Thursday, February 11, 2016

LIGO Reports Detection of Gravitational Wave

LIGO has officially acknowledged of the detection of gravitational wave.

Now, in a paper published in Physical Review Letters on February 11, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo collaborations announce the detection of just such a black hole merger — knocking out two scientific firsts at once: the first direct detection of gravitational waves and the first observation of the merger of so-called binary black holes. The detection heralds a new era of astronomy — using gravitational waves to “listen in” on the universe.

In the early morning hours of September 14, 2015 — just a few days after the newly upgraded LIGO began taking data — a strong signal, consistent with merging black holes, appeared simultaneously in LIGO's two observatories, located in Hanford, Washington and Livingston, Louisiana.

Notice that this is the FIRST time I'm even mentioning this here, considering that for the past 2 weeks, at least, the rumors about this have been flying around all over the place.

Looks like if this is confirmed, we know in which area the next Nobel prize will be awarded to.

There is also a sigh of relief, because we have been searching for this darn thing for years, if not decades. It is another aspect of General Relativity that is finally detected.

Zz.

This Educational Video on Accelerators Doesn't Get It

OK, before you send me hate mail and comments, I KNOW that I'm hard on this guy. He was probably trying to make a sincere and honest effort to explain something based on what he knew. And besides, this video is from 2009 and maybe he has understood a lot more since then.

But still, this video is online, and someone pointed this out to me. I get a lot of these kinds of "references" from folks online, especially with Wikipedia entries. And try as I might to ignore most of these things, they ARE out there, and some of these sources do have not only misleading information, but also outright wrong information.

This video, made presumably by a high-school science teacher, tries to explain what a particle accelerator is. Unfortunately, he described what a particle accelerator CAN do (i.e. use it in high energy physics colliders), but completely neglected the description of a "particle accelerator". This is a common error because most people associate particle accelerator with high energy physics, and think that they are one and the same.

They are not!



As I've stated in an earlier post, more than 95% of particle accelerators on earth has NOTHING to do with high energy physics. One of these things might even be in your doctors office, to generate x-rays to look at your insides. So using high energy physics experiment to explain what a particle accelerator is is like using creme brulee to describe what a dessert is. Sure, it can be a dessert, but it is such a small, SMALL part of a dessert.

A particle accelerator  is, to put it bluntly, a device to accelerator particles! Period. Once they are accelerated, the charge particles can then be used for whatever they are needed for.

Now, that may sounds trivial to you, but I can assure you that it isn't. Not only does one need to accelerate the charge particles to a set energy, but in some cases, the "quality" of the accelerated particles must be of a certain standard. Case in point is a quantity called "emittance". If these are electrons, and they are to be used to generate light in a free-electron laser, then the required emittance, especially the transverse emittance, can extremely low (in fact, the lower the better). This is where the study of beam physics is crucial (which is a part of accelerator physics).

The point I'm trying to make here is that the word "particle accelerator" is pretty generic and quite independent of "high energy physics" or "particle collider". Many accelerators don't even collide these particles as part of its operation (in fact, many do NOT want these particles to collider, such as in synchrotron radiation facilities).

What this teacher neglected to describe is HOW a particle accelerator works. The idea that there are these accelerating structures with a wide range of geometries, and they can have either static electric field, or oscillating electric field insides of these structures, that are responsible for accelerating these charged particles, be it electrons, protons, positrons, antiprotons, heavy nucleus, etc... And even for high energy physics experiments, they don't usually collide with a "fixed" target, as implied in the video. Both LEP, the Tevatron, the LHC, etc. all collide with beams moving in the opposite direction. The proposed International Linear Collider is a linear accelerator that will collide positrons and electrons moving toward each other in opposite direction.

So while the intention of this video is noble, unfortunately, the information content is suspect, and it missed its target completely. It does not really explain what a particle accelerator really is, merely what it can be used for. It also perpetuates the fallacy that particle accelerators are only for these exotic experiments, when they are definitely not.

Zz.

Friday, February 05, 2016

The Physics of Mirrors Falls Slightly Short

This is a nice, layman article on the physics behind mirrors.

While they did a nice job in explaining about the metal surface and the smoothness effect, I wish articles like this will also dive in the material science aspect of why light, in this case visible light, is reflected better off a metal surface than none metalllic surface. In other words, let's include some solid state/condensed matter physics in this. That is truly the physics behind the workings of a mirror.

Zz.

Wendelstein 7-X' Comes Online

ITER should look over its shoulder, because Germany's nuclear fusion reactor research facility is coming online. It is considerably smaller, significantly cheaper, but more importantly, it is built and ready to run!

Construction has already begun in southern France on ITER, a huge international research reactor that uses a strong electric current to trap plasma inside a doughnut-shaped device long enough for fusion to take place. The device, known as a tokamak, was conceived by Soviet physicists in the 1950s and is considered fairly easy to build, but extremely difficult to operate.

The team in Greifswald, a port city on Germany's Baltic coast, is focused on a rival technology invented by the American physicist Lyman Spitzer in 1950. Called a stellarator, the device has the same doughnut shape as a tokamak but uses a complicated system of magnetic coils instead of a current to achieve the same result.

Let the games begin!

Zz.

Wednesday, January 27, 2016

Will You Be Doing This Physics Demo For Your Students?

I like my students, and I love physics demos, but I don't think I'll be doing THIS physics demo anytime soon, thankyouverymuch!



It is a neat effect, and if someone else performed this, the media would have proclaimed this as "defying the laws of physics".

Maybe I can do a demo on this on a smaller scale, perhaps  using a Barbie doll. And if you ask me how in the world I have a Barbie doll in my possession, I'll send my GI Joe to capture you!

Zz.

Friday, January 15, 2016

2 Most Dangerous Numbers? Phooey!

Baloney!

This is a report on a TED talk by a CERN physicist Harry Cliff. In it, he discussed the conundrum theoretical physicists are facing with the current knowledge of the Higgs and dark energy.

At the core of Cliff's argument are what he calls the two most dangerous numbers in the universe. These numbers are responsible for all the matter, structure, and life that we witness across the cosmos.

So in the attempt to make this story more "sexy", we of course have to make sound as if we are reaching an apocalyptic problem that will spell "the end of physics" (how many times have you heard that already?). There are several problems with this reporting:

1. The degree of certainty on the validity of ANY of these theories is LOW. Anyone wants to argue that? So while it is certainly important to pursue it, the TED talk can only be seen as being a very quick and superficial snapshot of an ONGOING and still preliminary investigation! Our knowledge of the Higgs and dark energy are still in the extreme infancy when compared to many of the more established areas. This is like groping in the dark and then pronouncing that we're doom because someone  heard something moving.

2. The claim that "getting answers could be impossible" is false. In that section of the report, nothing that was described is impossible. The limit on the energy of the LHC isn't a limitation on the physics or our ability. We can certainly build a bigger, more energetic collider (the Superconducting Supercollider that was supposed to be built in Texas in the 80's would have had a higher energy than the LHC!). New research on advanced acceleration scheme, led by a slew of wakefield-type accelerators, has the potential of boosting particle energy even higher while making the accelerator more compact. So no, there is no ceiling yet, in terms of the physics, in going to higher and higher energies. What is hindering the building of such machines is the economics! This is not a physical impossibility, but rather a social "impossibility".

I am always skeptical whenever someone, or even a scientist, claim of "maybe" we might reach the end of something, or that we'll never get beyond such-and-such. Again, we seem to have never learned what happened when we claim that, with the state of our knowledge of superconductivity in the early 1980's being a prime example. Almost everyone thought that the field was fully matured, and that there's nothing left to discovery there other than refining our knowledge and the production of the material. Then high-Tc superconductors were discovered and all hell broke loose!

Scientists need to be aware that talks like this can be latched on by the public because news reporters like to over-emphasize the "dramatic" parts. Without intending it, something that many of us know to be still very much a "work in progress" becomes a "fact" to many people outside the field.

Zz.

Thursday, January 14, 2016

Quantum Field Theory

So you want to know what "Quantum Field Theory" is? It is not going to be easy, I tell ya!



Zz.

Wednesday, January 06, 2016

What Makes A Solid .... Well.... Solid?

The title of this Don Lincoln's video is "The Nature of Matter", but I'm re-titling it as "What Makes A Solid Solid", and you'll know why when you watch the video.

Still, while it is informative, what's with the planetary picture of the atom again? I hate to think that we will perpetuate this nasty picture and people who don't know any better will keep holding on with such an understanding.



Zz.

Monday, December 21, 2015

APS Physics Highlights of 2015

APS's Physics lists its highlight stories of 2015.

I need to point out something important that a casual reader might miss. The story on the 3D imaging  of a virus may appear to be an advancement in biology or medical science. And it is, because this allows us to understand a virus better than before. However, it should be pointed out that this capability came into being because of advances in accelerator  science. The imaging was done at SLAC's LCLS, which is a free-electron light source. This involves an advancement FIRST in accelerator science. Only after that are we able to create such a FEL that can produce light sources to do the imaging.

The point I'm trying to make here is that, if you value the field of biology and all the medical advances to help you live better, you should look at how these fields are able to accomplish such a thing. Just look at the National Institute of Health's funding projects, and see how many of them use instruments and facilities that all started out as something a physicist would use. Only later on were they adopted for use in other fields.

So without proper funding and support for the very basic research in physics, which in turn drives not only knowledge, but also the advancement in instrumentation and facilities, these new techniques and technology will not trickle down to the field of biology, chemistry, and medicine.

Zz.

Wednesday, December 16, 2015

The Physics of Car Crashes

I hope you never have to figure out the physics in this context, but it is still a nice scenario in basic mechanics.



Zz.

Saturday, November 28, 2015

What Good Is Particle Physics?

I've tackled this issue a few times on here, such as in this blog post. In this video, Don Lincoln decides to address this issue.



Zz.

Wednesday, November 25, 2015

Hot Cocoa Physics

Just in time for the cold weather, at least here in the upper northern hemisphere, APS Physics Central has a nice little experiment that you can do at home with your friends and family. Using just a regular mug, hot water/milk, cocoa mix, and a spoon, you can do a demo that might elicit a few questions and answers.

For those celebrating Thanksgiving this week, I wish you all a happy and safe celebration.

Zz.

Monday, November 16, 2015

Symmetry And Higgs Physics Via Economic Analogy?

Juan Maldacena is trying to do the impossible: explain the symmetry principles and the Higgs mechanism using analogies that one would find in economics.

I'm not making this up! :)

If you follow the link above, you will get the actual paper, which is an Open Access article. Read for yourself! :)

I am not sure if non-physicists will be able to understand it. If you are a non-physicist, and you went through the entire paper, let me know! I'm curious.

Zz.