Home Physics

Now FInd "Home Science" Projects at Your Bookstore!

2012-01-16T11:02:00.001-08:00

It's been a while since I updated this blog. Among the things that has been keeping me busy is contributing ideas to GeekDad editor Ken Denmead's series of activity books for parents and kids. The latest in the series, The Geek Dad Book for Aspiring Mad Scientists: The Coolest Experiments and Projects for Science Fairs and Family Fun, contains a dozen projects first seen here and on my other "home science" blogs. (Check the sidebar if you've never seen them!)

What's even more exciting is that I'm now at work along with my three co-editors at GeekMom.com on our own book! It is due out in the Fall of 2012 from Potter Crafts, a division of Crown Publishing. And my own activity book for kids, Robotics: Discover the Science and Technology of the Future with 20 Projects, will be out this summer from Nomad Press.

There's a lot going on, but in the meantime, drop by GeekMom.com and GeekDad.com for more great family activities!

Plasma Experiments on "Integrated Science"

2011-05-23T12:12:00.000-07:00

More interesting experiments on our current blog Integrated Science at Home:

Integrated Science at Home

2011-01-13T21:22:00.000-08:00

If you haven't visited our current science blog, Integrated Science at Home, go take a look. We're working our way through a Teaching Company video lecture series called The Joy of Science, which explains the major science concepts using a chronological approach. The series is a handy way of making sure we cover some of the basic material we may have skimmed or skipped over in our more focused courses.

As we watch each episode, I've been jotting down ideas for labs we can do related to each topic. So far most of the topics have been related to Classical Physics. (You know, that stuff I thought would be too boring to go over last year.) I've really been enjoying the projects we've done. Tonight when it got dark we did a demonstration of Total Internal Reflection using a laser pointer and a soda bottle full of water. Check it out!

The Pop-up LHC: A Big Bang in a Book

2010-12-15T18:20:00.000-08:00

My review of the pop-up book version of the Large Hadron Collider at CERN is over at GeekDad. It's a little more complicated than most pop-up books -- but then, the topic IS nuclear physics!

Buy it at Amazon!

Teaching Physics in Remote Places

2010-11-30T08:56:00.000-08:00

This year we are doing "Integrated Science" using a video course by Prof. Robert Hazen called The Joy of Science. Hazen takes a chronological approach, so we are currently learning about classical physics. In the video Hazen describes simple experiments that can be done at home. We just tried one today, trying to find the declination of a compass needle towards the Earth's North Pole using paper clips, corks and a bowl of water. Our experiment had some problems, so afterwards we went online to look up other ways we could have designed it.

One resource that popped up is from The Institute of Physics is a scientific charity devoted to increasing the practice, understanding and application of physics to all audiences, from specialists to the general public. One of their resources is an online book of experiments called Teaching Physics in Remote Places. It seems perfect for doing physics in the home or classroom -- chances are your set-up isn't any more primitive than that used by the authors of this books!

Now Blogging at GeekMom with Mythbuster Kari Byron!

2010-10-02T21:52:00.000-07:00

I've been busy the past few months helping to launch GeekMom, a site dedicated to moms who want to share their geeky passions with their kids. To start us off, we've got MythBusters host Kari Byron writing about her new adventure as mom to a one-year-old girl. Kari is also the host of the new hour-long kids' show Head Rush. Check us out!

And I'll still be blogging at GeekDad, so be sure to stop by there too!

New Institute of Physics Website

2010-06-29T05:23:00.000-07:00

The UK-based Institute of Physics is a scientific charity devoted to increasing the practice, understanding and application of physics. It has a worldwide membership of over 36,000 and is a leading communicator of physics-related science to all audiences, from specialists through to government and the general public.

From the IoP blog:

After a year in development and following several usability studies, the Institute of Physics (IOP) is today re-launching its website http://www.iop.org/.With its increased user-friendliness, the website makes it easier to navigate around and quicker to find information. Content has been specifically tailored for teachers, students, media, IOP members and those with a general interest in the Institute and physics.

There are separate links for teachers, students, and the general public.

I also found a link to the website Practical Physics -- with over 700 experiments! Below is an explanation of how ion trails are formed from their page on cloud chambers:

Alpha particle tracks (from Practical Physics)
Nuclear 'bullets' from radioactive atoms make the tracks in a cloud chamber. They hurtle through the air, 'wet' with alcohol vapour, detaching an electron from atom after atom, leaving a trail of ions in their path. Tiny drops of alcohol can easily form on these ions to mark the trail.

The trail of ions is made up of some ‘air molecules’ that have lost an electron (leaving them with a positive charge) and some that have picked up the freed electrons, giving them a negative charge.

There is no sighting of the particle which caused the ionisation, because it has left the ‘scene’ before the condensation happens. If you count the number of droplets an alpha particle might produce 100,000 pairs of ions by pulling an electron from 100,000 atoms.

Nuclear 'bullets' forming a trail of ions which are condensation nuclei

When the alpha particle has lost all its energy in collisions with the ‘air molecules’ it stops moving and is absorbed.

Particle Cloud Chamber

2010-06-10T07:43:00.000-07:00

This week, we made a cloud chamber to see radioactive particles just using dry ice. It was surprisingly easy to do, and anyone can make it. The only hassle was getting a few of the materials, and we had a couple setbacks, but when we got it working it was definitely worth it.

The set-up

All you need is:

A sturdy clear container (glass or plastic) which won't crack at low temperatures. We used a small Pyrex glass dish with a plastic lid from Wal-Mart.
A sheet of black sticky-back felt.
A sheet of black construction paper.
Isopropyl alcohol. The kind we used was 91% isopropyl alcohol, which is available in most drugstores or supermarkets. Be sure to use this in a well-ventilated space, because the fumes are poisonous and flammable. Try to avoid getting it on your skin as much as possible.
A Styrofoam container, like a picnic cooler. You want a container with a lid that's loose, because pressure will build up inside.
Winter or heavy work gloves and/or tongs.
Dry ice. Except around Halloween, this might be hard to find. We had to go to a welding supply store an hour from our house. It came in a 10-pound chunk, but we only used half of it. We asked them to cut it in half, so we had a flat slab. (We played around with the rest.) Bring the cooler when you go buy it. Be VERY careful with it -- dry ice has a temperature of -109 degrees Fahrenheit! Use gloves or tongs when handling it.
A heat source. We used a wet washcloth, folded into a square and wrapped with plastic wrap, then heated in the microwave.
A bright flashlight, like an LED light.

You'll also nee a radioactive source. We got some uranium marbles from United Nuclear which worked pretty well. For $10 you get 3 marbles and a piece of uranium ore. Keep your uranium in a plastic bag away from food, children or pets. Wash your hands after handling.

A quick side-experiment we did was light up the marbles with a blacklight, which came out really cool:

Assembly

We put a few different variations of the cloud chamber together, but we only got one to work. Our working version is detailed below, but we also have some links that have some more versions of how to make the chamber at the bottom of the post.

What we did was cut out a circle of the sticky-back felt, and attach it to the inside of the lid. We then cut a strip of construction paper and put it around the outside of the container to block out light. We left a little “window” to look in and a smaller window in the back to shine the light through.

To use the cloud chamber, we first soaked the felt with the alcohol. We did this outside. The next part was to simply place the uranium marble into the container. To hold the slab of dry ice, we set it in the lid of the Styrofoam cooler (on top of a metal tray). We put the container on top of the dry ice slab, and then put the heated washcloth on top. Last, we placed the flashlight so it shined in the back window and waited for clouds of alcohol vapor to form. This took a few minutes.

When the vapor forms, you'll see what looks like slowly-falling rain inside. Particles being emitted by the marble formed lines in the fog. If you look closely at the two photos below (click on them to enlarge), you can see the particles shooting off from the marble. Look about half an inch below the marble in the second shot and you'll see a white line heading off toward the left. That's the ionization trail.

Afterwards we decided that the experiment would have worked better if we had used a glass petri dish with a clear top, because it was hard to see through the little window.

How it works

So how do dry ice and marbles create visible particles? When the chamber is cooling down, the air can't hold the warm alcohol vapor. When this happens, the alcohol starts forming into small clouds. At the same time, the radiation source, the marble in this case, is decaying and releasing charged particles throughout the container. These particles leave a trail of ions which shoot through the vapor clouds, and make visible trails in the fog.

According to Theodore Gray's website, www.periodictable.com, the emissions from the uranium marbles are alpha particles. Other sources of radiation may also give you beta and gamma particles. (Here's a student-made explanation of the different types of radioactive decay.)

You might have to experiment with different types of chambers to get a good result. We combined two different versions, both of which work well. You can see them on YouTube. The first, from Jefferson Lab, uses a petri dish and a needle impregnated with Lead-210 as a radiation source. The second video is from Scottish student Holly Batchelor, who won the Intel International Science and Engineering Fair's First Award for physics and astronomy. She built her cloud chamber out of a plastic aquarium, and used naturally-occuring cosmic rays as her radiation source. A more complicated version by Andy Foland has diagrams explaining what you might see.

Zombie Feynman

2010-05-20T21:27:00.000-07:00

Because I was too busy getting over the flu this week to do any physics:

Physics on Stage

2010-05-14T14:37:00.000-07:00

We just finished watching the PBS video of the play Copenhagen by Michael Frayn. It was a little tough going, but the kids got through it. From the PBS companion website:

Copenhagen is about Niels Bohr and Werner Heisenberg, two of the great scientific minds of the 20th Century, trying to make sense of a meeting they had in September 1941, while World War II raged around them. From the vantage point of the hereafter, the spirits of Bohr and Heisenberg, along with Bohr's wife Margrethe, are uncomfortable with the many unanswered questions from that fateful evening in 1941, most significantly: why did Heisenberg, a Nobel Prize winning physicist leading the German atomic bomb team, go to Copenhagen to meet with his old mentor Bohr, a half-Jewish Dane living in Nazi-occupied Denmark?

The website gives a little more background on the events and how Frayn shaped them into a play, as well as how the film version chose to visualize them. There's also a page of resources about Heisenberg's Uncertainty Principle, Quantum Mechanics, the Atomic Bomb and other scientific and literary aspects of the play. However, Frayn says on the website that a lot of the science was cut out of the play -- so maybe we should make the effort to read it as well.

A few months ago, at my suggestion, we read Tom Stoppard's play Arcadia with our bookclub. Arcadia is less obviously about physics, and it is also funny, so I think the kids probably enjoyed it a little more than Copenhagen. Although it's somewhat bawdy, Arcadia does touch on a lot of higher math and physics. If you understand something of those concepts, it adds to the comedy. I was lucky enough to see a live performance of Arcadia by the theater department of Skidmore College several years ago. The entire freshman class read the play, and it was taught in several different departments. (You can see some essays dealing with different aspects of the play on the Skidmore website.) However, it is rarely performed, and I can't find a video of the play for the kids. Hopefully they'll get to see it sometime.

There are other plays, stories and novels dealing with physics that we may get to at some point. But in the meantime, you can see some of my other suggested literary tie-ins by clicking on the link for my Amazon store in the sidebar on the right of the screen.

7 Wonders of the Quantum World

2010-05-10T15:14:00.000-07:00

Over at New Scientist, Michael Brooks tours the quantum effects that are guaranteed to boggle our minds.

From undead cats to particles popping up out of nowhere, from watched pots not boiling – sometimes – to ghostly influences at a distance, quantum physics delights in demolishing our intuitions about how the world works.

PBS Nova's The Ghost Particle and The Particle Adventure

2010-04-22T07:21:00.000-07:00

I picked this DVD of The Ghost Particle off the library shelf because it deals with neutrinos, neutrally-charged particles which were originally believed to be massless energy, but which are now believed to be the basis for all mass in our universe. Although a little dated (it's from 2004) it was short and interesting. There is a PBS Nova companion website, but I don't think it adds much to the video itself. The classroom activities involve guessing what's in a box -- good perhaps on a conceptual level, but not really "physics."

So we are working on putting together a lab in which we build a small cloud chamber to detect radiation from cosmic rays and/or slightly radioactive material (such as thorium mantles from Coleman lanterns). However, we still need a good background on subatomic particles. For that, I think I will have the kids look over a website called The Particle Adventure.

It gives information in little bite-sized portions, along with trivia questions such as:

For how many years have physicists known that there were more than just protons, neutrons, electrons, and photons? Answer: 60 years! In the 1930's physicists found muons, but hundreds more were found with high energy accelerators in the 1960's and 1970's.

(Follow-up question: How many components of matter other than protons, neutrons, and electrons did you learn about in high school physics? My answer: None!)

Tape Emissions

2010-04-12T19:11:00.000-07:00

In 2008, scientists found that they could generate enough X-ray radiation to take an image of a researchers finger simply by unrolling a roll of adhesive tape. As the video above shows, the trick is to unroll the tape in a vacuum. According to Scientific American:

The reason, says Camara: electrons (negatively charged atomic particles) leap from a surface (peeling off of glass or aluminum works, too) to the adhesive side of a freshly yanked strip of tape, traveling so fast that they give off radiation, or energy, when they slam into it.

In a regular atmosphere, the electrons still give off radiation, but because the air molecules slow them down, they appear in the visible spectrum.

We tested this in a dark room (so dark that you can't see) using both adhesive tape and duct tape. Peeling the tape off quickly gave off a bright blue flash, but peeling it slowly produced a steady blue line where the tape was unrolling from the roll. With adhesive tape, at least, we could create the effect again and again with the same piece of tape. It's called called triboluminescence-- the same process that creates sparks when you bite into Wintergreen Life Savers.

Our little camera wasn't sensitive enough to pick up the blue flash, but here's a YouTube video made by someone with better equipment:

LaserFest Video Contest -- Win $1,000!

2010-04-02T17:50:00.000-07:00

The American Physical Society is holding a contest for short videos that use lasers to demonstrate physics. I think we'll have to enter this one! From their website, physicscentral.com:

Do you love lasers? Ever wanted to unravel the mystery of the stimulated emission? Then the LaserFest video contest is for you. Take any laser you want and use it to somehow express a physics concept. Shine, lase, bounce and wave your way into physics history.

The winner will receive a trophy lovingly made by APS staff from some of our favorite laser toys as well as $1,000 cash. All entries must be received by May 16th at midnight.

Today is First Physics Day

2010-03-30T06:39:00.000-07:00

The CERN Large Hadron Collider had its first stable event about an hour ago. Watch the live webcast!

The New York Times says:

Rolf Heuer, director general of CERN, speaking from Japan, said the new collider “opens a new window of discovery and it brings, with patience, new knowledge of the universe and the microcosm. It shows what one can do in bringing forward knowledge.” He added: “It will also bring out an army of children and young people who will get into the private sector and academia.”

Yesterday I posted on GeekDad about our visit with Chad Orzel, author of How to Teach Physics to Your Dog, at his lab at Union College. One commenter felt that there is no reason for non-scientists to spend time trying to understand this stuff. But the reason is that physicists need the public to fund their research and understand the significance of their discoveries. It was lack of public interest that led to the end of the US's attempt to build the time of facility that now exists in Europe. According to the Times:

The first modern accelerator was the cyclotron, built by Ernest Lawrence at the University of California, Berkeley, in 1932. It was a foot in diameter and boosted protons to energies of 1.25 million electron volts, the unit of choice for mass and energy in physics. By comparison, an electron, the lightest well-known particle, is about half a million electron volts, and a proton about a billion.

Over the last century, universities and then nations leapfrogged each other, building bigger machines to peer deeper into the origins of the universe. But the end was decreed in 1993, the U.S. Congress canceled the Superconducting Supercollider, a 54-mile 20-trillion-electron-volt machine being built underneath Waxahachie, Texas, after its projected cost ballooned to $11 billion.

The Famous Double-Slit Experiment and the DIY Quantum Eraser

2010-03-25T19:38:00.000-07:00

In How to Teach Physics to Your Dog, author and Union College Physics Professor Chad Orzel talks about an extension of the Double-Slit Experiment called the Quantum Eraser. According to Orzel -- and before him to physicist and wise guy Richard Feynman -- everything the average person needs to know about Quantum Physics is contained in the Double-Slit Experiment.

When Thomas Young first did the Double-Slit Experiment in 1803, he proved that light travels in a wave. He showed this by aiming a narrow beam of light at a barrier with one or two slits and placing a screen behind it. When the light went through one slit, it hit the screen in a single blob. But when it went through two slits, the light on the screen spread out into many stripes of dark and light -- which is what you would see if two waves were overlapping to create an interference pattern.

When Quantum Physics was introduced, the experiment was done with a stream of photons passing through the slits one photon at a time. Amazingly, over time the individual photons also created an interference pattern on a screen on the other side -- meaning that each single photon was interfering with itself as it passes through both slits at the same time!

The Quantum Eraser experiment just makes this weird result even weirder. First polarizing lenses with different orientations are put in place so that you can tell whether the light went left or right through the slits. "Labeling" the photons in this way makes the light go back to acting like particles -- the interference pattern is erased. And if you add still another polarizing filter, so that you can't tell which way the particles went, the pattern reappears!

When I read in Orzel's book that the May 2007 issue of Scientific American had a Quantum Eraser experiment you could do at home, I knew I had to try it! After a bit of searching, I was able to find the article online. (Actually, what I found is everything but the article, but the sidebars and other content include everything you need to do the experiment.) Like a lot of demonstrations that we try, it was a little hard to tell what, if anything, was happening, and I'm not sure it was completely successful. However, the results we did get were good enough to be worth sharing here. The article includes some trouble-shooting tips that may produce better outcomes if we ever try it again.

The experiment consists of four parts:

Create a double-slit set-up using a cheap laser pointer as a light source.
Add a right/left polarizing filter.
Hold up a polarizing filter on a diagonal, which allows some "left" and some "right" particles to pass through.
Make a polarizing lens which filters light on one diagonal on the top and the other on the bottom and add that to the set-up.

Obviously, since we were using a cheap laser pointer and weren't sending light through one photon at a time, this experiment doesn't prove that a single particle will go both ways at once, but it does give you a good approximation of what happens on a quantum level. Below is a description of what we did:

Materials:

laser pointer pen (from the supermarket)
polarized film (we used the lenses from cardboard 3D movie glasses)
thick rubber band
white foam-core board (for projection screen)
Styrofoam cups
unused twist ties
tape

First we made a stand for the laser pointer pen by pushing it through an upside-down Styrofoam cup.
Instead of a barrier with a slit, this version uses a vertical piece of wire to divide the light into "right" and "left." We cut the paper off of a twist tie and removed the wire without bending it. Then we made a stand for the wire by cutting around the top of a foam cup to make it shorter than the laser stand. We turned the cup upside down and poked the wire through the bottom so that it was standing straight up.
We wrapped a rubber band around the laser's ON button so that it would stay on.
The laser was put in its holder and placed on the seat of a chair. The foamcore projection screen was set up by leaning it against a chair about 6 feet away. We could see a small dot of laser light on the screen. (See directly above.)
Then the wire in its holder was set up a few inches away from the laser. We moved it until it was in the path of the laser light. An interference pattern appeared! (Photo at top of post.)
To make the labeler, we took the polarized glasses, and marked the lenses "right" and "left." Then we cut them out, leaving the cardboard frame around everywhere but the inside edge (towards the nose piece). The two lenses were taped together so that the inside edges were just touching (no overlap or gap). Another twist-tie wire was taped along the join and trimmed.
A holder was made by cutting off the top of another foam cup, then slicing a slot across the bottom. The labeler was set into the slot so that the wire was vertical in the center.
The labeler was put in place of the plain wire. The light hitting the screen returned to blob form.
Taking another pair of polarized lenses, we held up the "left" and "right" lens at a 45 degree angle between the labeler and the screen. At this point the light projected on the screen was hard to make out, but it did seem to spread out again like an interference pattern.
Finally, we took a left and right lens, cut them on a diagonal, and taped them together so that one was on top and one on the bottom. According to the SciAm directions, we should have seen an interference pattern split so that the top was off to one side and the bottom to the other, like misaligned teeth. All we could see was misaligned blobs, though. (See below.)

As I said, if we try this again we will try moving some of the parts around to get better results. Just for the record, the glasses we used had lenses which were tilted at 45 degree angles, rather than the traditional horizontal and vertical. However, they were still perpendicular to each other, and we rotated each the proper amount from its starting point, so I don't think it mattered.

In my opinion, we achieved some interesting effects, for a living-room physics lab.

What Every Dog Should Know About Quantum Physics

2010-03-22T18:26:00.000-07:00

Union College Physics Professor Chad Orzel was kind enough to give a talk based on his new book, How to Teach Physics to Your Dog to a group of local homeschoolers I organized. Even better, he posted the video and slides he showed us in the talk on his blog! The presentation included a look at helium and neon lights using diffraction grating and a demonstration of the double-slit experiment using a laser beam. I'm adding the books he recommended -- some for a popular audience, some aimed at freshman physics students -- to my Amazon store as well.

After the talk, Dr. Orzel brought in his famous dog and co-author Emmy for a photo op. Then we got a tour of his laser cooling lab, the school's own basement particle accelerator, and the astronomy department's observatory. One interesting fact about Union is that, because there are no graduate students to compete with, undergraduates get to use the fancy equipment right from the start.

The talk was entertaining and informative. As you can see, the kids were as interested as the parents. Thanks to Dr. Orzel for such a great program!

UPDATE: Listen to an interview with Chad Orzel from WAMC Northeast Public Radio.

The Many Worlds of Hugh Everett

2010-03-12T05:44:00.000-08:00

We recently watched the PBS NOVA show Parallel Worlds, Parallel Lives about the late physicist Hugh Everett. In 1957, Everett came up with a scenario that would eliminate the Schrödinger's cat -- which said that light didn't take shape as wave or particle until someone was observing it. He called his theory "many worlds," and it proposed the idea that where two states are possible, each splits off into its own universe. Science fiction, especially Star Trek, later adopted the idea for stories involving parallel universes. But at the time, Everett's theory was dismissed by the big guns of physics, like Niels Bohr. Rejected, Everett left academia and went to work for private firms, never developing his theory any further.

Parallel Worlds, Parallel Lives explores the physics of Hugh Everett through his son Mark Oliver Everett. Mark Everett, also known as "E," is a member of the indie rock band EELS and author of Things the Grandchildren Should Know. Mark grew up with his father but had very little contact with him. As an adult, he decides to investigate his father's life and work, meeting with physicists who are trying to further his theories, and visiting with his old colleagues and friends at Princeton and elsewhere. He also uncovers boxes of papers taken from his father's home after the death of his sister and mother and turns them over to his father's biographer. As he says in the documentary, he has become the ambassador from the Everett family to the world.

I really love the NOVA videos we have watched so far this school year, because they both bring in a human perspective and make the most of today's video effects to illustrate difficult physics concepts. This one is no exception, and it has the added plus of being told from the point of view of someone who, like us, has no scientific background. The video is only an hour long and well worth borrowing from your library or adding to your physics teaching materials. There is, as always, clips and lots of supplementary material at the PBS website. My only complaint is that the classroom "activity" doesn't include an actual double-slit experiment, but used a computer simulation instead.

Measuring Microwaves with Chocolate

2010-02-16T06:26:00.000-08:00

I wrote up our latest lab as a post for GeekDad, and it ended up going popular on Digg! (For those who care.) To see how we measured the speed of microwaves with a chocolate bar, follow the link.

However, we did several trials, so here are some photos from our earlier attempts. And yes, the scale did go up in the last few days...

We only got only hot spot with this one ... and the paper plate started to burn (note lower right corner).

We tried multiple bars to get broader coverage. This worked a little better.

A dish full of chips provided the best coverage of all, but was too hard to pinpoint the hot spots. After several minutes of microwaving, we got one fused, hard point of chocolate (indicated by spoon) but not a second spot to measure.

The results:

Best holder: glass baking dish

Best stand (to cover the rotating thing in the microwave): small plate

Best chocolate: Valentine's Day cherry cordials

This experiment has also been done with marshmallows and by kids on YouTube.

Big Blog Theory

2010-02-12T06:48:00.000-08:00

If you are a fan of The Big Bang Theory -- and I don't watch near as often as I should -- then you will enjoy the blog of UCLA particle physicist David Saltzberg, who is the show's consultant. The Big Blog Theory explains the science behind the episodes.

The show can be seen on CBS Monday nights at 9:30 EST.

Hat tip to a post by fellow GeekDad writer John Booth.And for other interesting physics blogs, check the list way down in the sidebar.

Wave Lab Part 2

2010-02-09T14:31:00.000-08:00

After watching some cool videos on YouTube, I decided it would be fun to make patterns with sound waves. These patterns are caused by the same kind of waves, and wave interference, that we saw with our pseudo-ripple tank experiment. Again, our setup was crude: we took a recycled container and set it over a tiny set of speakers and an mp3 player loaded with video game soundtracks. Then we sprinkled some salt on a plate and put it on top. We also tried sprinkling salt directly on the metal top, and then tried it with some water.

We didn't always get fancy patterns, but we did see some nice movement. Watch!

In the videos on YouTube done with real lab equipment, you can see cool Chladni patterns.

Here's an explanation from Teacher's Domain:

When an object vibrates at one of its natural frequencies (a rate of vibration at which it naturally tends to move), standing wave patterns are formed within the object. These patterns are the result of wave interference, which occurs at the meeting of two waves traveling within the same medium in different directions. The resulting disturbance within the material at the point where the waves meet is the net effect of the two waves. At certain points in the material, the waves cancel each other out through destructive interference and there is no net disturbance. These points are called nodes, or nodal points. Around the nodes, the waves constructively interfere; the points with the greatest disturbance are called antinodes, or anti-nodal points.

And here's an explanation of their origin and use from Robert Krampf:

These patterns are called Chladni patterns, named after Ernest Florens Friedrich Chladni of Saxony, who has been called the father of acoustics. He sprinkled sand onto metal plates and studied the way that they vibrated.

Besides being fun to play with, these patterns are useful. These patterns are used in designing musical instruments. If a part is attached to a place where the instrument vibrates, the sound will be dampened. By attaching parts at nodes, the instrument makes a full, rich sound. These patterns make the difference between an average instrument and a quality one.

Here are the rest of our videos:

Book Review: How to Teach Physics to Your Dog and The Macroscope

2010-02-06T09:00:00.000-08:00

(I wrote this article for the Albany, NY Times Union newspaper. It originally appeared, in edited form, on January 24, 2010.)

When you think about it, “modern physics” isn’t really all that modern anymore. Einstein began drafting his theory of relativity in 1905, and quantum mechanics – which describes how things work at the sub-atomic level – was described by Max Planck in 1900. Today quantum mechanics is at the core of everything from bar code scanners to computer chips. It’s the most accurately tested theory in the history of science.
And yet very few people are aware of even its most basic concepts. Ideas like particle-wave duality (the fact that light and matter has both wave and particle nature) are rarely covered in college physics classes, let alone high school. So when Internet rumors claim that the CERN Large Hadron Collider, which smashes atoms together to see what pops out, is about to suck the Earth into a black hole, or when the latest DaVinci Code book features a physicist who uses “thought particles” to transform matter, most people don’t know what to believe.

That’s a gap two new books by local educators are hoping to bridge. In “How to Teach Physics to Your Dog,” (Scribner, 2009) author Chad Orzel explains quantum mechanics to Emmy, his German Shepard mix, in language so down-to-Earth and entertaining that even humans can understand. Why a dog? As Orzel, an associate professor in the department of physics and astronomy at Union College in Schenectady, explained recently, dogs have no preconceptions about where things come from. That makes it much easier for them to accept the idea of virtual particles and parallel universes.

“As bizarre as it seems to a human, as far as a dog is concerned dog treats appear out of the air,” Orzel said. “She will sit there staring, hackling at evil squirrels from another dimension.”

For readers, following Orzel as he discusses the probability of bunnies made of cheese suddenly appearing in the backyard, or whether dogs can use their wave nature to pass around both sides of a tree at the same time, makes modern physics easier to understand.

“As scientists,” Orzel said, “we speak about it in math. I wanted to find ways to get around that, to show how fascinatingly weird the world is without forcing them to go through three years of physics.”

At the same time, Orzel added, “There is some heavy stuff in the book -- decoherence, ‘many worlds’ theories – that you don’t often encounter in popular treatments of the subject. The nice thing about writing with the dog is that whenever things get a bit thick, I can have her break in.” At those times Emmy pipes up to remind Orzel, “I don’t want to describe the universe, I want to catch squirrels.”
The goal for Orzel is to help readers understand that although the universe is a really strange place, it still has rules, and physicists have been sucessful so far in understanding them.

“You can’t will yourself into another universe where you’re wealthy,” he said. “I hope the dog is cute enough to carry people past some of the need for it to be magic.”

While Orzel’s book was written for adults whose schooldays are behind them, “The Macroscope,” the first in the Adventures in Atomville series, aims to inspire kids who have yet to set foot in a physics classroom. It’s a fantasy story in which all the characters are atoms which behave in ways that reflect the properties of their particular elements. They eat (and emit) photons, and swat away pesky electron gnats. But the physics is hinted at, not explained outright. (A website explaining the science behind Atomville is under development.) Co-authors Jill Linz, a senior physics teaching associate at Skidmore College in Saratoga Springs, and Cindy Schwarz, a professor of physics at Vassar College in Poughkeepsie, both said that the plan was to pique kids’ interest, not lecture to them.

“We don’t necessarily want these kids to walk away knowing what’s going on with subatomic particles,” explained Schwarz. “We want them to keep the words in the back of their heads and feel more comfortable when they hear them again.”

Linz first developed Atomville as a way to reach non-science majors, and later went on to produce physics videos for elementary schools. Schwarz uses creative writing and music in her physics classes for non-majors, and has published a book of her students’ physics poems and stories called Tales from the Subatomic Zoo.
Linz and Schwarz are hoping schools will invite them in to talk about their book and about physics. Last spring Schwarz showed students in Poughkeepsie how atoms emit photons and letting them look through diffraction glasses to see the spectrum created by an element. She was happy to find that, months later, they still remembered the concepts they learned.

“They really got something out of this,” she said.

Wave Lab Part 1

2010-02-05T18:58:00.000-08:00

Having read the wonderful book How to Teach Physics to Your Dog by Union College professor Chad Orzel (post to come), which talks about the conundrums posed by lighting behaving as both wave and particle, I decided to do a series of labs dealing with waves and leading up to some demonstrations of wave/particle duality.

We started out looking at the interference pattern created by splitting a laser beam (again, post and photos to come). But then I decided it would be helpful to go back and look at plain wave behavior. So I backtracked and did two simple demonstrations of waves -- one with water, one with sound.

For the water demonstration I made a very crude approximation of a "ripple tank." I took a shallow, dark colored plastic storage box, filled it with water, and created wave patterns with two spoons. We soon found that shining a light directly on the box made it easier to see the waves via the shadows they made. Although one source suggested tapping the water with the back of the spoons, we also found that we got better results by scooping up a little water and pouring back into the tank.

We observed how one wave moved away from the source (the drip) and then bounced back off the walls of the tank. Two simultaneous waves intersected and created a pattern with stronger crests and troughs (highs and lows) where they either added together or canceled each other out.

Here's a video of a real ripple tank courtesy of the Carleton University's YouTube Channel:

Stay tuned for Wave Lab Part 2: Sound Waves, coming soon!

Cycling Physics -- Watch a physics teacher in action

2010-02-03T07:52:00.000-08:00

I've got a post up on GeekDad today about Florida physics teacher Luther Davis, who will be riding his bike in his classroom for 7 hours tomorrow. While he's pedaling, he’ll have his students stream his bike ride/physics lesson live from the classroom and take questions via online chat.

Update! Update! Update!

Davis achieved his goal, pedaling 143.1 miles in 7 hours (while teaching), and raised more than $1,600 for the American Diabetes Association. Great Job Luther!

We got to watch Davis talking about angular and linear momentum, and even asked some questions via the chatroom. It was pretty cool! His website Cycling Physics now shows graphs of speed, heart rate, and cadence (pedal rotations per minute) for his ride. Video segments will be available soon.

We wish Davis luck when he undertakes the ADA Tour de Cure in Orlando on February 28, 2010.

We also challenged Davis to join us here in Upstate New York this summer for the Saratoga 12/24 and Adirondack 540 bike races (presented by Adirondack Ultra Cycling, aka my husband, John Ceceri)!

Kitchen Nanoscience

2010-01-24T14:00:00.000-08:00

Nano is the scientific term meaning one-billionth (1/1,000,000,000). It comes from a Greek word meaning “dwarf.” A nanometer (nm) is one one-billionth of a meter. One inch equals 25.4 million nm. A sheet of paper is about 100,000 nm thick. A human hair measures roughly 50,000 to 100,000 nm across. Your fingernails grow one nanometer every second.

Nanoscale refers to things that are between 1 – 100 nanometers in size. A virus is about 70 nm long. A cell membrane is about 9 nm thick. Ten hydrogen atoms are about 1 nm. At the nanoscale, many common materials exhibit unusual properties, such as remarkably lower resistance to electricity, or faster chemical reactions. Nanoscience, nanotechnology and nanoengineering take advantage of these properties by working with individual molecules of material.

Not surprisingly, most Americans have a very poor grasp of nanoscience. In fact, according to NISE Net, the Nanoscale Informal Science Education Network, many adults:
• Aren't sure whether atoms are composed of molecules or molecules are composed of atoms (they also confuse them with cells);
• Think everything microscopic is at the same scale
• Don't understand that matter is made up of particles, or believe there must be something in the space between particles;
•Believe that materials at the atomic or molecular level are simply shrunken versions of their real-world manifestations, with the same properties.

One of the ways NISE Net is working to change these misperceptions is by hosting events like NanoDays, which takes place in March. During NanoDays museums and schools around the country will hold demonstrations to explain nanoscience to kids and adults. Many of their past activities and educational materials are available at their website. Quite a few of these demonstrations are simple enough to do at home.

We did one very basic demonstration called Exploring Forces, which shows how the properties of materials differ according to scale using water and teeny-tiny containers. Although they weren't nanoscale, they did show -- as we saw in some of the documentaries we've been watching -- how the importance of forces like gravity change as quantities get smaller.

The experiment calls for doll-house teacups, but we used a Lego cup and goblet (natch!). After dipping the full-sized measuring cup into a bowl of water and pouring it out, we tried it with the Lego versions and found that it was harder to get the water to pour out. That's because the forces between the water molecules were stronger than gravity (this creates what is known as surface tension).

We also tried playing around with a variety of different sized measuring cups and spoons (including some very small "novelty" spoons, but only the very smallest (one "smidgen") exhibited surface tension, and only if you were very careful turning it over. However, I thought this was a fun and quick experiment to try.

Velocity Lab, Or Why We Don't Do "Real" Labs

2010-01-12T19:50:00.000-08:00

One of the most interesting things I noticed in the PBS series Einstein's Big Idea was how the early investigators looking into physical phenomena were able to make such precise measurements using such primitive equipment and facilities. If the re-enactments are to be believed, scientists like Antoine-Laurent Lavoisier and Emilie du Châtelet were basically conducting their research in a spare room at home. It must have taken a tremendous amount of patience to gather the data that proved, for example, the principle of conservation of matter or that the energy contained in a falling object was proportional to the square of its velocity.

In this experiment, we recreated Mme. Châtelet's demonstration by dropping marbles into cups of flour from various heights and measuring how far down into the flour they sank. Although I don't usually bother recording data -- no one is particularly interested in keeping track of what we're doing besides me -- in this case I thought we'd do it "the real way," like the classroom instructions call for. But right away we had to make changes. First, we could only find yard sticks, not meter sticks. So we cobbled together a meter stick by taping a tongue depressor onto our yard stick and marking off the extra centimeters.

(Note marble in mid-flight)

Next, the lab called for regular glass marbles, but we found that our results were rather random -- the marbles fell different depths without regard to what height they were dropped from. And sometimes they barely broke the surface of the flour. So we used some steel marbles we found, which tunneled into the flour an amount that could be measured.

Finally, the regular drink-sized paper cups called for in the lab were too shallow, and the (metal) marbles hit bottom and bounced back up. So I dug out some super-sized plastic cups that were about twice as tall as the original cups.

But in the end, our data was gibberish. We were simply too careless, and we didn't do enough trials to get a reliable answer. The whole experience reminded me of my traumatic days in high school science, where the top students (the ones who went onto med school, as it happens) routinely made up data to fit the expected results, so they'd get a good grade in the class.

(Stick marked in cm for measuring depth of marble)

In the three years since I began really focusing on science, I've been very proud of myself for getting nearly all the "labs" we do to work -- by which I mean they provide an impressive demonstration of the principle I'm hoping to illustrate. But I just think it's too much to ask for these demonstrations to provide useful data as well. We're not scientists, but we like watching cool things happen. I'm sorry to admit it, but it's true.

So if you're using this blog to find ideas for your own home or classroom science activities, take our example with a grain of salt. We're dilitantes with a capital "d," and we cannot be held responsible if your results vary.

Why Does Time Move Forward?

2010-01-07T08:17:00.000-08:00

Just read a Tweet(!) recommending Sean Carroll's new book From Eternity to Here. Carroll is a theoretical physicist at the California Institute of Technology who has done lectures for The Teaching Company called Dark Matter and Dark Energy: The Dark Side of the Universe. He also blogs at Cosmic Variance. Here's a video of Carroll talking about his book. If I get a chance to read it, I'll do a review.

In Other News, It's Newton's Birthday!

2010-01-04T12:18:00.000-08:00

We'll be covering him in more depth soon, but in the meantime here's another physics-related GeekDad post for today. Thanks to The Brothers Brick.

Science and Math Collide to Find the Shape of Space

2010-01-04T08:23:00.000-08:00

I've got a post up on GeekDad about computer games kids (and adults) can play to practice moving around in weird multi-dimensional spaces. Freelance geometer (geomatrician?) Jeff Weeks designed a 2-week-long middle-school curriculum called Exploring the Shape of Space. Several years ago I used it to put on a 1-day workshop for a group of elementary-school-age homeschoolers. I talked about the material (we had seen Weeks himself give a lecture at a local college), showed the video that came with the kit, and set up the different activities (making Moebius strips, playing tic-tac-toe on cylindrical boards, etc.) at stations around the meeting room so the kids could go around and try them all. Afterwards we gathered to talk about what they had found. It worked really well. The kit is still available from Amazon or the publisher, Key Press. Weeks has also written a high school level book on the subject.

What is the Large Hadron Collider good for?

2009-12-29T21:11:00.000-08:00

An essay in the New York Times by physicist and reporter Dennis Overbye. (Large Hadron Collider image: NYT)

Act Now to Own Your Own Higgs Boson

2009-12-26T17:36:00.000-08:00

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)
Spin: 0
Field: Non-zero
Antiparticle: Self
CP violation: None (even)
Colour: Possibly
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!)

Mass Lab: Conservation and Chemical Reactions

2009-12-18T17:51:00.000-08:00

Not all the labs we did using the teacher resources from Einstein's Big Idea worked the way we hoped. One problem was my kitchen scale -- although it had lots of little numbers, it really wasn't sensitive enough to measure anything within the accuracy of its scale. (I'll post about the outcome of those labs another time.)

This lab, which comes from the 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.

Explanation:

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.

Energy Labs: Battery-Powered Experiments

2009-12-17T14:50:00.000-08:00

Continuing on with the description of the labs we did in conjunction with the PBS NOVA video Einstein's Big Idea, here are our adaptations of the directions for two activities using batteries:

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.

Explanation: The point of this station is that the magnetic field can do work. It can lift objects as the energy of the field is transferred to the paper clips. Since the strength of the nail's magnetic field is proportional to the number of coils of wire around the nail, we also experimented with different lengths of wire and numbers of coils.

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)
compass

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.

Explanation: The light bulb demonstrates how electrical energy can be converted to light and heat energy. Most of the light bulb's energy is given off as heat. The electrical energy is also the result of a transformation, from chemical energy (in the battery). As we saw in the documentary, Michael Faraday, a self-taught scientist in 19th century England, was the first to propose that the compass was being affected by invisible lines of force flowing around the wire.

Richard Wiseman's Top 10 Quirky Science Tricks for Christmas Parties

2009-12-16T10:55:00.000-08:00

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.

Energy Labs: Mechanical and Heat Energy Lab

2009-12-14T23:17:00.000-08:00

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.)

Stretching Exercise

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.

Energy Labs: Electrical Fields and Magnetic Fields

2009-12-09T23:38:00.000-08:00

As mentioned previously, the companion website to the PBS show Einstein's Big Idea includes activities related to the three parts of Einstein's equation E=mc2: energy, mass and velocity. We worked our way through them, substituting and adjusting where necessary. Not all of them were as successful or illuminating as we hoped, but they were quick and easy to do and got us started on physics labs. The instructions below include the adaptations we made to the instructions from the PBS teachers' material.

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.

Electrical Field Lab

• one plastic spoon for each person
• 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:

Magnetic Field

• several types of magnets, including bar or horseshoe
• 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:

Physics2000 - Relativity First!

2009-12-05T18:01:00.001-08:00

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.

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.

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.

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.

Trailblazing Website Puts Scientific Discoveries Online

2009-11-29T16:56:00.000-08:00

Britain's Royal Society puts rare scientific manuscripts online (AFP)

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.

Einstein's Big Idea

2009-11-28T12:00:00.000-08:00

If it seems crazy to start our study of physics with relativity, then let me say that I had in fact, originally drawn up a nice teaching plan which followed a more traditional physics sequence -- motion and mechanics through December, heat and thermodynamics in January, electricity and magnetism in February -- and lightly touched on everything after classical physics in May or June. (The list of topics I made up came directly from the Physics4Kids website.) But as I began to look at the material to be covered and the possible activities we could do (some of which the kids did many years ago when a friend taught a co-op class using the book Teaching Physics with Toys), I thought about how much of this stuff I had retained from my own formal science classes in high school. The answer was, not much.

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.

Physics Learning Cycles

2009-11-25T20:20:00.000-08:00

Last week the kids and I watched a great PBS NOVA episode called Einstein's Big Idea, about the discoveries which led up to E=mc2. I'll be giving my review in another post, but I wanted to mention the wonderful companion website with activities you can do at home. We'll be doing the energy activities later this week.

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:

Introducing Newton's Laws with Learning Cycles

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.

The Arbor Scientific physics articles archive is in the sidebar. If it is as good as it looks, we'll be doing some of these activities as well.

Why Does E=mc2 and Why Should We Care?

2009-11-14T08:06:00.001-08:00

The Colbert Report

Mon - Thurs 11:30pm / 10:30c

Brian Cox

www.colbertnation.com

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Physicist Brian Cox, author of a new book about relativity, explains nuclear physics to comic Stephen Colbert.

Quantam Mechanics in Middle School?

2009-11-13T18:28:00.001-08:00

I was searching for middle school level physics teaching resources (the level I think worthwhile for general enthusiasts) when I came across this interesting essay about how to use science education to get kids actually interested in science. It was written by Douglas E. Richards, author of a series of middle school science thrillers called The Prometheus Project, and appeared on a website called EarthSky. Here's a taste:

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.

Physics at UAlbany's Community Day

2009-10-28T18:37:00.000-07:00

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.

Microsoft's Project Tuva Feynmann Lectures

2009-10-25T20:01:00.000-07:00

Sadly, work commitments have kept me from getting started on our physics projects, but by next week I hope to be done and ready to go. But I am adding resources to the sidebar, so check there, and posting snippets as they come in.

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.

Zen and the art of cantilever bridgebuilding

2009-10-18T14:24:00.000-07:00

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:

Thanks to Teacher's Domain for the clip!

2010 is Year of the Laser

2009-10-08T06:30:00.000-07:00

I'm starting to collect organizations and events for the public that relate to physics. Coming in 2010 is Laserfest. From the website:

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.

Physics Central

2009-10-04T10:57:00.001-07:00

I've started collecting physics education links (see the sidebar). And, as with chemistry, I was hoping to find a professional organization offering resources to people interested in, and teaching, physics. And I did. The American Physical Society has a website called Physics Central. Here's what they say about it:

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!

Welcome to Home Physics!

2009-06-17T05:15:00.000-07:00

This blog is a placeholder for next year's homeschooling science activities. In the meantime, visit my other blogs, Home Biology and Home Chemistry!