The Race To Make Quantum Computers

We still don't quite have a truly-accepted working model, even from D-Wave. So it is interesting to see this latest news of both Google and IBM launching projects to produce and eventually sell these quantum computers.

The folks from Google's Quantum AI Laboratory wrote a comment in Nature, while IBM's intention is reported in the news.

With the Chinese company Alibaba collaborating with the Chinese Academy of Sciences to also go into this area, the next several years will be fascinating to watch.

Zz.

Raman Spectroscopy Used To Detect Skin Cancer

I found this piece of news while reading the Flash Physics section on Physics World. And if you've followed this blog for a while, you know that I will highlight this without any shame.

Chalk this up to another important application of something that came out of physics research and subsequently finds a usefulness in medical diagnostics. Many of us in Material Science/Condensed Matter Physics/Chemistry are aware of Raman spectroscopy techniques in the study of molecules and materials. It has been a common technique in these areas of study for many, many years since its first proposal in.... get this.... 1929![1]

So already it is a very useful technique in chemistry and material science. But now it has found another application, in medical diagnostics. It turns out that this same technique can be used to find hard-to-detect skin cancer.[2]

Abstract: Melanoma is the most deadly form of skin cancer with a yearly global incidence over 232,000 patients. Individuals with fair skin and red hair exhibit the highest risk for developing melanoma, with evidence suggesting the red/blond pigment known as pheomelanin may elevate melanoma risk through both UV radiation-dependent and -independent mechanisms. Although the ability to identify, characterize, and monitor pheomelanin within skin is vital for improving our understanding of the underlying biology of these lesions, no tools exist for real-time, in vivo detection of the pigment. Here we show that the distribution of pheomelanin in cells and tissues can be visually characterized non-destructively and noninvasively in vivo with coherent anti-Stokes Raman scattering (CARS) microscopy, a label-free vibrational imaging technique. We validated our CARS imaging strategy in vitro to in vivo with synthetic pheomelanin, isolated melanocytes, and the Mc1r^e/e, red-haired mouse model. Nests of pheomelanotic melanocytes were observed in the red-haired animals, but not in the genetically matched Mc1r^e/e; Tyr^c/c (“albino-red-haired”) mice. Importantly, samples from human amelanotic melanomas subjected to CARS imaging exhibited strong pheomelanotic signals. This is the first time, to our knowledge, that pheomelanin has been visualized and spatially localized in melanocytes, skin, and human amelanotic melanomas.

This is another example where experimental technique in physics EVENTUALLY finds applications elsewhere. I've highlighted other examples of this, with this being the most recent one before this post. Also note the "gestation" period between when this method was first proposed, and then when it became common in physics, to when it found other applications outside of its original main use. This is not new. Look at how long between when NMR became a common technique to when it evolved into MRI. Medical technology would not have evolved and advanced without a much earlier advancement in physics and physics experiments!

What I'm trying to emphasize here is that you may not feel the pain NOW when you cut funding to basic science research. But the pain WILL be felt later, by your children and grandchildren, because it takes years for what we work on now to become a useful technique elsewhere. That physics that we used to detect some esoteric particles that you don't care about may just one day be the diagnostic tool that saves someone's life!

Zz.

[1]C.V. Raman and K.S. Krishnan, The optical analog of the Compton effect, Nature 121, 711 (1928); G. Landsberg and L. Mandelstam, A novel effect of light scattering in crystals, Naturwissenschaften 16, 557 (1928); C.V. Raman and K.S. Khrishnan, The production of new radiations by light scattering, Proc. Roy. Soc. (London) 122, 23, (1929).
[2] H. Wang et al., Scientific Reports 6, Article number: 37986 (2016). Paper is open access.

The Laws Of Life

Physics Today has made the article "The Laws of Life" from the March 2017 issue available for free. In the article, astrobiologist Charles Cockell describes how the fundamental laws of physics influences the forms of life on Earth.

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Online Homework Assignment - Are They Effective?

I read this news with a bit of interest. It appears that a student at Brooklyn College is gathering petition signatures to end the use of something called "Expert TA". This sounds like an online HW assignment that has been used by the physics department at that school.

Each homework assignment has about 15 to 20 questions, but each question has multiple parts. The number of questions, attempts, and credit reductions for wrong answers is dependent on the instructor. The instructor has the option to deduct points when a student accesses hints, and feedbacks. Expert TA consists of two types of feedback: Direct and Socratic. Direct feedback let’s a student know exactly what they did wrong, while a Socratic feedback poses a question such as “Have you considered the following?” Though this may sound quite useful, students feel otherwise.

It would be a bit more informative, and more persuasive, if a specific example on how this online tool is ineffective. For example, the best complaint that I can read from the report said this:

“The problem doesn’t lie in the concepts,” said Manasherov. “It’s more like how can we navigate this website and give the right answer—the right answer meaning what the website is looking for.”
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“The hints aren’t always helpful and the feedback isn’t always clear either,” said sophomore Melissa Beagle. “And they only give you a limited number of tries, which doesn’t really help.”

There types of comments are not really that informative. It is similar to you telling your doctor "I just don't feel right" without giving any specific description of what is wrong.

I have a bit of experience in dealing with such online HW assignment. I've written about it in an earlier blog post on here. In fact, I will also add that I actually worked though the online HW assignment that my students would be facing, and I can see and experience what they will have to go through. I can see good points and bad points about it. But as I've said in that earlier blog post, the biggest issue I have about online anything is the question on whether the student doing it had any external help. But that is an issue that would be present in the traditional, written HW assignment as well since the student can easily copy or had help in completing the assignment. Except for one major difference.

You see, traditional written HW assignment requires that the student show work in arriving at an answer. You normally do not see that with online assignment. From what I can gather when chatting with students, all they care about is getting the right answer to type into those answer boxes. Often time, their "work" in deriving the answer is either done haphazardly, or not as complete and clear as one that would be required in a written HW assignment that is being submitted for grading. So in some instances, these students really could not recall what they did right and what they did wrong.

I'm still divided on my opinion regarding this type of HW assignment. I see some value in it. It certainly makes the job of an instructor a bit easier. But I also see how this can make the student being lazy to really learn what is needed in solving a particular problem.

If you have gone through such online HW assignment, or if you're an instructor whose course use such a thing, I'd like to hear from you.

Zz.

Lenz's Law Is A "Quirk" Of Physics?

I've never heard of "fidget toys" before till after I read this piece. This one is describing a fidget toy that supposedly has "antigravity" effects that simulates the low gravitational field of the moon and Mars, making the object falls slower. The toy is called Moondrop.

Based around the principle of Lenz’s law — which *deep breath* states that the current induced in a circuit due to a change or motion in a magnetic field will create a field that opposes the charge that produced it — Moondrop is a gravity-defying fidget desk toy that imitates the differential gravitational free fall on Mars and the Moon.

OK, so immediately, there are two issues here:

1. Lenz's law is not a "quirk" of physics, as stated in the title of this report. In fact, it is quite a central phenomenon in physics that is responsible for power generators to create our household electricity! So how is that a "quirk"?

2. Any physics undergraduate can spot the error in the definition given for Lenz's law. Lenz's law is the effect whereby a magnetic field is generated to oppose the CHANGE in the external magnetic field. Maybe there is a typo in the definition given, that it should have been "change" instead of "charge". That one word (or in this case, one letter) change results in an astounding difference in the physics.

If I recall correctly, there are magnetic breaks that use the same principle. I remember reading something on roller coaster rides that made use of such magnetic breaks, so that it ensure that the vehicle can still be safely stopped even when the power goes off.

So the application of Lenz's law is neither that highly unusual, nor is it a quirk of physics.

Or maybe the writer meant a "quark" of physics?

Zz.

Mildred Dresselhaus In GE Commercial

So, if you did watch the 2017 Academy Awards last night and didn't run away during the commercials (at least here in the US), you may have seen the GE commercial to celebrate women in science that featured the late Millie Dresselhaus. She, of course, passed away on Feb 20, so this commercial has become a tribute to her and left a legacy to encourage women to enter science, and physics in particular.

In the commercial, GE asks what it would be like if we treated women scientists like celebrities and deserving of the accolades and recognition like any pop celebrities.

If you missed it, here's the commercial once again:



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SRF Technology For Particle Accelerator

Here's a brief video on the superconducting radiofrequency (SRF) cavity for particle accelerators.



I wouldn't call it "better particle accelerator" as in the video, because SRF cavity with Nb currently have a limit of 20-30 MV/m gradient, whereas normal conducting cavity can reach 100 MV/m or even higher at 1.3 GHz.

Still, these SRF cavities have properties that are "better" in other characteristics, especially in the Q-value. And in a number of applications, these cavities are the most efficient accelerating structures.

The technology for SRF is still evolving, especially in whether there is a need for superconducting photocathode sources for SRF guns. So there's a lot more to do in this field of study, both in terms of the physics, and in engineering.

Zz.

Dark Energy - What Is It?

I've posted many articles on Dark Energy. But here's another one aimed at the general public that actually is quite instructive. It describes not only why we think there is dark energy, but also the puzzling phenomenon of the apparent "switching" between one regime to another.

Please take note that, while it seems that this idea has been floating around for a while, the study of Dark Energy is very much still in its infancy. The general public may find it hard to understand, but we really do need a lot more experimental observations on this, and that is easier said than done. Detection of this is not easy and requires years of design and work, and not to mention, funding!

Zz.

Mildred Dresselhaus

An absolute giant in physics, and especially on condensed matter physics, Mildred Dresselhaus passed away recently at the age of 86.

Besides all of her accomplishments in physics, she was truly a trail-blazer for women in science, and in physics in particular with all of her "firsts". She, along with Vera Rubin and Deborah Jin, were the strongest candidates to break the drought of women winning the Nobel Prize in physics. Now we have lost all three.

Zz.

Will SMASH Be A Smash?

Here comes a new extension to the Standard Model!

A new theoretical paper in PRL has extended the Standard Model of elementary particles to include new particles, and tries to mash different ideas and theories into this new standard model called SMASH - Standard Model Axion See-saw Higgs portal inflation (yeah, it's a mouthful).

SMASH adds six new particles to the seventeen fundamental particles of the standard model. The particles are three heavy right-handed neutrinos, a color triplet fermion, a particle called rho that both gives mass to the right-handed neutrinos and drives cosmic inflation together with the Higgs boson, and an axion, which is a promising dark matter candidate. With these six particles, SMASH does five things: produces the matter–antimatter imbalance in the Universe; creates the mysterious tiny masses of the known left-handed neutrinos; explains an unusual symmetry of the strong interaction that binds quarks in nuclei; accounts for the origin of dark matter; and explains inflation.

Of course, with ANY theoretical ideas, which often has long gestation period, a lot of patient waiting and testing will have to be done to verify many of its predictions. But this seems to create quite an excitement in revamping the Standard Model.

Zz.

Politics And How It Affects US Physics Research

This is a very poignant article on how politics have impacted Physics research in the US for the past decade or so. Reading this can be very disheartening, so be forewarned!

The one impact that I had mentioned a few years ago is also mentioned here, and that had to do with not only the impact of budget cuts, but also the devastating impact of a budget cut AFTER several months of continuing resolution of the US budget.

I remember one year on December first, we had a faculty meeting where we heard funding levels would be up 10% across the board — a miraculous state of affairs after multiple years of flat-flat budgets (meaning no budgetary increases for cost of living adjustments — which ultimately means it’s a 3% cut). At our next faculty meeting on December fifteenth, we heard that it was going to be a flat-flat year — par for the course. On December nineteenth, we hear the news that there was a 30% cut in funding levels.

Now losing 30% of your budget is very bad in all circumstances, but you have to remember that the fiscal year begins on October first. The only thing you can do is fire people since all the funding is salaries and to do that legally takes about six weeks and with the holiday shutdown, that meant that this was a 50% cut in that year’s funding. There was some carry-forward and other budgetary manipulations, but 30% of the lab was lost, about three or four hundred if I recall. The lab tried to shield career scientists and engineers, but still many dozens were let go.

In a post from a few years ago, I showed the simple mathematics on why this effect is devastating for science research.

Unfortunately, I don't see this changing anytime soon. As the author of this article wrote, science in general does not have a "constituent". No politician pays a political price for not funding science, or wanting funding for science to be cut, unlike cutting funding for social programs, military, or other entitlements.

Regardless of who is in office or who is in control of the US Congress, it is business as usual.

Zz.

Gamma-Ray Imaging At Fukushima Plant

I mentioned earlier of the muon tomography imaging that was done at the damaged reactor at Fukushima, and tried to highlight this as an example of an application that came out of high energy physics. This time a gamma-ray imaging spectroscopy was performed at the same location to pin-point contamination sites.

But as with the muon tomography case, I want to highlight an important fact that many people might miss.

To address these issues of existing methods and visualize the Cs contamination, we have developed and employed an Electron-Tracking Compton Camera (ETCC). ETCCs were originally developed to observe nuclear gammas from celestial objects in MeV astronomy, but have been applied in wider  fields, including medical imaging and environmental monitoring.

So now we have an example of a device that was first developed for astronomical observation, but has found applications elsewhere.

This is extremely important to keep in mind. Experimental physics often pushes the boundaries of technology. We need better detectors, more sensitive devices, better handling of huge amount of data very quickly, etc...etc. Hardware have to be developed to do all this, and the technology from these scientific experiments often trickle down other applications. Look at all of medical technology, which practically owes everything to physics.

This impact from physics must be repeated over and over again to the public, because a significant majority of them are ignorant of it. It is why I will continue to pick out application like this and highlight it in case it is missed.

Zz.

Being Slowly Eaten For A Decade

This is the definition of the ultimate torture.

It appears that this black hole has been slowly feasting on this dead star for at least a decade. Ouch!

"We have witnessed a star's spectacular and prolonged demise," said Dacheng Lin, a research scientist at UNH's Space Science Center and the study's lead author. "Dozens of these so-called tidal disruption events have been detected since the 1990s, but none that remained bright for nearly as long as this one."

The arXiv version of this paper can be found here.

Moral of the story: Never piss off a black hole!

Zz.

Photons Steal Momentum From Sun's Surface?

We all know that photons carry momentum. But who knew that photons leaving the sun's surface actually may cause the varying rotation of the sun with its radius?

This new paper from PRL makes the confirmation that the sun's surface has a greater drag and a slower angular rotation than the deeper part of the sun. But not only that, it also proposes that this slowdown is due to the loss of momentum when photons are emitted from the plasma on the surface.

Kuhn and his colleagues also developed a model to explain their data. Photons are created in the Sun’s dense core, where the plasma behaves nearly like a solid. As they diffuse outward, they experience plasma that is less dense, faster flowing, and subject to turbulent convection. As the photons interact with the moving plasma, they exchange angular momentum with it. Inside the Sun, the photons scatter so frequently that they lose as much angular momentum as they gain. But in the photosphere, where photons escape the Sun, the plasma-photon momentum transfer results in a net loss of the plasma’s angular momentum, as photons radiate away. The effect on the plasma is a mild braking force, which slows its overall rotation. This braking is most effective at the outer edge of the Sun, where the plasma density is at its lowest.

Those photons! They can create havoc!

Zz.

The Emperor Has No Clothes

The impact of the Trump's executive order on the admission of citizens from the 7 countries continues to be felt and the topic of conversation in many college campuses, science labs, and conferences. But something triggered in my head when I read this Washington Post news article on how this ban would not have prevented the attacks in the US since Sept. 11. When I read this, I immediately remembered a similar scenario, and this is where I connect it to the theme of this blog.

Back in, oh, I forget exactly when, probably mid-2000s, there was a laser accident at a lab (I'm not gonna name names). I'm going to rely on my memory based on what I read as the official report on the accident, and from what I heard from a friend who happened to know the person involved.

To set up the scenario, most, if not the majority, of laser accident occurred when the laser is running and the safety mode is bypassed. The most frequent reason for doing this is that the laser is either being worked on, being repaired, being serviced, or the most common occurrence, it is being aligned. People who are authorized to do this are usually trained, and had to undergo safety classes to ensure that they know what they are doing.

What happened in this accident, from what I remember, is that this person, along with at least one other person, was doing a typical laser alignment. He was wearing a pair of safety glasses as required, which protected his eyes in case there were stray beam hitting his face. Unfortunately, while in the middle of doing this work (which was part of the standard operating procedure of the facility), he had an itch around his eyes. In a moment where instinct took over, before he had time to think about it, he reached inside his safety glasses with his hand to rub his eyes, causing the safety glasses to be lifted off his face. Unfortunately, without realizing it, a beam of the laserwas, at that time, pointing straight at him. It only happened probably less than a second, but it was enough that the laser hit his eyes and sufficient to cause damage.

I'm not going to go into detail of what happened immediately afterwards, because it isn't relevant to this story. So of course, after this incident is reported, the lab issued a lab-wide stand-down, and all operations of Class 2b laser and higher had to stop. We were told to evaluate our laser operations and safety procedure, and we had to get reauthorized before we can continue work. At the same time, all personnel that are involved in any laser work had to attend a safety seminar.

So I sat through this safety seminar where they described the accident, emphasize the need for us to work safely, re-enforce the requirements for safety procedure... etc...etc. But at the same time, in response to the accident, they produced a whole new set of policy and procedures for all laser facilities. We had to have yearly inspection, yearly authorization, and new documentation of our procedure and safety analysis. In other words, new set of administrative controls were introduced.

Of course, as you can guess, there were groans in the audience, because it meant that there would be more bureaucratic paperwork and administrative hoops that we had to go through. During the Q&A session, several people asked questions, and one could tell that a lot of people in the audience weren't too pleased by this. Finally, and this is where I came, in, I raised my hand, and asked something like this:

"So how would any of the new procedures that were introduced prevented this accident?"

Now, looking back on it afterwards, I would describe the audience reaction to my question as what I imagined would happen when someone finally yelled that the Emperor had no clothes. In this case, the Emperor truly had no clothes. It was an unfortunate accident, but no amount of training, regulation, safety briefing, paperwork, review, etc. would have prevented it, because that was something instinctual. The new administrative policy that was put in place didn't make any of us who work with these lasers any safer. I certainly didn't feel any safer than before. Yet, this was imposed upon us. It wasn't to make us any safer or to prevent any accident. It is simply to placate the higher-ups, the stakeholders, the policy makers, the regulators, the administrators, and finally and ultimately, the politicians (if they decided to look into this). They can say that they implemented this and that after the accident to make them look good. The rest of us who are actually doing the work get saddled with more paperwork and more hoops to jump through.

I'm certain that this isn't new, and that many people have gone through such similar situations where what is being done in the name of something really isn't effective and may miss the mark. Often times, we simply go along just to make the administration happy so that we can move on and continue with our work. But it still means that the Emperor has no clothes, and sometime, someone really needs to stand up and points out this ridiculousness.

Zz.

Fermilab's Greatest Hits

Highlights from the first 50 years at the historic Fermi National Accelerator Laboratory.



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Presidential Executive Order and US Conferences

With the two big conferences looming this year, the APS March and April Meetings, it will be interesting to hear how the recent presidential executive order banning entry by visitors from 7 predominantly-Muslim countries will have affect. Citizens from countries such as Iran already had a long and arduous process in gaining a visitor visa to come to the US, so much so that many won't even bother to try.

So now, with the entry ban, looks like this will have an impact on visiting scientists from these affected countries. Unfortunately, this will create an even bigger ramification, because international organizations will be less inclined to hold major conferences in the US where some of its members will not be allowed to attend. This should have both scientific and economic impacts.

So far, there has been no official word from the APS on this matter.

Zz.

3 Things Everyone Should Know About Physics

This is an exceptionally good answer to the question: "What do physicists wish the average person knew about physics?" The answer was written by Inna Vishik, Assistant Professor of Physics at the University of California, Davis.

• Physics makes predictive models about the natural world based on empirical observations (experiments), mathematics, and numerical simulations. These models are called ‘theories’, but this does not mean they are speculative; physics theories explain past behavior and predict future behavior. When a previously-validated theory fails to explain the behavior in a new physical system, it doesn’t mean the theory is suddenly ‘wrong’ altogether, it means that it is inapplicable in a certain regime. It is very exciting for physicists when these exceptions are found, and it is in these holes in our models that we propel our understanding of the physical world forward.
• The domain of physics is vast. Some physicists study the existing universe around us. Some study the smallest constituent particles and forces of matter in this universe. Some manipulate clusters of atoms, and some manipulate light. Some study crystalline solids and the myriad properties they can have when quadrillions of atoms and electrons are arranged in slightly different ways. Others study biological systems. This is not a full list of the many subfields in physics, but what they all have in common is they combine classical (including continuum) mechanics, quantum mechanics, statistical mechanics, general relativity, and electricity and magnetism in various configurations to explain the physical and engineered world around us.
• Research in physics and other fundamental sciences play three crucial roles in an advanced society; they cement our cultural legacy by exploring one aspect of the human condition (the universe we occupy), similar to the role of the arts; they educate a portion of the work force in solving difficult, open ended problems beyond the limits of prior human innovation; they provide the seeds for future technological developments, which is often realized decades in the future in an unpredictable manner (i.e. not amenable to quarterly earnings reports). At the time of their inception, electromagnetic waves (late 19th century), quantum mechanics (early 20th century) and lasers (mid 20th century) were viewed even by their progenitors as esoteric curiosities; now they permeate our life, technology, and medicine so deeply that no one would question their practical importance. In the modern physics research era, there are newer ideas that might have an equally important impact 50 years from now, but they will never be realized without continued investment in the public good known as fundamental science.

Zz.

Metallic Hydrogen?

The big news so far this week is the publication on the possible (key word) creation of solid metallic hydrogen.

If this is true, then this is a significant discovery and confirmation of a prediction from many years ago. Understandably, with the press releases on this work, the popular media have been going ga-ga over this.

 https://phys.org/news/2017-01-metallic-hydrogen-theory-reality.html

https://www.yahoo.com/news/u-scientists-create-metallic-hydrogen-possible-superconductor-ending-043206674.html

 http://www.businessinsider.com/metallic-hydrogen-created-2017-1

However, upon trolling all the various news reports, only the Independent so far has an update on the news story about doubts about this discovery.

http://www.independent.co.uk/news/science/hydrogen-metal-revolution-technology-space-rockets-superconductor-harvard-university-a7548221.html

This is taken from a news report published in Nature:

http://www.nature.com/news/physicists-doubt-bold-report-of-metallic-hydrogen-1.21379

As with ANYTHING in Science, we have to give this a period of gestation before we all jump onto the bandwagon. It needs to be independently verified, and even the authors admit that this needs to be refined even more to produce a conclusive evidence of metallic hydrogen.

Zz.

The Technology Of Detecting Gravitational Wave

The biggest physics news of 2016 was certainly the detection (finally!) of gravitational wave by LIGO.

In this CERN Courier article, the physics and methodology of making such a difficult detection is described. As you read this article, keep in mind that at each step of the development and evolution of the facility, there had to be advances and improvements in the detection method, which by itself, is significant. The technology and engineering involved in many this detection, and in many other science experiments, often drives the development of the technology that eventually finds applications in the rest of the population.

Zz.