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Tuesday, December 29, 2009

Importance of Imagery for Memory & Learning

Thanks to the Drs. Eide for a post on imagery studies and how they play a role in memory and learning. If you reflect on instances when there is some physical activity or complex calculation or cognitive exercise you need to do, can you remember a time when you tried to 'see' yourself doing it ahead of time? It may seem to be an instinctive process or action, but I certainly have imagined doing a tough calculation prior to a math test, or have caught myself imagining myself playing a tough trumpet lick on a bus as we drove to a music contest. Professional musicians and athletes often refer to this mental practice since they are on the road so often, without the ability to physically practice like they are used to doing. Read a good article on this topic here.

Mental imagery is something that can help build memory for particular actions or cognitive activities, largely because neuroimaging experiments show as much as 90% of the neurons that are used in the actual, physical activity are firing in mental imagery exercises. To the brain, imagery is not so different from the real thing. Imagery can help us with the following:

- not only visualizing what the activity is, but also gaining spatial, auditory and kinesthetic information and practice and memory for that activity;
- helps with activities with high levels of organization, multi-steps, and decision making;
- positive imagery has a positive effect on real performance results: for example, golfers do 30% better on putting when positively imagining sinking putts, and 20% worse when imagining missing putts;

For readers, 60% of 5th graders report naturally using some imagery during 'think aloud' breaks in reading stories. It appears to be a natural reaction, even for children, to try and 'see' the scenes that words are trying to convey in order to develop memories of a story that we, ourselves, are not part of in reality. Humans are more visual creatures, as I like to tell my own students, and it is important to remind and also teach students how to visualize physical events and experiences. In fact, in problem solving in physics, I try and teach as an essential part of every single problem to draw a picture and mentally 'see' what is happening in the problem. We use a technique that requires making pictures and labeling all forces on the picture, and then use the picture to actually set up the math (for F = ma problems). So science and imagery are naturally connected, just as reading, writing and imagery are connected. Memory improves when visualization and imagery are used for stories or for how physical events play out in reality. The experimental finding that a good majority of the brain used for the physical activity is used in imagery, too, begins to explain why this process works.

Imagery is used extensively in elementary grades, and the combination of mental imagery with drawing pictures and other hands-on, physical activities makes for a powerful way of building memory and learning. We tend to actually decrease the use of imagery techniques as students progress into higher grades. Perhaps imagery is used most extensively in science classes by the time students get to high school, but it seems as if the use of imagery and hands on activities decreases significantly in literature and history/social studies classes, at least via anecdotal evidence and through conversations with students. Perhaps this is something educators need to consider more in practice.

Friday, December 25, 2009

How to Play Einstein for a Day: Mass and Energy

We know that strange things happen when objects move relative to other objects. Clocks run more slowly, lengths get shorter, and mass increases for the moving object, relative to an observer at rest. These are well confirmed over the last century from countless experiments.  We also know E = mc^2 comes from special relativity. But how did Einstein do it? Where did he get the idea that energy and matter aren't just related, but actually equivalent to each other?

Check this out!!  It is one way of thinking about it, and getting to a result that shows energy and matter are of the form E = mc^2.  It makes use of the binomial approximation when thinking in terms of everyday speeds, which are far slower than light.

How to Find Capacitance for Spherical and Cylindrical Capacitors

There are three shapes of capacitors in practice: parallel-plate, spherical and cylindrical. Conveniently, these are the three shapes we have for Gauss's law applications. We will use Gauss's law to find the E-field in the capacitors, then integrate the fields to get the potential difference across the capacitor, and then use our definition of capacitance, C = Q / V, to get the capacitance expressions. Let's take a look at two of the three, spherical and cylindrical capacitors.

Tuesday, December 22, 2009

Scientific American's Top 10 Science Stories of 2009

Scientific American has its top 10 science stories of 2009. Perhaps the lead story for 2010 will be the discovery of the Higgs boson at either Fermilab or CERN.

How to Solve a Discharging RC Circuit

Here is an example of how to find and solve the differential equation for a discharging capacitor, as part of an RC circuit. This happens when the battery is disconnected from the charged capacitor...there is nothing left to hold the charge on the capacitor. It uses the stored energy to discharge, and that energy gets burned off by the resistance in the circuit as the charge and current die off exponentially.

How to Solve a Charging RC Circuit

RC circuits make up the next level of sophistication for us when it comes to circuits. We have done plain resistor circuits, plain capacitor circuits, and now RC circuits. Here is an example of how to find the charge as a function of time for a charging capacitor. It involves setting up a first-order differential equation for the circuit, and then solving that equation. In the end, we have exponential increase of charge on the capacitor, and exponential decay of current through the resistor and battery. Keep in mind the key is to write the equation for the circuit, and that depends on Kirchhoff's voltage rule, V = V(resistor) + V(capacitor).

How to Find Charge on Capacitors in Circuits

There are a lot of parallels (ha, ha) between resistor and capacitor circuits. For resistor circuits, we tend to re-draw the circuit as a series circuit in order to find the voltage differences across parallel sets of resistors. This allows us to then find how the current splits in any parallel sets. We do basically the same thing for capacitor circuits, where we re-draw the circuit as a series, find the voltages, and then go and find how the stored charge splits on parallel branches. Here is an example of this process.

Saturday, December 5, 2009

How to Start Science Research in High School

Many of our students have an interest in science research, but really do not have a clue as to how to go about the process. Don't feel bad if this is your situation...getting started is the most difficult part for anyone! This video gives a brief tour of my website with a couple useful resources for a student. You can come talk with me any time about any of the information on the site, and to sit down and brain-storm what your interests are and what is doable for a high school student. I strongly encourage you to look at some former student papers, to see the level that can be achieved and to get ideas for your own work. This type of work is absolutely long-term, as science is not done 'overnight.' Check it out, and if it seems like something you are interested in, let's talk!

How to Find the Basics of Binary Orbits

Most stars we see are actually two stars in orbit around each other. Technically, all orbiting systems are binary orbits, so understanding the basics of these is important in physics. Let's see how these work and get the basic concepts down, especially in terms of finding how fast things must be moving in order for these orbits (which we will assume are circular) form.

How to Find Gravitational Potential Energy when Gravity Changes (i.e. large heights)

We look at how to do gravitational energy the 'right way.' This is because gravity really is a non-constant force, and U = mgh is simply an approximation. While it works when the height is small compared to the radius of the earth, it does not work for space launches, orbits, and so on. Let us see what happens and how to do this, starting with Newton's law of gravity and our old gradient friend, F = -dU/dr. We will also see how this gets us escape velocity and Schwartzschild radius (for black holes).

How to Interpret Potential Wells

We have looked at potential wells, which are just graphs of potential energy as a function of position. The classic way of thinking about this is to imagine one object fixed at the origin, and have a second object moving along the x-axis. The graph tells us the potential energy between the two as you move that second object. We look at the potential energy gradient in order to determine the force function, F = -dU/dr, or in other words the force graph is found by plotting the negative slope of the potential energy graph. I outline this by using the 'Nike' problem from an old AP exam. Check it out!

Saturday, November 28, 2009

A Whole Map of Science - Paradigm Links

This is really crazy cool! Check out the map of science. You can click on it and magnify the view to read all the connections of discoveries, topics and paradigms for the major areas of science, and see how they link the disciplines together. The strands are like rubber bands that connect and hold together the disciplines in the map. This is wonderful to check and see all the amazing areas of research across all disciplines, and see what people are working on out in the world. This is a must check out sort of map, so have fun!

Monday, November 23, 2009

How to Analyze Resistor Circuits

For basic resistor circuits, there are 3 main rules we use: Ohm's law and Kirchhoff's 2 rules. This example shows a combination circuit with some series and parallel combinations, and outlines a 5-step analysis process that will hopefully become habit. The steps are:
- find the total resistance;
- find the total current with Ohm's law;
- redraw the circuit as a series circuit;
- find the voltage differences across all the resistors in the series circuit;
- go back the original circuit and use the voltage differences to find the currents on each branch, regardless of the branch resistance.

Take a look, and see Doc V if there are any questions at all.

Tuesday, November 10, 2009

Political Issues that will Require Science for Solutions

When one thinks about the variety of problems we face as both a national and global society, it becomes clear that science will be looked to to develop answers and solutions to many of these problems. It is also clear that we need to think of this as science in the broadest sense, as all areas and disciplines will need to contribute. This goes to the heart of the definition of consilience, as numerous areas of knowledge and expertise will need to mix together if we are to make solid progress in finding effective solutions.

To get the ball rolling, consider the following broad issues/problems. All of these will require contributions from a variety of scientific and technical areas of study...multidisciplinary tasks galore:

* Quality of air and water
* Fresh water supplies for much of the west and southwest
* Disposal of solid wastes (everyday garbage)
* Modernization and maintenance of national power grid
* New energy sources, better energy efficiency and conservation
* Climate change (both at an understanding level as well as preparing for consequences)
* Environmental engineering
* Improved electronic encryption algorithms as we digitize everything (medical, financial records, etc)
* Transportation infrastructure
* Telecommunications networks, both development and maintenance
* Continued improvement and progress in computing technologies
* Mass electronic data storage
* Medical treatments for the disease of your choice. This includes stem cell issues, genetic engineering, drug R&D, and so on.
* Military related technologies
* Improved search technologies for earth-crossing asteroids (something I have yet to hear policymakers talk about publicly, but there are literally many thousands of sizeable objects that cross earth's orbit we should try to identify and monitor)
* Food supplies and quality control
* Disposal of nuclear wastes, nuclear proliferation issues
* Nanotechnology in general
* Security technology of all types
* Robotics
* Implementation of educational strategies and structures based on brain research and learning theory to best prepare the next generation of workers
* Continued development of network theory, game theory, etc., and progress in our understanding of complex systems for physical and social applications
* Materials science and development

I encourage comments with additional major issues that are technical in nature and subject to progress via scientific avenues; this is not at all a complete list. What we cannot forget is that further inclusion of other areas of study are intimately connected with just about everything on the above list, such as ethics, state/national/international law, economics, political science, sociology, public policy, military concerns, all areas of engineering, business/industry, job creation, international relations, anthropology, and countless subfields that fall under these larger areas of specialization.

The quicker we as a society recognize and realize the complexity, multidisciplinarity, and difficulty level of finding both short-term and long-term solutions to problems found in any of these areas, the better off we will be. The next president will need to address all of these during the course of an administration, as will every other prominent political figure in every nation across the globe. We will not be able to ignore any of them, and these loom as multi-generational issues that need to be solved. This will require leaders who are able to connect with the masses and communicate the seriousness of the issues, as well as move his or her nation toward a mindset of long-term planning and policy, something we seem to not be very good at.

We need to find and create massive numbers of people who are trained in all of the sciences, mathematics, engineering and technology, and all the other fields mentioned above to remain competitive in a global marketplace, as well as the maintain and improve the quality of life for future generations. It is challenging work, but do we have any other choice but to address these challenges? Does our consumption-based and entertainment-driven society have the backbone and means to deal with these issues? Will we leave the world in better condition for our kids and grandkids than what we inherited?

Monday, November 2, 2009

Check out the Farthest Object Ever Observed!

Double-click on the picture to get the entire photo.

At some 13 BILLION LIGHT-YEARS,we have a new farthest object ever observed and photographed by astronomers. This object is the remnant of a gamma ray burst, relatively shortly after the Big Bang (about 600 million years after the creation of the universe). Gamma ray bursts rank as one of the most energetic events known in the universe, and the star that produced this one was part of the first generation of stars created in the universe. Truly remarkable!

Sunday, November 1, 2009

How to Integrate and Find Electric Potential in Gaussian Problems

We have the task of integrating electric fields of gaussian systems in order to find electric potential, or simply voltages, of various regions in order to fully understand such systems. This is all leading to understanding how capacitors work, which is a primary component of all electronic devices. This is a multi-layer example, with a conducting ball surrounded by a couple thin shells. The reference point of V = 0 is 'far away.' I hope this helps...

Wednesday, October 28, 2009

How to Define and Find Derivatives

Especially for the benefit of those students who are in trig this year, this is a quick review of what a derivative is and how we find them. Remember a derivative is nothing more than the slope of a tangent line. We can use the result as the instantaneous slope at a point. Here, we use the simple curve, y = x^2. Keep in mind that, fundamentally, we start with the normal, usual slope equation you have used for years: slope = (y2 - y1) / (x2 - x1). Check it out, and I hope it helps.

Saturday, October 24, 2009

How to Do Gauss's Law with NON-Conducting Materials

The previous video dealt with Gauss's law and conductors, where, when in electrostatic equilibrium, the electric field = 0 inside. Any net charge sits on the outer surface of a metal chunk. But, when we move to NON-conducting materials, things are more involved since there are NO de-localized electrons. It is OK to have net charge inside the material, spread throughout the volume, and therefore it is OK to have an electric field inside these materials. There would still just be static charge, and no currents. This is also the case where we would have charge densities. Check out how to do this for uniform charge densities, and I hope it helps while you review this topic.

Sunday, October 18, 2009

How to Do Gauss's Law with Conducting Materials

Conducting materials separate themselves from non-conductors due to the metallic bonds. Those delocalized electrons that are free and drifting randomly throughout a metal are forced to move when an electric field is present, and currents are formed. However, with Gauss's law, remember we only can apply it to electrostatic situations. This is why charges, through polarization, rearrange and give NO E-field inside when we have static charge. Any net charge sits on the outer surface; this is the only way to have equilibrium. Check it out or review it.

How To Deal With Air Friction Mathematically - Hockey Puck

Air friction is a different creature compared to static or kinetic friction. Static and kinetic frictions are forces between two solid surfaces, whereas air friction is between a solid surface and a fluid. Something like water friction behaves similar to air friction, where these friction forces depend on how fast you try to move through the fluid (think about how it is actually tougher to try and run in water than to walk in water). Check out how to handle this fluid friction is certainly more involved than dealing with static or kinetic friction, which we treat as constant forces. Air friction is non-constant, and calculus must be used to find an exponential behavior with time.

Saturday, October 17, 2009

2009 Nobel Prize in Physics

The Nobel Prize in Physics for 2009 has been given to three American scientists, for their work over the past few decades in fiber optics and the technology responsible for digital photography, which lies in something called a charge coupled device (CCD). The scientists are Charles Kao, Willard Boyle, and George Smith.

An enormous chunk of modern technology we take for granted exists only because of their work. For example, much of the ETHS computer network backbone is fiber optics, and new lines put in globally to expand the Internet backbone is fiber optic, as well as phone lines that are put in the ground (yes, your voice is ultimately transmitted as light!). There are fiber optic computers being developed, and particle and nuclear physicists have used fiber optics in detectors for some period of time. The CCD is in every digital camera, cell phone, telescope, and numerous types of satellites. CCDs are able to take photons falling on them and convert it into electrical signals, which can then be used to digitize data. Because we see final products as 'black boxes,' most people do not understand how modern electronic devices and the Internet work...this prize and the publicity it generates will help educate people a bit more so they can hopefully better appreciate the role science plays in our lives.

Thursday, October 15, 2009

Einstein's View of Gravity in General Relativity

We know a bit about gravity, and the fact that all masses attract all other masses. Newton figured this out in the 17th century. However, Newton never understood where gravity came from. We had to wait nearly 300 years before Einstein proposed the General Theory of Relativity, and the notion of 'warped space-time.' Check out this clip from Brian Greene's Elegant Universe.

Classic footage from Moon - Hammer vs Feather

A classic experiment, done by Apollo astronauts on the moon, proved that, minus air friction, even a feather has the same acceleration due to gravity as heavier objects, such as a hammer. You can even notice that the acceleration is less than on earth by watching the fall. The acceleration of gravity on the moon is about 1/6 the earth's value of 9.8 m/s^2, which puts it at about 1.6 m/s^2.

How to do Tension Problems with Systems of Objects

Here is an example of how to do a problem where we have a system of objects tied together, and need to find acceleration and a couple tension forces. These tend to be confusing when we first learn the process of applying the 2nd law, but with some practice and using the same strategy every time for a system, we'll get it down. The strategy is to draw the force diagram (always!), do F = ma for the entire system to get the acceleration, then isolate individual objects and do F = ma on those to get internal forces. Check it out!

Sunday, September 27, 2009

What is a Smart Grid?

Perhaps some of you have recently heard the term 'Smart Grid' in the news. This is an idea that many tech and power companies are interested in and working on, and an idea that the federal government is beginning to fund through the American Restructuring and Recovery Act that the Obama administration got through Congress earlier this year. Several billion dollars are designated to begin building and installing Smart Meters around the nation.

The 'Smart' refers to control systems within the power grid, which is the vast comple network that distributes power to all cities, towns and buildings. There is a good deal of wasted energy in the grid, and scientists and engineers are being tasked with designing and building a new distribution system where computers and sensors will determine where energy is needed, where it can be reduced and saved, and what demand is doing in real-time. by being more efficient, less waste will take place, less additional energy needs to be pumped into the grid, and energy costs and greenhouse emissions will be reduced, or so it should be theoretically.

I wanted to mention this on the blog because of the fact that if you have interests in electronics, computer science, and electrical, mechanical, or civil engineering, then there will be many jobs opening up as this project continues to grow over the next five years. New standards for a smart grid were just published by the Dept. of Commerce, and money is beginning to flow into the system to make this work. Keep in mind that a HUGE challenge to make a new grid work, as well as most sectors of life and business continue to work, is cyber security. We will be needing an army of computer scientists to develop secure software and encryption algorithms to keep all aspects of our national and private computer networks safe from hackers and cyber terrorism, which is the second greatest threat I personally believe is out there (with the only exception being a nuclear armed terror organization).

Keep this in mind, because it will be a constant effort being done in your lifetime.

Saturday, September 19, 2009

Off to Good Starts

In Physics, we had a first test today as we have built up some concepts in matter and reviewed skills in algebra and graphing (both by hand and via analysis on the computer with Excel) that will used all year. We are moving into Newton's laws of motion.

In 3 Chem-Phys, we've introduced differentiation and integration, vector algebra, and constant versus non-constant acceleration, and the juniors are presently in their first chemistry unit.

In 4 Chem-Phys, we are starting with static electricity as we have introduced the concept of electric fields and forces. We will be doing point charges and then move into Gauss's law, and introduce electric potential.

Keep in mind that notes and assignment calendars are on the Moodle pages. Check out how to access my Moodle pages here.

The phun has begun!

Wednesday, August 26, 2009

A Message From Sen. Durbin

I wanted to share with everyone an email reply I received from our U.S. Senator, Richard Durbin. This is in response to a message I sent him about my concern for updated technology accessibility in schools across the country. This is dated Aug. 26, 2009:


Dear Dr. Vondracek:

Thank you for your comments about technology in education.

I share your views about the need to increase access to technology in our schools. Federal support for education is an investment in our children's future and in our nation's competitiveness. Although funding for education is primarily a state and local responsibility, federal programs provide critical assistance to help local school districts strengthen educational programs. Federal assistance for technology in education helps prepare our children for the increasing demands of an information age.

Today, technology is a critical component of a strong educational system. Students need a working knowledge of computer hardware and software, and they need to use technology as part of the broader learning process. The problem-solving skills and other strengths developed through coursework that utilizes up-to-date technology are a valuable preparation for most jobs. Moreover, the U. S. Department of Labor projects that new jobs requiring science, engineering and technical training will increase four times faster than the average national job growth rate. Therefore, adequate education technology is an enormous and pressing need.

As co-chair of the Senate Science, Technology, Engineering and Math Education Caucus, and as a member of the Appropriations Committee, I will continue to work to ensure that support for education - including science, technology, and math education - is a high priority, and I will keep your comments in mind as federal funding for technology in education is considered in the Senate.

Thank you again for your interest. I hope you will continue to stay in touch.


Richard J. Durbin

United States Senator"

Notice the highlighted section, stating how technology related job growth is projected to increase 4 times faster than the rest of the job market. This means it is in your best interests to at least have some background with technology and science, just so you have the option of moving into a technical field if you so desire. It starts NOW, at ETHS!!

Monday, August 24, 2009

Emergence and the universe

This is an old post from my main blog some of you may find interesting and relevant to class. It deals with emergence, or the natural formation of something new from a variety of individual parts. The collective system is very different and follows different rules than what the individual components of the system follow. An example is how society emerges from individuals, whether it is humans or ants. Check this out for the 'emergence' of our universe:

Our Universe: Continual Emergence

In my last post I tried to offer some mix of examples of systems that involve emergence. Again, emergence refers to many-body systems of all types (physical, biological, social, economic, etc) where the rules/principles that govern the behavior of individual components of the system are different from the organizational rules/principles that govern the behavior of the collective system.

As others pointed out in comments, the field of complex systems and emergent behavior includes phase transitions and environmental concerns and influences as well. This discussion has got me thinking about the role complexity theory and the notion of emergent behavior will play in the next few decades. Being a relatively new area of study (at least new in the sense that large numbers of people are working on it...perhaps on order of 15-20 years), it is difficult to predict exactly where it will end up, but just from a physical science point of view consider the following progression of events and phenomena where new levels of organization, i.e. emergence, are reached:

  • Big Bang, where energy and spacetime itself emerges from a singularity.
  • Fundamental particles, the quarks, organize into baryons (such as protons and neutrons) and mesons, via strong nuclear force.
  • Nuclei (isotopes of hydrogen, some helium) emerge from a sea of baryons and gluons.
  • Simplest atoms emerge from sea of hydrogen and helium nuclei and electrons, via electromagnetic force.
  • Gas molecules of hydrogen and helium emerge from sea of atoms.
  • Gas clouds emerge from sea of gas atoms, via gravity.
  • Protostars and stars emerge from gas clouds.
  • Heavier elements (up to iron) emerge from thermonuclear processes inside star cores (nucleosynthesis).
  • Clouds of heavier elements (up to uranium) emerge from first generation supernovae.
  • Second generation stars, first generation planets/solar systems emerge from gas and heavy element clouds.
  • Primitive atmospheres and terrestrial environments emerge on various planets.
  • For earth, more complex molecules, including carbon-based molecules, emerge in the chemical mixtures of the atmosphere and oceans (this includes amino acids, which can be formed naturally when lightning occurs in the primitive atmosphere, as shown in experiments).
  • Still more complicated molecules, including proteins and RNA, emerge, and from this mixture first set of single-celled life emerge.
  • Multicellular systems emerge from sea of single-celled critters.
  • Ultimately great variety of life emerges, including humans, from evolutionary processes.
  • From this point, social organization occurs, language emerges, technology emerges, social networks emerge, economies emerge, and so on.

In each of these separate eras of the development of the universe and life as we know it, we are talking about a transition from simpler, smaller components that organize into larger entities whose behavior and properties are vastly different from the individual components that make it up. We are at the point where we know an awful lot of the physics that describes how particles, atoms, molecules, stars, galaxies, planets, geological processes, and solar systems behave individually. Chemists and biologists know an awful lot about individual reactions, molecules, organelles, cells, tissues, organs, and organisms. This is what science has worked on for the last few centuries. In other words, we know a lot about the basic rules and principles that govern individual components for each individual step of the evolution of the universe and life on earth.

However, what we don’t understand very well is how steps make the transition to the next step. We don’t understand the organizational principles or the rules that govern the phase transitions between steps, which means we don’t understand the emergence of complexity in our universe. This is where we are now and, in my opinion, such studies will dominate whole fields of physical science, biological science, mathematics, economics, social science, behavioral science, technology, and even philosophy, for decades to come. To those who have suggested the end of science is near, think again.

How to access Interactive Physics Computer Experiments

Try this one out, especially if you are a visual learner. Interactive Physics is a program we have where you can use existing experiments in numerous areas of physics, or make your own simulation from scratch. This video is for accessing existing simulations and experiments. You can make graphs in real time, as well as change parameters of the system and of the world! See what it would look like on other planets, with or without air friction or charge, change materials in collisions, and so on. It is pretty cool!

Saturday, August 22, 2009

How to Access iLab Data

This video is for those who have run the radioactivity iLab, and then came back to it later. You will need to find the data file, and then use it for your analysis.

How to Access Radioactivity iLab

Here is a 'How to' video showing how to access and run the radioactivity iLab. The equipment will run down in Queensland, Australia.

Accessing the Chem-Phys Moodle Page as a Guest - Especially for Parents

This shows how to get into the Chem-Phys Physics Moodle page as a guest. Students get full access to everything on the site, and guests can access most of it. This access may be of interest to parents, so you can see some of what we are doing in class.

Welcome to Physics!

This is Doc V's blog for his physics classes. While most class materials will be on the class Moodle pages, numerous "How to" and other instructional videos will be posted on this blog. This is but one more tool to help all of us on our quest to discover how the world works!