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.



Zz.

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.

Rick Perry Backtracks On DOE

During his confirmation hearing today, Rick Perry changed his mind about wanting to shut down the US Dept. of Energy.

I have learned a great deal about the important work being done every day by the outstanding men and women of the Department of Energy. I have spoken several times to Secretary Moniz about the operation. I have spoken to his predecessors. And if confirmed, my desire is to lead this agency in a thoughtful manner surrounding myself with the expertise on the core function of the department. My past statements made over five years ago about abolishing the Department of Energy do not reflect my current thinking. In fact, after being briefed on some of the vital functions of the Department of Energy, I regret recommending its elimination.

While it is good of him to chance his mind once he learned a bit more of what he's talking about, it doesn't diminish the fact that he and many other politicians are in a habit of going public with ideas and policies out of IGNORANCE. For some odd reason, many of them do not care that they make up their minds AND going public with such decision BEFORE they actually gather proper information about these things.

And if you think this is an isolated incident, you'd be wrong. I've highlighted several rather DUMB AND STUPID actions or comments made in public by these elected officials, all out of ignorance (read this and this, for example). I think that this is a common, standard-operating-procedure by many elected officials, that they really didn't do their homework in many decisions that they make.

Zz.

Fermions and Bosons

Fermilab's Don Lincoln describes what bosons and fermions are, for those who don't know.



Zz.

Imaging Fukushima Reactor Core Using Muons

If you are in the US, did you see the NOVA episode on PBS last night titled "The Nuclear Option"? If you did, did you miss, or not miss, the technique of imaging the Fukushima reactor core using the muon tomography developed at Los Alamos?

You see, whenever I see something like this, I want to shout out loud to the public on another example where our knowledge from high energy physics/elementary particle physics can produce a direct practical benefit. A lot of people still question whether our efforts in these so-called esoteric areas are worth funding. So whenever I see something like this, there should be a conscious and precise effort to point out that:

1. We had to first understand the physics of muons from our knowledge of the Standard Model of elementary particle.

2. Then those who do understand this often will start to figure out, often with collaboration of those in other areas of physics, of what could possibly be done with such knowledge.

3. And finally, they come up with a practical application of that knowledge, which originated out of an area that often produces no immediate and obvious application.

Things like this must be pointed out in SIMPLE TERMS to both the public and the politicians, because that is the only level that they can comprehend. I've pointed out previously many examples of the benefits that we get, directly or indirectly, from such field of study. It should be a requirement that any practical application should present a short "knowledge genealogy" of where the idea came from. It will be an eye-opener to many people.

Zz.

Mpemba Effect Is Still Hot After All These Years

OK, maybe not hot, but it is certainly at least lukewarm.

If you don't know anything about this, I've made several posts on the Mpemba effect before (read here, here, here, and here). Briefly, this is the effect where hot water is seen to freeze faster than cold water. Even after its purported discovery many years ago, the validity of this effect, and the possible explanation for it are still being debated.

Add this report to the body of discussion. It seems that there are new papers that are using molecular bonds in water as the possible explanation for this effect.

Now researchers from the Southern Methodist University in Dallas and Nanjing University in China think they might have a solution - strange properties of bonds formed between hydrogen and oxygen atoms in water molecules could be the key to explaining the elusive Mpemba effect.

Simulations of water molecule clusters revealed that the strength of hydrogen bonds (H-bonds) in a given water molecule depends on the arrangements of neighbouring water molecules.

"As water is heated, weaker bonds break, and groups of molecules form into fragments that can realign to form the crystalline structure of ice, serving as a starting point for the freezing process," Emily Conover reports for Science News.

"For cold water to rearrange in this way, weak hydrogen bonds first have to be broken."

I'm sure this will not be the last time we hear about this.

Zz.

The Brachistochrone Problem

There are many sources that describes this problem. Mary Boas also devoted a substantial portion of it in her classic text "Mathematical Methods in the Physical Sciences". Here, Rhett Allain describes it once more in his Wired article.

Laymen might find it fascinating just to know the shape of the path, while physics students might find it useful especially if you're just about to take class in Least Action principle.

Zz.

Happy New Year!

A belated Happy New Year to everyone. I hope you all had a great holiday season.

Those of us in the US are facing a rather uncertain next few months. With the new administration taking office and the issue of science and science funding being trivialized during this last presidential election, no one knows where things are going. With Rick Perry slated to be nominated as the Secretary for the Dept. of Energy, it is like having the wolf looking after the sheep, since he had stated on more than one occasion of abolishing this part of the US govt. Sorry, but I don't think he has a clue what the DOE actually does.

This is not the first time someone who has no expertise in STEM is heading a dept. that deals with STEM. I've always wondered about the logic and rational of doing that. You never seen someone who is not an expert in finance or economics heading, say, the Treasury! So why is the DOE, which has been a significant engine in research, science, and technology, and which is the area that has been attributed to be responsible for the significant growth in our economy, being relegated as an ugly stepchild? Is it because STEM and STEM funding does not have a built-in constituent that will make public and political noise?

At this point, I have very low expectations for a lot of things during these next few years.

Zz.

Sidney Drell And Vera Rubin

We lost two incredible and important figures in physics during this holiday season.

Sidney Drell, the elementary particle theoretical physicist responsible for the Drell-Yan process, passed away on Dec. 21, 2016. As important as his work in physics, he was also a central figure in the effort of nuclear disarmament. His accomplishments and efforts are just too numerous to list here, and you should do yourself a favor and read about him. He has no doubt had a hand in shaping our world today.

We lost Vera Rubin on Christmas day. She was one of the first astronomers to make the Dark Matter detection, and someone whom I thought should have already been awarded the Nobel Prize. So this year, we lost two extremely strong women candidates for the Nobel prize, Rubin and Deborah Jin.

Zz.

Antihydrogen Looks Just Like Hydrogen

The ALPHA collaboration at CERN has measured the first ever 2s-1s transition in antihydrogen atoms, and it looks like the Standard Model and CPT symmetry are still correct!

Carrying out the whole procedure 11 times, the group found that on average just under 60% of antiatoms left the trap with the laser tuned to the 1s-2s transition, while no antiatoms (within the bounds of statistical error) dropped out when the laser was tuned to a different frequency or when it was switched off. The researchers say that the antiatoms underwent the transition at the expected frequency and therefore behaved no differently from normal hydrogen.

I'm sure there will be many more to come. The ability to store antihydrogen long enough to study it is a major accomplishment in itself.

Zz.

"Germany's Wildly Complex Fusion Reactor Is Actually Working" - Fake News?

Does qualify as "Fake news", or are they just being stupid?

I posted yesterday about the successful test of the Wendelstein 7-X Stellerator magnetic field. It definitely should deserve the media publicity, because the topology of the magnetic field is very complex and very crucial to how they intend to hold the plasma that they will generate. But this is simply just ONE STEP towards the operation of this machine. They still haven't achieve yet what they intend to do.

So it is with a bit of a dismay that I read news reports that somehow indicated that this "fusion reactor" is "actually working"! Now, I wouldn't have paid much attention had this come from some obscure site, but this one actually came from Popular Mechanics!

However, the stellerator design is still relatively untested, so a group of researchers spent the past year studying the W7-X reactor to ensure that it was working the way it was supposed to. They found an incredibly small error rate, less than 1 in 100,000, which the researchers characterized as "unprecedented accuracy."

This is good news for the W7-X reactor, which was intended as a proof-of-concept for the stellerator design. Now that the researchers know the accuracy of the reactor's magnetic fields, they can begin building new reactors that focus on efficiency.

I'm sorry, but if you don't know any better, you'd think that this darn thing is now working, and they're now going to design "new reactors" with better performance. 

Bullcrap!

How dense can one be to get this report wrong? The actual paper, which one can read freely online, clearly indicated that this was a test of the complicated magnetic field, not the actual working of the reactor.

I would not be surprised if this is nothing more than a wrong piece of information that got passed around. I see Science Alert having the same type of headlines in their report.

All of these are misleading, and worst still, they are misleading the public who do not have the awareness of what is going on. And this is sad because the public often relies on these type of news sources, and yet, they are being given, at best, a misleading information.

Zz.

Confirmation Of Wendelstein 7-X Magnetic Field

I mentioned a while back that Germany's Wendelstein 7-X Stellerator was about to go on with their tests. One of the most novel aspect of this fusion machine is the complex topology of its magnetic field.

We now have a report that confirms the topology of this magnetic field, with an agreement of better than 1:100,000. The field lines that they saw as shown in Fig. 2 of the paper is astounding and science-fictiony!

Well done, people!

Zz.

What Is The Big Deal With This Math Problem?

For at least a year now, I've seen this math problem being floated about the various new websites. And I don't understand why it is such a big deal.

The problem involves a simple math problem that many students first learned in an intro algebra class:

Now, any child learning something like this would have to also learn about the SEQUENCE of operations that one has to perform to do this correctly. If you simply start to enter this into your calculator in order that it is written, you'll get the wrong answer.

And of course, you have to know that dividing by 1/3 is equivalent to multiplying by 3.

There are many mnemonic guides that one can use to know which one to perform first. In this case, you first perform the division, thus simplifying the equation into:

9 - 9 + 1 = ?

which will obviously leave you with the answer of 1.

This problem is getting rather a lot of publicity because it claims that a lot of people didn't get the right answer for something that seemingly looks very simple. My response to that is: Yeah, so?

When one learns this rule in school, one is given many similar problems of this type. This is not an unusual problem, and certainly something a lot of people will get wrong if they don't remember what the rule is. This is not surprising.

But why is it getting this much publicity?

Zz.

What So Spooky About Quantum Entanglemnt?

I hate to keep beating a dead horse, but this question DOES keep popping up regularly on many websites and forums. And when a new article tries to explain this again, it bares repeating.

This article tries to explain what is so "spooky" about quantum entanglement. The "spookiness" comes from Einstein's description of quantum mechanics which he showed, via the EPR-type measurement, that information about a quantum property can be "transferred" instantaneously between entities across space.

You'll notice that in the article, the author had to go back and explain the concept of superposition of states. This is what makes this type of phenomenon different than the classical phenomenon.

Let’s go over the issue of entanglement to start. The experiment is normally done with photons: you pass a single quantum of light through a specialized material (e.g., a down-conversion crystal) which splits it into two photons. These photons will be entangled in a particular sense, where one has a spin, or internal angular momentum, of +1, and the other has a spin of -1. But you don’t know which is which. In fact, there are some experiments you can do where, if you had large numbers of these photons, you’d see a difference between:

• the statistical results if the spin was +1,
• the statistical results if the spin was -1,
• or the statistical results if the spin was undetermined.

If you had been following this blog for a while, this is the same attempt that I made to explain quantum entanglement before. This is because most people who are just trying to understand this only pay attention to the "entanglement" aspect of it, i.e. a property being "linked" over a distance, rather than actually understanding the superposition concept, which is actually more well-established. It is the presence of superposition, and the lack of classical realism on a system (before a measurement) that separates this from an ordinary classical conservation-of-quantity phenomenon.

Zz.