Search This Blog

Sunday, November 27, 2011

One of the More Interesting Quantum Experiments!

Thanks to Jeff for forwarding this article.

We all now know that quantum mechanics is bizarre. One of the more incredible predictions and requirements of this theory is that the once thought concept of empty space, or the vacuum of space, is in fact teaming with activity. The concept of virtual particles lies at the heart of quantum field theories, with unobservable particles zooming in and out of existence, allowed by the uncertainty principle (you know things are weird when uncertainty is a rule of Nature!). Uncertainty allows for brief violations of the conservation of energy and momentum.

A team of scientists have published a paper stating they have measured the dynamical Casimir effect. This states that high-speed motion in a vacuum should be able to transfer some of its energy to virtual photons, and force those unobservables into observables! Here is the abstract from the paper, which has yet to be formally peer-reviewed and published in Nature.

"One of the most surprising predictions of modern quantum theory is that the vacuum of space is not empty. In fact, quantum theory predicts that it teems with virtual particles flitting in and out of existence. While initially a curiosity, it was quickly realized that these vacuum fluctuations had measurable consequences, for instance producing the Lamb shift of atomic spectra and modifying the magnetic moment for the electron. This type of renormalization due to vacuum fluctuations is now central to our understanding of nature. However, these effects provide indirect evidence for the existence of vacuum fluctuations. From early on, it was discussed if it might instead be possible to more directly observe the virtual particles that compose the quantum vacuum. 40 years ago, Moore suggested that a mirror undergoing relativistic motion could convert virtual photons into directly observable real photons. This effect was later named the dynamical Casimir effect (DCE). Using a superconducting circuit, we have observed the DCE for the first time. The circuit consists of a coplanar transmission line with an electrical length that can be changed at a few percent of the speed of light. The length is changed by modulating the inductance of a superconducting quantum interference device (SQUID) at high frequencies (~11 GHz). In addition to observing the creation of real photons, we observe two-mode squeezing of the emitted radiation, which is a signature of the quantum character of the generation process. "

Find the whole article here.

Friday, November 25, 2011

Gaming in Education

OK, something you may have been waiting for. Here is a TED talk about how gaming makes kids smarter, and argues that gaming should be a major part of school. While I agree that there are certain skills that are captured in playing computer and video games, such as being able to process large amounts of information, analyze it and make quick decisions based on that information, and in many games this could be a collaborative activity, let's remind ourselves that this is a different skill set than, say, being able to have patience and focus on a complex problem that requires long periods of time to collect information, keep records and notes, stay organized with ideas as they come up in this thought process, perhaps, in the case of science, develop a physical experiment to test ideas, or build a device or object or model to further investigate aspects of this complex problem, find other information about it from numerous sources, and develop logical conclusions from all this work. Gaming does not really jive with such a skill set.

My point is this: this video, while making a good point, is not a silver bullet. I will always argue that there is no single solution to the optimal education of any individual. There are so many good ways to learn, and it is a useful exercise to experience multiple ways of learning a topic or subject. In real life, one is faced with countless possible problems at a moment's notice, and depending on the type of problem and the environment you are exposed to that problem, some solutions will fall back to what you learn in a 'classical' or traditional manner, while others will make use of a skill set developed best through video gaming systems. Others will require the use of physical tools such as hammers and nails and saws, which one will never learn through gaming. Do NOT fall into the trap that you need to do all of one thing over none of some other things...learn about both methods and have a broad set of intellectual approaches to take on any problem! Remember, if you can talk about an idea or concept in multiple ways with multiple examples, chances are you have mastered the information.

Sunday, November 20, 2011

Young and Want to Change the World? It CAN be Done!!

For an inspirational TED talk by Natalie Warne, who helped begin and run a national movement to recognize and do something about children being forced to become soldiers in Africa, watch this. You CAN make a difference if you work hard and are passionate about something, and are willing to go out and do something about it. This will likely include being challenged, being frustrated, and perhaps even ridiculed, but if you persist you will be amazed by what can happen!

Wednesday, November 9, 2011

Binary Stars and Air Friction Videos

Hey, juniors - here are two links for learning how to do binary orbits and air friction (the hockey puck example, and a sky diver example). For the air friction, this could be review of our derivations in class. For binary orbits, check out the video and see what you can do with the AP problem over the weekend. Feel free to do this with a friend or study group, and help each other through it.