How To Destroy A Magnet

Besides learning how to destroy a magnet, you get to learn why certain things are magnetic, or can be magnetized.



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Nanoscale NMR/MRI? Why, Yes We Can!

An amazing improvement in science technology and instrumentation. A new paper reports on the recent achievement of performing NMR on nanoscale size targets. You can also read the paper for free since it is published in the new APS family journal Phys. Rev. X. The one interesting aspect of this journal is that it includes a "Popular summary" of the paper that has been published. The popular summary accompanying this paper is this:

Popular Summary: Magnetic resonance imaging (MRI) is a commonly used technique for medical imaging. MRI uses static and time-dependent magnetic fields to detect the collective response of large ensembles of nuclear spins from molecules localized within millimeter-scale volumes in the body. Increasing the detection resolution from the millimeter to nanometer range would be a technological dream come true. However, detection of nanoscale magnetic resonance signals within the realm of the conventional MRI faces two challenges: The magnetic field strength and configurations required are either unrealistic or impractical, and the naturally occurring quantum spin fluctuations can overwhelm the thermal spin polarization—a fundamental property of nanoscale collections of spins. It is not difficult to imagine, then, that radically different techniques that can achieve such resolution enhancement in magnetic resonance detection would be a new breakthrough. In this experimental paper, we demonstrate a new paradigm for nuclear magnetic resonance imaging and spectroscopy on the nanometer scale.

Our technique is based on two unique components: (i) a novel spin-manipulation protocol that encodes temporal correlations in the statistical polarization of nuclear spins in the sample by periodically applying radio-frequency magnetic field pulses and (ii) the generation of intense magnetic field pulses by focusing current through a nanoscale metal constriction. Together with an ultrasensitive magnetic resonance sensor based on a silicon-nanowire oscillator, our approach allows us to coherently manipulate and detect nanoscale ensembles of nuclear spins. In a proof-of-principle demonstration, we have successfully imaged proton spins in a polystyrene sample with a roughly 10-nm spatial resolution.

Although remarkably different from the conventional MRI techniques in the two fundamental aspects discussed above, our technique can easily incorporate all established pulsed magnetic resonance techniques. Looking forward, we foresee this technique becoming a paradigm for nanoscale magnetic resonance imaging and spectroscopy.

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Any Guesses For 2013 Nobel Prize In Physics?

As the leaves turn color (at least here in the higher latitude in the Northern Hemisphere), the thoughts of many physics academics and professionals turn to Sweden and guessing at who will win this year's Nobel Prize for physics.

The obvious front runner is anything related to the Higgs. It's confirmed discovery this year means that it will not be a surprise if the award goes to people related to it. Questions remains on how they will be honored, considering that only a maximum of three individuals can be awarded the prize at any given time. Will they honor the theorists and the experimentalists in separate years? After all, there are already at least 4 deserving theorists who could easily be given the honors for formulating the Higgs mechanism, and the number is even larger for leading the experimental discovery of the Higgs.

The outcome of this will be very interesting. Or maybe the Nobel committee will forgo awarding the prize for the Higgs another year, and go with some other discovery in physics. That will be a fascinating surprise in itself!

:)

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When Belief Trumps Scholarship

The most significant argument against Creationism/Intelligent Design is that the proponents of these beliefs tends to try to find faults in existing concept of evolution, but without providing evidence of their own in support of their beliefs. The most often line of attack by these people is what we often normally refer to using the concept of "god of the gaps", where one tries to find some evidence or observations that defies current scientific explanation.

The problem with this, of course, is that these "gaps" often continue to shrink over time, and as our understanding of the world around us expand and improve. The ancient civilization used to think that the moving clouds, the eclipses, the ebb and flow of ocean tides, etc., were all due to some act of gods, because they didn't have any knowledge of what caused them. Now, we know better and these events are no longer mysterious or mystical.

And that's where we come back to the ID crowd. More often than not, they lack the necessary scientific evidence to strengthen their arguments. And when they try, the only people they could convince are people who really are not well-equipped to actually decipher the science. This appears to be the case of the latest book titled "Darwin's Doubt" written by Stephen Meyer, who runs the Discovery Institute. He's a non-biologist, who is trying to argue that the rapid explosion of animal phylia in the Cambrian period cannot be explained via the slow and tedious process of evolution, and thus, via invoking the god-of-the-gaps, points to evidence of an intelligent designer.

Whenever someone brings up a scientific point, it must be countered with equivalent scientific point. And this is exactly what has been done in this case. A review of this book written by UC Berkeley's Charles Marshall in this week's issue of Science (Science, v.341, p.1344 (2013)) did just that. In this review, Marshall pointed out several flaws in the biological/scientific points presented in Meyer's book.

However, my hope soon dissipated into disappointment. His case against current scientific explanations of the relatively rapid appearance of the animal phyla rests on the claim that the origin of new animal body plans requires vast amounts of novel genetic information coupled with the unsubstantiated assertion that this new genetic information must include many new protein folds. In fact, our present understanding of morphogenesis indicates that new phyla were not made by new genes but largely emerged through the rewiring of the gene regulatory networks (GRNs) of already existing genes (1). Now Meyer does touch on this: He notes that manipulation of such networks is typically lethal, thus dismissing their role in explaining the Cambrian explosion. But today's GRNs have been overlain with half a billion years of evolutionary innovation (which accounts for their resistance to modification), whereas GRNs at the time of the emergence of the phyla were not so encumbered. The reason for Meyer's idiosyncratic fixation with new protein folds is that one of his Discovery Institute colleagues has claimed that those are mathematically impossibly hard to evolve on the timescale of the Cambrian explosion.

In other words, this scientific argument doesn't hold water.

Unfortunately, and I can see this happening often, the counter argument to this book will not reach those who should be aware of it. The same with the perpetual argument that evolution violates the 2nd law of Thermodynamics, those who belief in ID will use this as the scientific argument against the evolution of life on Earth, without being aware of the holes in Meyer's book.

But at least now, you know that there is a scientific counter argument to what Meyer has brought up, and you can point to this Science review article.

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Superconductivity And The Environment - A Roadmap

A rather interesting and unusual review article. It describes how superconductivity and superconductors can actually help in improving our environment. As stated in this PhysicsWorld blog, it is an unusual assertion because "... superconductors only work at very low temperatures and lots of energy is needed to cool them.. "

Still, you might want to check out the list of things that have been argued that superconductors can do to help with the environment. The review paper is available for free.

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Graphene - The Aspirin Of Microelectronics

A while back, aspirin was touted as a miracle drug. Its use beyond just being a pain killer was being discovered constantly, ranging from an efficient blood thinner to prevent heart attack and stroke.

That is why I'm calling graphene as the aspirin of microelectronics. It seems that almost every year we hear more and more use of this miracle material. It's a good conductor, it is very strong, and now, in the latest chapter of what graphene can do, it has been touted as a very efficient converter of light into electricity.

Now the one-atom-thick lattice of carbon has added another string to its bow. Three research groups have independently shown that graphene can efficiently convert infrared light into electrical signals, as part of devices known as photodetectors. As fast and accurate translators of optical data, graphene photodetectors could speed up computers and significantly cut their power consumption. The devices, each with a slightly different architecture, are reported in Nature Photonics.

This performance already rivals that of existing photodetectors. “We’re seeing graphene getting to a point where it can compete with today’s technologies,” says Dirk Englund, a physicist at the Massachusetts Institute of Technology in Cambridge who developed one of the graphene photodetectors. “That’s an important new step.”

I expect it to be able to clean windows soon.

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Fermilab's Neutrino Beam Source

Here's a short article on Fermilab's repurposed Main Injector into a neutrino beam source for MINOS and NOvA. The article is OK. It kinda stopped short in describing the mechanism of generating neutrinos (why did it stop at creating pions?) Luckily, it linked to a YouTube video that explains how we get neutrinos at the end of the process.



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Feynman Lectures On Physics

I just read a note by Mike Gottlieb on the availability of the famous Feynman Lectures on Physics online, for free!

Not sure how long this has been available, but in case you didn't know, now you do!

Now, let me clarify something. I think this book is a classic, and advanced physics students, and graduate students, should read parts of it (or if you have time, read as much as you want). It provide quite a bit of insight into many different physics subjects.

However, as a pedagogical tool to teach physics to new students, I think this book is unsuitable and may be beyond what such students can comprehend. So if you are a freshman, or just trying to pick up some physics, you may still read it, but don't be surprised if you find it rather difficult to learn from. It is one of the reasons why this book isn't a popular intro physics text in most schools.

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The Quantum Quest

Again, I don't know how long this article from Nature will be available freely on the web. So read it while you can. It describes the continuing effort to decipher the fundamental issues surrounding Quantum Mechanics, and the effort to formulate it from some set of axioms.

Over the past decade or so, a small community of these questioners have begun to argue that the only way forward is to demolish the abstract entity and start again. They are a diverse bunch, each with a different idea of how such a 'quantum reconstruction' should proceed. But they share a conviction that physicists have spent the past century looking at quantum theory from the wrong angle, making its shadow odd, spiky and hard to decode. If they could only find the right perspective, they believe, all would become clear, and long-standing mysteries such as the quantum nature of gravity might resolve themselves in some natural, obvious way — perhaps as an aspect of some generalized theory of probability.

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Cow Tipping - It's A Myth!

What better way to break up the monotony of important advances in elementary particles, of topological insulators, of neutrino physics, etc. then to talk about the myth of cow-tipping! This article in Modern Farmer collects up-to-date info on why this is a myth, including a physics calculation on what it would take to do such a thing, which would make it even more unlikely.

But say our hypothetical cow tippers got lucky enough to get close to a cow at night. There’s still the matter of the brute force needed to get the cow over. In 2005, University of British Columbia student Tracy Boechler and doctor of zoology Margo Lillie ran the numbers on cow tipping. Their findings? There’s no way one person could tip a cow. Two people? Maybe — but not in real world conditions.

“Two could do it in theory,” says Dr. Lillie. “But it’s not going to be easy, and as soon as the cow responds by bracing herself or leaning into you — which she will do — it will be even harder.” Cows, after all, stand on four legs and will quickly shift their weight to a wider, more stable stance if pushed against. And Lillie and Boechler’s calculations are based on an unmoving cow in equilibrium in which slow, steady force could be applied without pushback — an optimum (and unrealistic) state for cow tipping. Pull out your high-school text book and look up Newton’s Second Law: Force equals mass times acceleration. A cow has a lot of mass, and you’ll want to move that mass quite quickly, before the cow can react. Which means you’ll need to generate a lot more force. Per her calculations, that would require at least five, and probably more like six pushers. “It just makes the physics of it all, in my opinion, impossible,” says Dr. Lillie.

There ya go, kids! Don't try this at home, or more accurately, at a farm near you!

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It's About Time

One of the most common arguments that I've seen online is the question on whether time is "real" or is it an "illusion" or doesn't exist. I've addressed this before quite a while back. In fact, that blog entry actually became a "reference" in a Wikipedia entry!

Last week's issue of Science had an interesting article. It is actually a review of Smolin's book "Time Reborn", with the review written by Huw Price (Science v.341, p.960 (2013)). What is interesting about the review here is the impression that I got that, even in philosophical circles, there is really no serious argument on the question on whether time exists or not (it does!). Rather, the question is really on the nature of time.

The differences between the two camps on the nature of time is described in the article:

I’ll come back to that question, but first to the dispute itself, which is one of philosophy’s oldest feuds. One team thinks of time as we seem to experience it, a locus of flow and change, centered on the present moment-“All is flux,” as Heraclitus asserted around 500 BCE. The other, my clan, is loyal instead to Heraclitus’s near contemporary, Parmenides of Elea. We think of time as it is described in history: simply a series or block of events, lined up in a particular order, with no distinguished present moment. For us, now is like here—it marks where we ourselves happen to stand but has no significance at all from the universe’s point of view.

And it brings me to the main point in which the differences really is not about the question whether time exists, or if it is real.

To Parmenideans such as Williams and myself, this attitude is just linguistic imperialism, cheeky and rather uncharitable. Of course we believe that time is real, we insist. (It is as real as space is, the two being simply different aspects of the same fourdimensional manifold.) What we deny is just that time comes carved up into past, present, and future.

You'll notice that the argument that time is as real as space is the same argument that I used in that earlier post that I linked above.

So really, enough of this nonsense on whether time exists or not, or if it is real or not.

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Mission Seeks Lunar Air

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