Tuesday, December 29, 2009
Saturday, December 26, 2009
There are 6 days left in an eBay auction for the "God Particle." This won't last long!
Here are the specs:
Mass: 114.4 GeV/c2 (just about none - or all)
CP violation: None (even)
Size available: Small (fits all)
Optional extras: Large Hadron Collider, W and Z bosons (available in packs of 2,800,000)
Delivery: In envelope with CERTIFICATE OF AUTHENTICITY. (For a small extra charge we can secure your Higgs boson in a small lump of Blu-Tac and jam it in a matchbox. Please declare if you'd prefer that option.)
(Thanks to John Baichtal, via Twitter!)
Friday, December 18, 2009
Messing with Mass activity, also required a scale. So instead, I tried a technique from The Joy of Chemistry. We made up two identical bags of materials (see below) and hung them from a wire coat hanger set up as a balance. Then we mixed the contents of one bag while leaving the other untouched. The balance did not tip, theoretically showing that the mass remained the same even as the materials underwent a change of state from solid and liquid to gas. However -- like our insensitive scale -- it could just have been that the balance we set up wasn't very accurate. But basically the lab illustrated, if not demonstrated, what conservation of mass looks like. Here's what we did:
- citric acid
- baking soda
- quart freezer bag
- film canister, filled with water
- wire coat hanger
- rod for hanging
- clips for hanging bag
- measuring spoons
- Examine the two chemicals involved. (Ours came in packets left over from a root beer making kit. Although the original instructions warns students not to taste, if they're from your kitchen they're perfectly safe.)
- Measure out 1 teaspoon of citric acid into each bag. (We found the original 1/4 teaspoon too little to see much reaction.)
- Add 1 teaspoon of baking soda to the bags.
- Fill the film canisters with water and close the lids. Dry off the outside if needed and place 1 canister in each bag. Seal the bags tightly, squeezing out as much air as possible.
- Set up the rod so that the hanger can be hung from it. (We laid it across two tables.)
- Use the clips to attach the bags to the hanger as shown.
- Place the hanger on the rod, positioning the bags so that they are balanced. Use tape to hold them in place. (We didn't, and the bags did slide around.)
- Keeping the bag sealed, carefully open the film canister in one of the bags and pour the water out. You might want to leave the lid loose to make it easier to open.
- The chemicals and the water will react and produce a gas (carbon dioxide). The two bags should stay in balance.
Mass is the amount of matter an object contains -- as opposed to weight, which is a measurement of the force of gravity acting on it. As we saw in the documentary, Antoine-Laurent Lavoisier was the first to demonstrate that mass is conserved in a chemical reaction. Lavoisier made careful measurements of changes including water to steam in the late 1700s, aided by his wife, Marie Anne. Mass is always conserved in a chemical reaction in a closed system (except for an extremely small amount which is lost or gained in the form of light and/or heat energy).
We know a chemical reaction has taken place in the bag where the water was opened because the matter changed state, and because there was a temperature change. As the baking soda and citric acid combined, energy was absorbed producing an endothermic reaction. That means the bag got colder.
Thursday, December 17, 2009
Make An Electromagnet
- insulated copper wire
- rubber band
- "D" battery
- 2 large nails
- small paper clips
- wire stripper (or scissors)
- Cut a piece of wire about 40 cm long.
- Use a wire stripper (or scissors, carefully) to remove about 1 cm of insulation from the ends of the wire.
- Using the center of the wire, coil the wire around one nail, leaving about the same amount of wire on either side.
- Wrap the rubber band around the ends of the battery to hold the the wire in place.
- Connect the wires to the battery to create an electromagnet. Try to pick up paper clips and the other nail. Only keep the battery connected to the wires for 30 seconds.
- Touch the head of the nail after the circuit has been connected for 30 seconds to feel how the electrical current is making the metal heat up.
Electrical to Heat Energy
- batteries (we used pre-made "battery packs" with 4 AAs held together with tape and rubber bands and connected + to - with wires)
- small lightbulb (we used one from an electrical set which came with wires)
- Connect the lightbulb to the batteries using the wires.
- Leave it lit for 15 seconds and feel the bulb heat up.
- Using the compass, see if you can detect the magnetic field generated by the electrical energy traveling through the wire.
Wednesday, December 16, 2009
These "stunts" aren't just great for parties, they're also perfect quick and easy science demonstrations for kids. They come from the Quirkology YouTube channel created by Prof. Richard Wiseman from the University of Hertfordshire (UK). For more quirky science visit Wiseman's blog -- but be aware the blog has some not-safe-for-the-classroom informality.
Thanks to a whole bunch of people on Twitter.
Monday, December 14, 2009
The Einstein's Big Idea teaching guide activities included a lab to demonstrate the conversion of mechanical energy to heat energy. It involved stirring cups of glycerin to raise the temperature a "few tenths of a degree." Since I doubted (a) that we had a thermometer which could measure such a small change accurately and (b) that anyone would be impressed by this, I went looking for a different lab we could do to demonstrate this phenomena. We did two labs, quoted below, from Arbor Scientific's CoolStuff newsletter. Both were simple, dramatic, and worked as described. They were part of a larger lesson on thermodynamics. I hope to do more of the lab another time!
Heating up a Hanger
The conversion of mechanical energy into heat may be dramatically demonstrated by simply bending a coat hanger. First cut a 30-cm length of coat hanger with wire cutters. Grab the ends of the wire in each hand and rapidly bend it back and forth several times. Now touch the point on the wire where the bending occurred. (Caution! The coat hanger can sometimes get surprisingly hot, so only touch the hot spot briefly.)
Place a rubber band loosely looped over the index fingers in contact with skin just above your upper lip. Now quickly stretch the rubber band. What do you experience? Now let the rubber band relax quickly. What do you feel now?
When the rubber band is stretched quickly, work is done on it, causing its internal energy to rise. This rise reveals itself as a small increase in temperature. When the rubber band is allowed to quickly contract, it performs work and suffers a reduction in internal energy which produces a cooling sensation.
Wednesday, December 9, 2009
The energy lab consists of seven activities, which they suggest you set up at different stations. We did these over the course of a few days. On day one, we did the electrical and magnetic field activities. Here is what the teacher's guide calls its "learning objectives:"
Students will be able to:
- explain what the E in E = mc2 represents.
- name different kinds of energy.
- show examples of how one kind of energy can be converted into another kind of energy.
- describe how a field can exert a force and cause an object to move.
• 10 cm x 10 cm piece of wool or fur (we used a woolen scarf, and the hair on our heads!)
• pieces of plastic foam cup, crumbled into bits
• pieces of paper, about 0.5 cm by 1 cm each
1. Rub a plastic spoon with a piece of wool, some fur, or your hair. Place the spoon next to a small piece of paper. Can you make the piece of paper stand on edge and move back and forth?
2. Try to pick up several pieces of paper at the same time by touching the spoon to one edge of each.
3. Recharge the spoon by rubbing it again. Try to drop a small bit of plastic foam into the spoon from different heights above it.
Explanation: Students are examining the effects of an electric field produced by rubbing a plastic spoon on fur. Once the spoon is charged (negatively), it will attract an uncharged object like a piece of paper through electrostatic induction. The large negative charge on the spoon repels the electrons in the piece of paper and leaves the side of the paper near the spoon slightly positive. (Positive charges-in the nucleus of each atom within the paper-hardly move at all.) Then, the negative spoon attracts the now positive side of the paper. If students are careful in their approach to the paper, they should be able to make it "dance."
Plastic foam becomes instantly negatively charged when in contact with another negatively charged object. The bits of plastic foam acquire a negative charge when they touch the spoon and are repelled immediately. It is impossible to catch a piece of plastic foam, no matter how close to the spoon it is held. If students claim they can, have them recharge their spoons. Watch the pieces of foam cup go veering away from the spoon in this video:
• small shallow cardboard box
• piece of white paper (cut to fit box)
• small container of iron filings (I found one in an old chemistry set.)
1. If the box is not white inside, fit a white piece of paper into the bottom of the box.
2. Center one or more of the magnets under the box.
3. Sprinkle iron filings into the box over the magnet. Lines of magnetic force should begin to become visible. (See photo at top.)
Explanation: Students should realize that the field from the magnet is exerting a force on the iron particles. The filings will align with the north and south field lines. Watch as the lines form in the video below:
Saturday, December 5, 2009
Continuing my investigation into the idea of teaching modern physics before classical, I've come across a website called Physics2000. Here's a description:
Physics2000 is a college level introductory physics course that begins with special relativity, ends with quantum mechanics, and in-between covers the usual topics with a 20th century focus. This approach eliminates the great divide between classical and modern physics.According to the website, the Physics2000 course can be ordered on CD, including the text (there are calculus and non-calculus versions) and videos, for $10. Several of the chapters are available to preview online. It looks worth checking out.
BEGIN WITH SPECIAL RELATIVITY?
Introducing Einstein’s special relativity in Chapter 1 means that you cannot rely on the usual mathematical techniques because no mathematics has been discussed yet. You have no choice but to focus on the physical ideas like the behavior of clocks and measurements of distance. The result is that you remove the mathematical fear factor usually associated with the subject. The only mathematics you need is the Pythagorean theorem.
NOTE: There is also an old, apparently unrelated website from the University of Colorado called Physics 2000. It contains online interactives on modern physics from a conceptual viewpoint.
Sunday, November 29, 2009
LONDON — Historic manuscripts by Sir Isaac Newton, Benjamin Franklin and other ground-breaking scientists will be published online for the first time, Britain's Royal Society said Monday. The society, the world's oldest scientific institution, will release famous literature on the web that it has published in its journals over the centuries as part of celebrations to mark its 350th anniversary. The works include a 1770 scientific study confirming that composer Wolfgang Amadeus Mozart was a genius and, more recently, acclaimed British scientist Stephen Hawking's early writings on black holes. Called Trailblazing, the interactive site contains 60 articles chosen from among the 60,000 that have appeared in the Royal Society's journals.
"The scientific papers on Trailblazing represent a ceaseless quest by scientists over the centuries, many of them Fellows of the Royal Society, to test and build on our knowledge of humankind and the universe," said Royal Society president Lord Martin Rees. "Individually they represent those thrilling moments when science allows us to understand better and to see further."
Newton's theory on light and colours in the 1600s, that continues to provide the basis for theoretical physics, will be published along with a gruesome account of a 17th-century blood transfusion. A paper by Benjamin Franklin, one of the founding fathers of the United States, will also be released on an experiment to fly his kite in a storm to prove that lightning is electricity rather than a supernatural force. The Royal Society will also be running events over the next 12 months to celebrate its anniversary "to inspire scientists, families, young people and interested members of the public alike to see further into science," Rees said.
Saturday, November 28, 2009
If you have been following me through our adventures with chemistry and biology, you know that I am an English major with a geeky bent who got high marks in high school science and then promptly forgot everything I “learned.” My goal is to do some interesting activities that might help my kids and I grasp some of the concepts of each science discipline with worrying about getting the “right result” or memorizing a lot of jargon. Right after I made up my traditional teaching plan, I read the essay mentioned in the post Quantum Mechanics in Middle School? And I realized that – as with biology, when we focused on microorganisms where much exciting research is being done today – what I really wanted to find out about was the new stuff being done in physics. In the few weeks that I’ve been working on putting this course together, I’ve heard several times that the theory of relativity is the basis of all modern physics. I imagine that it is the equivalent of evolutionary theory to biology – to study the subject without starting with that game-changing idea is to get a skewed picture of how the field is treated today.
All of which leads us to Einstein’s Big Idea, the PBS NOVA episode which we watched last week. I literally pulled it off the library shelf without really knowing what it was about. But as luck would have it, I think this has been an excellent entry point for our study of physics. Einstein’s Big Idea uses actors to recreate the lives of Einstein and his predecessors: Michael Faraday, Sir Humphry Davy, Antoine-Laurent Lavoisier, James Clerk Maxwell. There are also comments from living physicists and David Bodanis, author of the book E=mc2 on which the episode was based. Taking this personal approach, the show highlights something I never realized: how many women were involved in the development of modern physics. Along the names already mentioned, we meet Mme Lavoisier, who greatly helped her husband in his work; Emilie du Châtelet, math genius and companion of Voltaire; Lise Meitner, who split the atom and helped prove Einstein’s theory, but who had to leave Germany when the Nazis began persecuting Jewish scholars. And of course Mileva Maric, who gave up her own physics studies in college when she became Einstein's first wife and mother to his son. All of these women have been neglected in the popular history of science, and it was a revelation to discover their existence.
Beyond the personalities, Einstein’s Big Idea did a good job of explaining the concepts involved in a way that most teens and adults can understand, and showing how Einstein’s theory was built upon the work of others while forging a new path at the same time. I highly recommend this video to anyone who wants to begin to understand the basis of all physics today.
Wednesday, November 25, 2009
However, as sometimes happens, one of the activities looks too subtle to be worth the set-up involved. And in looking for another activity I could substitute to demonstrate the same concept, I found an archive of physics activities at the Arbor Scientific catalog website. I really like what the author, Chris Chiaverina, has to say about introducing science concepts using something called "Learning Cycles." It seems to describe exactly what the NOVA website activities are designed to do:
As many of you know, the Learning Cycle is an approach to science instruction developed by Atkin and Karplus in 1962 while working on the SCIS (Science Curriculum Improvement Study) project. This approach puts the phenomena first. Names and numbers are brought into the picture only after students are allowed direct contact with the phenomena. Although there are a number of variations on the theme, the essential learning cycle consists of three phases. These phases include exploration, concept development and application. The "Learning Cycle" method may be used to teach virtually any topic in physics.
Here is how Chiaverina sets up a Learning Cycle activity:
- An exploratory is a collection of introductory science activities that relate to a single topic or concept. Exploratories provide students with a common experiential base while igniting their interest.
- The activities are arranged as numbered stations around the room. Manipulatives at each station provide opportunities for exploration and discovery.
- The exploratory uses a guided inquiry approach. The guidance is provided through instructions and questions that accompany each station. The teacher remains in the background and assists only when asked.
- The activities may be done in any order.
- A non-judgmental approach is used. At this point, the teacher should be focusing on the quality of a student’s reasoning, not whether an answer is right or wrong. The teacher is given an opportunity to listen to students dialog with peers and formulate explanations. Student pre-conceptions are revealed during this phase of the learning cycle.
- Exploratories encourage student engagement. Intriguing manipulatives tend to get even the most disinterested students involved. Since discrepant events leave the students with a need to know, the class discussion that follows an exploratory is teacher led, but student-driven.
- Exploratories provide qualitative experiences. Quantitative laboratory work is done later.
- Placing instructions at each station eliminates duplicating costs. Laminating the instructions allows them to be reused.
Saturday, November 14, 2009
|The Colbert Report||Mon - Thurs 11:30pm / 10:30c|
Physicist Brian Cox, author of a new book about relativity, explains nuclear physics to comic Stephen Colbert.
Friday, November 13, 2009
Bringing relativity, quantum physics, and genetic engineering to middle school
Imagine a seventh-grade science teacher announcing to her class, “For the next week, we’re going to do something different. First, you’ll never, ever, be tested on the material we’ll be covering. Second, we’ll be talking about scientific ideas so awesomely cool that you’ll swear I’m making them up. Concepts such as Einstein’s theory of relativity, quantum physics, cosmology, genetic engineering, and nanotechnology. Amazing science that I promise will be more surprising and harder to believe than anything you’ve ever read in a Harry Potter novel.”
Do you think this would get the class’s attention? You bet it would.
Given the importance of science to our collective futures, it isn’t enough for us to teach sets of facts for given scientific topics. It’s our job to stoke young imaginations as well. To show how fascinating, surprising, and mind-blowingingly cool science can be. To show that along with the rote memorization of scientific knowledge, science is about the infinity of what we still don’t know. It’s about world-changing ideas; about experiments that show the universe to be, in the words of Arthur Eddington, “not only stranger than we imagine, but stranger than we can imagine.”
And this is something that we, as a society, are not doing as well as we should.
Wednesday, October 28, 2009
When we studied Chemistry a couple years ago, we started off with a trip to see local colleges put on demonstrations for "National Chemistry Week." There's nothing like that for physics, but luckily the University at Albany's Physics Department had several demonstrations as part of the school's Community Day. We saw Lego models of the Mars Rover and other robots, some cool (sorry!) liquid nitrogen tricks, a hologram of King Kong, and a mad scientist-type Jacob's Ladder. (I couldn't help but notice how much of the department's equipment looked like it belonged in Frankenstein's lab -- I guess the nanotech money hasn't spread to the physics dept.) Still, the professors and students were very friendly and willing to answer questions, and it was cool to see some stuff we probably won't be doing at home!
This is a Jacob's Ladder. Look closely between the upright bars and you will see a spark rising up.
The magnetic rings are repelled when the current is turned on, creating a like magnet charge on the center bar.
Also a little hard to see, this is a rotating hologram which shows an animated image of King Kong dangling from the top of the Empire State building.
Dipping an inflated balloon in liquid nitrogen makes it contract. As it re-warms, the air inside expands to fill the balloon again.
Sunday, October 25, 2009
I just came across a resource on the Microsoft website -- the Feynman lectures. Richard Feynman is of course one of my (and a lot of people's) heroes when it comes to making science seem interesting, even to the layperson. The Microsoft site is called Project Tuva. (Tuva is a region of Siberia which interested Feynman because of its rare stamps -- one of his many side interests.) It requires downloading a new player called Silverlight, which enables you to read related texts and makes notes. (Perhaps too much going on, but that's how it's set up.) Here's what Microsoft says:
The enhanced Video Player offers you the following functionality:
What is Project Tuva?
Microsoft Research’s Project Tuva explores core scientific concepts and theories through presenting timeless videos with its new enhanced Video Player featuring searchable video, linked transcripts, notes and interactive extras.
Featured Video Series
The Messenger Lectures include seven videos of Dr. Richard Feynman speaking on physics at Cornell University in 1964. His signature speaking style, humor, and clarity is enhanced by Project Tuva’s interactive annotations and full transcripts.
The following lectures are included in this material.
- Lecture 1: The Law of Gravitation – An Example of Physical Law (55:37)
- Lecture 2: The Relation of Mathematics and Physics (55:32)
- Lecture 3: The Great Conservation Principles (56:03)
- Lecture 4: Symmetry in Physical Law (57:06)
- Lecture 5: The Distinction of Past and Future (46:00)
- Lecture 6: Probability and Uncertainty – The Quantum Mechanical View of Nature (56:32)
- Lecture 7: Seeking New Laws (57:56)
- Fully Searchable Content – Search the transcripts from any of the seven videos.
- Interactive Transcripts - While watching the videos you can see transcripts from the lectures and skip to any section of the lecture by clicking on the text in the transcript.
- Integrated Timelines – You can click on any section of the video as it is playing and either skip to another section or select any of the extras integrated directly into the video presentations.
- Interactive Extras – In addition to the seven videos there are numerous links to other sites for more information about that specific topic.
- Insert Notes – Insert your own notes during any portion of the videos and use these notes for navigation on the integrated timelines.
Sunday, October 18, 2009
This lovely photo by my fellow GeekDad writer Nathan Barry shows what you can do when you understand physics, and forces, and all that stuff. As Wikipedia explains:
A cantilever bridge is a bridge built using cantilevers, structures that project horizontally into space, supported on only one end. For small footbridges, the cantilevers may be simple beams; however, large cantilever bridges designed to handle road or rail traffic use trusses built from structural steel, or box girders built from prestressed concrete. The steel truss cantilever bridge was a major engineering breakthrough when first put into practice, as it can span distances of over 1,500 feet (460 m), and can be more easily constructed at difficult crossings by virtue of using little or no falsework.Everything I know about bridges I learned from the Building Big book/TV series/website by David Macaulay. Here's how he explains cantilever bridges, using the Firth of Forth bridge as an example:
Thursday, October 8, 2009
Begun as a collaboration between the American Physical Society, the Optical Society and SPIE, LaserFest is a yearlong celebration of the 50th anniversary of the laser, which was invented in 1960. From DVD players to eye surgery, the laser is one of the greatest inventions of the 20th century—one that has revolutionized the way we live.
Sunday, October 4, 2009
The American Physical Society represents some 45,000 physicists, and most of our work centers on scientific meetings and publications-the primary ways that physicists communicate with each other. With PhysicsCentral, we communicate the excitement and importance of physics to everyone. We invite you to visit our site every week to find out how physics is part of your world. We'll answer your questions on how things work and keep you informed with daily updates on physics in the news. We'll describe the latest research and the people who are doing it and, if you want more, where to go on the web. So stick with us. It's a big, interesting world out there, and we look forward to showing you around.I plan on adding loads of other links and articles, as well as lab reports, so stayed tuned!