient does not lead us to the conclusion that all of the rest of the warming must be driven by CO2.

Of course not! What a bizarre idea!

That's arguing that anything we don't know (which is legion), must be explained by a magical gas.

Magical gas? Really? CO2 is a magical gas?

When we derive the effect of CO2 by observation, and elimination of all other known effects, we are inconsiderately ignoring unknown effects.

I think I understand the source of your confusion. You think that we know the effects of CO2 by measuring CO2 and measuring temperature and attributing any correlation to CO2. You are wrong. We know the effects of CO2 because of physics, and because we can measure incoming radiation and outgoing radiation at the bandwidth absorbed by CO2, and because we can measure that differential over time. It is also nice that there is a correlation, but correlation does not provide proof of causation.

It is quite possible that we *need* (unknown forcings) in order to *properly* explain observations, and that currently, we are *improperly* explaining observations.

Ever heard of Occam's razor? You keep trying to invoke unknown forces that are not necessary to explain any known phenomenon.

if I was to infer from your argument thus far, you believe it is a major driver of climate.

No. There is a yearly cycle that dwarfs every other cycle (called "seasons" ;-) ). There are other cycles that dwarf CO2 such as ENSO but are dwarfed by these "seasons". But none of these cycles will drive a trend. The trend is driven by CO2.

Here's one example of a turnaround:

I feel like this Watts guy may be misleading you. Here is the APS policy on global warming: http://www.aps.org/policy/statements/07_1.cfm Nothing in this statement is inconsistent with the consensus view.

I believe the assertion was within a century

Nope. Schneider never said any such thing - and it is clear from his publications that he never believed any such thing.

there has been no statistically significant trend of warming since 1998.

No statistically significant warming trend does not mean that there has been no warming trend. There has. If this seems confusing or contradictory, then you will want to research what statistically significant means. It doesn't mean what you think it means.

You also provided a link detailing what may be inconsistencies in the US record. When I pr

I would bring your attention to graphene nanoribbons and bilayer graphene FETs where scientists have been able to induce a bandgap. nanoribbon, bilayer, bilayer and nanoribbons (the last two are by people from my school, and I know some more papers by them in the pipleline about opening up a gap in graphene).

It might be a while before CNTs or graphene penetrate commercial market. But there is a big reason for that: the inertia of the semiconductor manufacturing industry. A lot of equipment will need to be upgraded and even changed in the foundries. There has to be a huge return on investments for such a major overhaul, e.g., 100's of GHz of operating frequencies (IBM FET), better manufacturability, cheaper raw material (which it is for carbon) and not to mention compatibility with CMOS design and architectures. There's a long way to be trodden, and I wouldn't lose heart at this point just because we've not been able to deliver on CNTs.

I would bring your attention to graphene nanoribbons and bilayer graphene FETs where scientists have been able to induce a bandgap. nanoribbon, bilayer, bilayer and nanoribbons (the last two are by people from my school, and I know some more papers by them in the pipleline about opening up a gap in graphene).

It might be a while before CNTs or graphene penetrate commercial market. But there is a big reason for that: the inertia of the semiconductor manufacturing industry. A lot of equipment will need to be upgraded and even changed in the foundries. There has to be a huge return on investments for such a major overhaul, e.g., 100's of GHz of operating frequencies (IBM FET), better manufacturability, cheaper raw material (which it is for carbon) and not to mention compatibility with CMOS design and architectures. There's a long way to be trodden, and I wouldn't lose heart at this point just because we've not been able to deliver on CNTs.

I would bring your attention to graphene nanoribbons and bilayer graphene FETs where scientists have been able to induce a bandgap. nanoribbon, bilayer, bilayer and nanoribbons (the last two are by people from my school, and I know some more papers by them in the pipleline about opening up a gap in graphene).

It might be a while before CNTs or graphene penetrate commercial market. But there is a big reason for that: the inertia of the semiconductor manufacturing industry. A lot of equipment will need to be upgraded and even changed in the foundries. There has to be a huge return on investments for such a major overhaul, e.g., 100's of GHz of operating frequencies (IBM FET), better manufacturability, cheaper raw material (which it is for carbon) and not to mention compatibility with CMOS design and architectures. There's a long way to be trodden, and I wouldn't lose heart at this point just because we've not been able to deliver on CNTs.

It's simply survival of the fittest. At the turn of the century, nanotubes and buckyballs were "cool" academically. Now it's graphene. Though these have been around since 60 years (see the 1947 paper The Band Theory of Graphite ).

I agree that fads are fads, but this is how science will progress from hereon. It used to be a practice of a handful of people in the early days, even towards the first half of the 20th century. Academic research now is a valid career option for a large number of people. Just like any other career, it has certain "return on investments". The ROI's in this case are papers, patents and awards. This IS the yardstick with which your success is measured in the scientific field. It goes to logic people are going to try and stay at the top of their game by going after "modern" and "cutting-edge" topics.

I wouldn't completely agree with your argument of only a few applications remaining. I am not an expert on buckyballs, so I'll refrain from commenting on that, but for Carbon Nanotubes (CNT) there are an insane number of applications already in place. They range from CNT based logic, radio, Atomic force microscopy etc (too many to fit here)

Scientific (or otherwise in the BBC case) media will always glamorize any scientific discovery and exaggerate its potential, as it does for everything else. This is not necessarily an issue with the scientific community who does the research work. If anything, media stories like these end up slapping unreal expectations on scientists and engineers. This ultimately results in a "disappointment" on the public's side when all the proclaimed applications are not realized and electronics industry still runs on Silicon.

Hmmm this is making me ponder how this applies to certain classes of complex systems.

There is a principle called universality which means roughly that there are universal simple
behaviours of some complex systems which are governed by only a few rules involving some
aspects of the constituents of the system. Usually the relevant aspects are some constraints
on how the constituents interact, which in turn may be governed by some (abstract) property
of the constituents.

e.g. http://physics.aps.org/articles/v2/1

Roughly I think what this principle means is that a) the system is complex enough that its
exact evolution is in principle unpredictable. b) Therefore you can only say something
statistical about the stochastic behaviour of the system. and c) These few simple properties
and rules govern that stochastic behaviour, regardless of whatever else may be present or going on.

Would you say that that kind of universal property is a precisive or non-precisive abstraction?
On the one hand, it is saying that everything about the system other than this simple local property
we've noticed is unknown. (non-precisive?)

BUT it's also asserting that everything other than the known simple local property DOES NOT MATTER
to the predictable aspects of the system's future evolution. (precisive?)

I'm pretty sure that economic games are examples of the kinds of complex systems to which these sorts
of simple universal local rules apply. They don't tell you exactly how it's going to turn out in each case,
but they may very well tell you as much as you CAN know about the statistics of the outcomes, regardless
of how other factors on the game field are arrayed.

I suggested to the Blender folks that they might want to look at elastons, as animation is a key area for Blender but they didn't have many ideas for how to improve it. Got no response and they didn't update their page, but I still think it'd be a worthy extension that could very well be helpful in their movie series (as rigid models only go so far).

Elastons are the "new thing" in computer graphics, so a benchmark that involves running the software used to create the APS' video would seem "fair".

Wow @ 4:06

-AI

Elastons are the "new thing" in computer graphics, so a benchmark that involves running the software used to create the APS' video would seem "fair".