Friday, August 30, 2013

The Birth Of Photonic Crystals

If you've read this blog for any period of time, you will have seen that, as many times as I can, I try to highlight the application side of physics. This is because a lot of people who are not familiar with the field tend to think that physics is only the LHCs, the Brian Greenes, the particle physics, the String theories, etc. If I can't contribute anything to physics, I want to at least contribute to destroying such myth.

This is one such example. APS Physics has recently highlighted a landmark paper that marked the birth of the idea of photonic crystals.

Semiconductors and band insulators are material that has a gap in the electronic band structure. On the other hand, photonic crystals have gaps in the photonic band band structure, whereby the material simply does not propagate photons having energies within that gap.

You may read the article to find out what applications such materials are good for.

Zz.

Thursday, August 29, 2013

The Origins of Space Time

I guess theoretical physics is supposed to extrapolate and make these types of conjectures. Still, it would be nice if there are already experimental indications that they are on the right path, rather than just continue on blindly.

This is a rather interesting article from Nature on some very fundamental issues in physics, and the theories (yes, there are many of them, which is common when there are no experimental evidence to weed them out) that claim to describe them. Not sure how long the article is available for free online, so read it while you can.

Zz.

Carl Wieman Moves to Stanford

I mean, where else would highly-sought-after, Nobel laureate end up?

Carl Weiman has taken up a faculty position in the Physics Dept. and in the Graduate School of Education at Stanford University. He brings with him quite a program in physics education, I must say.

Carl Wieman’s crusade to improve undergraduate science education is now based at Stanford University.

The physics Nobelist and former White House science education czar has been named a faculty member in both the physics department and Stanford’s Graduate School of Education. The joint appointments, effective 1 September, give Wieman an academic perch to take his research on learning in new directions while continuing to incorporate those insights into the classroom.
Zz.

11-Year Old Starts College Majoring In Physics

Here's a piece of news to make all of us mere mortals feel highly inadequate.

A lot of people have a hard time choosing a major when they start college at 18, but that isn't the case for Carson Huey-You, who's just 11 years old.        

"I am studying physics," the youngest student to ever enroll at Texas Christian University who started college on Monday says. "That's my major."

But like all college freshman, the 11-year-old is starting out by taking some required courses. His ultimate goal? Becoming a quantum physicist.

"I'm taking calculus, physics, history and religion – those are my core classes," says Huey-You, who seems to be adapting to college life quite well.  

I certainly wish him the best! It would be nice if the news organization continues to track him through his program. I would be curious to learn where he'd end up.

Zz.

Friday, August 23, 2013

An Actual Test To Verify A Quantum Computer?

We may just have one, according to this Wired article.

In the April 25 issue of the journal Nature, Vazirani, together with Ben Reichardt of the University of Southern California in Los Angeles and Falk Unger of Knight Capital Group Inc. in Santa Clara, showed how to establish the precise inner state of such a computer using a favorite tactic from TV police shows: Interrogate the two components in separate rooms, so to speak, and check whether their stories are consistent. If the two halves of the computer answer a particular series of questions successfully, the interrogator can not only figure out their internal state and the measurements they are doing, but also issue instructions that will force the two halves to jointly carry out any quantum computation she wishes.

Wonder if the D-Wave people would like to subject their machines to such a test?

The article also has some coverage of quantum entanglement and the basics of quantum computation.

Zz.

Thursday, August 22, 2013

Your Proposal Received Glowing Reviews, But We Are Not Going To Fund It

It is the sign of the times, I suppose.

I've submitted quite a few funding proposals, and some got rejected, while others got funded. Nothing unusual. However, the ones that got rejected typically have mixed reviews. I remember one where 2 of the reviewers liked it, and one was not too thrilled about it. It got rejected, which was not surprising. But in all my years of doing this, I don't ever recall where a proposal got really glowing reviews, and then it was summarily rejected!

That is what just happened to me (I'm not going to name the agency and anything else, because I am not bitter, really!). We just heard the news of the rejection, and I went to look at the reviews. At the end of reading all three of them, my jaw dropped. I can't remember reading a more positive, glowing reviews of my proposals before. The reviewers did read the proposal carefully, and actually got the novel method we were proposing. The whole proposal got very good rating. But, obviously, these mean nothing because, in the end, it got rejected.

I will also say that I am not surprised. Disappointed, yes, but not surprised considering the severe budget constraints that many of the US funding agencies are under right now. It is up to the fractured US legislators, and ultimately, the people, to put a value on science research and how it has affected the US economy and our lives thus far. If this is not of any value, then the US certainly deserves to undergo its current, slow decline of its civilization and suffers from the same fate as other great civilizations of the world throughout history.

Oh, did I say that I'm not bitter? :)

Zz.

Wednesday, August 21, 2013

Quantum Zeno Effect Observed In Diamonds

Diamonds could be quantum physicists best friends!

Turns out that the quantum Zeno effect has been observed in diamond.

The researchers focused on nitrogen–vacancy (NV) centres, imperfections in diamond that arise where an atom of nitrogen and an empty space replace carbon atoms at two neighbouring spots in the crystal lattice. The team used microwaves to change the magnetic spin state of an electron located at an NV centre, and then used a laser beam to trigger red fluorescence that revealed which of two possible states the electron was in at any given moment. When they measured the NV centre in this way, the researchers found that the oscillation between the two states was disrupted — just as would be expected if the quantum Zeno effect were operating.

The paper is to be published in PRA, but the preprint is online.

Zz

Tuesday, August 20, 2013

Science, Religion, and the Big Bang

This should stir up the pot, and I think it already has, judging from the comments accompanying this YouTube video.



Zz.

Wednesday, August 14, 2013

The Dynamics of Hyperloop

I heard about this on the new yesterday because the infamous Elon Musk has thrown his support behind it. It is a new high-speed transportation method that primarily depends on an evacuated (or partially evacuated) tube to reduce air friction.

I was going to do a quick study on it, but Rhett Allain at Dot Physics has already done a preliminary analysis on it, so I'll just point to his page.

As someone who works with vacuum/ultra-high vacuum systems, all I can say is that this thing will need a lot of huge vacuum pumps, although for what it intends to do, I think all they need is to get into probably just the milliTorr pressure range, just enough to be below the viscous flow regime.

Zz.

Monday, August 12, 2013

Google Physics Doodle

Google celebrates Erwin Schrodinger's 126th birthday today with a physics-themed doodle that most physicists and physics students will get.

Zz.

Sunday, August 11, 2013

How To Find Black Holes With Lasers

It's a bit tedious to follow, but you might learn something. And one camera angle has a bit of a problem with aspect ratio.



Zz.

Saturday, August 10, 2013

Higgs Boson: The Inside Scoop



Zz.

Why Aren't More Girls Attracted To Physics?

This is not a new topic. In fact, I'm sure it has been discussed, published, and talked about many other times. I've also posted several items on this, including this one about the shortage of women physicists.

The latest study aims at understanding why girls aren't not as interested in physics as boys.

But when Riegle-Crumb controlled for those and other possibilities, she found one reason remained: "What we found is that in communities that had a higher percentage of women in the labor force who are working in science, technology, engineering and math, that in those schools, girls were as likely as boys to take physics, or even more likely."

Riegle-Crumb's finding about the importance of local role models meshes with a broad range of that shows the decision to pursue math and science is not about innate differences between boys and girls, but about and norms. Countries with greater , for example, reveal more equal math test scores among boys and girls.

This is interesting. In my participation on the various outreach program to get girls to go into science/engineering, I've asked these girls many times on whether it was important for them to have a female role model before the chose a career. Fascinatingly enough, the overwhelming majority of the girls said no! Those who said no told me that in this day and age, they are used to the idea that they can pursue whatever career that they want.

Now, I'm not saying that anecdotal accounts contradict the study. I think the girls who showed up or have been selected to participate in many of the events that I attended were already from an environment in which they no longer significantly need role models. So my observation can definitely be skewered. This study clearly shows that there is a significant influence on having a role model within the environment that the girls live in.

Zz.

Wednesday, August 07, 2013

The Utility Of Physics

In the section titled "To The Student" from Mary Boas's classic text "Mathematical Methods In The Physical Sciences", there is this passage:

There is a story about a young mathematics instructor who asked an older professor "What do you say when students ask about the practical applications of some mathematical topic?" the experienced professor said "I tell them!"

About a few weeks ago, my graduate students and I were just chatting away while we were waiting for the start of our meeting, and the topic of our conversation meandered into dealing with the "applications" of physics, and the usefulness of various topics in physics. I indicated that, as someone who have been involved in hosting open houses, tours, Q&A, etc. with the public, I've had to deal with trying not only to explain certain aspect of what I did, but also why what I did was important and deserved to be supported. That was when one of the students asked me what I tell a general public if I was asked what are the useful applications of certain topics in physics. I found myself replying "I tell them!" Thus, the connection with what I quoted out of Mary Boas's text.

In my years of being a physicist, I have tried to impress upon people that physicists don't just do esoteric, theoretical, no-applications-in-sight-type of work. In fact, as someone who was trained as a condensed matter physicist, I tried to impress upon the public that many of the things they enjoy today, especially their modern electronics, are all part of the areas that physicists work in. I've pointed out earlier that physics is not just the LHC, but it is also the iPod and the iPhone.

Unfortunately, being able to "tell them" the applications of various aspects of physics requires someone who is not only knowledgeable, but also someone who has a wider view of physics, and the ability to make connections between many of the common conveniences, devices, procedures, etc. that we enjoy that came into being due to physics. Many students aren't that well-equipped yet on being able to handle such breadth of knowledge that tends to come about from experience. I have done this, and have faced this type of question countless times that I can pull things out of my back pocket in an instant. However, what if you are just starting out, or what if you yourself want to know how to deal with the question of the usefulness of physics?

There are 3 different points that you can make:

1. Many areas of physics have a DIRECT and OBVIOUS applications. Condensed matter physics, atomic/molecular physics, medical physics, etc. can all boast a very obvious connection to modern electronics, medical advances, understanding of materials, etc. So point these out first, and in fact, point out that people in these fields are the MAJORITY of practicing physicists. You'd be surprised how many in the public area actually shocked by that revelation.

2. The utility of knowledge. Even in areas in which it is difficult to argue for the application and usefulness to the public, we can bring out the argument that it is difficult know the future applications of such knowledge. The history of physics is littered with many such examples, including quantum mechanics. The early development of quantum mechanics had almost no emphasis on the usefulness and application. If we only want to fund work that had such clear utility, then we would have missed out on the development of quantum mechanics. And yet, as we now know, our entire modern conveniences are based on this amazing theory. So while there is certainly value in the knowledge itself, demanding that it must have an immediate and obvious application is extremely shortsighted and ignorant.

3. The "side effect" of esoteric knowledge. One may doubt the usefulness of high energy physics, or astrophysics. However, there is no argument on the fact that the pursue to verify various aspects of theories from these fields via the advancement in particle accelerators, detectors, and other devices have had significant impact on our lives. Modern facilities and devices, ranging from synchrotron radiation centers, medical accelerators, light detectors, high-speed electronics, advance data/computations, etc. were all developed or came into being due to the advances that had to be made for various high energy physics and astrophysics experiments. These found applications, what I called the side effects, in other areas, and into our everyday lives. So the experiments to study these "esoteric" topics actually drive the innovation in many different areas that eventually trickled down to us the consumers!

So if you are starting out in physics, or already knee deep into it, do not run way from the question of the usefulness and applications of physics. You stand your ground and you tell them!

Zz.

Monday, August 05, 2013

The Sun's Magnetic Field is About to Flip

Our sun's magnetic field is about to flip. But don't panic, this happens pretty often, roughly once every 11 years or so.



Zz.

Rush Holt On Physics And Politics

One of the few physicists in the US Congress (I think he and Bill Fosters are the only two left, if I'm not mistaken), Rush Holt has been in the US House of Representatives for quite a few years.

This news article reveals a bit more of his position on several different hot-topic issues.

* On himself:
"I've always been an unusual member of Congress, partly because of my background, partly because of my approach to problems, partly because of my philosophy of governing. … I have a real commitment to the basic principles of equality and liberty."


* On climate change:
"This is an urgent problem. … Climate change has to be dealt with by removing our emphasis on fossil fuels. … We are ruining our planet and killing people by the millions. … How do we do it? We have to keep presenting the facts. Presenting the evidence. And confronting those who would deny the evidence until they would deny it no more. … A transition to more sustainable energy need not be costly. In fact, it could be a real boon to us economically. The sooner we do it, the sooner we can sell the technologies to the world, rather than buy them."
You can read more at the link above.

Zz.

Friday, August 02, 2013

Do We Expand With The Universe?



Zz.

Sorry, Capt. Kirk. Teleporting You Will Just Take Too Long

... in fact, longer than the age of the universe!

This fun, amusing, and back-of-the-envelope calculations done by a group of students at the University of Leicester in England shows that to sample and transport all the information about a human to another location (as in the Star Trek teleportation device) will just take too long for it to feasible right now.

Our universe has been around for 13.8 billion years. But the seriously tongue-in-cheek paper shows that at a beaming speed of 30 gigahertz, transmitting all the data within a single human would take 4,850,000,000,000,000 (4.85 quadrillion) years. The human dataset includes not only the person's genetic code but also all the memories and knowledge stored in his/her brain. While DNA would take up about 10 billion bits, the brain's information would bring the data total up to 2.6 x 1042 (26 followed by 41 zeroes) in bits.

Why not simply increase the bandwidth to speed up the process? That would require an impossible increase in power consumption beyond earth's capabilities.

I think there's something else here that should be pointed out, and something that many non-scientists should be aware of. When we think "outside of the box", we must (i) first know where the box is and where its boundary is (which means one must have the established knowledge first), and (ii) be able to make quick, back-of-the-envelope estimation to tell us if the quantitative aspect of what we wish to do or study produce a reasonable, achievable goal.

The latter is quite important, because it tells us if there's any reasonable chance that we can verify, or accomplish our goal. This means that a device, a detector, an instrument, etc. of certain parameter can either produce, detect, or accomplish that goal. When we seek support to do such work, we must show this because, as is very obvious, no one is going to fund something based on some handwaving argument, and they are especially not going to fund something if the numbers tell us that there's no REASONABLE chance for success!

So if someone wants funding to build such a teleportation device above, would you fund it knowing that it will take 4.85 quadrillion years to transport a human being? If you would, I have a bridge to sell to you.

Zz.